Gestational Diabetes Influences Cardiovascular Disease Risk in Women

Deirdre Tobias, ScD

Gestational diabetes in women can be an indicator of risk for cardiovascular disease (CVD) events later in life. However, lifestyle interventions may help offset that risk, according to results of a recent study.

The study, the Nurses’ Health Study II (NHS II), is a prospective, observational cohort study established in 1989. It includes nearly 90,000 women over age 26 who had reported at least one pregnancy, and had no CVD or cancer when they enrolled in the study. More than 90% of patients completed the study, which included ongoing follow-up through 2015.

The research team reported that women who had experienced gestational diabetes (GD) were at a 43% higher risk for CVD events, such as myocardial infarction or stroke, compared with women who had not had gestational diabetes.

“The findings from our study highlight that women with prior gestational diabetes are at an elevated risk of heart disease, even years after their pregnancy, but this is not written in stone,” Deirdre K. Tobias, ScD, the lead author and an instructor and associate epidemiologist at Harvard Medical School and Brigham and Women's Hospital’s Division of Preventive Medicine, told MD Magazine:

Patients in NHS II completed questionnaires every 2 years, reporting their health and lifestyle factors. Their self-reported responses to the questionnaires were confirmed by medical records, and indicated that 1161 patients experienced a non-fatal or fatal stroke or myocardial infarction. Their estimated hazard ratio (HR) and 95% Confidence Interval for CVD risk were established by multivariable Cox models.

The patients mean age was 34.9 years (SD 4.7). The authors noted in the results that when “adjusting for age, pre-pregnancy 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).”

When classifying GD by the progression to T2D in relation to the risk for CVD, there was an indication of a positive association for GD with progression to T2D compared to no GD or T2D (HR, 4.02; 95% CI, 1.94-8.31), and reduced the relationship for only GD (HR, 1.30; 95% CI, 0.99-1.71).”

“Despite having a history of gestational diabetes, women who maintained a healthy body weight and lifestyle (healthy diet, physical activity, non-smoker) throughout middle age were less likely to experience this elevation in cardiovascular disease risk,” Tobias said. “Even among women that we might consider at higher risk due to their gestational diabetes history, cardiovascular disease is still largely preventable.”

The study’s cohort had low absolute rates, and participants were young and predominantly white.

This topic had been studied before, but most were not perspective, and didn’t look at hard endpoints for cardiovascular disease, nor did they take into account risk factors such as body weight or lifestyle.

In an accompanying editorial, Erica P. Gunderson, PhD, MPH, MS, and Marc G. Jaffe, MD, noted that “the increased physiologic and metabolic demands of pregnancy act as a ‘stress test’ that may reveal underlying subclinical disease or provide insight into future chronic disease. Pregnancy complications, such as gestational diabetes (GD) and hypertensive disorders, are ‘early warning’ signs [of] chronic disease in women decades before the menopausal transition.”

The study, “Association of History of Gestational Diabetes With Long-term Cardiovascular Disease Risk in a Large Prospective Cohort of US Women,” was published in JAMA Internal Medicine.