Decreased inhibin tone and increased activin A secretion characterize reproductive aging in women.
OBJECTIVE
We hypothesized that the increased FSH noted in older reproductive-aged women is due to both decreased inhibin and increased activin A secretion.


METHODS
Comparative clinical study.


METHODS
An academic research center.


METHODS
Five cycling women, aged 43 to 47, were compared to five midreproductive women, aged 19 to 38.


METHODS
Specimens taken every 2 to 3 days were assayed for inhibin A and B and activin A.


METHODS
Integrated concentrations of inhibin A, inhibin B, and activin A in the follicular phase, luteal phase, and whole cycle.


RESULTS
Follicular inhibin B was reduced in older versus younger women (504 +/-82 versus 748+/-72 total pg). Luteal inhibin A was reduced in older versus younger women (668 +/-72 versus 1152+/-216 total pg). Activin A was elevated throughout the cycle of older versus younger women, without within-cycle fluctuations (21+/-2 versus 11+/-1 total ng).


CONCLUSIONS
Lack of restraint by inhibin A and inhibin B contributes to the FSH rise associated with reproductive aging. This loss of restraint occurs in a tandem fashion, with inhibin B reduction before ovulation and inhibin A reduction after ovulation. Activin A may also play an endocrine role in maintaining elevated FSH in older reproductive-aged women.
Santoro
N
N
Department of Obstetrics and Gynecology, UMDNJ-New Jersey Medical School, Newark, USA. nsantoro@aecom.yu.edu
Adel
T
T
Skurnick
J H
JH
D028341:Activins; D000328:Adult; D000375:Aging; D004958:Estradiol / Q000097:blood; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood; D005498:Follicular Phase / Q000097:blood; D006801:Humans; D007265:Inhibins / Q000097:blood*; D008183:Luteal Phase / Q000097:blood; D007986:Luteinizing Hormone / Q000097:blood; D008875:Middle Aged; D011374:Progesterone / Q000097:blood; D011786:Quality Control
D028341:Activins; D011374:Progesterone; D004958:Estradiol; D007265:Inhibins; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone