Age-Dependent Change of Serum 5α-Dihydrotestosterone and its Relation to Testosterone in Man

Abstract

Serum 5α-dihydrotestosterone (DHT) and testosterone (T) were measured in 78 normal men aged between 12 and 89 years, separating DHT and T by celite microcolumn and using reliable radioimmunoassay.
In four age groups of young (20-39 years), middle aged (40-59 years) and old (60-79 years and 80-89 years) men, the mean±SEM for serum DHT were 98±12, 91±9, 82±7 and 54±15 (ng/100 ml), respectively. The corresponding values for T were 696±27, 698±18, 624±20 and 457±21 (ng/100ml). DHT and T showed significant correlation in each age group: r=0.625, p<0.05 (young men), r=0.727, p<0.02 (middle aged men), r=0.673, p<0.05 and r=0.734, p<0.02 (old men), respectively. There was a significant decline in DHT and T levels of 80-to 89-year-age group compared those of 30-to 39-year-age group (p<0.05 and p<0.005 respectively). But there was no significant changes in DHT and T levels between other age groups. After 3 daily im injections of 4, 000 IU human chorionic gonadotropin (hCG) the levels of serum DHT of the young group (20-32 years) and old group (72-78 years) increased 2.6 times and 1.9 times more, respectively. T increased 2.7 times and 1.4 times more, respectively.