Age-related differences in features associated with polycystic ovary syndrome in normogonadotrophic oligo-amenorrhoeic infertile women of reproductive years

Objective: To assess the effect of age on clinical, endocrine and sonographic features associated with polycystic ovary syndrome (PCOS) in normogonadotrophic anovulatory infertile women of reproductive years. Design: Cross-sectional study. Methods: Four hundred and seventy-two oligo-amenorrhoeic infertile patients, presenting with normal FSH and oestradiol concentrations, aged 17-42 years underwent a standardised initial evaluation including: cycle history, body mass index, waist-to-hip ratio and transvaginal ultrasound scanning of ovaries. Fasting blood samples were obtained for extensive endocrine evaluation. Cycle duration, serum levels of gonadotrophins, androgens, oestradiol, insulin, glucose, inhibin B as well as mean number of follicles, ovarian volume and ovarian stroma echogenicity were assessed. Results: Older women had significantly lower LH and androgen and inhibin B serum levels. Similarly, older women presented with a reduced number of ovarian follicles. Age was inversely correlated with cycle duration (r = -0.112, P = 0.02), LH (r = -0.154, P = 0.001), testosterone (r = -0.194, P = 0.001), androstenedione (r = -0.170, P = 0.001), dehydroepiandrosterone (r = -0.157 P = 0.001), insulin (r = -0.126, P = 0.02), inhibin B (r = -0.118, P = 0.03) serum levels and mean follicle number (r = -0.100, P = 0.03). A positive correlation was observed between age and glucose to insulin ratio (r = 0.138, P = 0.009). Conclusions: Advanced age in normogonadotrophic anovulatory infertile women is associated with lower LH and androgen levels and with a decreased number of ovarian follicles. Although during reproductive years observed differences are relatively small, these age-related changes may affect the observed incidence of PCOS.