Gestational diabetes and risk of cardiovascular disease up to 25 years after pregnancy: a retrospective cohort study

AIMS: The risk of cardiovascular disease in women with gestational diabetes is poorly understood. We sought to determine whether gestational diabetes increases the risk of cardiovascular disease more than two decades after pregnancy. METHODS: We carried out a retrospective cohort study of 1,070,667 women who delivered infants in hospitals within Quebec, Canada, between 1989 and 2013. We followed 67,356 women with gestational diabetes and 1,003,311 without gestational diabetes for a maximum of 25.2 years after the index delivery. The main outcome measures were hospitalization for ischemic heart disease, myocardial infarction, coronary angioplasty, coronary artery bypass graft, and other cardiovascular disorders. We used Cox regression to estimate hazard ratios (HR) and 95% confidence intervals (CI) comparing women with gestational diabetes to no gestational diabetes, adjusted for age, parity, socioeconomic deprivation, time period, and preeclampsia. RESULTS: Women with gestational diabetes had a higher cumulative incidence of hospitalization for cardiovascular disease 25 years after delivery (190.8 per 1000 women) compared with no gestational diabetes (117.8 per 1000 women). Gestational diabetes was associated with a higher risk of ischemic heart disease (HR 1.23, 95% CI 1.12-1.36), myocardial infarction (HR 2.14, 95% CI 1.15-2.47), coronary angioplasty (HR 2.23, 95% CI 1.87-2.65), and coronary artery bypass graft (HR 3.16, 95% CI 2.24-4.47). CONCLUSIONS: In this population of pregnant women, gestational diabetes was associated with an increased risk of heart disease 25 years after delivery. Women with gestational diabetes may merit closer monitoring for cardiovascular disease prevention after pregnancy.