1. |
- Andersson, Linda, 1973, et al.
(författare)
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Glucosylceramide synthase deficiency in the heart compromises β1-adrenergic receptor trafficking
- 2021
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Ingår i: European Heart Journal. - : Oxford University Press. - 0195-668X .- 1522-9645. ; 42:43, s. 4481-4492
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Tidskriftsartikel (refereegranskat)abstract
- AIMS: Cardiac injury and remodelling are associated with the rearrangement of cardiac lipids. Glycosphingolipids are membrane lipids that are important for cellular structure and function, and cardiac dysfunction is a characteristic of rare monogenic diseases with defects in glycosphingolipid synthesis and turnover. However, it is not known how cardiac glycosphingolipids regulate cellular processes in the heart. The aim of this study is to determine the role of cardiac glycosphingolipids in heart function.METHODS AND RESULTS: Using human myocardial biopsies, we showed that the glycosphingolipids glucosylceramide and lactosylceramide are present at very low levels in non-ischaemic human heart with normal function and are elevated during remodelling. Similar results were observed in mouse models of cardiac remodelling. We also generated mice with cardiomyocyte-specific deficiency in Ugcg, the gene encoding glucosylceramide synthase (hUgcg-/- mice). In 9- to 10-week-old hUgcg-/- mice, contractile capacity in response to dobutamine stress was reduced. Older hUgcg-/- mice developed severe heart failure and left ventricular dilatation even under baseline conditions and died prematurely. Using RNA-seq and cell culture models, we showed defective endolysosomal retrograde trafficking and autophagy in Ugcg-deficient cardiomyocytes. We also showed that responsiveness to β-adrenergic stimulation was reduced in cardiomyocytes from hUgcg-/- mice and that Ugcg knockdown suppressed the internalization and trafficking of β1-adrenergic receptors.CONCLUSIONS: Our findings suggest that cardiac glycosphingolipids are required to maintain β-adrenergic signalling and contractile capacity in cardiomyocytes and to preserve normal heart function.
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2. |
- Sjöberg, Sara, 1979, et al.
(författare)
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CD44-deficiency on hematopoietic cells limits T-cell number but does not protect against atherogenesis in LDL receptor-deficient mice
- 2009
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Ingår i: Atherosclerosis. - : Elsevier. - 0021-9150 .- 1879-1484. ; 206:2, s. 369-374
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Vascular and inflammatory cells express adhesion molecule CD44. We demonstrated previously that enhanced CD44 localizes in human atherosclerotic lesions. Apolipoprotein E/cd44 double-deficient mice and apolipoprotein E-deficient mice transplanted with CD44-deficient bone marrow (BM) exhibit reduced atherosclerosis. Since CD44 is a novel factor in atherogenesis, it is imperative that it is investigated in more than one animal model to conclusively determine its role in this particular disease pathology. To test the hypothesis that CD44 expressed by hematopoietic cells plays a critical role in atherogenesis in the low density lipoprotein (LDL) receptor-deficient mouse model, we performed BM reconstitution experiments.METHODS: Lethally irradiated LDL receptor-deficient mice were transplanted with either CD44-deficient or wild-type BM. Beginning 10 weeks after successful reconstitution, mice consumed a cholesterol-enriched atherogenic diet for 6 or 11 weeks.RESULTS: Surprisingly, CD44-deficiency on BM-derived inflammatory cells did not affect lesion size. Additionally, neither group displayed differences in smooth muscle cell, macrophage, collagen, or elastin content as well as lipoprotein levels. However, lesions in CD44-deficient BM-recipient mice contained fewer T-cells compared to wild-type BM mice. Interestingly, CD44-deficient T-cells expressed less chemokine receptor-5 mRNA. Furthermore, in vivo leukocyte adhesion decreased in CD44-deficient mice compared to wild-type mice.CONCLUSION: This study surprisingly revealed that atherogenesis does not require CD44 expression on hematopoietic cells in the LDL receptor-deficient mouse model. However, CD44 promotes T-cell recruitment, downregulates chemokine receptor-5, and participates critically in leukocyte adhesion in vivo. Consequently, the anti-atherogenic role of CD44 may require CD44-deficiency on cell types other than inflammatory cells in the LDL receptor-deficient mouse model.
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3. |
- Özel, Faith, et al.
(författare)
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Exploring gender dysphoria and related outcomes in a prospective cohort study: protocol for the Swedish Gender Dysphoria Study (SKDS)
- 2023
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Ingår i: Bmj Open. - : BMJ Publishing Group Ltd. - 2044-6055. ; 13:4
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Tidskriftsartikel (refereegranskat)abstract
- Introduction There has been a drastic increase in the reported number of people seeking help for gender dysphoria in many countries over the last two decades. Yet, our knowledge of gender dysphoria and related outcomes is restricted due to the lack of high-quality studies employing comprehensive approaches. This longitudinal study aims to enhance our knowledge of gender dysphoria; different aspects will be scrutinised, focusing primarily on the psychosocial and mental health outcomes, prognostic markers and, secondarily, on the underlying mechanisms for its origin. Methods and analysis The Swedish Gender Dysphoria Study is an ongoing multicentre longitudinal cohort study with 501 registered participants with gender dysphoria who are 15 years old or older. Participants at different phases of their clinical evaluation process can enter the study, and the expected follow-up duration is three years. The study also includes a comparison group of 458 age- and county-matched individuals without gender dysphoria. Data on the core outcomes of the study, which are gender incongruence and experienced gender dysphoria, body satisfaction and satisfaction with gender-affirming treatments, as well as other relevant outcomes, including mental health, social functioning and life satisfaction, are collected via web surveys. Two different research visits, before and after starting on gender-affirming hormonal treatment (if applicable), are planned to collect respective biological and cognitive measures. Data analysis will be performed using appropriate biostatistical methods. A power analysis showed that the current sample size is big enough to analyse continuous and categorical outcomes, and participant recruitment will continue until December 2022. Ethics and dissemination The ethical permission for this study was obtained from the Local Ethical Review Board in Uppsala, Sweden. Results of the study will be presented at national and international conferences and published in peer-reviewed journals. Dissemination will also be implemented through the Swedish Gender Dysphoria Study network in Sweden.
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4. |
- Carlzon, Daniel, et al.
(författare)
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Both Low and High Serum Insulin-like Growth Factor-I Levels Associate with Increased Risk of Cardiovascular Events in Elderly Men.
- 2014
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Ingår i: The Journal of clinical endocrinology and metabolism. - : The Endocrine Society. - 1945-7197 .- 0021-972X. ; 99:11
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Tidskriftsartikel (refereegranskat)abstract
- Aims: Most previous prospective studies suggest that low serum insulin-like growth factor-I (IGF-I) associates with increased risk of cardiovascular disease (CVD) events while other studies suggest that high serum IGF-I associates with increased risk of CVD events. We tested the hypothesis that not only low, but also high, serum IGF-I associate with increased risk of CVD events in elderly men. Methods and Results: Serum IGF-I levels were measured in 2901 elderly men (aged 69 to 81 years) included in the prospective population-based MrOS-Sweden cohort. Data for CVD events were obtained from national Swedish registers with no loss of follow-up. During follow-up (median 5.1 yrs) 589 of the participants experienced a CVD event. The association between serum IGF-I and risk of CVD events was nonlinear, and restricted cubic spline Cox regression analysis revealed a U-shaped association between serum IGF-I levels and CVD events (p<0.01 for nonlinearity). Low as well as high serum IGF-I (quintile 1 or 5 vs. quintiles 2-4) significantly associated with increased risk for CVD events (hazard ratio (HR) = 1.25, 95% confidence interval (CI) 1.02-1.54; and HR = 1.35, 95% CI 1.10-1.66, respectively). These associations remained after adjustment for prevalent CVD and multiple risk factors. High serum IGF-I associated with increased risk of coronary heart disease (CHD) events but not with risk of cerebrovascular events. Conclusion: Both low and high serum IGF-I levels are risk markers for CVD events in elderly men. The association between high serum IGF-I and CVD events is mainly driven by CHD events.
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5. |
- Eriksson, Anna-Lena, 1971, et al.
(författare)
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The Bone Sparing Effects of 2-Methoxyestradiol Are Mediated via Estrogen Receptor-α in Male Mice.
- 2016
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Ingår i: Endocrinology. - : The Endocrine Society. - 1945-7170 .- 0013-7227. ; 157:11, s. 4200-4205
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Tidskriftsartikel (refereegranskat)abstract
- 2-Methoxyestradiol (2ME2), a metabolite of 17β-estradiol (E2), exerts bone sparing effects in animal models. We hypothesized that the underlying mechanism is back conversion of 2ME2 to E2, which subsequently acts via estrogen receptor (ER)α. We measured serum E2 levels in orchidectomized wild-type (WT) mice treated with 2ME2 66.6 μg/d or placebo. In placebo-treated animals, E2 was below the detection limit. In 2ME2-treated mice, the serum E2 level was 4.97 ± 0.68 pg/mL. This corresponds to the level found in diesterus in cycling female mice. Next, we investigated bone parameters in orchidectomized WT and ERα knockout mice treated with 2ME2 or placebo for 35 days. 2ME2 (6.66 μg/d) preserved trabecular and cortical bone in WT mice. Trabecular volumetric-bone mineral density was 64 ± 20%, and trabecular bone volume/total volume was 60 ± 20% higher in the metaphyseal region of the femur in the 2ME2 group, compared with placebo (P < .01). Both trabecular number and trabecular thickness were increased (P < .01). Cortical bone mineral content in the diaphyseal region of the femur was 31 ± 3% higher in the 2ME2 group, compared with placebo (P < .001). This was due to larger cortical area (P < .001). Three-point bending showed an increased bone strength in WT 2ME2-treated animals compared with placebo (maximum load [Fmax] +19±5% in the 2ME2 group, P < .05). Importantly, no bone parameter was affected by 2ME2 treatment in ERα knockout mice. In conclusion, 2ME2 treatment of orchidectomized mice results in increased serum E2. ERα mediates the bone sparing effects of 2ME2. The likely mediator of this effect is E2 resulting from back conversion of 2ME2.
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6. |
- Esposito, Daniela, et al.
