| 1. |
- Andersson, Niklas, 1970, et al.
(författare)
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A variant near the interleukin-6 gene is associated with fat mass in Caucasian men
- 2010
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Ingår i: International Journal of Obesity. - : Springer Science and Business Media LLC. - 0307-0565 .- 1476-5497. ; 34:6, s. 1011-9
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Tidskriftsartikel (refereegranskat)abstract
- CONTEXT: Regulation of fat mass appears to be associated with immune functions. Studies of knockout mice show that endogenous interleukin (IL)-6 can suppress mature-onset obesity. OBJECTIVE: To systematically investigate associations of single nucleotide polymorphisms (SNPs) near the IL-6 (IL6) and IL-6 receptor (IL6R) genes with body fat mass, in support for our hypothesis that variants of these genes can be associated with obesity. DESIGN AND STUDY SUBJECTS: The Gothenburg Osteoporosis and Obesity Determinants (GOOD) study is a population-based cross-sectional study of 18- to 20-year-old men (n=1049), from the Gothenburg area (Sweden). Major findings were confirmed in two additional cohorts consisting of elderly men from the Osteoporotic Fractures in Men (MrOS) Sweden (n=2851) and MrOS US (n=5611) multicenter population-based studies. MAIN OUTCOME: The genotype distributions and their association with fat mass in different compartments, measured with dual-energy X-ray absorptiometry. RESULTS: Out of 18 evaluated tag SNPs near the IL6 and IL6R genes, a recently identified SNP rs10242595 G/A (minor allele frequency=29%) 3' of the IL6 gene was negatively associated with the primary outcome total body fat mass (effect size -0.11 standard deviation (s.d.) units per A allele, P=0.02). This negative association with fat mass was also confirmed in the combined MrOS Sweden and MrOS US cohorts (effect size -0.05 s.d. units per A allele, P=0.002). When all three cohorts were combined (n=8927, Caucasian subjects), rs10242595(*)A showed a negative association with total body fat mass (effect size -0.05 s.d. units per A allele, P<0.0002). Furthermore, the rs10242595(*)A was associated with low body mass index (effect size -0.03, P<0.001) and smaller regional fat masses. None of the other SNPs investigated in the GOOD study were reproducibly associated with body fat. CONCLUSIONS: The IL6 gene polymorphism rs10242595(*)A is associated with decreased fat mass in three combined cohorts of 8927 Caucasian men.
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| 2. |
- Andersson, Niklas, 1970, et al.
(författare)
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Drug-induced prevention of gastrectomy- and ovariectomy-induced osteopaenia in the young female rat.
- 2002
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Ingår i: The Journal of endocrinology. - : Bioscientifica. - 0022-0795 .- 1479-6805. ; 175:3, s. 695-703
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Tidskriftsartikel (refereegranskat)abstract
- Both ovariectomy (Ovx) and gastrectomy (Gx) induce osteopaenia in rats and humans. While the effect of Ovx has been ascribed to oestrogen deficiency, the underlying mechanism behind Gx is poorly understood. Alendronate, oestrogen and parathyroid hormone (PTH) are known to prevent the osteopaenia induced by Ovx in rats. The purpose of the present study was to determine whether alendronate, oestrogen or PTH could also prevent Gx-evoked osteopaenia. Rats were Ovx-, Gx-, or were sham-operated (Sham) and were then treated with alendronate (50 micro g/kg/day), oestrogen (10 micro g/kg/day) or PTH(1-84) (75 micro g/kg/day) for eight weeks. At sacrifice, serum PTH was unaffected by surgery (Ovx, 64+/-8 pg/ml; Gx, 75+/-13 pg/ml; Sham, 58+/-11 pg/ml). The bone mineral density (BMD) of the fifth lumbar vertebra (L5) was analysed. Ovx and Gx reduced the BMD (ash weight/Volume) of the L5 by 15+/-4% and 22+/-3% respectively. Trabecular BMD and the cortical bone mineral content (BMC) of the femur were assessed using peripheral computed tomography. Both Ovx and Gx markedly reduced trabecular BMD in the metaphyseal area of the distal femur (Ovx, -37+/-7%; Gx, -49+/-7%). The cortical BMC of the femur was only slightly reduced. Alendronate prevented trabecular bone loss after both Ovx and Gx, while oestrogen and PTH prevented trabecular bone loss after Ovx but not after Gx. In conclusion, the bisphosphonate alendronate prevented both Ovx- and Gx-induced trabecular bone loss. In contrast, PTH and oestrogen prevented Ovx-induced but not Gx-induced trabecular bone loss, suggesting that the mechanism behind the trabecular bone loss in Ovx rats differs from that in Gx rats. The results support the notion that the mechanism of action for the bone-sparing effect of these drugs differs. The ability of alendronate, and probably also other bisphosphonates, to prevent Gx-evoked osteopaenia in the rat might be of potential clinical interest when dealing with post-Gx osteopaenia in humans.
