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- Eklund, E, et al.
(författare)
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IGF-I and IGFBP-1 in Relation to Body Composition and Physical Performance in Female Olympic Athletes
- 2021
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Ingår i: Frontiers in endocrinology. - : Frontiers Media SA. - 1664-2392. ; 12, s. 708421-
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Tidskriftsartikel (refereegranskat)abstract
- Insulin- like growth factor-I (IGF-I) is an anabolic hormone that may affect athletic performance in female athletes, and insulin-like growth factor binding protein-1 (IGFBP-1) is an important regulator of bioactive IGF-I. There is limited knowledge of the role of endogenous IGF-I and IGFBP-1 for body composition and physical performance in female elite athletes.PurposeTo examine IGF-I, age adjusted IGF-I (IGFSD), IGFBP-1 and insulin in female Olympic athletes compared with controls and different sport categories, and in relation to body composition and physical performance in the athletes.MethodsFemale athletes (n=103) and untrained controls (n=113) were included in this cross-sectional study. Body composition was established by dual-energy X-ray absorptiometry. Serum IGF-I and IGFBP-1 were analyzed by radioimmunoassay and IGFSD was calculated. Insulin was analyzed by electrochemiluminescence immunoassay. Athletes were offered to participate in standardized physical fitness tests.ResultsThe athletes demonstrated significantly higher IGF-I, IGFSD and IGFBP-1 and lower insulin levels than controls (p<0.05, p<0.05, p<0.01, p<0.001 respectively). Power athletes had significantly higher IGFSD compared to both endurance and technical athletes (p<0.05, p<0.01, respectively). In athletes and controls combined, significant positive correlations were found between IGF variables and higher bone mineral density (BMD) and lean mass and lower fat percent. IGF-I was positively correlated with squat jump (rs = 0.28, p<0.05) and IGFBP-1 correlated positively with squats (rs =0.35, p<0.05).ConclusionWe found higher IGF-I, IGFSD and IGFBP-1 in female athletes than controls, and the highest IGFSD in power athletes. IGF-I and IGFBP-1 were related to increased BMD and lean mass and lower fat percent, as well as were positively associated with physical fitness tests. Future studies are needed to elucidate if these results reflect adaptive responses to physical activity or genetic predisposition.
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- Eklund, E, et al.
(författare)
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Urinary Steroid Profile in Elite Female Athletes in Relation to Serum Androgens and in Comparison With Untrained Controls
- 2021
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Ingår i: Frontiers in physiology. - : Frontiers Media SA. - 1664-042X. ; 12, s. 702305-
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Tidskriftsartikel (refereegranskat)abstract
- In female athletes, the interpretation of doping tests is complex due to hormonal variations during the menstrual cycle and hormonal contraceptive use, both influencing the urinary steroid profile. Exercise is suggested to affect circulating steroid hormone levels, and in women, the urinary steroid profile differs between in competition testing and out of competition testing. No previous study has investigated the relationship between amount of exercise and the urinary steroid profile in female elite athletes.PurposeTo compare the urinary steroid profile between female Olympic athletes and age- and BMI-matched untrained controls, and to study the urinary steroid profile in relation to serum hormones and amount of exercise.MethodsIn this cross-sectional study conducted at the Women’s Health Research Unit, Karolinska University Hospital, Stockholm, 94 female elite athletes and 86 untrained controls were included. Serum estrogens and testosterone and the urinary steroid profile were analyzed by liquid chromatography–tandem mass spectrometry and gas chromatography-tandem mass spectrometry, respectively. Exercise hours/week were evaluated by questionnaire.ResultsAlthough serum steroid hormones were comparable between groups, the athletes demonstrated approximately 30% lower urinary steroid metabolites of testosterone, epitestosterone, androsterone, etiocholanolone, 5α-androstan-3α, 17β-diol, and 5β-androstan-3α, 17β-diol compared to the controls. The urinary steroid metabolites correlated positively with serum steroid hormones. In the athletes, urinary steroid metabolites: androsterone (rs = −0.28, p = 0.007), epitestosterone (rs = −0.22, p = 0.034), 5αAdiol (rs = −0.31, p = 0.002) and testosterone (rs = −0.24, p = 0.026), were negatively correlated with amount of training (hours per week).ConclusionThe urinary concentrations of steroid metabolites were lower in elite athletes than in sedentary controls, although serum steroids were comparable between groups. Moreover, exercise time was negatively associated with the urinary concentrations. Our findings suggest alternative excretion routes of androgens in the athletes related to training.