(författare)
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Androgen deficiency in hypopituitary women: its consequences and management
- 2024
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Ingår i: REVIEWS IN ENDOCRINE & METABOLIC DISORDERS. - 1389-9155 .- 1573-2606. ; 25, s. 479-488
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Forskningsöversikt (refereegranskat)abstract
- Women with hypopituitarism have various degrees of androgen deficiency, which is marked among those with combined hypogonadotrophic hypogonadism and secondary adrenal insufficiency. The consequences of androgen deficiency and the effects of androgen replacement therapy have not been fully elucidated. While an impact of androgen deficiency on outcomes such as bone mineral density, quality of life, and sexual function is plausible, the available evidence is limited. There is currently no consensus on the definition of androgen deficiency in women and it is still controversial whether androgen substitution should be used in women with hypopituitarism and coexisting androgen deficiency. Some studies suggest beneficial clinical effects of androgen replacement but data on long-term benefits and risk are not available. Transdermal testosterone replacement therapy in hypopituitary women has shown some positive effects on bone metabolism and body composition. Studies of treatment with oral dehydroepiandrosterone have yielded mixed results, with some studies suggesting improvements in quality of life and sexual function. Further research is required to elucidate the impact of androgen deficiency and its replacement treatment on long-term outcomes in women with hypopituitarism. The lack of transdermal androgens for replacement in this patient population and limited outcome data limit its use. A cautious and personalized treatment approach in the clinical management of androgen deficiency in women with hypopituitarism is recommended while awaiting more efficacy and safety data.
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7. |
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8. |
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9. |
- Fagman, Johan Bourghardt, 1980, et al.
(författare)
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Androgen receptor-dependent and independent atheroprotection by testosterone in male mice.
- 2010
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Ingår i: Endocrinology. - : The Endocrine Society. - 1945-7170 .- 0013-7227. ; 151:11, s. 5428-37
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Tidskriftsartikel (refereegranskat)abstract
- The atheroprotective effect of testosterone is thought to require aromatization of testosterone to estradiol, but no study has adequately addressed the role of the androgen receptor (AR), the major pathway for the physiological effects of testosterone. We used AR knockout (ARKO) mice on apolipoprotein E-deficient background to study the role of the AR in testosterone atheroprotection in male mice. Because ARKO mice are testosterone deficient, we sham operated or orchiectomized (Orx) the mice before puberty, and Orx mice were supplemented with placebo or a physiological testosterone dose. From 8 to 16 wk of age, the mice consumed a high-fat diet. In the aortic root, ARKO mice showed increased atherosclerotic lesion area (+80%, P < 0.05). Compared with placebo, testosterone reduced lesion area both in Orx wild-type (WT) mice (by 50%, P < 0.001) and ARKO mice (by 24%, P < 0.05). However, lesion area was larger in testosterone-supplemented ARKO compared with testosterone-supplemented WT mice (+57%, P < 0.05). In WT mice, testosterone reduced the presence of a necrotic core in the plaque (80% among placebo-treated vs. 12% among testosterone-treated mice; P < 0.05), whereas there was no significant effect in ARKO mice (P = 0.20). In conclusion, ARKO mice on apolipoprotein E-deficient background display accelerated atherosclerosis. Testosterone treatment reduced atherosclerosis in both WT and ARKO mice. However, the effect on lesion area and complexity was more pronounced in WT than in ARKO mice, and lesion area was larger in ARKO mice even after testosterone supplementation. These results are consistent with an AR-dependent as well as an AR-independent component of testosterone atheroprotection in male mice.
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10. |
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11. |
- Fagman, Johan Bourghardt, 1980, et al.
(författare)
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The androgen receptor confers protection against diet-induced atherosclerosis, obesity, and dyslipidemia in female mice.
- 2015
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Ingår i: FASEB journal : official publication of the Federation of American Societies for Experimental Biology. - : Wiley. - 1530-6860 .- 0892-6638. ; 29:4, s. 1540-1550
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Tidskriftsartikel (refereegranskat)abstract
- Androgens have important cardiometabolic actions in males, but their metabolic role in females is unclear. To determine the physiologic androgen receptor (AR)-dependent actions of androgens on atherogenesis in female mice, we generated female AR-knockout (ARKO) mice on an atherosclerosis-prone apolipoprotein E (apoE)-deficient background. After 8 weeks on a high-fat diet, but not on a normal chow diet, atherosclerosis in aorta was increased in ARKO females (+59% vs. control apoE-deficient mice with intact AR gene). They also displayed increased body weight (+18%), body fat percentage (+62%), and hepatic triglyceride levels, reduced insulin sensitivity, and a marked atherogenic dyslipidemia (serum cholesterol, +52%). Differences in atherosclerosis, body weight, and lipid levels between ARKO and control mice were abolished in mice that were ovariectomized before puberty, consistent with a protective action of ovarian androgens mediated via the AR. Furthermore, the AR agonist dihydrotestosterone reduced atherosclerosis (-41%; thoracic aorta), subcutaneous fat mass (-44%), and cholesterol levels (-35%) in ovariectomized mice, reduced hepatocyte lipid accumulation in hepatoma cells in vitro, and regulated mRNA expression of hepatic genes pivotal for lipid homeostasis. In conclusion, we demonstrate that the AR protects against diet-induced atherosclerosis in female mice and propose that this is mediated by modulation of body composition and lipid metabolism.-Fagman, J. B., Wilhelmson, A. S., Motta, B. M., Pirazzi, C., Alexanderson, C., De Gendt, K., Verhoeven, G., Holmäng, A., Anesten, F., Jansson, J. -O., Levin, M., Borén, J., Ohlsson, C., Krettek, A., Romeo, S., Tivesten, A. The androgen receptor confers protection against diet-induced atherosclerosis, obesity, and dyslipidemia in female mice.
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12. |
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13. |
- Fagman, Johan Bourghardt, 1980, et al.
(författare)
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The endogenous estradiol metabolite 2-methoxyestradiol reduces atherosclerotic lesion formation in female apolipoprotein E-deficient mice
- 2007
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Ingår i: Endocrinology. - : Endocrine Society. - 0013-7227 .- 1945-7170. ; 148:9, s. 4128-4132
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Tidskriftsartikel (refereegranskat)abstract
- Estradiol, the major endogenous estrogen, reduces experimental atherosclerosis and metabolizes to 2-methoxyestradiol in vascular cells. Currently undergoing evaluation in clinical cancer trials, 2-methoxyestradiol potently inhibits cell proliferation independently of the classical estrogen receptors. This study examined whether 2-methoxyestradiol affects atherosclerosis development in female mice. Apolipoprotein E-deficient mice, a well-established mouse model of atherosclerosis, were ovariectomized and treated through slow-release pellets with placebo, 17beta-estradiol (6 microg/d), or 2-methoxyestradiol [6.66 microg/d (low-dose) or 66.6 microg/d (high-dose)]. After 90 d, body weight gain decreased and uterine weight increased in the high-dose but not low-dose 2-methoxyestradiol group. En face analysis showed that the fractional area of the aorta covered by atherosclerotic lesions decreased in the high-dose 2-methoxyestradiol (52%) but not in the low-dose 2-methoxyestradiol group. Total serum cholesterol levels decreased in the high- and low-dose 2-methoxyestradiol groups (19%, P < 0.05 and 21%, P = 0.062, respectively). Estradiol treatment reduced the fractional atherosclerotic lesion area (85%) and decreased cholesterol levels (42%). In conclusion, our study shows for the first time that 2-methoxyestradiol reduces atherosclerotic lesion formation in vivo. The antiatherogenic activity of an estradiol metabolite lacking estrogen receptor activating capacity may argue that trials on cardiovascular effects of hormone replacement therapy should use estradiol rather than other estrogens. Future research should define the role of 2-methoxyestradiol as a mediator of the antiatherosclerotic actions of estradiol. Furthermore, evaluation of the effects of 2-methoxyestradiol on cardiovascular disease endpoints in ongoing clinical trials is of great interest.
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14. |
- Isgaard, Jörgen, 1959, et al.
(författare)
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Cardiovascular activities of ghrelin and synthetic GHS
- 2004
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Ingår i: Ghrelin. - Dordrecht, Netherlands : Kluwer Academic Publisher. - 140207770X ; , s. 113-121
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Recent experimental data demonstrate cardiovascular effects of synthetic growth hormone secretagogues (GHS). These cardiovascular effects include improvement of systolic function in rats after experimental infarction, cardioprotection against postischemic dysfunction in perfused rat hearts and increase of left ventricular ejection fraction in hypopituitaric patients. The proposed natural ligand ghrelin has been isolated and characterized from rat stomach. It was recently reported that a single injection of ghrelin to healthy volunteers decreased blood pressure and increased stroke volume and cardiac output. Similar beneficial cardiovascular effects were observed when ghrelin was administered to patients with chronic heart failure and to rats with experimental myocardial infarction. Specific binding of GHS to rat cardiac membranes and human cardiac tissue has been reported and possible growth hormone (GH) independent effects of GHS have been suggested. We have recently used H9c2 cardiac cells to demonstrate specific and dose-dependent stimulation of thymidine incorporation by GHS and ghrelin. Moreover, binding studies on H9c2 cells demonstrate specific binding of GHS and ghrelin and add further support for an alternative subtype-binding site in the heart compared to the pituitary. In conclusion, accumulating data suggest beneficial effects of GHS and ghrelin on cardiovascular function and these effects may be at least partly independent of GH.
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15. |
- Johansson, Helena, 1981, et al.
(författare)
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Low bone mineral density is associated with increased mortality in elderly men : MrOS Sweden
- 2011
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Ingår i: Osteoporosis International. - : Springer Science and Business Media LLC. - 0937-941X .- 1433-2965. ; 22:5, s. 1411-1418
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Tidskriftsartikel (refereegranskat)abstract
- We studied the nature of the relationship between bone mineral density (BMD) and the risk of death among elderly men. BMD was associated with mortality risk and was independent of adjustments for other co-morbidities. A piecewise linear function described the relationship more accurately than assuming the same gradient of risk over the whole range of BMD (p = 0.020). Low BMD was associated with a substantial excess risk of death, whilst a higher than average BMD had little impact on mortality. Previous studies have demonstrated an association between low BMD and an increased risk of death among men and women. The aim of the present study was to examine the pattern of the risk in men and its relation to co-morbidities. We studied the nature of the relationship between BMD and death among 3,014 elderly men drawn from the population and recruited to the MrOS study in Sweden. Baseline data included general health questionnaires, life style questionnaires and BMD measured using DXA. Men were followed for up to 6.5 years (average 4.5 years). Poisson regression was used to investigate the relationship between BMD, co-morbidities and the hazard function of death. During follow-up, 382 men died (all-cause mortality). Low BMD at all measured skeletal sites was associated with increased mortality. In multivariate analyses, the relationship between BMD and mortality was non-linear, and a piecewise linear function described the relationship more accurately than assuming the same gradient of risk over the whole range of BMD (p = 0.020). Low BMD is associated with a substantial excess risk of death compared to an average BMD, whereas a higher than average BMD has a more modest effect on mortality. These findings, if confirmed elsewhere, have implications for the constructing of probability-based fracture risk assessment tools.