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| 3. |
- Andersson, Niklas, 1970, et al.
(författare)
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Investigation of central versus peripheral effects of estradiol in ovariectomized mice
- 2005
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Ingår i: J Endocrinol. - : Bioscientifica. - 0022-0795 .- 1479-6805. ; 187:2, s. 303-9
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Tidskriftsartikel (refereegranskat)abstract
- It is generally believed that estrogens exert their bone sparing effects directly on the cells within the bone compartment. The aim of the present study was to investigate if central mechanisms might be involved in the bone sparing effect of estrogens. The dose-response of central (i.c.v) 17beta-estradiol (E2) administration was compared with that of peripheral (s.c.) administration in ovariectomized (ovx) mice. The dose-response curves for central and peripheral E2 administration did not differ for any of the studied estrogen-responsive tissues, indicating that these effects were mainly peripheral. In addition, ovx mice were treated with E2 and/or the peripheral estrogen receptor antagonist ICI 182,780. ICI 182,780 attenuated most of the estrogenic response regarding uterus weight, retroperitoneal fat weight, cortical BMC and trabecular bone mineral content (P<0.05). These findings support the notion that the primary target tissue that mediates the effect of E2 on bone is peripheral and not central.
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| 4. |
- Andersson, Niklas, 1970, et al.
(författare)
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Pharmacological treatment of osteopenia induced by gastrectomy or ovariectomy in young female rats.
- 2004
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Ingår i: Acta orthopaedica Scandinavica. - : Medical Journals Sweden AB. - 0001-6470 .- 1651-1964. ; 75:2, s. 201-9
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Both gastrectomy (GX) and ovariectomy (OVX) induce osteopenia in man and experimental animals. The present study addresses the question--can alendronate, estrogen or parathyroid hormone (PTH) be used to treat established GX- or OVX -evoked osteopenia? METHODS: Rats were GX-, OVX- or SHAM-operated 8 weeks before starting the treatment with drugs. Each group was then treated for 8 weeks with 50 microg/kg/day alendronate, 10 microg/kg/day estrogen or 75 microg/kg/day PTH(1-84); n = 8 rats/group. Peripheral Quantitative Computed Tomography (pQCT) was used to measure trabecular bone mineral density (BMD) and various cortical bone parameters. RESULTS: At killing, 16 weeks after surgery, GX and OVX rats had a greatly reduced trabecular BMD in the metaphysis of the distal femur (GX -44% and OVX -55%). Alendronate increased the trabecular BMD by 44% in GX rats and by 64% in OVX rats, while PTH increased it by 51% and 115%, respectively. However, estrogen increased the trabecular BMD in GX rats (35%), but not in OVX rats (15%, not significant). Cortical bone parameters were adversely (but moderately) affected by GX, but not by OVX or by treatment with the three drugs. INTERPRETATION: Alendronate, estrogen and PTH restored the trabecular bone loss in rats with an established GX-evoked osteopenia. In contrast, alendronate and PTH, but not estrogen, restored the trabecular bone loss after OVX. Hence, the mechanism underlying GX-evoked bone loss differs from that underlying OVX-evoked bone loss. The ability of alendronate, estrogen and PTH to reverse the GX-evoked osteopenia in the rat may be of clinical interest when dealing with bone loss in humans after GX.
