Endogenous sex hormones in men aged 40-80 years

Abstract

Objective: To determine the relationship between aging, life-style factors and health-related factors and endogenous sex hormone levels. Design: Cross-sectional study of 400 independently living men between 40 and 80 years of age. Methods: After exclusion of subjects who were not physically or mentally able to visit the study center, 400 men were randomly selected from a population-based sample. Total testosterone (TT), bioavailable testosterone (BT) (i.e. not bound to sex hormone-binding globulin (SHBG)), SHBG, estradiol (E 2 ) and dehydroepiandrosterone-sulfate (DHEA-S) were investigated for their relationship with age, body mass index (BMI), waist circumference, smoking, physical activity and general health status. Multivariate models using ANCOVA analyses were used to examine the contribution of life-style factors to sex hormone variability. Results: TT, BT and DHEA-S decreased with age; 0.2, 0.7 and 1.2%/year respectively. SHBG showed an increase with age of 1.1%/year. No changes with age were found for E 2 . General health status modified the association of TT and SHBG with age (P interaction 0.10 and 0.002 respectively). Increased BMI and waist circumference were associated with decreased TT, BT, SHBG and DHEA-S and increased E 2 (all P , 0.01). Current smoking, lower alcohol intake and a higher physical activity score were associated with higher TT and SHBG levels. Conclusion: This study showed the important determinants of sex hormones were age, BMI, waist circumference, smoking, general health status and physical activity. Furthermore, it can be concluded that general health status modified the effect between sex hormones and age. For future observational studies it should be taken into account that the above-mentioned determinants may alter the association between sex hormones and diseases and related conditions.

Are declining testosterone levels a major risk factor for ill-health in aging men?

“…Higher BMI and waist circumference are associated with lower total, bioavailable or free testosterone and SHBG. 6,7,[144][145][146] The association between higher BMI and lower total testosterone appears more consistent that between BMI and free testosterone. 146,147 Smoking, lower alcohol intake and physical activity or vigorous exercise are factors associated with higher total testosterone and SHBG levels.…”

“…146,147 Smoking, lower alcohol intake and physical activity or vigorous exercise are factors associated with higher total testosterone and SHBG levels. 6,7,147 However, other studies have not confirmed these associations. 148,149 It is important to note the severe damaging effects of smoking on cardiovascular and respiratory health far outweigh any possible benefit it may confer on testosterone levels.…”

“…In cross-sectional and longitudinal studies of men aged 30 or 40 years and above, total, bioavailable and free testosterone concentrations fall with increasing age with a steeper decline in bioavailable and free compared with total testosterone concentrations. [5][6][7][8][9][10][11][12] It is noteworthy that the falls in total and bioavailable or free testosterone levels are consistently greater in longitudinal studies than in cross-sectional analyses. 11,12 Thus, in the Massachusetts Male Aging Study of 1709 men aged 40-70 years at baseline, total testosterone declined cross-sectionally by 0.8% per year of age compared with a 2% decline in free and bioavailable testosterone, whereas the longitudinal declines within participating men were 1.6 and 2-3% per year of age, respectively.…”

Male hypogonadism. Part I: Epidemiology of hypogonadism

“…8 In one cross-sectional study of 400 communitydwelling men ages 40-80 years, increases in both BMI and central adiposity (waist circumference) were associated with low levels of T, BT, and dehydroepiandrosterone sulfate, whereas both current smoking and greater physical activity were associated with higher T concentrations. 14 Some grossly obese patients have reduced total T and SHBG levels, as well as diminished T-SHBG binding, such that FT levels remain normal. 11,22 Obesity may lower circulating androgens or reduce T-SHBG binding via (1) excessive metabolic clearance of androgens in adipose tissues; 11 (2) aromatization of androgens in adipose tissues; or (3) increased formation of inflammatory cytokines (eg tumor necrosis factor-a, interleukin-1b), which may also blunt secretion of LH and gonadotropin-releasing hormone (GnRH).…”

A high pretreatment plasma oestradiol level is associated with a low risk of acute myocardial infarction in parenteral oestrogen therapy for locally advanced prostate cancer

“…smoking, alcohol use, physical activity, obesity and pretreatment serum lipids, and thus cannot draw any firm conclusions about their possible effect in these patients. However, from previous reports, moderate alcohol consumption decreases the risk of AMI and might be associated with an increased plasma oestradiol level [12,29], whereas a low endogenous oestradiol level might increase the risk of AMI by lowering the high-density lipoprotein level before the onset of the therapy [30].…”