Aim: To assess the age-related change in plasma androgen levels in healthy middle-aged men and whether any clinical parameters are associated with the hormonal change.
Methods: The study was comprised of male Japanese office-workers aged 40-64 years, who had undergone an annual health check-up in 2002 and 2007 (96 and 76 men, respectively). Body mass index and blood pressure were measured, and serum concentration of lipids, glucose and uric acid in addition to plasma total testosterone, free testosterone and dehydroepiandrosterone sulfate (DHEA-S) levels were determined in the morning after an overnight fast. The 5-year hormonal changes and their associations with clinical parameters were analyzed in 33 men who repeated the examination at both check-ups. The cross-sectional associations of hormonal levels with clinical parameters were also investigated.
Results: Age was negatively associated with free testosterone (r = -0.399, P < 0.001 in 2002; r = -0.458, P < 0.001 in 2007) and DHEA-S (r = -0.233, P = 0.02 in 2002; r = -0.336, P < 0.01 in 2007) but not with total testosterone, while the 5-year changes of free testosterone and DHEA-S levels were not significant and showed no associations with major cardiovascular risk factors. Cross-sectionally, after adjustment for age, linear regression analysis showed a positive association between free testosterone and blood hemoglobin and a negative association between total testosterone and serum uric acid.
Conclusion: In Japanese middle-aged men, 5-year androgen decline is too subtle to detect, and endogenous androgen levels seem to have relatively weak association with cardiovascular risk profiles.