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| 5. |
- Andersson, Niklas, 1970, et al.
(författare)
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Repeated in vivo determinations of bone mineral density during parathyroid hormone treatment in ovariectomized mice.
- 2001
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Ingår i: The Journal of endocrinology. - 0022-0795 .- 1479-6805. ; 170:3, s. 529-37
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Tidskriftsartikel (refereegranskat)abstract
- The recent development of different genetically modified mice with potentially interesting bone phenotypes has increased the demand for effective non-invasive methods to evaluate effects on bone of mice during growth and development, and for drug evaluation. In the present study, the skeleton was analyzed by repeated in vivo scans using dual energy X-ray absorptiometry (DXA) and peripheral quantitative computed tomography (pQCT). Ovariectomized (ovx) mice treated with parathyroid hormone (PTH) were used as an animal model to evaluate these two techniques at different times after the onset of treatment. Female mice (6 weeks of age) were allocated randomly to four groups: (1) sham-operated+vehicle; (2) ovx+vehicle; (3) sham-operated+PTH(1-84) 150 microg/kg per day; (4) ovx+PTH. Six weeks after ovariectomy the drug treatment began and was continued for 8 weeks. The total body bone mineral content (BMC) and total body areal bone mineral density (BMD) were measured by DXA. Ovariectomy reduced total body BMC and total body areal BMD by 6.2+/-1.7% and 2.6+/-0.9% respectively. No effect of PTH on total body BMC was seen during the treatment period. The trabecular volumetric BMD was measured by pQCT. Ovariectomy reduced the trabecular volumetric BMD by 52+/-6.7%. The pQCT technique detected a clear effect on trabecular volumetric BMD after 2 weeks of PTH treatment (ovx 94+/-29% and sham-operated 46+/-10% more than vehicle-treated). The cortical bone was measured in a mid-diaphyseal pQCT scan of the tibia. Ovariectomy reduced the cortical BMC by 9+/-2%. PTH treatment for 8 weeks increased cortical BMC in ovx mice. In conclusion, the pQCT technique is more sensitive than the DXA technique in the detection of bone loss after ovariectomy and increased bone mass after PTH treatment in mice. Notably, the pQCT, but not the DXA, technique detected a dramatic effect as early as after 2 weeks of PTH treatment. Dynamic pQCT measurements will be useful for monitoring skeletal changes during growth and development, and for drug evaluation in mice.
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| 6. |
- Andersson, Niklas, 1970, et al.
(författare)
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Variants of the interleukin-1 receptor antagonist gene are associated with fat mass in men
- 2009
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Ingår i: International Journal of Obesity. - : Springer Science and Business Media LLC. - 0307-0565 .- 1476-5497. ; 33:5, s. 525-533
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Tidskriftsartikel (refereegranskat)abstract
- Context: Immune functions seem to have connections to variations in body fat mass. Studies of knockout mice indicate that endogenous interleukin (IL)-1 can suppress mature-onset obesity. Objective: To systematically investigate our hypotheses that single- nucleotide polymorphisms (SNPs) and/or haplotypes variants in the IL-1 gene system are associated with fat mass. Subjects: The Gothenburg osteoporosis and obesity determinants (GOOD) study is a population-based cross-sectional study of 18-20 year-old men (n = 1068), from Gothenburg, Sweden. Major findings were confirmed in elderly men (n = 3014) from the Swedish part of the osteoporotic fractures in men (MrOS) multicenter population-based study. Main Outcome Measure: The genotype distributions and their association with body fat mass in different compartments, measured with dual-energy X-ray absorptiometry (DXA). Results: Out of 15 investigated SNPs in the IL-1 receptor antagonist (IL1RN) gene, a recently identified 30 untranslated region C4T (rs4252041, minor allele frequency 4%) SNP was associated with the primary outcome total fat mass (P = 0.003) and regional fat masses, but not with lean body mass or serum IL-1 receptor 1 (IL1RN) levels. This SNP was also associated with body fat when correcting the earlier reported IL1RN_2018 T4C (rs419598) SNP (in linkage disequilibrium with a well-studied variable number tandem repeat of 86 bp). The association between rs4252041 SNP and body fat was confirmed in the older MrOS population (P = 0.03). The rs4252041 SNP was part of three haplotypes consisting of five adjacent SNPs that were identified by a sliding window approach. These haplotypes had a highly significant global association with total body fat (P < 0.001). None of the other investigated members of the IL-1 gene family displayed any SNPs that have not been described previously to be significantly associated with body fat. Conclusions: The IL1RN gene, shown to enhance obesity by suppressing IL-1 effects in experimental animals, have no previously described gene polymorphisms and haplotypes that are associated with fat, but not lean mass in two populations of men. International Journal of Obesity (2009) 33, 525-533; doi: 10.1038/ijo.2009.47; published online 17 March 2009
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| 7. |
- Eriksson, Anna-Lena, 1971, et al.
