Endometriosis subtypes and risk of type 2 diabetes: the Advancing Research on Cardiovascular Health and Endometriosis Study (ARCHES) retrospective cohort study

Abstract Aims/hypothesis Endometriosis is a heterogeneous inflammatory condition that may influence long-term metabolic health. Prior studies have reported largely null associations with type 2 diabetes, potentially missing subtype-specific and subgroup heterogeneity. We investigated the association between endometriosis, including clinically relevant subtypes, and incident type 2 diabetes, and assessed effect modification by menopausal status, BMI and history of gestational diabetes mellitus. Methods We assembled a dynamic population-based cohort of 2,939,364 individuals assigned as female at birth from the Utah Population Database (1996–2021). Endometriosis and subtypes were identified using validated ICD-9/10 codes and modelled as time-varying exposures. Incident type 2 diabetes was ascertained using ICD codes. Cox proportional hazards models with calendar time as the time scale were used to estimate HRs and 95% CIs, adjusting for birth year, birth state, race/ethnicity, age and BMI at cohort entry. Stratified analyses evaluated effect modification by menopausal status, BMI and history of gestational diabetes mellitus. Results During a mean follow-up duration of 10.8 years, 99,978 women were diagnosed with endometriosis. Endometriosis was associated with a 46% higher risk of type 2 diabetes compared with no endometriosis (aHR 1.46; 95% CI 1.43, 1.50). Risk varied by subtype, with the strongest associations observed for ‘other site’ endometriosis (specified site: aHR 2.67; 95% CI 2.51, 2.84; unspecified site: aHR 2.47; 95% CI 2.35, 2.60). Associations were stronger among premenopausal women than postmenopausal women (aHR 1.55; 95% CI 1.50, 1.60) and those with BMI