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- Mellström, Dan, 1945, et al.
(författare)
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Free testosterone is an independent predictor of BMD and prevalent fractures in elderly men: MrOS Sweden.
- 2006
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Ingår i: Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research. - : Wiley. - 0884-0431. ; 21:4, s. 529-35
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Tidskriftsartikel (refereegranskat)abstract
- The role of androgens for bone health in elderly men is unclear. We show that free testosterone within the normal range is a predictor of BMD at predominantly cortical bone sites and of previous osteoporosis-related fractures in elderly Swedish men. INTRODUCTION: Osteoporosis-related fractures constitute a major health concern not only in women but also in men. Previous studies have clearly shown that serum levels of estradiol are associated with BMD, whereas more conflicting data have been presented regarding the predictive value of testosterone (T) for bone health in elderly men. The aim of this study was to investigate if serum levels of T are associated with BMD and/or prevalent fractures in a large cohort of elderly men. MATERIALS AND METHODS: In the Swedish part of the MrOS study (n = 2908; average age, 75.4 years), bone parameters were measured using DXA, and prevalent fractures were recorded using standardized questionnaires and by vertebral X-ray analyses. Serum levels of total T, total estradiol (E2), and sex hormone-binding globulin (SHBG) were measured by radioimmunoassay, and free T (FT) and free E2 (FE2) were derived from the mass action equations. Height, weight, age, physical activity, smoking habits, and calcium intake were included together with FT and FE2 in regression models for BMD. RESULTS: FT was an independent positive predictor of BMD in total body, total hip, femur trochanter, and arm but not in the lumbar spine. The highest independent predictive value of FT was found in the arm and the hip (with a relatively high content of cortical bone). FE2 was an independent predictor of BMD at all bone sites studied, and the highest predictive value was seen for lumbar spine (with relatively high content of trabecular bone) BMD. FT but not FE2 was a positive predictor of total body bone area and BMC. FT levels below the median were independent predictors of prevalent osteoporosis-related fractures (OR, 1.56; 95% CI, 1.14-2.14; p < 0.01) and X-ray-verified vertebral fractures (OR, 2.00; 95% CI, 1.34-2.86; p < 0.001). The predictive value of FT for prevalent fractures was not affected by adjustment for BMD. CONCLUSIONS: These findings show that variation of FT within the normal range is an independent but modest predictor of BMD at predominantly cortical bone sites and of previous osteoporosis-related fractures in elderly men. Our data indicate that not only estrogens but also androgens are of importance for bone health in elderly men. Longitudinal studies investigating the predictive value of T for fracture risk in elderly men are required.
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- Mellström, Dan, 1945, et al.
(författare)
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Older men with low serum estradiol and high serum SHBG have an increased risk of fractures.
- 2008
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Ingår i: Journal of bone and mineral research. - 1523-4681. ; 23:10, s. 1552-60
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Tidskriftsartikel (refereegranskat)abstract
- Osteoporosis-related fractures constitute a major health concern not only in women but also in men. To study the predictive role of serum sex steroids for fracture risk in men, serum sex steroids were analyzed by the specific gas chromatography-mass spectrometry technique at baseline in older men (n = 2639; mean, 75 yr of age) of the prospective population-based MrOS Sweden cohort. Fractures occurring after baseline were validated (average follow-up of 3.3 yr). The incidence for having at least one validated fracture after baseline was 20.9/1000 person-years. Estradiol (E2; hazard ratio [HR] per SD decrease, 1.34; 95% CI, 1.22-1.49), free estradiol (fE2; HR per SD decrease, 1.41; 95% CI, 1.28-1.55), testosterone (T; HR per SD decrease, 1.27; 95% CI, 1.16-1.39), and free testosterone (fT; HR per SD decrease, 1.32; 95% CI, 1.21-1.44) were all inversely, whereas sex hormone-binding globulin (SHBG; HR per SD increase, 1.41; 95% CI, 1.22-1.63) was directly related to fracture risk. Multivariable proportional hazards regression models, adjusted for age, suggested that fE2 and SHBG (p < 0.001), but not fT, were independently associated with fracture risk. Further subanalyses of fracture type showed that fE2 was inversely associated with clinical vertebral fractures (HR per SD decrease, 1.57; 95% CI, 1.36-1.80), nonvertebral osteoporosis fractures (HR per SD decrease, 1.42; 95% CI, 1.23-1.65), and hip fractures (HR per SD decrease, 1.44; 95% CI, 1.18-1.76). The inverse relation between serum E2 and fracture risk was nonlinear with a strong relation <16 pg/ml for E2 and 0.3 pg/ml for fE2. In conclusion, older Swedish men with low serum E2 and high SHBG levels have an increased risk of fractures.
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- Swanson, Charlotte, 1975, et al.
(författare)
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The UDP Glucuronosyltransferase 2B15 D85Y and 2B17 Deletion Polymorphisms Predict the Glucuronidation Pattern of Androgens and Fat Mass in Men.
- 2007
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Ingår i: Journal of clinical endocrinology and metabolism. - : The Endocrine Society. - 0021-972X .- 1945-7197. ; 92:12, s. 4878-82
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Tidskriftsartikel (refereegranskat)abstract
- Context: Previous in vitro studies have demonstrated that the UDP glucuronosyltransferase (UGT) 2B15 and UGT2B17 glucuronidate androgens and their metabolites. Objective: To determine in vivo if the UGT2B15 D(85)Y and the UGT2B17 deletion polymorphisms predict androgen glucuronidation and body composition. Participants: Two population-based cohorts including young adult (n=1068, age=18.9 years) and elderly (n=1001, age=75.3 years) men. Main Outcome Measures: Serum and urine levels of testosterone (T) and dihydrotestosterone (DHT) measured by GC-MS and serum levels of the major glucuronidated androgen metabolites androstane-3alpha,17beta-diol(androstanediol)-3glucuronide, androstanediol-17glucuronide and androsterone-glucuronide measured by LC-MS/MS. Body composition measured by DXA. Results: Both the UGT2B15 D(85)Y and the UGT2B17 deletion polymorphisms were associated with serum levels of androstanediol-17glucuronide (p<0.001) but not with levels of androstanediol-3glucuronide or androsterone-glucuronide in both cohorts. Glucuronidation of T and DHT was associated with the UGT2B17 deletion but not with the UGT2B15 D(85)Y polymorphism, suggested by strong associations between the deletion polymorphism and urine levels of these two hormones. Both polymorphisms were associated with several different measures of fat mass (p<0.01). The UGT2B17 deletion polymorphism was associated with insulin sensitivity (p<0.05) as indicated by the HOMA index. Conclusions: The UGT2B15 D(85)Y and the UGT2B17 deletion polymorphisms are both predictors of the glucuronidation pattern of androgens/androgen metabolites. Our findings indicate that UGT2B17 is involved in 17 glucuronidation of mainly T but also of DHT and androstanediol and that UGT2B15 is involved in the 17 glucuronidation of androstanediol. Furthermore, these two polymorphisms are predictors of fat mass in men.
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