Association between endometriosis and risk of type 2 diabetes: Results from the prospective E3N cohort

Objective: Several studies suggest an association between endometriosis and the risk of cardio-metabolic diseases. This study aimed to prospectively evaluate the association between history of endometriosis and incident type 2 diabetes.Study design: E3N is a prospective cohort of 98,995 French women aged 40-65 years at inclusion. Multivariable Cox regression models were used to estimate hazard ratios and 95 % confidence intervals for the association between endometriosis and incident type 2 diabetes. We evaluated effect modification by age, body mass index, infertility treatment, adherence to the Mediterranean diet, and menopausal status.Results: Age at inclusion was 51 & PLUSMN; 6 years and there were 2672 incident cases of type 2 diabetes. A total of 4606 women reported surgically-confirmed endometriosis among 83,582 women with no history of diabetes at in-clusion. Endometriosis was not associated with type 2 diabetes risk in a model adjusted for age, BMI, physical activity, smoking, education, age at menarche and oral contraceptive use (hazard ratio [HR] = 1.09; 95 % confidence interval [CI] = 0.92-1.29), neither after further adjustment for family history of diabetes, hyper-tension and menopausal status (HR = 0.97;95%CI = 0.80-1.16). The relationship did not differ by age at in-clusion, BMI, infertility treatment, diet or menopausal status (p > 0.05).Conclusions: Surgically-confirmed endometriosis was not associated with the risk of type 2 diabetes in this large cohort, confirming that endometriosis is not a risk marker for type 2 diabetes.