The Association Between Endometriosis and Cardiovascular Disease Risk Factors

Background: Prior research suggests that women with endometriosis are at a greater risk of cardiovascular disease outcomes. Therefore, our objective was to investigate the association of endometriosis related infertility and cardiovascular disease risk factors such as hypertension, type 2 diabetes, and hypercholesterolemia among postmenopausal women. Methods: We used data from Women’s Health Initiative (WHI), a prospective cohort followed for 17 years since 2005, (N= 161,705). Participants were considered to have endometriosis if they self- reported infertility and the reason for their infertility was endometriosis (n=1,970). We used Cox proportional hazards to estimate hazard ratios of incident hypertension, type 2 diabetes and hypercholesterolemia among women with endometriosis-related infertility. We additionally investigated differences in the relationship between endometriosis-related infertility and CVD risk outcomes by BMI (<30 Kg/m2 vs BMI < 30 kg/m2). We also used log-binomial regression to estimate risk ratios of ever having a CVD risk factor. Results: In women with a history of endometriosis-related infertility we observed no increased risk of hypertension (HR: 1.00 ,95% CI: 0.93 - 1.08). We observed a 18% increased risk of incident diabetes (HR: 1.18, 95% CI: 1.01 - 1.37) and a 10% increased risk of incident hypercholesterolemia (HR: 1.10, 95% CI: 1.01 - 1.19). After adjustment for a priori confounding factors, the associations with incident diabetes (HR: 1.07, 95% CI: 0.92 - 1.25) and hypercholesterolemia (HR: 1.01, 95% CI: 0.93 - 1.10) attenuated and were no longer statistically significant. The association of endometriosis related infertility and hypercholesterolemia was stronger among women with BMI < 30 kg/m2 (p-value, test for interaction:0.02) in the main analyses investigating incident diagnoses, as well as in the sensitivity analyses investigating ever having a CVD risk factor. Conclusion: Women with endometriosis related infertility were not at an increased risk of cardiovascular disease risk factors such as hypertension, type 2 diabetes, and hypercholesterolemia. However, among subgroups of leaner women (BMI<30kg/m2), endometriosis related infertility was associated with an elevated risk of hypercholesterolemia.