Similar but Distinct Comorbidity Patterns Between Polycystic Ovary Syndrome and Endometriosis in Korean Women: A Nationwide Cohort Study

Background: Polycystic ovary syndrome (PCOS) and endometriosis are widely recognized as significant risk factors affecting the reproductive health of women. The underlying mechanisms impacting fertility may vary, potentially leading to divergent outcomes. We aimed to examine and contrast the prevalence patterns of diseases coexisting with PCOS and endometriosis, using a large-scale nationwide insurance claims data from Asian women of reproductive age. Methods: We analyzed health insurance and examination data of 157, 662 Korean women aged 15–45 years, drawn from the Korea National Health Insurance Service-National Sample Cohort database. International Classification of Disease, Tenth Revision codes were mapped to phenome-wide association study codes (phecodes). Subsequently, multivariate logistic regression was performed to assess the comorbidity patterns among patients diagnosed with PCOS and endometriosis and healthy control groups. Results: Our analysis revealed that PCOS was correlated with a wider range of metabolic disorders and symptoms, such as hyperlipidemia, type 2 diabetes, various gastrointestinal (GI) issues, and an array of pregnancy-related complications. Conversely, endometriosis was more prevalent among benign neoplasms of female reproductive and digestive organs, endometrial hyperplasia, and angina pectoris. Notably, infertility and glaucoma demonstrated significant associations with both conditions. Furthermore, a comparison of symptom-related codes in women with endometriosis revealed a predominance of pain-related symptoms, whereas those with PCOS exhibited a broader spectrum, encompassing pain, pruritus, GI problems, cough, fever, menstrual cycle disorders, edema, and dizziness. Conclusion: PCOS and endometriosis, which are prevalent gynecological disorders affecting similar age groups of women, rarely co-occur and exhibit unique comorbidity profiles. Tailored healthcare strategies that take into account these distinct patterns have the potential to enhance long-term healthcare outcomes of affected patients. Further research is required to elucidate the underlying mechanisms and contrasting comorbidity profiles between PCOS and endometriosis.