Is there a clinical relevance of partial androgen deficiency of the aging male?

PURPOSE: Aging in men is characterized by a progressive, generally moderate decrease in plasma testosterone (T) levels and T substitution is increasingly prescribed. However, the association of partial androgen deficiency of the aging male with clinical symptoms and the ideal screening test are controversial. We investigate the association between various T measures and clinical and biochemical parameters of the aging male. MATERIALS AND METHODS: We investigated the association between total (TT), calculated free (FTcalc) and bioavailable (BT) testosterone, and various clinical and biochemical parameters in 51 healthy community living male volunteers, 55 and 75 years old. The parameters included serum levels of sex hormone-binding globulin, estradiol and lipid profile after an overnight fast; questionnaires assessing clinical symptoms, erectile function and mood; bone mineral density and body composition. RESULTS: TT correlated with FTcalc (r2 = 0.71, p >0.001) but not with BT (r2 = 0.04, p not significant) and FTcalc correlated moderately with BT (r2 = 0.23, p >0.001). Testicular volume correlated with TT levels (r2 = 0.17, p >0.001) and FTcalc (r2 = 0.17, p >0.001) but not with BT. There was neither a correlation of TT, FTcalc nor BT values with clinical symptoms nor with biochemical and radiological parameters, ie affective symptoms and sexual interest, circulating estradiol, lipid levels, bone mineral density or lean body mass. CONCLUSIONS: T values in our study sample did not correlate with clinical signs and symptoms of hypogonadism. Thus, according to our data, symptoms of the aging male could be rather multifactorial and should not be indiscriminately assigned to the age associated decrease in T levels.