Bioavailable testosterone with age and erectile dysfunction

Purpose: Symptoms of partial androgen deficiency of the aging male (PADAM), such as sexual dysfunction and depression, are receiving increased attention. Currently bioavailable testosterone (BT) is considered the most reliable marker for establishing the presence of hypogonadism. We clarified the relationship between BT and other hormones with respect to patient age and PADAM symptoms. Materials and Methods: A total of 130 patients who visited our special clinics for sexual function were included in this study. Endocrinological profiles were evaluated as appropriate, and sexual dysfunction and depression as symptoms of PADAM were assessed by a self-reported questionnaire. The relationship between age and several measures of testosterone, between BT and other hormonal measures, and between BT and PADAM symptoms were analyzed. Results: Although serum total testosterone did not decrease with age, sex hormone binding globulin increased significantly. BT and free testosterone decreased significantly, and total and free testosterone correlated significantly with BT. The International Index of Erectile Function-5 score for erectile function increased significantly with increases in BT. However, the relationship between the depression score and BT was not significant. Conclusions: We consider that BT is a useful marker for diagnosing and treating patients with PADAM because BT correlates significantly with age and International Index of Erectile Function-5 scores. We emphasize that measuring serum testosterone is necessary in aging males.