Expectant moms whose blood sugar levels spiked during pregnancy (called gestational diabetes) were twice as likely to show early signs of heart disease in midlife, more than a decade after having their babies, according to new research published this month in Circulation. This finding remained true regardless of glucose levels, including among women whose blood sugar returned to healthy levels after pregnancy.
Previous research has shown that gestational diabetes can lead to prediabetes or type 2 diabetes, both of which make heart disease more likely. Less clear is whether gestational diabetes itself may influence a woman’s risk of future heart disease—even
if blood sugar levels return to normal.
But results from this study suggest that gestational diabetes may trigger changes that promote a buildup of calcium deposits, or plaque, within the heart’s arteries (coronary artery calcium), which is a strong predictor of future heart attack and
stroke. In fact, evidence of coronary artery calcium (CAC) was found in 25% of women with a history of gestational diabetes and only in 15% of women without.
The study drew from data the Coronary Artery Risk Development in Young Adults (CARDIA) Study, a multicenter, community-based study. A total of 1,133 women (50% black) were included in the study—all of whom gave birth at least once during the 25-year
study period and did not have diabetes before pregnancy. They were followed with periodic heart scans and blood tests for an average of nearly 15 years since their last birth and were between 47 and 48 years old, on average, at the end of the follow-up.
A total of 139 (12%) developed gestational diabetes during pregnancy. Of these, 36% developed prediabetes and 26% developed type 2 diabetes, compared to 35% and 9% of women with no history of gestational diabetes. But women with a history of diabetes
during pregnancy had a two-fold higher risk of CAC regardless of whether they attained normal blood sugar levels or developed prediabetes or type 2 diabetes after pregnancy.
The authors noted, “normal blood glucose after gestational diabetes is still related to higher coronary artery calcium risk.” The fact that a woman develops diabetes with pregnancy could be a red flag for other conditions that can worsen and
contribute to cardiovascular disease.
In 2018, the American College of Cardiology/American Heart Association Cholesterol Guideline specified that a history of gestational diabetes enhances women's risk of coronary artery buildup that leads to cardiovascular disease.
“Risk assessment for heart disease should not wait until a woman has developed prediabetes or T2D," said study author
Erica P. Gunderson, PhD, in a statement. "Diabetes and other health problems that develop during pregnancy serve as early harbingers of future chronic disease risk, particularly heart disease.”
The study did not factor in preeclampsia or other pregnancy complications linked to cardiovascular disease. Also, it’s important to note that CAC is a proxy or marker for heart disease risk.
It is estimated that gestational diabetes affects nearly 1 out of 10 pregnancies in the U.S. and up to 1 in 5 worldwide.
Women who had gestational diabetes should tell their care team about it as part of their complete medical history. Also, it’s important to check blood sugar regularly, exercise and maintain a healthy diet.
To learn more, visit CardioSmart.org/Women. For information about how diabetes affects the heart, visit CardioSmart.org/DiabetesandHeartDisease.