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16. |
- Johansson, Helena, 1981, et al.
(författare)
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Low serum vitamin D is associated with increased mortality in elderly men: MrOS Sweden
- 2012
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Ingår i: Osteoporosis International. - : Springer Science and Business Media LLC. - 1433-2965 .- 0937-941X. ; 23:3, s. 991-999
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Tidskriftsartikel (refereegranskat)abstract
- In elderly man, low serum 25-hydroxyvitamin D (25(OH)D) was associated with a substantial excess risk of death compared to 25(OH)D values greater than 50-70 nmol/l, but the association attenuated with time. The aim of the present study was to determine whether poor vitamin D status was associated with an increase in the risk of death in elderly men. We studied the relationship between serum 25(OH)D and the risk of death in 2,878 elderly men drawn from the population and recruited to the MrOS study in Sweden. Baseline data included general health and lifestyle measures and serum 25(OH)D measured by competitive RIA. Men were followed for up to 8.2 years (average 6.0 years). Mortality adjusted for comorbidities decreased by 5% for each SD increase in 25(OH)D overall (gradient of risk 1.05; 95% confidence interval 0.96-1.14). The predictive value of 25(OH)D for death was greatest below a threshold value of 50-70 nmol/l, was greatest at approximately 3 years after baseline and thereafter decreased with time. Low serum 25(OH)D is associated with a substantial excess risk of death compared to 25(OH)D values greater than 50-70 nmol/l, but the association attenuates with time. These findings, if causally related, have important implications for intervention in elderly men.
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17. |
- Kindblom, Jenny, 1971, et al.
(författare)
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Plasma osteocalcin is inversely related to fat mass and plasma glucose in elderly Swedish men
- 2009
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Ingår i: Journal of bone and mineral research. - : Wiley. - 1523-4681 .- 0884-0431. ; 24:5, s. 785-91
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Tidskriftsartikel (refereegranskat)abstract
- The osteoblast-derived protein osteocalcin has recently been shown to affect adiposity and glucose homeostasis in mice, suggesting that the skeleton influences energy metabolism through an endocrine mechanism. The aim of this study was to investigate the relationship between plasma osteocalcin and parameters reflecting fat mass and glucose homeostasis in humans. Fasting levels of plasma osteocalcin, plasma glucose, serum insulin, and lipids were analyzed in elderly men (75.3 +/- 3.2 yr of age) in the Gothenburg part (all subjects, n = 1010; nondiabetic, n = 857; diabetic, n = 153) of the MrOS Sweden study. Fat mass and lean mass were analyzed using DXA. Diabetic subjects had lower plasma osteocalcin (-21.7%, p < 0.001) than nondiabetic subjects. For both all subjects and nondiabetic subjects, plasma osteocalcin was clearly inversely related to body mass index (BMI), fat mass, and plasma glucose (p < 0.001), whereas it was not associated with height or lean mass. Plasma osteocalcin explained a substantial part (6.3%) of the variance in plasma glucose, whereas it associated moderately with serum insulin. Multiple linear regression models adjusting for serum insulin and fat mass showed that plasma osteocalcin was an independent negative predictor of plasma glucose (p < 0.001). We herein, for the first time in humans, show that plasma osteocalcin is inversely related to fat mass and plasma glucose. Although one should be cautious with mechanistic interpretations of cross-sectional association studies, our human data support recently published experimental studies, showing endocrine functions of osteoblast-derived osteocalcin on glucose and fat homeostasis.
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18. |
- Langenskiöld, Marcus, 1972, et al.
(författare)
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Leukocyte subsets and abdominal aortic aneurysms detected by screening in men
- 2020
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Ingår i: Journal of Internal Medicine. - : Wiley. - 0954-6820 .- 1365-2796. ; 288:3, s. 345-355
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Tidskriftsartikel (refereegranskat)abstract
- Objective: In the present case–control study, we describe the associations between leukocyte subsets in blood and early, screening-detected AAA in men. An abdominal aortic aneurysm (AAA) may result in a life-threatening rupture of the aortic wall. The trigger for AAA formation remains unknown, but the vascular adventitia of advanced AAAs is infiltrated by various leukocytes, indicating that the pathogenesis may involve inflammation. Methods: In Sweden, all 65-year-old men are invited to an ultrasound examination for detection of AAA. At the Gothenburg screening site, 16256 men were examined in 2013–2017, 1.2% of whom had an AAA (diameter of the infrarenal aorta ≥30mm). All men with AAA at screening as well as a randomized selection of AAA-free screened men were invited to participate in a case–control study. Results: The median diameter of AAAs was 33mm. Men with an AAA (n=151) had a higher frequency of smoking, hypertension and statin use than controls (n=224). Blood levels of neutrophils, lymphocytes, monocytes and basophils were higher in individuals with an AAA, but eosinophil count did not differ from controls. Odds ratios (95% confidence interval) for AAA were 8.6 (4.2–17.4), 3.5 (1.9–6.6) and 3.3 (1.8–6.3) for the highest versus lowest quartile of neutrophils, lymphocytes and monocytes, respectively. For neutrophils and lymphocytes, the association with AAA remained significant after adjustment for smoking and other known risk factors/markers. Conclusion: Several, but not all, subsets of circulating leukocytes are associated with screening-detected AAA in men, which is insufficiently explained by associations with smoking and other confounders. © 2020 The Authors. Journal of Internal Medicine published by John Wiley & Sons Ltd on behalf of Association for Publication of The Journal of Internal Medicine
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19. |
- Lantero Rodriguez, Marta, et al.
(författare)
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Testosterone reduces metabolic brown fat activity in male mice
- 2021
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Ingår i: Journal of Endocrinology. - : Bioscientifica. - 0022-0795 .- 1479-6805. ; 251:1, s. 83-96
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Tidskriftsartikel (refereegranskat)abstract
- Brown adipose tissue (BAT) burns substantial amounts of mainly lipids to produce heat. Some studies indicate that BAT activity and core body temperature are lower in males than females. Here we investigated the role of testosterone and its receptor (the androgen receptor; AR) in metabolic BAT activity in male mice. Castration, which renders mice testosterone deficient, slightly promoted the expression of thermogenic markers in BAT, decreased BAT lipid content, and increased basal lipolysis in isolated brown adipocytes. Further, castration increased the core body temperature. Triglyceride-derived fatty acid uptake, a proxy for metabolic BAT activity in vivo, was strongly increased in BAT from castrated mice ( 4.5-fold increase vs sham-castrated mice) and testosterone replacement reversed the castration-induced increase in metabolic BAT activity. BAT-specific AR deficiency did not mimic the castration effects in vivo and AR agonist treatment did not diminish the activity of cultured brown adipocytes in vitro, suggesting that androgens do not modulate BAT activity via a direct, AR-mediated pathway. In conclusion, testosterone is a negative regulator of metabolic BAT activity in male mice. Our findings provide new insight into the metabolic actions of testosterone.
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20. |
- Lukes, Daniel J, et al.
(författare)
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Early onset of rejection in concordant hamster xeno hearts display signs of necrosis, but not apoptosis, correlating to the phosphocreatine concentration.
- 2003
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Ingår i: Transplant immunology. - 0966-3274. ; 12:1, s. 29-40
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The importance of apoptosis contra necrosis for ischemia/reperfusion (RP) and acute rejection in concordant rodent xenotransplantation is largely unknown. We explored this question by comparing rodent allo and concordant xenotransplants with different morphological methods to detect apoptosis and biochemical data on the levels of high-energy phosphates obtained with in vitro 31Phosphorous Magnetic Resonance Spectroscopy (31P MRS). More specifically, we applied a hitherto unused method in transplantation research, apoptosis specific biotin labeled oligonucleotides designed with a 10 base pair stem region and a 20 nucleotides large loop that form a hairpin like shape. The results obtained with this method were compared to results obtained with the more widely used in situ 3'-end labeling of DNA (TUNEL) assay and extraction and gel electrophoresis of labeled DNA (DNA laddering). METHODS: Cervical heart transplantations were performed between inbred Lewis (L) (RT1l) to L, L to DA (RT1a) rats, hamster (H) to H and H to L (X) (n=5 for all groups except for X, n=9). All hearts were subjected to 30 min of cold ischemia (+4 degrees C) and 6 h of RP before explantation. In vitro 31P MRS was used to determine the phosphocreatine (PCr), beta-adenosine triphosphate (beta-ATP) concentrations and the PCr/beta-ATP ratio of the transplants. We correlated the biochemical data to haematoxylin and eosin (H & E) stained tissue slides scored for rejection, infiltration of antibodies and complement depositions, DNA extraction and gel electrophoresis of labeled DNA (DNA laddering), in situ 3'-end labeling of DNA (TUNEL) and the apoptosis specific hairpin probe assays scoring. RESULTS: The rejection score of the xeno grafts differed significantly compared to their syngeneic hamster to hamster controls (2.40 +/- 0.25 vs. 1.20 +/- 0.20; P=0.005) and they had a significantly higher TUNEL score, 228 +/- 15 vs. 2.44 +/- 0.32 (P=0.009), that correlated to changes in PCr concentration (P<0.001) and to the PCr/beta-ATP ratio (P=0.01). The uptake was mainly (90-95%) located to 1-2 microm large extra cellular 'granule'. A picture resembling early necrosis was seen on the H & E stainings and reflected in the Billingham rejection score above. CONCLUSIONS: After 6 h of RP the onset of acute rejection in the concordant hamster xeno hearts displayed features of early, possibly mitochondrial, necrosis, but not apoptosis, which correlated to changes in the PCr concentration and the PCr/beta-ATP ratio. The mechanism for the early rejection observed is unclear and might be caused by other factors in the sera apart from cellular components, antibodies and complement factors. Identification of the underlying mechanisms could enable us to design rational therapies that prevent activation of the recipient's innate immune response.
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21. |
- Lundell, Anna-Carin, 1976, et al.
(författare)
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Dihydrotestosterone levels at birth associate positively with higher proportions of circulating immature/naïve CD5+ B cells in boys.
