Diabetes caused by pregnancy can cause problems for a woman later, even if her blood sugar levels return to normal. That finding, based on an extensive long-term study, suggests that doctors should pay close attention to the hearts of people who previously had gestational diabetes.
The results, published online Feb. 1 in Circulation, come from data collected by the CARDIA study, a project designed to track heart health in young adults in the United States. As of 1985, CARDIA has registered an equal number of black and white people, aged 18 to 30, from four cities. Following these people for 25 years, researchers have been looking for coronary artery calcification or CAC, a hardening of blood vessels that can signal future heart disease.
More than a thousand participants gave birth during the study. Of these women, 139 had gestational diabetes, an often temporary disease in which blood sugar levels rise. About a quarter of women who had this complication in pregnancy [34 women] went on to have CAC, even when blood sugar levels normalized after pregnancy, the researchers report. A smaller proportion of women who did not have gestational diabetes [149 of 994, or about 15 percent] went on to have CAC.
The study does not indicate whether any aspect of gestational diabetes causes CAC, only that the two are related. But it is possible that changes in the blood vessels that may accompany gestational diabetes could play a role in heart health later, the researchers say.
Although the link between gestational diabetes and the future CAC is discouraging, "most women with gestational diabetes do not develop coronary artery calcification," says Khadijah Breathett, a cardiologist at the University of Arizona College of Medicine in Tucson who did not participate in the study. Still, the results highlight the importance of keeping blood sugar under control, she said.