Evolution with ageing of four plasma androgens in postmenopausal women

Abstract

Plasma androgens were measured in 119 postmenopausal women classified according to age: group M1 = 45–59, group M2 = 60–70, group M3 = 71–95, as well as in 51 menstruating women under 40 (group R1), 19 menstruating women over 40 (group R2), and 17 castrated women between 40 and 53 (group C). The mean androstenedione level decreased significantly between group M1 and groups M2 and M3, respectively, (ovbar|x ± S.E.M.) 3.1 ± 0.17, 2.6 ± 0.17 and 2.2 ± 0.24 nmol/l. The levels in groups R1 and R2 were significantly higher. The mean level in group C did not differ from that in groups M2 and M3. The mean dehydroepiandrosterone sulfate level decreased significantly between group M 1 and groups M2 and M3: respectively, 2300 ± 210, 1500 ± 170 and 970 ± 90 nmol/l. The levels in groups R1 and R2 were significantly higher. The mean level in group C was also significantly higher than in group M3. The mean testosterone level in group R1 was significantly higher than in group R2, whereas there was no significant difference between groups R2, M1, M2 and M3, respectively, 1.0 ± 0.07, 0.97 ± 0.07, 1.0 ± 0.07 and 0.97 ± 0.07 nmol/l. The mean level in castrated women (0.55 ± 0.07 nmol/1) was significantly lower than in postmenopausal women. Dihydrotestosterone levels decreased significantly in groups M1, M2 and M3 (respectively, 0.24 ± 0.02, 0.21 ± 0.02 and 0.10 ± 0.01 nmol/l). The levels in the two latter groups did not differ from the level in castrated women (0.17 ± 0.03 nmol/1). These results confirm the existence of a decrease in ovarian androstenedione and dehydroepiandrosterone production with ageing, and a relative conservation of ovarian testosterone production. They also confirm the existence of decrease in adrenal androgen production, due both to ageing and to estrogen deprivation. Finally, they indicate that there is a deficiency in the conversion of testosterone into 5α-dihydrotestosterone in ageing women.