- 2017
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Ingår i: Scientific reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 7:1
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Tidskriftsartikel (refereegranskat)abstract
- Boys present with higher proportions of immature/naïve CD5+ B cells than girls up to 3 years of age. Boys also have higher fractions of regulatory T cells (Tregs) in early infancy, but the mechanisms for these sex-related differences are unknown. In the prospective FARMFLORA follow-up study of 23 boys and 25 girls, we investigated if these immunological differences remained at 8 years of age. We also examined if testosterone or dihydrotestosterone (DHT) levels at birth and at 8 years of age were associated with immune maturation. Immunological variables and androgen levels were examined and measured in blood samples obtained at birth, 3-5 days and at 8 years of age. Boys had higher proportions of CD5+ and immature/transitional CD24hiCD38hi B cells, whereas girls had higher fractions of B cells with a memory phenotype at 8 years of age. School-aged boys also presented with higher frequencies of Tregs, and a greater capacity to produce T-cell-associated cytokines. Among boys, higher cord blood DHT levels were associated with higher proportions of CD5+ B cells in early infancy and at 8 years of life. These results suggest that DHT actions in utero might be involved in the mechanism for delayed peripheral B-cell maturation in boys.
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22. |
- Lundell, Anna-Carin, 1976, et al.
(författare)
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Umbilical Cord Blood Androgen Levels in Girls and Boys Assessed by Gas Chromatography-Tandem Mass Spectrometry.
- 2017
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Ingår i: The Journal of steroid biochemistry and molecular biology. - : Elsevier BV. - 1879-1220 .- 0960-0760. ; 171, s. 195-200
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Tidskriftsartikel (refereegranskat)abstract
- Androgen exposure of the fetus during gestation plays an important role in human physiology and pathophysiology, but assessment of androgens, in particular dihydrotestosterone (DHT), in human umbilical cord blood is technically challenging. The aim of this study was to assess umbilical cord androgen levels, including DHT, at birth by a highly sensitive assay, and study their association with sex of the infant, sex-hormone-binding globulin (SHBG) levels, and gestational age at delivery. Swedish infants (27 girls, 26 boys) were recruited at maternity care clinics in Southern Sweden. Umbilical cord blood levels of dehydroepiandrosterone (DHEA), androstenedione, testosterone and DHT at delivery were assessed by a gas chromatography-tandem mass spectrometry assay. Cord blood levels of DHT were 2.4-fold higher in boys (median 27.8pg/mL) than in girls (11.5pg/mL), while the sex difference was less pronounced for testosterone (1.3-fold higher in boys) and non-significant for DHEA and androstenedione. Gestational age at delivery associated inversely with DHT levels in boys and with DHEA levels in girls. There was a strong inverse correlation between SHBG and DHEA in both sexes, while there were no associations between SHBG and testosterone or DHT levels. In conclusion, using state of the art technology, we report that there is a pronounced sexual dimorphism in human umbilical cord blood DHT levels. The possibility to assess a complete androgen profile in human cord blood opens up for future increased understanding of the biological impact of the fetal androgen milieu.
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23. |
- Marriott, Ross J, et al.
(författare)
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Factors Associated With Circulating Sex Hormones in Men : Individual Participant Data Meta-analyses.
- 2023
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Ingår i: Annals of internal medicine. - 1539-3704. ; 176:9, s. 1221-1234
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Forskningsöversikt (refereegranskat)abstract
- Various factors modulate circulating testosterone in men, affecting interpretation of testosterone measurements.To clarify factors associated with variations in sex hormone concentrations.Systematic literature searches (to July 2019).Prospective cohort studies of community-dwelling men with total testosterone measured using mass spectrometry.Individual participant data (IPD) (9 studies; n= 21074) and aggregate data (2 studies; n= 4075). Sociodemographic, lifestyle, and health factors and concentrations of total testosterone, sex hormone-binding globulin (SHBG), luteinizing hormone (LH), dihydrotestosterone, and estradiol were extracted.Two-stage random-effects IPD meta-analyses found a nonlinear association of testosterone with age, with negligible change among men aged 17 to 70 years (change per SD increase about the midpoint, -0.27 nmol/L [-7.8 ng/dL] [CI, -0.71 to 0.18 nmol/L {-20.5 to 5.2 ng/dL}]) and decreasing testosterone levels with age for men older than 70 years (-1.55 nmol/L [-44.7 ng/dL] [CI, -2.05 to -1.06 nmol/L {-59.1 to -30.6 ng/dL}]). Testosterone was inversely associated with body mass index (BMI) (change per SD increase, -2.42 nmol/L [-69.7 ng/dL] [CI, -2.70 to -2.13 nmol/L {-77.8 to -61.4 ng/dL}]). Testosterone concentrations were lower for men who were married (mean difference, -0.57 nmol/L [-16.4 ng/dL] [CI, -0.89 to -0.26 nmol/L {-25.6 to -7.5 ng/dL}]); undertook at most 75 minutes of vigorous physical activity per week (-0.51 nmol/L [-14.7 ng/dL] [CI, -0.90 to -0.13 nmol/L {-25.9 to -3.7 ng/dL}]); were former smokers (-0.34 nmol/L [-9.8 ng/dL] [CI, -0.55 to -0.12 nmol/L {-15.9 to -3.5 ng/dL}]); or had hypertension (-0.53 nmol/L [-15.3 ng/dL] [CI, -0.82 to -0.24 nmol/L {-23.6 to -6.9 ng/dL}]), cardiovascular disease (-0.35 nmol/L [-10.1 ng/dL] [CI, -0.55 to -0.15 nmol/L {-15.9 to -4.3 ng/dL}]), cancer (-1.39 nmol/L [-40.1 ng/dL] [CI, -1.79 to -0.99 nmol/L {-51.6 to -28.5 ng/dL}]), or diabetes (-1.43 nmol/L [-41.2 ng/dL] [CI, -1.65 to -1.22 nmol/L {-47.6 to -35.2 ng/dL}]). Sex hormone-binding globulin was directly associated with age and inversely associated with BMI. Luteinizing hormone was directly associated with age in men older than 70 years.Cross-sectional analysis, heterogeneity between studies and in timing of blood sampling, and imputation for missing data.Multiple factors are associated with variation in male testosterone, SHBG, and LH concentrations. Reduced testosterone and increased LH concentrations may indicate impaired testicular function after age 70 years. Interpretation of individual testosterone measurements should account particularly for age older than 70 years, obesity, diabetes, and cancer.Medical Research Future Fund, Government of Western Australia, and Lawley Pharmaceuticals. (PROSPERO: CRD42019139668).
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24. |
- Mirza, Majd, et al.
(författare)
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Circulating fibroblast growth factor-23 is associated with fat mass and dyslipidemia in two independent cohorts of elderly individuals
- 2011
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Ingår i: Arteriosclerosis, Thrombosis and Vascular Biology. - 1079-5642 .- 1524-4636. ; 31:1, s. 219-227
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Tidskriftsartikel (refereegranskat)abstract
- Objective—Disturbances in mineral metabolism define an increased cardiovascular risk in patients with chronic kidney disease. Fibroblast growth factor-23 (FGF23) is a circulating regulator of phosphate and vitamin D metabolism and has recently been implicated as a putative pathogenic factor in cardiovascular disease. Because other members of the FGF family play a role in lipid and glucose metabolism, we hypothesized that FGF23 would associate with metabolic factors that predispose to an increased cardiovascular risk. The goal of this study was to investigate the relationship between FGF23 and metabolic cardiovascular risk factors in the community.Methods and Results—Relationships between serum FGF23 and body mass index (BMI), waist circumference, waist-to-hip ratio, serum lipids, and fat mass were examined in 2 community-based, cross-sectional cohorts of elderly whites (Osteoporotic Fractures in Men Study: 964 men aged 75±3.2; Prospective Investigation of the Vasculature in Uppsala Seniors study: 946 men and women aged 70). In both cohorts, FGF23 associated negatively with high-density lipoprotein and apolipoprotein A1 (7% to 21% decrease per 1-SD increase in log FGF23; P<0.01) and positively with triglycerides (11% to 14% per 1-SD increase in log FGF23; P<0.01). A 1-SD increase in log FGF23 was associated with a 7% to 20% increase in BMI, waist circumference, and waist-to-hip ratio and a 7% to 18% increase in trunk and total body fat mass (P<0.01) as determined by whole-body dual x-ray absorptiometry. FGF23 levels were higher in subjects with the metabolic syndrome compared with those without (46.4 versus 41.2 pg/mL; P<0.05) and associated with an increased risk of having the metabolic syndrome (OR per 1-SD increase in log FGF23, 1.21; 95% CI, 1.04 to 1.40; P<0.05).Conclusion—We report for the first time on associations between circulating FGF23, fat mass, and adverse lipid metabolism resembling the metabolic syndrome, potentially representing a novel pathway(s) linking high FGF23 to an increased cardiovascular risk.
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25. |
- Nilsson, Maria E., et al.
(författare)
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Measurement of a comprehensive sex steroid profile in rodent serum by high-sensitive gas chromatography-tandem mass spectrometry.
- 2015
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Ingår i: Endocrinology. - : The Endocrine Society. - 1945-7170 .- 0013-7227. ; 156:7, s. 2492-502
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Tidskriftsartikel (refereegranskat)abstract
- Accurate measurement of sex steroid concentrations in rodent serum is essential to evaluate mouse and rat models for sex steroid-related disorders. The aim of the present study was to develop a sensitive and specific gas chromatography-tandem mass spectrometry (GC-MS/MS) method to assess a comprehensive sex steroid profile in rodent serum. A major effort was invested in reaching an exceptionally high sensitivity for measuring serum estradiol concentrations. We established a GC-MS/MS assay with a lower limit of detection for estradiol, estrone, testosterone, dihydrotestosterone, progesterone, androstenedione and dehydroepiandrosterone of 0.3, 0.5, 4, 1.6, 8, 4 and 50 pg/ml, respectively, while the corresponding values for the lower limit of quantification were 0.5, 0.5, 8, 2.5, 74, 12 and 400 pg/ml, respectively. Calibration curves were linear, intra- and inter-assay CVs were low and accuracy was excellent for all analytes. The established assay was used to accurately measure a comprehensive sex steroid profile in female rats and mice according to estrus cycle phase. In addition, we characterized the impact of age, sex, gonadectomy, and estradiol treatment on serum concentrations of these sex hormones in mice. In conclusion, we have established a highly sensitive and specific GC-MS/MS method to assess a comprehensive sex steroid profile in rodent serum in a single run. This GC-MS/MS assay has, to the best of our knowledge, the best detectability reported for estradiol. Our method therefore represents an ideal tool to characterize sex steroid metabolism in a variety of sex steroid-related rodent models and in human samples with low estradiol levels.
