“Our research shows that just having a history of gestational diabetes elevates a woman’s risk of developing early atherosclerosis before she develops type 2 diabetes or metabolic syndrome,” said lead author Erica P. Gunderson, PhD, MPH, senior research scientist in the Kaiser Permanente Northern California, Division of Research in Oakland, Calif. “Pregnancy has been under-recognized as an important time period that can signal a woman’s greater risk for future heart disease. This signal is revealed by gestational diabetes.”
“It’s a shift in thinking about how to identify a subgroup at risk for atherosclerosis early. The concept that reproductive complications unmask future disease risk is a more recent focus. It may inform early prevention efforts,” Dr. Gunderson said.
The researchers used data from 898 women (47% African American; age 18 to 30 years) enrolled in the Coronary Artery Risk Development in Young Adults (CARDIA) study. The women did not have diabetes or heart disease at baseline (1985-1986) and gave birth at least once after baseline. Overall, 119 of the 898 women developed gestational diabetes. Measurement of common carotid intima media thickness (ccIMT) was used to assess for early signs of atherosclerosis in all of the participants between 2005 and 2006—an average of 12 years after pregnancy when the women were 38 to 50 years old.
Factors Predictive of Future Risk for Heart Disease
In the overall group, mean ccIMT was not significantly higher in women with a history of gestational diabetes than in those without this disorder after adjusting for prepregnancy body mass index (BMI).
However, among women who did not develop diabetes or the metabolic syndrome during the follow up period, women with a history of gestational diabetes had a 0.023 mm larger average ccIMT compared to those without previous gestational diabetes (ie, 0.784 mm versus 0.761 mm, P=0.039), after controlling for race, age, parity, and prepregnancy BMI. This difference represents a 3- to 5-year increase in vascular aging. The presence of insulin resistance before pregnancy at high blood pressure at 20-year followup modestly attenuated the association of gestational diabetes on ccIMT in this subgroup.
“In contrast, among women who had developed diabetes or the metabolic syndrome after pregnancy, average ccIMT did not differ by history of gestational diabetes,” Dr. Gunderson said.
“Weight gain and blood pressure elevations after pregnancy in women with gestational diabetes were responsible for the greater carotid artery wall thickness,” Dr. Gunderson said.
Interpreting the Findings
“The authors found that women with gestational diabetes had a greater ccIMT than those without gestational diabetes. I think the main clinical message is that we should think of gestational diabetes as a marker of a woman who is at increased risk for metabolic and cardiovascular problems in her future,” commented Baiju Shah MD, PhD, Associate Professor of Medicine at the University of Toronto, Canada.
Dr. Shah called for “further research into behavioral interventions for women with prior gestational diabetes to maintain healthy weight, diet, and physical activity levels, to see whether these can lead to improvements in cardiometabolic health for these women.”
Gunderson EP, Chiang V, Pletcher MJ, et al. History of gestational diabetes mellitus and future risk of atherosclerosis in mid-life: The Coronary Artery Risk Development in Young Adults Study. J Am Heart Assoc. 2014 Mar 12;3(2):e000490. doi: 10.1161/JAHA.113.000490.