| 1. |
- Mellström, Dan, 1945, et al.
(författare)
-
Older men with low serum estradiol and high serum SHBG have an increased risk of fractures.
- 2008
-
Ingår i: Journal of bone and mineral research. - 1523-4681. ; 23:10, s. 1552-60
-
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.
|
|
| 2. |
- Vandenput, Liesbeth, 1974, et al.
(författare)
-
Androgens and Glucuronidated Androgen Metabolites are Associated with Metabolic Risk Factors in Men.
- 2007
-
Ingår i: Journal of clinical endocrinology and metabolism. - : The Endocrine Society. - 0021-972X .- 1945-7197. ; 92:11, s. 4130-7
-
Tidskriftsartikel (refereegranskat)abstract
- Context: Androgens are associated with metabolic risk factors in men. However, the independent impact of androgens and androgen metabolites on metabolic risk factors in men is unclear. Objective: Our objective was to determine the predictive value of serum levels of androgens and glucuronidated androgen metabolites for metabolic risk factors. Design and Study Subjects: We conducted a population-based study of two Swedish cohorts (1068 young adult and 1001 elderly men). Main Outcome Measures: We measured correlation of serum dihydrotestosterone (DHT), testosterone (T) and glucuronidated androgen metabolites with fat mass, fat distribution, serum lipids and insulin resistance. Results: Both DHT and T were negatively associated with different measures of fat mass in both cohorts (P<0.001). Further statistical analysis indicated that DHT, but not T, was independently negatively associated with different measures of fat mass and insulin resistance (P<0.001). The glucuronidated androgen metabolite androstane-3alpha,17beta-diol-17glucuronide (17G) was independently positively associated with fat mass (P<0.001). Most importantly, the 17G/DHT ratio was strongly correlated, not only with fat mass, but also with central fat distribution, intra-hepatic fat, disturbed lipid profile, insulin resistance and diabetes, explaining a substantial part of the total variance in total body fat (12% in young adult men, 15% in elderly men), the HOMA index (10%) and HDL cholesterol (7%). Conclusion: Our findings demonstrate that 17-glucuronidation of the DHT metabolite androstane-3alpha,17beta-diol is strongly associated with several metabolic risk factors in men. Future longitudinal studies are required to determine the possible impact of the 17G/DHT ratio as a metabolic risk factor in men.
|
|
| 3. |
- Ohlsson, Claes, 1965, et al.
(författare)
-
The role of estrogens for male bone health.
- 2009
-
Ingår i: European journal of endocrinology. - 1479-683X. ; 160:6, s. 883-9
-
Tidskriftsartikel (refereegranskat)abstract
- Sex steroids are important for the growth and maintenance of both the female and the male skeleton. However, the relative contribution of androgens versus estrogens in the regulation of the male skeleton is unclear. Experiments using mice with inactivated sex steroid receptors demonstrated that both activation of the estrogen receptor (ER)alpha and activation of the androgen receptor result in a stimulatory effect on both the cortical and trabecular bone mass in males. ERbeta is of no importance for the skeleton in male mice while it modulates the ERalpha-action on bone in female mice. Previous in vitro studies suggest that the membrane G protein-coupled receptor GPR30 also might be a functional ER. Our in vivo analyses of GPR30-inactivated mice revealed no function of GPR30 for estrogen-mediated effects on bone mass but it is required for normal regulation of the growth plate and estrogen-mediated insulin-secretion. Recent clinical evidence suggests that a threshold exists for estrogen effects on bone in men: rates of bone loss and fracture risk seem to be the highest in men with estradiol levels below this threshold. Taken together, even though these findings do not exclude an important role for testosterone in male skeletal homeostasis, it is now well-established that estrogens are important regulators of bone health in men.
|
|
| 4. |
- Tivesten, Åsa, 1969, et al.
(författare)
-
Low serum testosterone and estradiol predict mortality in elderly men.
- 2009
-
Ingår i: The Journal of clinical endocrinology and metabolism. - : The Endocrine Society. - 1945-7197 .- 0021-972X. ; 94:7, s. 2482-8
-
Tidskriftsartikel (refereegranskat)abstract
- CONTEXT: Age-related reduction of serum testosterone may contribute to the signs and symptoms of aging, but previous studies report conflicting evidence about testosterone levels and male mortality. No large prospective cohort study has determined a possible association between serum estradiol and mortality in men. OBJECTIVE: The main objective was to examine the association between serum testosterone and estradiol and all-cause mortality in elderly men. DESIGN, SETTING, AND PARTICIPANTS: We used specific gas chromatography-mass spectrometry to analyze serum sex steroids at baseline in older men who participated in the prospective population-based MrOS Sweden cohort (n = 3014; mean age, 75 yr; range, 69-80 yr). MAIN OUTCOME MEASURE: All-cause mortality by serum testosterone and estradiol levels. RESULTS: During a mean follow-up period of 4.5 yr, 383 deaths occurred. In multivariate hazards regression models, low levels (within quartile 1 vs. quartiles 2-4) of both testosterone [hazard ratio (HR), 1.65; 95% confidence interval (CI), 1.29-2.12] and estradiol (HR, 1.54; 95% CI, 1.22-1.95) associated with mortality. A model including both hormones showed that both low testosterone (HR, 1.46; 95% CI, 1.11-1.92) and estradiol (HR, 1.33; 95% CI, 1.02-1.73) predicted mortality. Risk of death nearly doubled (HR, 1.96; 95% CI, 1.46-2.62) in subjects with low levels of both testosterone and estradiol compared with subjects within quartiles 2-4 of both hormones. CONCLUSIONS: Elderly men with low serum testosterone and estradiol have increased risk of mortality, and subjects with low values of both testosterone and estradiol have the highest risk of mortality.
|
|
| 5. |
- Vandenput, Liesbeth, 1974, et al.
(författare)
-
Estrogens as regulators of bone health in men.
- 2009
-
Ingår i: Nature reviews. Endocrinology. - : Springer Science and Business Media LLC. - 1759-5037 .- 1759-5029. ; 5:8, s. 437-43
-
Tidskriftsartikel (refereegranskat)abstract
- Bone metabolism is influenced by sex steroids during growth and adulthood in both men and women. Although this influence is well described in women, the relative importance of androgens and estrogens in the regulation of the male skeleton remains uncertain. Even though estradiol has been considered the 'female hormone', levels of serum estradiol in elderly men are higher than those in postmenopausal women. Estradiol levels are more strongly associated with BMD, bone turnover and bone loss than testosterone levels are in adult men. Case reports of young men with estrogen resistance or aromatase deficiency also suggest a crucial role for estradiol in regulation of skeletal growth in men. Moreover, serum levels of both estrogens and androgens are inversely associated with the risk of fracture in aging men. A large, prospective, population-based study showed that levels of serum estradiol predict the risk of fracture, independently of serum testosterone. Evidence suggests that a threshold level of estradiol exists below which the male skeleton is impaired; rates of bone loss and fracture seem to be increased and bone maturation delayed in men with estradiol levels below this threshold. On the basis of these findings, we propose that not only androgens, but also estrogens, are important regulators of bone health in men.
|
|