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- Ekstroem, L, et al.
(författare)
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Klotho Polymorphism in Association With Serum Testosterone and Knee Strength in Women After Testosterone Administration
- 2022
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Ingår i: Frontiers in physiology. - : Frontiers Media SA. - 1664-042X. ; 13, s. 844133-
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Tidskriftsartikel (refereegranskat)abstract
- Administration of testosterone (T) is associated with increased serum T concentrations and improved physical performance in women. However, the inter-individual variation in T concentrations after T treatment is large and may in part be due to genetic variations. Serum T, as well as dihydrotestosterone (DHT), androstenedione (A) and the T/A ratio have been suggested as promising doping biomarkers for testosterone intake. Here, polymorphisms in androgen metabolic enzyme genes have been investigated in healthy women prior to and after 10 weeks administration of testosterone cream. Klotho is a protein that has been associated with anaerobic strength and here a genetic variation in klotho gene was studied in relation to performance as measured by isokinetic knee strength, as well as to serum androgen disposition. The AKR1C3 genotype (rs12529) was associated with serum T levels at baseline, whereas serum concentrations post T treatment did not differ between genotypes. The SLCO2B1 (rs12422149) and UGT2B17 deletion polymorphisms were not associated with serum concentration of either T, DHT or A. The klotho polymorphism (rs9536314) was associated with serum concentrations of both total T and T/A ratio after T administration. Individuals with the GT genotype increased T concentrations and T/A ratio more than women homozygous for the T allele. No significant difference in the association of klotho genotype with knee muscle strength was observed between placebo and T treatment. However, individuals homozygous for the T allele showed higher isometric mean torque scores at exit than GT subjects after T administration. This is the first time a genotype has been associated with androgen concentrations after T administration and muscle strength in women. Our results imply that subjects with a polymorphism in klotho may be more prone to detection using serum T and A as biomarkers.
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- Hirschberg, AL
(författare)
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Approach to Investigation of Hyperandrogenism in a Postmenopausal Woman
- 2023
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Ingår i: The Journal of clinical endocrinology and metabolism. - : The Endocrine Society. - 1945-7197 .- 0021-972X. ; 108:5, s. 1243-1253
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Tidskriftsartikel (refereegranskat)abstract
- Postmenopausal hyperandrogenism is a condition caused by relative or absolute androgen excess originating from the ovaries and/or the adrenal glands. Hirsutism, in other words, increased terminal hair growth in androgen-dependent areas of the body, is considered the most effective measure of hyperandrogenism in women. Other symptoms can be acne and androgenic alopecia or the development of virilization, including clitoromegaly. Postmenopausal hyperandrogenism may also be associated with metabolic disorders such as abdominal obesity, insulin resistance, and type 2 diabetes. Mild hyperandrogenic symptoms can be due to relative androgen excess associated with menopausal transition or polycystic ovary syndrome, which is likely the most common cause of postmenopausal hyperandrogenism. Virilizing symptoms, on the other hand, can be caused by ovarian hyperthecosis or an androgen-producing ovarian or adrenal tumor that could be malignant. Determination of serum testosterone, preferably by tandem mass spectrometry, is the first step in the endocrine evaluation, providing important information on the degree of androgen excess. Testosterone >5 nmol/L is associated with virilization and requires prompt investigation to rule out an androgen-producing tumor in the first instance. To localize the source of androgen excess, imaging techniques are used, such as transvaginal ultrasound or magnetic resonance imaging (MRI) for the ovaries and computed tomography and MRI for the adrenals. Bilateral oophorectomy or surgical removal of an adrenal tumor is the main curative treatment and will ultimately lead to a histopathological diagnosis. Mild to moderate symptoms of androgen excess are treated with antiandrogen therapy or specific endocrine therapy depending on diagnosis. This review summarizes the most relevant causes of hyperandrogenism in postmenopausal women and suggests principles for clinical investigation and treatment.
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