DIMERIC INHIBIN - A DIRECT MARKER OF OVARIAN AGING

Objective: To investigate whether luteal secretion of inhibin-a is alt ered in the perimenopausal transition and to evaluate whether luteal i nhibin secretion is correlated with other markers of ovarian reserve s uch as FSH and inhibin-b. Design: Prospective study. Setting: Reproduc tive Endocrinology Laboratories at The Ohio State University.Patient(s ): Twenty-five women 39-52 years of age with regular menstrual cycles. Intervention(s): Daily urine samples were monitored (LH predictor kit ) to identify the day of ovulation. Blood samples obtained on days 6 a nd 8 after the LH surge and on day 3 of the subsequent follicular phas e were assayed for FSH, E-2, progesterone, inhibin-a, and inhibin-b. M ain Outcome Measure(s): Serum levels of inhibin-a, inhibin-b, FSH, E-2 , and progesterone. Result(s): Luteal phase inhibin-a and follicular p hase inhibin-b were correlated inversely with age in perimenopausal wo men. In addition, luteal phase inhibin-a and follicular phase inhibin- b levels were correlated inversely with follicular phase FSK levels. C onclusion(s): Both luteal phase inhibin-a and follicular phase inhibin -b levels are correlated inversely with age during the fifth decade of life. These findings suggest that corpus luteum function is altered d uring the perimenopausal transition. Moreover, these direct measures o f ovarian function may be more sensitive indicators of ''ovarian reser ve'' than indirect indicators such as pituitary FSH secretion. (Fertil Steril(R) 1998;70:119-23. (C) 1998 by American Society for Reproducti ve Medicine.).