Testosterone Levels Do Not Decline with Age in Healthy Men

Abstract

Aim: To establish norms for reproductive hormones in healthy males with normal urologic and sexual function, and to assess the change in reproductive hormon e levels with respect to age among healthy males. Methods: Healthy volun teers aged 18 - 29 (group 1) and 45 - 65 (group 2) were recruited for enrollment in a prospective study. Inclusion criteria comprised normal urinary, ejaculatory, orgasmic, and erectile function, as determined by IPSS, MSHQ, and IEFF-15. Men with history of chronic medical illnesses or chronic medication use were excluded. Fifty men met the study criteria. Each participant underwent physical examination and standardized serum hormone evaluation using ELISA and EIA methods. Statistical analysis was performed using JMP 8.0 software (SAS Institute Inc., Cary , NC ), to compare hor mone levels between the two groups of men. Results: There were 25 men each in groups 1 (mean age 26) and 2 (mean age 51). Overall, 46% were Caucasian, 31% African American, 15% Hispanic, and 8% Asian. There was no statistically significant difference in serum total T, SHBG, E2, or LH between groups 1 and 2. Notably, the 95% CI for serum T levels for both groups of men w ere considerably higher than commonly accepted lower-end cut-off limits. Conclusion: Serum T levels do not vary significantly with age, in otherwise healthy men with normal sexual and urologic function. Furthermore, healthy men have much higher serum total and free T levels than the lower-end reference limits provided by commercial laboratories.