The Association Between Obesity and Polycystic Ovary Syndrome: An Epidemiologic Study of Observational Data

BACKGROUND: Polycystic ovary syndrome (PCOS) is a common female cardiometabolic-reproductive disorder. It is unclear whether the global obesity epidemic is impacting the high PCOS prevalence. OBJECTIVE: To determine the association between the prevalence of PCOS and obesity. MATERIALS AND METHODS: A systematic review was conducted to identify population studies on PCOS prevalence globally through July 2023. Linear regression and random-effect models were applied to examine the association of mean body mass index (BMI) or obesity prevalence with the prevalence of PCOS diagnosed by 1990 National Institutes of Health (NIH), 2003 Rotterdam (Rotterdam), and 2006 Androgen Excess-PCOS (AE-PCOS) criteria. Subgroup analyses were also conducted for recruitment methods and study quality. RESULTS: Fifty-eight studies with 85 956 adults from 24 countries were included. Considering all available data, a borderline association was observed between PCOS and obesity prevalence when using the AE-PCOS but not the NIH or Rotterdam criteria. Alternatively, subgroup analysis of studies with better recruitment methods demonstrated a significant positive association of population mean BMI or obesity prevalence with PCOS prevalence when using the Rotterdam or AE-PCOS criteria, while using only high-quality studies revealed an association using NIH as well as Rotterdam and AE-PCOS criteria. Overall, we observed that a 1% increase in obesity prevalence resulted in an approximately 0.4% increase in PCOS prevalence by the Rotterdam criteria. CONCLUSION: The prevalences of PCOS and obesity appear to be modestly associated, although our data cannot establish causality. This study also emphasizes the need to undertake only high-quality studies in assessing PCOS epidemiology.