(författare)
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SHBG gene promoter polymorphisms in men are associated with serum sex hormone-binding globulin, androgen and androgen metabolite levels, and hip bone mineral density.
- 2006
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Ingår i: The Journal of clinical endocrinology and metabolism. - : The Endocrine Society. - 0021-972X .- 1945-7197. ; 91:12, s. 5029-37
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Tidskriftsartikel (refereegranskat)abstract
- CONTEXT: SHBG regulates free sex steroid levels, which in turn regulate skeletal homeostasis. Twin studies have demonstrated that genetic factors largely account for interindividual variation in SHBG levels. Glucuronidated androgen metabolites have been proposed as markers of androgenic activity. OBJECTIVE: Our objective was to investigate whether polymorphisms in the SHBG gene promoter [(TAAAA)(n) microsatellite and rs1799941 single-nucleotide polymorphism] are associated with serum levels of SHBG, sex steroids, or bone mineral density (BMD) in men. DESIGN AND STUDY SUBJECTS: We conducted a population-based study of two cohorts of Swedish men: elderly men (MrOS Sweden; n congruent with 3000; average age, 75.4 yr) and young adult men (GOOD study; n = 1068; average age, 18.9 yr). MAIN OUTCOME MEASURES: We measured serum levels of SHBG, testosterone, estradiol, dihydrotestosterone, 5alpha-androstane-3alpha,17beta-diol glucuronides, androsterone glucuronide, and BMD determined by dual-energy x-ray absorptiometry. RESULTS: In both cohorts, (TAAAA)(n) and rs1799941 genotypes were associated with serum levels of SHBG (P < 0.001), dihydrotestosterone (P < 0.05), and 5alpha-androstane-3alpha,17beta-diol glucuronides (P < 0.05). In the elderly men, they were also associated with testosterone and BMD at all hip bone sites. The genotype associated with high levels of SHBG was also associated with high BMD. Interestingly, male mice overexpressing human SHBG had increased cortical bone mineral content in the femur, suggesting that elevated SHBG levels may cause increased bone mass. CONCLUSIONS: Our findings demonstrate that polymorphisms in the SHBG promoter predict serum levels of SHBG, androgens, and glucuronidated androgen metabolites, and hip BMD in men.
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| 8. |
- Forsgard, Niklas, et al.
(författare)
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Cardiac arrest in Wilson's disease after curative liver transplantation: a life-threatening complication of myocardial copper excess?
- 2019
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Ingår i: ESC Heart Failure. - : Wiley. - 2055-5822. ; 6:1, s. 228-231
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Tidskriftsartikel (refereegranskat)abstract
- We report the case of a 38-year-old man who presented with cardiac arrest 1 year after curative liver transplantation for Wilson's disease. Clinical work-up proofed myocardial copper and iron accumulation using mass spectrometry, which led most likely to myocardial fibrosis as visualized by cardiovascular magnetic resonance (unprecedented delayed enhancement pattern) and endomyocardial biopsy. Consequently, cardiac arrest due to ventricular fibrillation and subsequent episodes of sustained ventricular tachycardia were considered as primary cardiac manifestation of Wilson's disease. This can, as illustrated by our case, occur even late after curative liver transplantation, which is an important fact that treating physicians should be aware of during clinical follow-up of these patients.
