Association between endometriosis and cardiovascular disease: a population-based cohort study

Background: The relationship between endometriosis and cardiovascular disease (CVD) risk remains unclear. This study aimed to evaluate the association between endometriosis and CVD risk, to examine whether the association was affected by age group, and to exploratorily assess the mediating role of medications in these associations. Methods: A historical, population-based cohort study was conducted based on the Beijing Medical Claim Data for Employees between 2010 and 2017. A total of 19,903 women with endometriosis and 79,612 controls were identified by matching age and year of endometriosis diagnosis in a 1:4 ratio. The primary outcome was the incident diagnosis of any CVD events, and secondary outcomes were major CVD and cerebrovascular disease. The hazard ratios (HRs) were estimated by Cox proportional hazards models representing the association between endometriosis and CVD. Results: Endometriosis was associated with an increased risk of CVD after adjusting for urbanisation, hypertension and diabetes mellitus (HR = 1.69; 95% CI = 1.35-2.12). The adjusted HRs for major CVD and cerebrovascular disease in women with endometriosis were 1.83 (95% CI = 1.32-2.55) and 1.57 (95% CI = 1.12-2.22) compared with controls, respectively. Interaction analyses between endometriosis and age group (18-44 years vs. 45-55 years) yielded P-values of 0.942, 0.552, and 0.211 for all CVD, major CVD, and cerebrovascular disease, respectively, indicating no statistically significant heterogeneity in the associations across age groups. In the overall population, a proportion of the association between endometriosis and all CVD risk was statistically mediated by statins (68.30%) and aspirin (78.15%). Conclusions: Endometriosis was associated with an increased risk of CVD.