Bilateral oophorectomy and the risk of incident diabetes in postmenopausal women.

OBJECTIVE Ovarian hormones regulate glucose uptake and insulin sensitivity. Despite the high frequency of surgical menopause, its relationship with diabetes has not been extensively investigated. We assessed the association between hysterectomy with or without bilateral oophorectomy (BSO) status, menopausal age, and reproductive life span with incident diabetes. RESEARCH DESIGN AND METHODS Data were from a cohort of 2,597 postmenopausal women enrolled in the National Health and Nutrition Examination Survey I Epidemiologic Follow-up Study without diabetes mellitus at baseline. Cox proportional hazards regression models were used to calculate adjusted hazard ratios (HRs) and 95% CIs. RESULTS After a median follow-up time of 9.2 years, the incidence of diabetes (in cases per 1,000 person-years) was 7.4 for women with no hysterectomy or BSO, 8.2 for hysterectomy alone, and 8.5 for hysterectomy with BSO. Hysterectomy status was associated positively with diabetes (HR 1.66, 95% CI 1.23-2.23). However, the elevated risk was restricted to women with both hysterectomy and BSO after adjustment for relevant confounders (HR 1.57, 95% CI 1.03-2.41). An earlier age at menopause and a shorter reproductive life span also exhibited a linear relationship with the development of diabetes irrespective of type of menopause (P for trend = 0.001). CONCLUSIONS Women with hysterectomy concomitant with BSO may represent a unique population with elevated risk for diabetes and other chronic diseases. Therefore, the decision to remove the ovaries at the time of hysterectomy for benign conditions during the premenopausal years should be balanced with the risk of diabetes and its potential complications. Furthermore, the mechanism linking BSO to diabetes mellitus needs to be clarified.