Abstract 28: Relationship between endometriosis and cardiovascular disease: Insights from mediation analyses within the UK Biobank

Background: Endometriosis has been linked to a higher risk of cardiovascular disease, although the mechanisms are not fully understood. It has been suggested that undergoing a hysterectomy, with or without removal of the ovaries (oophorectomy), may partly explain the relationship between endometriosis and cardiovascular disease. Methods: We used data from the UK Biobank to examine the association between endometriosis and composite cardiovascular disease, defined as a combination of fatal and non-fatal coronary heart disease and stroke, as well as cardiovascular mortality and overall mortality. Cox regression models were applied, adjusting for conventional and emerging cardiovascular risk factors, lifestyle and demographic risk factors, and female-specific risk factors. In addition, we conducted counterfactual mediation analyses to explore whether hysterectomy with or without oophorectomy contributes to the link between endometriosis and cardiovascular disease. Results: Our study included 261,581 females with a median age of 57 years, of whom 8,101 had endometriosis. Over a total of 3,440,869 person-years of follow-up, 22,066 females developed cardiovascular disease. Endometriosis was associated with an 18% higher risk of cardiovascular disease (HR 1.18 [95% CI 1.09-1.28, P