Gestational Diabetes Increases Risk of Cardiovascular Events During Pregnancy

Erica P. Gunderson, PhD

Gestational diabetes (GD) can lead to earlier onset and heightened risk of type 2 diabetes, which is a risk factor for cardiovascular disease, but it is not entirely known if attainting normoglycemia can decrease the excess cardiovascular disease risk associated with these patients.

A team, led by Erica P. Gunderson, Division of Research, Kaiser Permanente Northern California, evaluated gestational diabetes history and glucose tolerance following pregnancy associated with coronary artery calcification (CAC) in women, which is a manifestation of atherosclerotic cardiovascular disease and a predictor of cardiovascular clinical events.

Study Parameters

In the study, the investigators obtained data from the Coronary Artery Risk Development in Young Adults (CARDIA) study, a multicenter, community-based prospective cohort of young Black (50%) and white adults aged 18-30 years at baseline in the US.

Overall, 1133 women without diabetes at baseline who had at least 1 singleton births (n = 2066) during follow-up, glucose tolerance testing at baseline and up to 5 times during 25 years (1986-2011), gestational diabetes status, and coronary artery calcification measurements obtained from 1 or more follow-up examinations at years 15, 20, and 25 (2001-2011) were included in the final analysis.

The researchers measured coronary artery calcification using noncontrast cardiac computed tomography, which was dichotomized as any CAC (score >0) or no CAC (score = 0).

They also used complementary log-log models for interval-censored data estimated adjusted hazard ratios of CAC and 95% confidence intervals for gestational diabetes history and subsequent glucose tolerance groups—normoglycemia, prediabetes, or incident diabetes—on average 14.7 years following the last birth adjusted for prepregnancy and follow-up covariates.

Findings

A total of 139 (12.3%) individuals reported gestational diabetes. The average age of this subgroup was 47.6 years old at follow-up.

Overall, CAC was present in 34 (25%) of these patients, while it was present in 149 (15%) of the women with no gestational diabetes.

Adjusted hazard ratios were 1.54 (95% CI, 1.06-2.24) for the patients with no gestational diabetes/normoglycemia and 2.17 (95% CI, 1.09-4.17 for the individuals with gestational diabetes or prediabetes and 2.02 (95% CI, 0.98-4.19) for individuals with gestational diabetes or incident diabetes (overall P = 0.003).

“Women without previous GD showed a graded increase in the risk of CAC associated with worsening glucose tolerance,” the authors wrote. “Women with a history of GD had a 2-fold higher risk of CAC across all subsequent levels of glucose tolerance. Midlife atherosclerotic CVD risk among women with previous GD is not diminished by attaining normoglycemia.”

Gestational diabetes and glucose intolerance recognized during pregnancy impacts 250,000 women in the US, accounting for 8-9% of all pregnancies.

The study, “Gestational Diabetes History and Glucose Tolerance After Pregnancy Associated With Coronary Artery Calcium in Women During Midlife: The CARDIA Study,” was published online in Circulation.