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26. |
- Ohlsson, Claes, 1965, et al.
(författare)
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Comparisons of Immunoassay and Mass Spectrometry Measurements of Serum Estradiol Levels and Their Influence on Clinical Association Studies in Men
- 2013
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Ingår i: Journal of Clinical Endocrinology & Metabolism. - : The Endocrine Society. - 0021-972X .- 1945-7197. ; 98:6
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Tidskriftsartikel (refereegranskat)abstract
- Context: Immunoassay-based techniques, routinely used to measure serum estradiol (E2), are known Objective: Our objective was to compare immunoassay and MS measurements of E2 levels in men and Design and Setting: Middle-aged and older male subjects participating in the population-based Main Outcome Measures: Immunoassay and MS measurements of serum E2 were compared and Results: Within each cohort, serum E2 levels obtained by immunoassay and MS correlated moderately Conclusions: Our findings suggest interference in the immunoassay E2 analyses, possibly by CRP or a
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27. |
- Ohlsson, Claes, 1965, et al.
(författare)
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DHEA and mortality: What is the nature of the association?
- 2015
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Ingår i: The Journal of steroid biochemistry and molecular biology. - : Elsevier BV. - 1879-1220 .- 0960-0760. ; 145C, s. 248-253
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Tidskriftsartikel (refereegranskat)abstract
- Although very little is known about the importance of dehydroepiandrosterone (DHEA) and DHEA sulfate (DHEA-S) in human physiology and pathophysiology, emerging observations imply pivotal roles of DHEA/-S. One such observation is the association between serum DHEA/-S levels and mortality risk. In this review, we focus on the literature addressing DHEA/-S and mortality with the aim to describe and discuss patterns and potential underlying mechanisms. Although the literature reports somewhat inconsistent results, we conclude that several larger population-based studies support an association between low DHEA/-S and risk of death, at least in elderly men. In women, the association may not be present; alternatively, there may be a U-shaped association. In men, most available evidence suggests an association with cardiovascular (CV) mortality rather than cancer mortality. Further, there are biologically plausible mechanisms for an effect of DHEA/-S on the development of CV disease. On the other hand, there is also strong evidence supporting that any disease may lower DHEA/-S. Thus, the cause-effect relation of this association is less clear. Future studies may employ a mendelian randomization approach using genetic determinants of DHEA-S levels as predictors of clinical outcomes, to delineate the true nature of the association between DHEA/-S and mortality.
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28. |
- Ohlsson, Claes, 1965, et al.
(författare)
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High Serum Testosterone is Associated with Reduced Risk of Cardiovascular Events in Elderly Men
- 2011
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Ingår i: Journal of the American College of Cardiology. - : Elsevier BV. - 0735-1097. ; 58:16, s. 1674-1681
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Tidskriftsartikel (refereegranskat)abstract
- Objectives We tested the hypothesis that serum total testosterone and sex hormone-binding globulin (SHBG) levels predict cardiovascular (CV) events in community-dwelling elderly men. Background Low serum testosterone is associated with increased adiposity, an adverse metabolic risk profile, and atherosclerosis. However, few prospective studies have demonstrated a protective link between endogenous testosterone and CV events. Polymorphisms in the SHBG gene are associated with risk of type 2 diabetes, but few studies have addressed SHBG as a predictor of CV events. Methods We used gas chromatography/mass spectrometry to analyze baseline levels of testosterone in the prospective population-based MrOS (Osteoporotic Fractures in Men) Sweden study (2,416 men, age 69 to 81 years). SHBG was measured by immunoradiometric assay. CV clinical outcomes were obtained from central Swedish registers. Results During a median 5-year follow-up, 485 CV events occurred. Both total testosterone and SHBG levels were inversely associated with the risk of CV events (trend over quartiles: p = 0.009 and p = 0.012, respectively). Men in the highest quartile of testosterone (>= 550 ng/dl) had a lower risk of CV events compared with men in the 3 lower quartiles (hazard ratio: 0.70, 95% confidence interval: 0.56 to 0.88). This association remained after adjustment for traditional CV risk factors and was not materially changed in analyses excluding men with known CV disease at baseline (hazard ratio: 0.71, 95% confidence interval: 0.53 to 0.95). In models that included both testosterone and SHBG, testosterone but not SHBG predicted CV risk. Conclusions High serum testosterone predicted a reduced 5-year risk of CV events in elderly men. (J Am Coll Cardiol 2011;58:1674-81) (C) 2011 by the American College of Cardiology Foundation
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29. |
- Ohlsson, Claes, 1965, et al.
(författare)
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Low Progesterone and Low Estradiol Levels Associate with Abdominal Aortic Aneurysms in Men.
- 2022
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Ingår i: The Journal of clinical endocrinology and metabolism. - : The Endocrine Society. - 1945-7197 .- 0021-972X. ; 107:4
-
Tidskriftsartikel (refereegranskat)abstract
- Male sex is a major risk factor for abdominal aortic aneurysms (AAA) but few studies have addressed associations between sex hormone levels and AAA.To describe the associations between serum sex steroids and early, screening-detected AAA in men.We validated a high-sensitivity liquid chromatography-tandem mass spectrometry assay for comprehensive serum sex hormone profiling. This assay was then employed in a case-control study including 147 men with AAA (infrarenal aorta ≥30mm) and 251 AAA-free controls recruited at the general population-based ultrasound screening for AAA in 65-year-old Swedish men.Associations between dehydroepiandrosterone, progesterone, 17α-hydroxyprogesterone, androstenedione, estrone, testosterone, dihydrotestosterone, and estradiol and AAA presence.Dehydroepiandrosterone, progesterone, 17α-hydroxyprogesterone, testosterone, and estradiol, but not the other hormones, were lower in men with AAA. In models with adjustments for known AAA risk factors and comorbidity, only progesterone (odds ratio per SD decrease 1.62 [95% CI 1.18-2.22]) and estradiol (1.40 [95% CI 1.04-1.87]) remained inversely associated with the presence of AAA. Progesterone and estradiol contributed with independent additive information for prediction of AAA presence; compared with men with high (above median) levels, men with low (below median) levels of both hormones had a 4-fold increased odds ratio for AAA (4.06 [95% CI 2.25-7.31]).Measured by a high-performance sex steroid assay, progesterone and estradiol are inversely associated with AAA in men, independently of known risk factors. Future studies should explore whether progesterone and estradiol, which are important reproductive hormones in women, are protective in human AAA.
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30. |
- Ohlsson, Claes, 1965, et al.
(författare)
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Low Serum Levels of Dehydroepiandrosterone Sulfate Predict All-Cause and Cardiovascular Mortality in Elderly Swedish Men
- 2010
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Ingår i: Journal of Clinical Endocrinology and Metabolism. - : The Endocrine Society. - 0021-972X .- 1945-7197. ; 95:9, s. 4406-4414
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Tidskriftsartikel (refereegranskat)abstract
- Context: The age-related decline in dehydroepiandrosterone (DHEA) levels is thought to be of importance for general and vascular aging. However, data on the association between DHEA and mortality are conflicting. Objectives: We tested the hypothesis that low serum DHEA and DHEA sulfate (DHEA-S) levels predict all-cause and cardiovascular disease (CVD) death in elderly men. Design, Setting, and Participants: We used gas/liquid chromatography-mass spectrometry to analyze baseline levels of DHEA and DHEA-S in the prospective population-based MrOS Sweden study (2644 men, aged 69-81 yr). Mortality data were obtained from central registers and analyzed using Cox proportional hazards regressions. Main Outcome Measures: All-cause and CVD mortality by serum DHEA(-S) levels. Results: During a mean 4.5-yr follow-up, 328 deaths occurred. Low levels of DHEA-S (quartile 1 vs. quartiles 2-4), predicted death from all causes [hazard ratio (HR) 1.54,95% confidence interval (CI) 1.21-1.96; adjusted for traditional cardiovascular risk factors], from CVD (n = 123 deaths; HR 1.61, 95% CI 1.10-2.37) and ischemic heart disease (n = 73; HR 1.67, 95% CI 1.02-2.74) but not cancer. Analyses with DHEA gave similar results. The association between low DHEA-S and CVD death remained after adjustment for C-reactive protein and circulating estradiol and testosterone levels. When stratified by the median age of 75.4 yr, the mortality prediction by low DHEA-S was more pronounced among younger (age adjusted HR for CVD death 2.64, 95% CI 1.37-5.09) than older men (HR 1.30, 95% CI 0.83-2.04). Conclusions: Low serum levels of DHEA(-S) predict death from all causes, CVD, and ischemic heart disease in older men.
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31. |
- Ohlsson, Claes, 1965, et al.
(författare)
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Serum DHEA and Testosterone Levels Associate Inversely With Coronary Artery Calcification in Elderly Men
- 2023
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Ingår i: Journal of Clinical Endocrinology & Metabolism. - 0021-972X. ; 108:12, s. 3272-3279
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Tidskriftsartikel (refereegranskat)abstract
- Context Epidemiological and preclinical data support cardiovascular, mainly protective, effects of sex steroids in men, but the mechanisms underlying the cardiovascular actions of sex steroids are poorly understood. Vascular calcification parallels the development of atherosclerosis, but is increasingly recognized as a diversified, highly regulated process, which itself may have pathophysiological importance for clinical cardiovascular events. Objective To investigate the association between serum sex steroids and coronary artery calcification (CAC) in elderly men. Methods We used gas chromatography tandem mass spectrometry to analyze a comprehensive sex steroid profile, including levels of dehydroepiandrosterone (DHEA), androstenedione, estrone, testosterone, estradiol, and dihydrotestosterone, in men from the population-based AGES-Reykjavik study (n = 1287, mean 76 years). Further, sex hormone-binding globulin (SHBG) was assayed and bioavailable hormone levels calculated. CAC score was determined by computed tomography. The main outcome measures were cross-sectional associations between dehydroepiandrosterone, androstenedione, estrone, testosterone, dihydrotestosterone, and estradiol and quintiles of CAC. Results Serum levels of DHEA, androstenedione, testosterone, dihydrotestosterone, and bioavailable testosterone showed significant inverse associations with CAC, while estrone, estradiol, bioavailable estradiol, and SHBG did not. DHEA, testosterone, and bioavailable testosterone remained associated with CAC after adjustment for traditional cardiovascular risk factors. In addition, our results support partially independent associations between adrenal-derived DHEA and testes-derived testosterone and CAC. Conclusion Serum levels of DHEA and testosterone are inversely associated with CAC in elderly men, partially independently from each other. These results raise the question whether androgens from both the adrenals and the testes may contribute to male cardiovascular health.
