BMI as a Determinant of Menstrual Health: A Comparative Analysis Across Weight Categories

Abstract

Obesity is an excessive accumulation of adipose tissue in the body. Obese women are at increased risk of developing various metabolic, endocrine, and gynaecological problems, including menstrual dysfunction and subfertility. Objectives: The objective of the study was to determine the association of body mass index with menstrual cycle abnormalities in young women. Methodology: This study was conducted in Hail from September 2025 to February 2026, with a sample size of 315 participants. The data were collected using a pre-designed questionnaire from young women aged 18-35 years living in Hail who had no prior gynaecological disease. The questionnaire included demographic information, details of their menstrual cycle, and any associated problems. Participants were asked about their weight (kg) and height (cm), and their BMI was calculated. These indices were then analysed statistically using SPSS version 22. The 95% confidence level and confidence intervals were employed. The chi-square test was used to assess the association between obesity indices and menstrual problems. P<0.05 will be considered significant. Multivariable logistic regression analyses were conducted for all menstrual outcomes to identify independent associations between BMI and menstrual characteristics. Results: BMI showed significant associations with multiple menstrual parameters. Higher BMI was linked to greater cycle irregularity, altered cycle duration, and disrupted cycle frequency. Obese participants exhibited the highest rates of irregular, shortened, and prolonged cycles. Dysmenorrhea severity also varied by BMI, with pain patterns shifting across weight categories. Multivariable logistic regression demonstrated that higher BMI independently predicted lower odds of irregular cycles (AOR 0.70, 95% CI 0.50–0.93) and reduced dysmenorrhea (AOR 0.95, 95% CI 0.92–0.99), while cycle length decreased slightly with increasing BMI. No significant associations were observed for menstrual flow, intermenstrual bleeding, or cycle frequency after adjustment. Conclusion: This study demonstrates that BMI is significantly associated with multiple menstrual cycle abnormalities. This research could help identify targeted treatments for women with abnormal BMI and menstrual dysfunction, potentially improving reproductive health. It supports that weight management should be a key part of menstrual health treatments