Interactions among age, adiposity, bodyweight, lifestyle factors and sex steroid hormones in healthy Singaporean Chinese men

Aim: To examine the inter-relationships among age, lifestyle factors, anthropometric parameters, percent body fat and steroid hormone parameters in 531 healthy Singaporean Chinese men aged between 29 and 72 years old. Methods: Various lifestyle parameters were quantified through a survey, and testosterone (T), estradiol (E2), dehydroepi-androsterone sulphate (DHEAS) and sex hormone binding globulin (SHBG) were measured using established methods. Anthropometric parameters were collected and computed, and percent body fat (Siri) was measured using the DEXA scanner. Results: SHBG, DHEAS, bioavailable-T (Bio-T), E2, Siri, Ht, W/H, W/Ht and work stress were independently correlated with age. Using multivariate analyses and adjusting for age and other related factors, exercise, smoking and alcohol consumption have positive impacts on androgen levels and body composition. However, black and green tea consumption was associated with negative effects on body composition and with higher levels of E2 and Free Estradiol Index (FEI). Men with shorter sleep duration had significantly lower T levels as compared to those with 6 h or more of nightly sleep. Higher T levels were associated with lower levels of adiposity and other indices of adiposity, whereas higher E2 levels were related to higher levels of adiposity. Men with higher DHEAS were significantly taller and heavier than those with low DHEAS levels. Conclusion: The study showed the close interactions among the gonadal/adrenal and metabolic compartments, with age being a key determinant in their interactions. Lifestyle factors such as exercise, smoking, sleeping and alcohol and tea consumption might play significantly roles in determining the status of health in men.