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32. |
- Ohlsson, Claes, 1965, et al.
(författare)
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The role of liver-derived insulin-like growth factor-I.
- 2009
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Ingår i: Endocrine reviews. - : The Endocrine Society. - 1945-7189 .- 0163-769X. ; 30:5, s. 494-535
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Forskningsöversikt (refereegranskat)abstract
- IGF-I is expressed in virtually every tissue of the body, but with much higher expression in the liver than in any other tissue. Studies using mice with liver-specific IGF-I knockout have demonstrated that liver-derived IGF-I, constituting a major part of circulating IGF-I, is an important endocrine factor involved in a variety of physiological and pathological processes. Detailed studies comparing the impact of liver-derived IGF-I and local bone-derived IGF-I demonstrate that both sources of IGF-I can stimulate longitudinal bone growth. We propose here that liver-derived circulating IGF-I and local bone-derived IGF-I to some extent have overlapping growth-promoting effects and might have the capacity to replace each other (= redundancy) in the maintenance of normal longitudinal bone growth. Importantly, and in contrast to the regulation of longitudinal bone growth, locally derived IGF-I cannot replace (= lack of redundancy) liver-derived IGF-I for the regulation of a large number of other parameters including GH secretion, cortical bone mass, kidney size, prostate size, peripheral vascular resistance, spatial memory, sodium retention, insulin sensitivity, liver size, sexually dimorphic liver functions, and progression of some tumors. It is clear that a major role of liver-derived IGF-I is to regulate GH secretion and that some, but not all, of the phenotypes in the liver-specific IGF-I knockout mice are indirect, mediated via the elevated GH levels. All of the described multiple endocrine effects of liver-derived IGF-I should be considered in the development of possible novel treatment strategies aimed at increasing or reducing endocrine IGF-I activity.
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33. |
- Olivius, C., et al.
(författare)
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Prevalence and treatment of central hypogonadism and hypoandrogenism in women with hypopituitarism
- 2018
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Ingår i: Pituitary. - : Springer Science and Business Media LLC. - 1386-341X .- 1573-7403. ; 21:5, s. 445-453
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Tidskriftsartikel (refereegranskat)abstract
- Purpose Women with hypopituitarism have increased morbidity and mortality, and hypogonadism has been suggested to be a contributing mechanism. The purpose of this study was to investigate the prevalence of central hypogonadism and hypoandrogenism in women with hypopituitarism at a single Swedish center. Methods All consecutive women (n=184) who commenced growth hormone (GH) replacement therapy at Sahlgrenska University Hospital in Gothenburg between 1995 and 2015 were included. In accordance with the Endocrine Society Clinical Practice Guidelines, strict criteria, based on menstrual history combined with laboratory measurements, were used to define central hypogonadism. Hypoandrogenism was defined as subnormal levels of dehydroepiandrosterone sulfate and/or androstenedione. Results Central hypogonadism was present in 78% of the women, in 75% of those≤52 years and in 82% of those>52 years of age. Hypoandrogenism was found in 61% of all the women and in 92% of those with adrenocorticotropic hormone (ACTH) deficiency. The estrogen substitution rate in hypogonadal women≤52 years was lower than the hormonal substitution rate in the other pituitary hormone axes (74% versus 100%, P<0.001). The use of estrogen substitution tended to decrease between 2000 and 2016. Few women received androgen treatment. Conclusions In this first study of hypogonadism in women with hypopituitarism, using stringent diagnostic criteria for hypogonadism, the prevalence of central hypogonadism and low androgen levels was high and estrogen substitution was insufficient. Further studies are needed to elucidate the importance of hypogonadism and insufficient sex steroid replacement for the increased morbidity in hypopituitary women.
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34. |
- Ottarsdottir, Kristin, et al.
(författare)
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Cardiometabolic Risk Factors and Endogenous Sex Hormones in Postmenopausal Women: A Cross-Sectional Study
- 2022
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Ingår i: Journal of the Endocrine Society. - : The Endocrine Society. - 2472-1972. ; 6:6
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Tidskriftsartikel (refereegranskat)abstract
- Context: it is uncertain which cardiovascular risk factors are associated with sex hormone levels in postmenopausal women. Objective: This work aimed to investigate the association between cardiometabolic risk factors and sex hormones in a cross-sectional, observational population study. Methods: In this Swedish population study, participants were physically examined from 2002 to 2004, and endogenous sex hormones were analyzed by liquid chromatography-tandem mass spectrometry. Women aged 55 years or older with estradiol levels below 20 pg/mL and not using any hormonal therapy were eligible for inclusion in the study (N = 146). Variable selection and bootstrap stability analyses were performed and linear regression models presented, with each of the 8 hormones as outcome variables. Results: Body mass index (BMI) was positively associated with estradiol (beta = 0.054, P < .001), but negatively associated with 17-alpha-hydroxyprogesterone (beta = -0.023, P = .028). Waist-to-hip ratio (WHR) was negatively associated with dihydrotestosterone (beta = -2.195, P = .002) and testosterone (beta = -1.541, P = .004). The homeostatic model assessment of insulin resistance was positively associated with androstenedione (beta = 0.071, P = .032), estradiol (beta = 0.091, P = .009), estrone (beta = 0.075, P = 0.009), and 17-alpha-hydroxyprogesterone (beta = 0.157 P = .001). Age was positively associated with testosterone (6 = 0.017, P = .042). C-reactive protein showed an inverse association with progesterone (beta = -0.028, P = .037). Lower low-density lipoprotein cholesterol was associated with higher estradiol levels (beta = -0.093, P = .049), whereas lower triglycerides were associated with higher concentrations of dihydrotestosterone (beta = -0.208, P = .016). Conclusion: In postmenopausal women, WHR was strongly inversely associated with androgens, while BMI was positively associated with estrogens.
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35. |
- Pirazzi, Carlo, et al.
(författare)
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PCSK9 Inhibitors in a Statin-Intolerant Transgender Man With Heterozygous Familial Hypercholesterolemia: A Case Report
- 2019
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Ingår i: Journal of the Endocrine Society. - : The Endocrine Society. - 2472-1972. ; 3:8, s. 1461-1464
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Tidskriftsartikel (refereegranskat)abstract
- In female-to-male transgender individuals, testosterone is used to induce masculinization. Sex steroid therapy may increase circulating triglyceride and low-density lipoprotein cholesterol (LDL-C) levels and may decrease high-density lipoprotein cholesterol (HDL-C) levels, resulting in a more atherogenic lipid profile. These potentially adverse effects of androgen therapy may be exacerbated by the presence of familial hypercholesterolemia (FH). We describe the case of a transgender man with genetically diagnosed FH who was intolerant to statins and was started on a proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor to control his lipoproteins more effectively. The 35-year-old female-to-male transgender individual was referred to our center with a history of elevated LDL-C levels. Despite treatment with high doses of high-potency statins and ezetimibe, he had never achieved a sustained reduction in LDL-C; his levels of LDL-C were fluctuating between 170 and 344 mg/dL (4.4 and 8.9 mmol/L). Moreover, he developed side effects to statins in the form of myalgia and discontinued statin treatment. At the Sahlgrenska Lipid Clinic, a genetic diagnosis of heterozygous FH was established, and PCSK9 inhibitor therapy was started. The patient's LDL-C level has been reduced by approximately 40% for 23 months, and no adverse events have been reported.
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36. |
- Sarwar, Nadeem, et al.
(författare)
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Interleukin-6 receptor pathways in coronary heart disease : a collaborative meta-analysis of 82 studies
- 2012
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Ingår i: The Lancet. - New York, NY, USA : Elsevier. - 0140-6736 .- 1474-547X. ; 379:9822, s. 1205-1213
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Tidskriftsartikel (refereegranskat)abstract
- Background: Persistent inflammation has been proposed to contribute to various stages in the pathogenesis of cardiovascular disease. Interleukin-6 receptor (IL6R) signalling propagates downstream inflammation cascades. To assess whether this pathway is causally relevant to coronary heart disease, we studied a functional genetic variant known to affect IL6R signalling. Methods: In a collaborative meta-analysis, we studied Asp358Ala (rs2228145) in IL6R in relation to a panel of conventional risk factors and inflammation biomarkers in 125 222 participants. We also compared the frequency of Asp358Ala in 51 441 patients with coronary heart disease and in 136 226 controls. To gain insight into possible mechanisms, we assessed Asp358Ala in relation to localised gene expression and to postlipopolysaccharide stimulation of interleukin 6. Findings: The minor allele frequency of Asp358Ala was 39%. Asp358Ala was not associated with lipid concentrations, blood pressure, adiposity, dysglycaemia, or smoking (p value for association per minor allele >= 0.04 for each). By contrast, for every copy of 358Ala inherited, mean concentration of IL6R increased by 34.3% (95% CI 30.4-38.2) and of interleukin 6 by 14.6% (10.7-18.4), and mean concentration of C-reactive protein was reduced by 7.5% (5.9-9.1) and of fibrinogen by 1.0% (0.7-1.3). For every copy of 358Ala inherited, risk of coronary heart disease was reduced by 3.4% (1.8-5.0). Asp358Ala was not related to IL6R mRNA levels or interleukin-6 production in monocytes. Interpretation: Large-scale human genetic and biomarker data are consistent with a causal association between IL6R-related pathways and coronary heart disease.
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37. |
- Stubelius, Alexandra, 1983, et al.
