Association between body mass index, waist circumference, and age at natural menopause: a population-based cohort study in Chinese women

The purpose of the study was to investigate whether premenopausal body mass index (BMI) and waist circumference (WC) influence age at menopause. A total of 2116 women aged 35-64 years from two communities of the CMCS Beijing cohort were recruited in 1992 and followed up to 2018. Of 1439 premenopausal women at baseline, 6 women data were missing. Finally, 1433 women were included for analysis. Overweight was defined as BMI 24-27.99 kg/m(2). Central obesity was defined as WC >= 80 cm. Age at menopause was categorized as <45 years, 45-49 years, 50-51 years (reference), and >51 years. Multinomial logistic regression models were used to estimate relative odds ratios (RORs) and 95% confidence intervals (CIs). Compared to women with normal weight and normal WC, overweight women with normal WC had higher risk of menopause at >51 years (ROR 1.64, 95% CI 1.10-2.45; P = .01); and overweight women with central obesity had higher risk of menopause at not only >51 years (ROR 1.82, 95% CI 1.13-2.93; P = .01) but also <45 years (ROR 3.13, 95% CI 1.20-8.43; P = .02) and 45-49 years (ROR 2.76, 95% CI 1.71-4.46; P < .001). When overweight women combine with central obesity, the risk of early menopause will increase in some of them.