Racial Differences in Age-Related Variations of Testosterone Levels Among US Males: Potential Implications for Prostate Cancer and Personalized Medication.

Abstract

The magnitude of the age-related declines in testosterone rather than levels measured at single point in time may be related to the genesis of prostate cancer (PCa). We examined age-related variations of testosterone levels among black and white males, which may provide important insights into racial disparities in PCa incidence and mortality. We analyzed data from the 1999-2004 National Health and Nutritional Examination Survey to compare age-related variations in the testosterone levels of 355 black and 631 white males. Overall, between the ages of 12 and 15, black males had lower testosterone levels than white males. Testosterone levels increased rapidly with age and reached higher and earlier peak levels in black males compared to white males at 20-30 years of age. After reaching a peak level, testosterone levels declined earlier in blacks than in whites. Further analyses showed that black males had considerably higher levels of testosterone compared to white males aged 20-39 years after adjusting for covariates, including age, body mass index, cigarette smoking, physical activity, and waist circumference; however, no statistically significant differences were observed between the groups at any other age. Our study revealed that testosterone levels in black males decrease substantially with increasing age compared to those in white males. This rapid drop in testosterone levels may contribute to racial disparities in PCa. Our findings also suggest that personalized medication for hormone replacement therapy may be necessary to avoid sudden drops in testosterone levels, particularly for black males.