(författare)
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Role of 2-methoxyestradiol as inhibitor of arthritis and osteoporosis in a model of postmenopausal rheumatoid arthritis
- 2011
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Ingår i: Clinical Immunology. - : Elsevier BV. - 1521-6616. ; 140:1, s. 37-46
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Tidskriftsartikel (refereegranskat)abstract
- In postmenopausal rheumatoid arthritis, both the inflammatory disease and estrogen deficiency contribute to the development of osteoporosis. As hormone replacement therapy is no longer an option, we hypothesized that 2-methoxyestradiol (2me2) could be beneficial, and asked if such therapy was associated with effects on reproductive organs. Mice were ovariectomized and arthritis was induced, whereafter mice were administered 2me2, estradiol, or placebo. Clinical and histological scores of arthritis, together with bone mineral density were evaluated. Uteri weight, reactive oxygen species (ROS) from spleen cells, and characterization of cells from joints and lymph nodes were analyzed. In addition, in vivo activation of estrogen response elements (ERE) by 2me2 was evaluated. Treatment with 2me2 and estradiol decreased the frequency and severity of arthritis and preserved bone. Joint destruction was reduced, neutrophils diminished and ROS production decreased. The uterine weight increased upon long-term 2me2 exposure, however short-term exposure did not activate ERE in vivo.
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38. |
- Stubelius, Alexandra, 1983, et al.
(författare)
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Sexual dimorphisms in the immune system of catechol-O-methyltransferase knockout mice
- 2012
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Ingår i: Immunobiology. - : Elsevier BV. - 0171-2985. ; 217:8, s. 751-760
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Tidskriftsartikel (refereegranskat)abstract
- The enzyme catechol-O-methyltransferase (COMT) is part of the metabolic pathway of 17 beta-estradiol, converting 2-hydroxyestradiol to 2-methoxyestradiol. We recently showed that administration of the COMT product 2-methoxyestradiol has anti-inflammatory and anti-osteoporotic effects. We have now investigated whether COMT affects the immune system, by immunologically phenotyping COMT deficient (COMT-/-) mice. Immunoglobulin production, T lymphocyte proliferation, NK cell cytotoxicity and oxygen radical production were assessed. In male COMT-/--mice, the total number of T-, and B-lymphocytes from spleen increased but the T-cell proliferative response decreased. The NK cell population shifted toward less mature cells, leaving cytotoxic capacity unaffected. In COMT-/--females, a higher frequency of neutrophils was found but the oxygen radical production was unaltered. In conclusion, only minor changes of the immune system were seen in COMT deficient mice, and the changes were usually seen in males. This study provides clues into how COMT activity, and hence gender differences, affects the immune system. (c) 2012 Elsevier GmbH. All rights reserved.
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39. |
- Svedlund Eriksson, Elin, et al.
(författare)
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Castration of Male Mice Induces Metabolic Remodeling of the Heart
- 2022
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Ingår i: Journal of the Endocrine Society. - : The Endocrine Society. - 2472-1972. ; 6:11
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Tidskriftsartikel (refereegranskat)abstract
- Androgen deprivation therapy of prostate cancer, which suppresses serum testosterone to castrate levels, is associated with increased risk of heart failure. Here we tested the hypothesis that castration alters cardiac energy substrate uptake, which is tightly coupled to the regulation of cardiac structure and function. Short-term (3-4 weeks) surgical castration of male mice reduced the relative heart weight. While castration did not affect cardiac function in unstressed conditions, we observed reductions in heart rate, stroke volume, cardiac output, and cardiac index during pharmacological stress with dobutamine in castrated vs sham-operated mice. Experiments using radiolabeled lipoproteins and glucose showed that castration shifted energy substrate uptake in the heart from lipids toward glucose, while testosterone replacement had the opposite effect. There was increased expression of fetal genes in the heart of castrated mice, including a strong increase in messenger RNA and protein levels of beta-myosin heavy chain (MHC), the fetal isoform of MHC. In conclusion, castration of male mice induces metabolic remodeling and expression of the fetal gene program in the heart, in association with a reduced cardiac performance during pharmacological stress. These findings may be relevant for the selection of treatment strategies for heart failure in the setting of testosterone deficiency.
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40. |
- Svensson, Johan, 1964, et al.
(författare)
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Both low and high serum igf-I levels associate with cancer mortality in older men.
- 2012
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Ingår i: The Journal of clinical endocrinology and metabolism. - : The Endocrine Society. - 1945-7197 .- 0021-972X. ; 97:12, s. 4623-30
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Tidskriftsartikel (refereegranskat)abstract
- Background: Although recent population-based studies suggest a U-shaped relationship between serum IGF-I concentration and all-cause mortality, the distribution of death causes underlying this association remains unclear. We hypothesized that high IGF-I levels associate with increased cancer mortality, whereas low IGF-I levels associate with increased cardiovascular disease (CVD) mortality. Methods: Serum IGF-I levels were measured in 2901 elderly men (mean age 75.4, range 69-81 yr) included in the prospective population-based Osteoporotic Fractures in Men Study (Sweden) study. Mortality data were obtained from central registers with no loss of follow-up. The statistical analyses included Cox proportional hazards regressions with or without a spline approach. Results: During the follow-up (mean 6.0 yr), 586 of the participants died (cancer deaths, n = 211; CVD deaths, n = 214). As expected, our data revealed a U-shaped association between serum IGF-I levels and all-cause mortality. Low as well as high serum IGF-I (quintile 1 or 5 vs. quintiles 2-4) associated with increased cancer mortality [hazard ratio (HR) = 1.86, 95% confidence interval (CI) = 1.34-2.58; and HR = 1.90, 95% CI = 1.37-2.65, respectively]. Only low serum IGF-I associated with increased CVD mortality (quintile 1 vs. quintiles 2-4, HR = 1.48, 95% CI = 1.08-2.04). These associations remained after adjustment for multiple covariates and exclusion of men who died during the first 2 yr of follow-up. Conclusions: Our findings demonstrate that both low and high serum IGF-I levels are risk markers for increased cancer mortality in older men. Moreover, low IGF-I levels associate with increased CVD mortality.
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41. |
- Svensson, Johan, 1964, et al.
(författare)
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Endocrine, liver-derived IGF-I is of importance for spatial learning and memory in old mice.
- 2006
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Ingår i: The Journal of endocrinology. - : Bioscientifica. - 0022-0795 .- 1479-6805. ; 189:3, s. 617-27
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Tidskriftsartikel (refereegranskat)abstract
- IGF-I is a neuroprotective hormone, and neurodegenerative disorders, including Alzheimer's disease, have been associated with decreased serum IGF-I concentration. In this study, IGF-I production was inactivated in the liver of adult mice (LI-IGF-I(-/-)), resulting in an approximately 80-85% reduction of circulating IGF-I concentrations. In young (6-month-old) mice there was no difference between the LI-IGF-I(-/-) and the control mice in spatial learning and memory as measured using the Morris water maze test. In old (aged 15 and 18 months) LI-IGF-I(-/-) mice, however, the acquisition of the spatial task was slower than in the controls. Furthermore, impaired spatial working as well as reference memory was observed in the old LI-IGF(-/-) mice. Histochemical analyses revealed an increase in dynorphin and enkephalin immunoreactivities but decreased mRNA levels in the hippocampus of old LI-IGF-I(-/-) mice. These mice also displayed astrocytosis and increased metabotropic glutamate receptor 7a-immunoreactivity. These neurochemical disturbances suggest synaptic dysfunction and early neurodegeneration in old LI-IGF-I(-/-) mice. The decline in serum IGF-I with increasing age may therefore be important for the age-related decline in memory function.
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42. |
- Svensson, Johan, 1964, et al.
(författare)
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Growth hormone and the cardiovascular function.
- 2005
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Ingår i: Minerva endocrinologica. - 0391-1977. ; 30:1, s. 1-13
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Forskningsöversikt (refereegranskat)abstract
- In this review, the great importance of growth hormone (GH) for the maintenance of cardiac function in adult life is discussed. Physiological effects of GH are discussed as well as the cardiac dysfunction caused both by GH excess (acromegaly) and by GH deficiency in adult hypopituitary patients. In both acromegaly and adult GH deficiency, there is also increased cardiovascular morbidity and mortality. Finally, the effect of GH treatment in heart failure is discussed.
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43. |
- Svensson, Johan, 1964, et al.
(författare)
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Increased diet-induced fatty streak formation in female mice with deficiency of liver-derived insulin-like growth factor-I.
- 2016
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Ingår i: Endocrine. - : Springer Science and Business Media LLC. - 1559-0100 .- 1355-008X. ; 52:3, s. 550-560
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Tidskriftsartikel (refereegranskat)abstract
- The role of endocrine IGF-I for atherosclerosis is unclear. We determined the importance of circulating, liver-derived IGF-I for fatty streak formation in mice. Mice with adult, liver-specific IGF-I inactivation (LI-IGF-I(-/-) mice, serum IGF-I reduced by approximately 80%) and control mice received an atherogenic (modified Paigen) diet between 6 and 12months of age. At study end, Oil Red O staining of aortic root cryosections showed increased fatty streak area and lipid deposition in female but not in male LI-IGF-I(-/-) mice compared to controls. Mac-2 staining of aortic root and measurements of CD68 mRNA level in femoral artery revealed increased macrophage accumulation in proportion to the increased fatty streak area in female LI-IGF-I(-/-) mice. Moreover, female LI-IGF-I(-/-) mice displayed increased serum cholesterol and interleukin-6 as well as increased vascular cell-adhesion molecule 1 (VCAM1) mRNA levels in the femoral artery and elevated VCAM1 protein expression in the aortic root. Thus, increased diet-induced fatty streak formation in female LI-IGF-I(-/-) mice was associated with increased serum cholesterol and signs of systemic inflammation, endothelial activation, lipid deposition, and macrophage infiltration in the vascular wall.
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44. |
- Svensson, Johan, 1964, et al.
(författare)
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Leukocyte telomere length is not associated with mortality in older men
- 2014
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Ingår i: Experimental Gerontology. - : Elsevier BV. - 0531-5565 .- 1873-6815. ; 57, s. 6-12
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Tidskriftsartikel (refereegranskat)abstract
- Leukocyte telomere length (LTL) is related to the aging of somatic cells. We hypothesized that LTL is inversely associated with mortality in elderly men. LTL was measured in 2744 elderly men (mean age 75.5, range 69-81 years) included in the prospective population-based MrOS-Sweden study. Mortality data were obtained from national health registers with no loss of follow-up. During the follow-up (mean 6.0 years), 556 (20%) of the participants died. Using Cox proportional hazards regression, tertile of LTL did not associate with all-cause mortality [tertile 1 (shortest) or 2 (middle) vs. tertile 3 (longest); hazard ratio (HR) = 1.05, 95% confidence interval (CI) 0.85-1.28 and HR = 0.97, 95% CI 0.79-1.19, respectively]. Furthermore, LTL did not associate with cancer (197 events) or cardiovascular disease (CVD, 206 events) mortality (tertile 1 vs. tertile 3; HR = 0.94, 95% CI 0.67-1.34 and HR = 0.94, 95% CI 0.68-1.30, respectively). The lack of association between LTL and mortality remained also after adjustment for multiple covariates. Our results demonstrate that LTL is not associated with all-cause mortality or mortality due to cancer or CVD in elderly men. Further studies are needed to determine whether LTL can predict the risk of mortality in elderly women.
