Association of History of Gestational Diabetes With Long-term Cardiovascular Disease Risk in a Large Prospective Cohort of US Women

IMPORTANCE Previous studies identify gestational diabetes (GD) as a risk factor for intermediate markers of cardiovascular disease (CVD) risk; however, few are prospective, evaluate hard CVD end points, or account for shared risk factors including body weight and lifestyle. OBJECTIVE To prospectively evaluate history of GD in relation to incident CVD risk. DESIGN, SETTING, AND PARTICIPANTS The Nurses' Health Study II (NHS II) is an observational cohort study of US female nurses established in 1989, with ongoing follow-up. Biennial questionnaires updated behavioral characteristics, health outcomes, and lifestyle factors. Multivariable Cox models estimated the hazard ratio (HR) and 95% CI for CVD risk. We included 89 479 women who reported at least 1 pregnancy and were free of CVD and cancer at baseline. Follow-up through May 31, 2015, was complete for more than 90% of eligible participants. EXPOSURES History of GD was self-reported at baseline (1989) via questionnaire and updated every 2 years. MAIN OUTCOMES AND MEASURES We observed 1161 incident self-reported nonfatal or fatal myocardial infarction or stroke, confirmed via medical records. RESULTS Participants had a mean (SD) age of 34.9 (4.7) years. Adjusting for age, prepregnancy body mass index, and other covariates, GD vs no GD was associated with subsequent CVD (HR, 1.43; 95% CI, 1.12-1.81). Additional adjustment for weight gain since pregnancy and updated lifestyle factors attenuated the association (HR, 1.29; 95% CI, 1.01-1.65). Classifying GD by progression to T2D in relation to CVD risk indicated a positive association for GD with progression to T2D vs no GD or T2D (HR, 4.02; 95% CI, 1.94-8.31), and an attenuated relationship for GD only (HR, 1.30; 95% CI, 0.99-1.71). CONCLUSIONS AND RELEVANCE Gestational diabetes was positively associated with CVD later in life, although the absolute rate of CVD in this younger cohort of predominantly white women was low. This relationship is possibly mediated in part by subsequent weight gain and lack of healthy lifestyle.