Factors predicting age at menopause among Iranian women in the Bandare-Kong cohort study (a cross-sectional survey of PERSIAN cohort study).

Background: Menopause is a natural period in women's life and can be affected by several factors. The aim of this study was to identify the associated factors for age of natural menopause and among women with early and premature menopause based on a cohort study in Iran.

Methods: This population-based study was conducted on 894 post menopause women between 35 and 70 years old who participated in the Bandare-Kong Non-Communicable Diseases (BKNCD) Cohort Study, a part of Prospective Epidemiological Research Studies in Iran (PERSIAN) from March 2016 to February 2019. All women completed a standard self-reported questionnaire. Data were analyzed using chi-square test, independent t test, and ANOVA as well as a multivariable linear regression model.

Results: The mean age at natural menopause was 48.31 ± 6.34 years. After adjusting other variables, gravida, history of cardiac disease, socioeconomic status and residence status were predictive of age at menopause (P < 0.001). Among the premature menopause group, the mean age at menopause was significantly higher among women with diabetes compared to women without diabetes group (35.68 ± 2.92 vs. 33.82 ± 3.06; P = 0.043), while the mean age at menopause was significantly lower in women with infertility compared to women without infertility (29.13 ± 5.22 vs. 34.84 ± 2.826; P = 0.048).

Conclusions: This study suggests that the predictors of menopausal age differed in women with premature menopause compared to overall menopause age. Prospective studies are needed to evaluation the effects of these factors on menopausal age.