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| 9. |
- Lindberg, Marie K, 1975, et al.
(författare)
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Estrogen receptor specificity for the effects of estrogen in ovariectomized mice.
- 2002
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Ingår i: The Journal of endocrinology. - : Bioscientifica. - 0022-0795 .- 1479-6805. ; 174:2, s. 167-78
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Tidskriftsartikel (refereegranskat)abstract
- Estrogen exerts a variety of important physiological effects, which have been suggested to be mediated via the two known estrogen receptors (ERs), alpha and beta. Three-month-old ovariectomized mice, lacking one or both of the two estrogen receptors, were given estrogen subcutaneously (2.3 micro g/mouse per day) and the effects on different estrogen-responsive parameters, including skeletal effects, were studied. We found that estrogen increased the cortical bone dimensions in both wild-type (WT) and double ER knockout (DERKO) mice. DNA microarray analysis was performed to characterize this effect on cortical bone and it identified four genes that were regulated by estrogen in both WT and DERKO mice. The effect of estrogen on cortical bone in DERKO mice might either be due to remaining ERalpha activity or represent an ERalpha/ERbeta-independent effect. Other effects of estrogen, such as increased trabecular bone mineral density, thymic atrophy, fat reduction and increased uterine weight, were mainly ERalpha mediated.
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| 10. |
- Lorentzon, Mattias, 1970, et al.
(författare)
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Free testosterone is a positive, whereas free estradiol is a negative, predictor of cortical bone size in young Swedish men: the GOOD study.
- 2005
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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. ; 20:8, s. 1334-41
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Tidskriftsartikel (refereegranskat)abstract
- In this study, we evaluated the predictive roles of sex steroids for skeletal parameters in young men (n = 1068) at the age of peak bone mass. Serum free estradiol was a negative predictor, whereas free testosterone and SHBG were positive predictors of cortical bone size. INTRODUCTION: Previous studies have shown that free estradiol in serum is an independent predictor of areal BMD (aBMD) in elderly men. The aim of this study was to determine whether sex steroids are predictors of volumetric BMD (vBMD) and/or size of the trabecular and cortical bone compartments in young men at the age of peak bone mass. MATERIALS AND METHODS: The Gothenburg Osteoporosis and Obesity Determinants (GOOD) study consists of 1068 men, 18.9 +/- 0.6 years of age. Serum levels of testosterone, estradiol, and sex hormone binding globulin (SHBG) were measured, and free levels of testosterone and estradiol were calculated. The size of the cortical bone and the cortical and trabecular vBMDs were measured by pQCT. RESULTS: Regression models including age, height, weight, free estradiol, and free testosterone showed that free estradiol was an independent negative predictor of cortical cross-sectional area (tibia beta = -0.111, p < 0.001; radius beta = -0.125, p < 0.001), periosteal circumference, and endosteal circumference, whereas it was a positive independent predictor of cortical vBMD (tibia beta = 0.100, p < 0.003; radius beta = 0.115, p = 0.001) in both the tibia and radius. Free testosterone was an independent positive predictor of cortical cross-sectional area (tibia beta = 0.071, p = 0.013; radius beta = 0.064, p = 0.039), periosteal circumference, and endosteal circumference in both the tibia and radius. Neither cortical nor trabecular vBMD was associated with free testosterone. SHBG was an independent positive predictor of parameters reflecting the size of the cortical bone, including cross-sectional area (beta = 0.078, p = 0.009), periosteal circumference, and endosteal circumference. CONCLUSIONS: Free estradiol is a negative, whereas free testosterone is a positive, predictor of cortical bone size in young men at the age of peak bone mass. These findings support the notion that estrogens reduce, whereas androgens increase, cortical bone size, resulting in the well-known sexual dimorphism of cortical bone geometry.
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