[The age-related changes in serum 17-hydroxyprogesterone secretion in men]

In order to clarify the age-related changes in serum 17-hydroxyprogesterone (17-OHP) secretion in men, serum basal 17-OHP levels were determined in 203 healthy male subjects from 10 months to 116 years of age, and serum 17-OHP responses to dexamethasone (Dex), fluoxymesterone (FM), HCG and ACTH were compared between the young and elderly groups. The mean basal 17-OHP level remarkably increased from pubescence to the third decade and gradually decreased with advance in age after fifty. Basal serum 17-OHP level was correlated more closely with serum testosterone (T) than cortisol (F), and was suppressed more remarkably after the administration of FM than Dex in both groups. Serum 17-OHP increased with 2 peaks at 6 and 24 hours after HCG injection, and serum 17-OHP response to HCG was significantly greater in the young than in the elderly group. Furthermore, in the aged subjects with low serum T levels, serum 17-OHP response to HCG was remarkably decreased. Within 3 hours after ACTH injection, serum 17-OHP response to ACTH was significantly lower in the elderly than in the young group. On the other hand, 12 hours after ACTH administration, serum 17-OHP response was remarkably greater in the elderly group, and the F/17-OHP ratio was significantly lower than in the young. These data indicate a decline of Leydig cell function in the testis of the elderly male and also suggest the occurrence of enzyme deficiencies, especially impaired C17, 20 lyase activity, in adrenal steroid hormone synthesis with aging.