Is polycystic ovary syndrome an exception for reproductive aging?

BACKGROUND: Anti-Mullerian hormone (AMH) is increased in women with polycystic ovary syndrome (PCOS), suggesting a delay in ovarian aging. We examined AMH levels in PCOS and normo-ovulatory women in a population-based cohort over a period of 10 years and used this information to estimate their menopausal age. METHODS: Of a subset of 1002 non-menopausal women randomly selected from the Tehran Lipid and Glucose Study, 85 cases of PCOS were diagnosed. We frequency-matched our control subjects with PCOS cases based on age and BMI. AMH levels were assessed at the time of recruitment (T1) and twice after that (T2 and T3). AMH levels were then plotted against age of the individual at the time of the measurement and the most appropriate model was selected. Menopause was calculated based on AMH levels below 0.2 ng/ml. RESULTS: AMH levels were significantly higher in PCOS cases compared with controls at the beginning of the study (5.58 +/- 3.64 versus 4.35 +/- 2.90 ng/ml, P = 0.03), but the difference diminished considerably in subsequent assessments. The rate of AMH decline in PCOS cases decreased in the second compared with the first interval; however, no apparent change in the rate of decline was observed in controls. Estimated ages at menopause were 51 95% confidence interval (CI), 34-81 and 49 (95% CI, 38-63) years in PCOS cases and controls, respectively. CONCLUSIONS: The reproductive lifespan of PCOS women extends on average 2 years beyond that of normo-ovulatory women.