Poor blood glucose control during pregnancy was linked to worse heart health in women down the road, researchers reported.
In a study of over 1,100 women, those with previous gestational diabetes had more than a two-fold increased risk for coronary artery calcification later, regardless of glucose levels, reported Erica Gunderson, PhD, MS, MPH, of Kaiser Permanente in Oakland, California, and colleagues in Circulation.
Even if women maintained normal glucose levels after pregnancy in which they had gestational diabetes, they still carried an increased heart risk decades later compared with women without a history of gestational diabetes:
- Normoglycemia after pregnancy: adjusted hazard ratio [aHR] 2.34 (95% CI 1.34-4.09)
- Prediabetes after pregnancy: aHR 2.13 (95% CI 1.09-4.17)
- Incident diabetes after pregnancy: aHR 2.02 (95% CI 0.98-4.19)
As expected, women who didn’t have gestational diabetes but had high blood glucose levels in the years following pregnancy also carried a higher risk for coronary artery calcification. Specifically, women with prediabetes saw a 54% increased risk (aHR 1.54, 95% CI 1.06-2.24), while women who developed type 2 diabetes saw more than a two-fold increased risk (aHR 2.17, 95% CI 1.30-3.62).
“We were surprised to discover that women with a history of gestational diabetes are at a significantly greater risk of heart artery calcification, even if they maintain normal blood sugar levels after pregnancy,” Gunderson said in a statement.
“Risk assessment for heart disease should not wait until a woman has developed prediabetes or type 2 diabetes,” she recommended. “Diabetes and other health problems that develop during pregnancy serve as early harbingers of future chronic disease risk, particularly heart disease.”
She pointed out that “health care systems need to integrate the individual’s history of gestational diabetes into health records and monitor risk factors for heart disease, as well as the recommended testing for type 2 diabetes in these women at regular intervals, which is critical to target prevention efforts.”
These findings are reflected by the 2018 cholesterol clinical practice guidelines from 10 medical organizations including the American Diabetes Association and American Heart Association, which highlight gestational diabetes as a risk factor for atherosclerotic cardiovascular disease risk.
“After pregnancy and throughout the life course of every woman, a thorough pregnancy history should be obtained, and risk factors and risk-enhancing factors should be identified,” according to the guideline, which suggests possible interventions including lifestyle counseling and statin therapy.
Drawing on data from the U.S.-based CARDIA (Coronary Artery Risk Development in Young Adults) study, the analysis included 1,133 women (50% Black, ages 18-30) free of diabetes at baseline who had one or more singleton births over 25 years of follow-up.
Gestational diabetes was defined as a report of diabetes only during pregnancy, meaning no presence of diabetes prior to pregnancy, diagnosed using the 3-hour 100 g of the oral glucose tolerance test results.
Of the women who had gestational diabetes, 62% progressed to develop incident diabetes or prediabetes in the years after giving birth. Only 44% of those who never developed gestational diabetes went on to develop elevated glucose levels later on.
During follow-up, 16.2% of women developed coronary artery calcification (score >0). While only 15% of women free of gestational diabetes developed coronary plaque, a quarter of those who had previous gestational diabetes did.
Gunderson’s group noted that a history of gestational diabetes “may represent a constellation of risk factors,” such as dyslipidemia, rising blood pressure, increasing insulin resistance, endothelial dysfunction, and inflammatory responses, which could lead to the development of coronary plaque in the absence of hyperglycemia.
The study was supported by grants from the National Institute of Diabetes and Digestive and Kidney Diseases.
Gunderson and co-authors reported a relationship with Janssen Pharmaceuticals Inc. No other disclosures were reported.