Influence of age on metabolism of testosterone, dihydrotestosterone, and 3-alpha-androstanediol in muscle biopsies from patients with neuromuscular diseases

We investigated the possible effect of age on the metabolism of androgens i n muscle biopsies from patients with neuromuscular diseases. The conversion of testosterone, dihydrotestosterone (DHT) and 5-alpha-androstane-3-beta-1 7-beta-diol (3-alpha-androstanediol) was measured in muscle biopsies from 2 4 patients with neuromuscular diseases and seven controls. The reductive me tabolism of 3-alpha-HSDH was significantly higher than the oxidative metabo lism. Significant metabolism of testosterone to DHT was not found. Only the age of the patients emerged as a significant negative predictor in a stepw ise multiple linear regression model for V-max and K-m (Lineweaver-Burke pl ots) of the reductive metabolism of 3-alpha-HSDH. Therefore, altered metabo lism of anabolic androgens in skeletal muscles could be demonstrated. We co nclude that this could alter the androgenic catabolic/anabolic balance in t he (androgenic target organ) skeletal muscle. (C) 1999 Elsevier Science Ire land Ltd. All rights reserved.