Prevalence of early and late menopause and its determinants in Rafsanjan cohort study.

Our investigation aimed to evaluate the prevalence of early and late menopause and its determinants in adult women of Rafsanjan cohort study. We used data obtained from the Rafsanjan Cohort Study, as a part of the prospective epidemiological research studies in Iran. In this cross-sectional research, 2002 postmenopausal women were included in the present study. Menopause age were divided into three groups (≤ 41 years, 42-54 years, and ≥ 55 years) based on the 10th and 90th percentile. The association between age at menopause with demographic and reproductive characteristics and some clinical risk factors of women was evaluated by logistic regressions. The mean age at menopause among the study participants was 48.63 ± 5.37 years. In this study, 11.49% and 11.39% of the women experienced early and late menopause respectively. After adjusting for all potential confounders, the results showed that taller and smoker women had higher odds of early menopause (OR 1.03, 95% CI 1.00-1.06) and OR 1.85, 95% CI 1.01-3.41) respectively) and women with history of using hormonal contraceptive more than median had lower odds of early menopause (OR 0.61, 95% CI 0.41-0.91). Also older women (OR 8.65, 95% CI 5.31-14.08) and women with a history of diabetes (OR 2.42, 95% CI 1.63-3.60), hypertension (OR 2.06, 95% CI 1.42-2.97), thyroid disease (OR 1.85, 95% CI 1.07-3.20) and depression (OR 2.00, 95% CI 1.35-2.97) had higher odds of late menopause. The results showed that the year of birth, height, smoking, history of diabetes, hypertension, thyroid disease and depression and using hormonal contraceptive were significantly associated with the menopausal age. Since age at menopause can affect subsequent health in women, understanding the determinants of menopausal age is important and should be pursued.