What influences the age of menopause?

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.

Age of Natural Menopause and Related Factors among the Tabari Cohort

OBJECTIVES

The age of menopause is affected by several factors. In this study we aimed to identify the age of natural menopause and its related factors in a large-scale population-based cohort in Iran.

METHODS

In this study, a subset of data collected during the enrollment phase of the Tabari cohort study was utilized. Reproductive history and other related data were collected using a structured questionnaire. Blood samples were obtained from all participants. Data were analyzed using chi-square test, independent t test, and ANOVA as well as a multivariate linear regression model.

RESULTS

Among participants of the Tabari cohort, 2,753 were menopausal women. The mean age of natural and induced menopause was 49.2 ± 4.7 and 43.2 ± 6.4 years, respectively (P = 0.001). The number of pregnancies, duration of breastfeeding, level of education, residency, presence of thyroid disease, and body mass index affected the age of menopause. After adjustments for confounding variables, the number of pregnancies remained significantly associated with late menopause.

CONCLUSIONS

The age of natural menopause in this study was similar to that in other studies, and the number of pregnancies was positively associated with the age of menopause after adjustments for confounding variables.