Association between obesity and oligomenorrhea or irregular menstruation in Chinese women of childbearing age: a cross-sectional study

In this study, we aimed to investigate the relationship between body mass index (BMI), waist circumference (WC) or waist-to-hip ratio (WHR) and oligomenorrhea or irregular menstruation in Chinese women of childbearing age. A total of 1,423 Han women aged 19–39 years who were routinely examined at the Physical Examination Center of Peking University People's Hospital were enrolled by convenience sampling method. All participants were asked to fill up menstrual questionnaires. Binary logistic regression models were used to assess the odds ratio (OR) of different BMI, WC and WHR groups for the prevalence of oligomenorrhea and irregular menstruation. Moreover, we used the ROC curves to compare the predictive effects of BMI, WC and WHR on oligomenorrhea and irregular menstruation. Among the 1,423 participants, 93 women (6.5%) had BMI ≥ 30 kg/m2, 6.5% of the participants had oligomenorrhea, and 22.6% had irregular menstrual menstruation. Overall, those with BMI ≥30 kg/m2 (OR = 2.543; 95%CI 1.332–4.856; p = .005) or WC ≥ 90 cm (OR = 2.023; 95%CI 1.198–3.416; p = .008) were more likely to have long menstrual cycle. The prevalence of irregular menstruation was higher in the BMI ≥30 kg/m2 (OR = 2.509; 95%CI 1.591–3.958; p < .001), WC ≥ 90 cm (OR = 2.299; 95%CI 1.619–3.265; p < .001) and WHR ≥ 0.86 (OR = 1.739; 95%CI 1.293–2.339; p < .001) groups. The ROC curve showed that all three anthropometric indices had predictive effect, while there was no significant difference in predicting oligomenorrhea. WC was a better predictor for irregular menstruation compared with BMI. Obesity, oligomenorrhea and irregular menstruation were common in Chinese women of childbearing age, and obesity was associated with oligomenorrhea and irregular menstruation. Abdominal obesity might have a stronger predictive effect on irregular menstruation.