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45. |
- Svensson, Johan, 1964, et al.
(författare)
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Liver-derived IGF-I regulates kidney size, sodium reabsorption, and renal IGF-II expression.
- 2007
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Ingår i: The Journal of endocrinology. - 0022-0795. ; 193:3, s. 359-66
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Tidskriftsartikel (refereegranskat)abstract
- The GH/-IGF-I axis is important for kidney size and function and may also be involved in the development of renal failure. In this study, the role of liver-derived endocrine IGF-I for kidney size and function was investigated in mice with adult liver-specific IGF-I inactivation (LI-IGF-I(-/-) mice). These mice have an 80-85% reduction of serum IGF-I level and compensatory increased GH secretion. Seven-month-old as well as 24-month-old LI-IGF-I(-/-) mice had decreased kidney weight. Glomerular filtration rate, assessed using creatinine clearance as well as creatinine clearance corrected for body weight, was unchanged. The 24-h urine excretion of sodium and potassium was increased in the LI-IGF-I(-/-) mice. In the 24-month-old mice, there was no between-group difference in kidney morphology. Microarray and real-time PCR (RT-PCR) analyses showed a high renal expression of IGF-II in the control mice, whereas in the LI-IGF-I(-/-) mice, there was a tissue-specific decrease in the renal IGF-II mRNA levels (-79%, P < 0.001 vs controls using RT-PCR). In conclusion, deficiency of circulating liver-derived IGF-I in mice results, despite an increase in GH secretion, in a global symmetrical decrease in kidney size, increased urinary sodium and potassium excretion, and a clear down regulation of renal IGF-II expression. However, the LI-IGF-I(-/-) mice did not develop kidney failure or nephrosclerosis. One may speculate that liver-derived endocrine IGF-I induces renal IGF-II expression, resulting in symmetrical renal growth.
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46. |
- Tivesten, Åsa, 1969, et al.
(författare)
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Additive protective effects of estrogen and androgen treatment on trabecular bone in ovariectomized rats.
- 2004
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Ingår i: Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research. - 0884-0431. ; 19:11, s. 1833-9
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Tidskriftsartikel (refereegranskat)abstract
- Both ER and AR activation regulates trabecular bone mass. We show that combined estrogen and androgen treatment results in additive protection of trabecular bone in OVX rats. This may in part be attributable to the effect of AR activation to attenuate the inhibitory effect of ER activation on bone formation. INTRODUCTION: Sex steroids are important regulators of trabecular bone mass. Both estrogen receptor (ER) and androgen receptor (AR) activation results in increased trabecular bone mass. The aim of this study was to investigate if combined estrogen and androgen treatment might be beneficial in the treatment of trabecular bone loss. MATERIALS AND METHODS: Twelve-week-old female rats were ovariectomized (OVX) and treated with vehicle (V), 17beta-estradiol (E2; ER activation), dihydrotestosterone (DHT; AR activation), or the combination (E2 + DHT) for 6 weeks. The skeletal phenotype was analyzed by pQCT, microCT, histomorphometry of growth plates, and serum levels of biochemical bone markers. RESULTS: Both E2 (+121% over V) and DHT (+34%) preserved the trabecular volumetric BMD (tvBMD) in OVX rats. The effect of E2 and DHT on tvBMD was additive, resulting in a 182% increase over V in the rats given E2 + DHT. MicroCT analyses of the trabecular bone microstructure revealed that the effect of E2 and DHT was additive on the number of trabeculae. E2 treatment reduced serum markers of both bone resorption (collagen C-terminal telopeptide) and bone formation (osteocalcin), indicating reduced bone turnover. Addition of DHT to E2 treatment did not modulate the effects of E2 on the marker of bone resorption, whereas it attenuated the inhibitory effect of E2 on the bone formation marker, which might explain the additive protective effect of E2 and DHT on trabecular bone mass. In contrast, DHT partially counteracted the suppressive effect of E2 on longitudinal bone growth and the E2-induced alterations in growth plate morphology. CONCLUSIONS: These findings show that combined estrogen and androgen treatment results in additive protective effects on trabecular bone in OVX rats. Our data suggest that a combined treatment with selective ER and AR modulators might be beneficial in the treatment of osteoporosis.
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47. |
- Tivesten, Åsa, 1969, et al.
(författare)
-
Cardiac concentric remodelling induced by non-aromatizable (dihydro-)testosterone is antagonized by oestradiol in ovariectomized rats
- 2006
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Ingår i: J Endocrinol. ; 189:3, s. 485-91
-
Tidskriftsartikel (refereegranskat)abstract
- Previous studies on the cardiovascular effects of androgens in females, most of them using testosterone treatment, have yielded conflicting results. Testosterone is metabolized into oestradiol (E2) and dihydrotestosterone (DHT) within cardiovascular tissues. The aim of the present study was to explore the cardiovascular effects exerted by E2 and the non-aromatizable androgen DHT and to study possible interactions between these in female rats. Ovariectomized rats were treated with DHT, E2, or DHT+E2 for 6 weeks. DHT increased left-ventricular posterior wall thickness, assessed by echocardiography, whereas left-ventricular dimension, as well as total heart weight and calculated left-ventricular mass, were unchanged. DHT also increased the levels of insulin-like growth factor-I mRNA in the left ventricle. E2 abolished the effect of DHT on left-ventricular remodelling and insulin-like growth factor-I mRNA when the two treatments were given in combination. E2 also reduced androgen receptor mRNA levels in the heart. Neither E2 nor DHT changed blood pressure measured by telemetry. In conclusion, treatment with the endogenous non-aromatizable androgen DHT causes cardiac concentric remodelling in ovariectomized rats, possibly mediated by increased local levels of insulin-like growth factor-I. The effect of DHT on cardiac wall thickness was antagonized by E2, possibly through downregulation of cardiac androgen receptors. These mechanisms may be of importance for the concentric left-ventricular geometric pattern developing in women after menopause.
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48. |
- Tivesten, Åsa, 1969, et al.
(författare)
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Cardiovascular and respiratory systems.
- 2005
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Ingår i: Advances in experimental medicine and biology. - 0065-2598. ; 567, s. 149-66
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Forskningsöversikt (refereegranskat)
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49. |
- Tivesten, Åsa, 1969
(författare)
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Cardiovascular effects of growth hormone, IGF-I and growth hormone secretagogues
- 2003
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Growth hormone (GH) may exert direct growth-promoting and metabolic actions on target tissues, but most of its effects are mediated by circulating (endocrine) or local (auto-/paracrine) insulin-like growth factor-I (IGF-I). The GH/IGF-I system has an important role during cardiac development and for maintaining the structure and function of the heart. Attention has recently been focused on the endogenous GH secretagogue ghrelin, which, besides amplification of GH secretion, has metabolic and possibly also cardiovascular effects. The aim of this thesis was to elucidate the relative importance of circulating IGF-I for cardiovascular function, to elucidate which genes are involved in the cardiac effects of GH, and to examine the cardiovascular effects of natural (ghrelin) and synthetic (hexarelin) GH secretagogues. We found that similar hemodynamic effects were evoked by GH and IGF-I in rats 4 weeks after myocardial infarction, including increased stroke volume and reduced peripheral resistance, supporting the notion of a role of IGF-I in mediating the cardiovascular actions of GH. Cardiovascular phenotyping of transgenic mice with liver-specific deletion of IGF-I (LI-IGF-I-/- mice) and approximately 80 per cent reduction of IGF-I levels in serum revealed that these mice have increased systolic blood pressure levels and impaired endothelium-dependent relaxation in resistance vessels. LI-IGF-I-/- mice also had reduced cardiac output and increased wall thickness of the heart, which probably reflects adaptations to the increased blood pressure. Two weeks of GH treatment in hypophysectomised rats increased circulating IGF-I, heart weight and stroke volume. When global gene expression of the GH-regulated genes (quantified in microarray) was correlated to stroke volume, genes involved in cardiac calcium-handling, hypertrophy and turnover of extracellular matrix showed the highest correlation coefficients. In particular, down-regulation of Na+/K+-ATPase and up-regulation of Na+/Ca2+-Exchanger by GH may contribute to increase cardiac contractility and/or hypertrophy. The synthetic GH secretagogue hexarelin decreased total peripheral peripheral resistance and increased cardiac output to a similar extent as GH in the rat model of myocardial infarction, despite unchanged body weight gain and levels of serum IGF-I. GH-independent cardiovascular effects of ghrelin were studied in hypophysectomised rats, showing that ghrelin decreased blood pressure but had no effects on cardiac output or gene regulation. In conclusion, the results presented in this thesis show that both circulating, liver-derived IGF-I and natural as well as synthetic GH secretagogues are major regulators of peripheral resistance. In contrast to its vascular actions, the cardiac effects of ghrelin seem to be dependent on its ability to release GH. Furthermore, we show that GH increases the mRNA expression of a broad range of genes in the heart in order to increase cardiac performance.
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50. |
- Tivesten, Åsa, 1969, et al.
(författare)
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Cardiovascular risk with androgen deprivation therapy for prostate cancer: Potential mechanisms.
- 2015
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Ingår i: Urologic oncology. - : Elsevier BV. - 1873-2496. ; 33:11, s. 464-75
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Forskningsöversikt (refereegranskat)abstract
- Androgen deprivation therapy (ADT) is frequently used for the treatment of advanced prostate cancer. ADT is associated with numerous side effects related to its mode of action, namely the suppression of testosterone to castrate levels. Recently, several large retrospective studies have also reported an increased risk of diabetes and cardiovascular disease in men receiving ADT, although these risks have not been confirmed by prospective randomized trials. We review the literature to consider the risk of cardiovascular disease with different forms of ADT and examine in detail potential mechanisms by which any such risk could be mediated. Mechanisms discussed include the metabolic syndrome resulting from low testosterone level and the potential roles of testosterone flare, gonadotropin-releasing hormone receptors outside the pituitary gland, and altered levels of follicle-stimulating hormone. Finally, the clinical implications for men prescribed ADT for the treatment of advanced prostate cancer are considered.
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