With Deirdre K. Tobias, ScD, and JoAnn Manson, MD
Women with a history of gestational diabetes (GD) appear to have an elevated risk of cardiovascular disease (CVD), based on findings from the well-recognized, Nurses’ Health Study (NHS) II.1 However, modifiable lifestyle factors including weight, dietary intake, smoking status, and physical activity appear to mediate the onset of heart disease.
“Collectively, these findings support the role of lifestyle for the prevention of CVD among high-risk women with a history of GD,” the researchers stated in a report1 published in JAMA Internal Medicine.
The study encompassed almost 90,000 eligible women enrolled in the NHS II, which is a longitudinal prospective cohort of female nurses across the United States, ages 24-44 years old. Participants complete questionnaires biannually to update lifestyle and health-related information. Women were included if they reported a previous birth at enrollment or had a first birth up to 2001. Those with a history of type 1 diabetes, cardiovascular disease, or cancer before their first pregnancy were excluded, leaving a total of 89,479 women.1 Of these, 5,292 reported a diagnosis of gestational diabetes.
A total of 1,161 women reported primary cardiovascular events — 612 myocardial infarctions (MI) and 553 strokes.1 Women with a history of GD were 60% more likely to have developed CVD during the follow-up period (median 25.7 years old) than parous women without GD.1 However, after adjusting for lifestyle and behavioral risk factors—including weight gain since prepregnancy, current smoking status, diet, alcohol intake, aspirin use, and physical activity—the association was moderately attenuated (hazard ratio, 1.29). Additionally, GD was positively associated with MI (HR, 1.45) but not stroke risk (HR, 1.10) after full adjustment.
“The overall message is that GM outcomes are not set in stone—that adopting a healthy lifestyle might prevent CVD risk — is an important one,” lead author Deirdre K. Tobias, ScD, told EndocrineWeb. Dr. Tobias is an associate epidemiologist in the division of preventive medicine at Brigham and Women’s Hospital and an instructor at Harvard Medical School.
JoAnn Manson, MD, professor of medicine at Harvard Medical School and chief of the division of preventive medicine at Brigham and Women’s Hospital, agreed, “Lifestyle and behavioral factors are key to reducing the risk of developing cardiovascular disease and type 2 diabetes i(T2D) n a high-risk woman, who has had one or more pregnancies with gestational diabetes. So GD offers a window into her future risk of cardiovascular disease, and, of course, as well as her risk of type 2 diabetes.”
These findings emphasize importance for “clinicians to ask about history of gestational diabetes or to look at the medical records to identify the women, who have prior GD, because it serves as a window into their risk — as a marker of future risk — and to be particularly vigilant about recommending lifestyle modifications that will lower future risk of type 2 DM and cardiovascular disease,” Dr. Manson told EndocrineWeb.
The researchers also found that of the women with history of GD who subsequently developed type 2 diabetes (N=1,008) had a more than a three-fold greater risk of CVD in the fully adjusted model compared with women with no history of diabetes (HR, 3.71).1
Likewise, women with a history of T2D alone also had a more than three-fold greater CVD risk (HR, 3.74). However, women with a history of GD without an onset of type 2 diabetes did not have an elevated risk for cardiovascular risk after adjusting for weight change and other lifestyle factors (HR, 1.20).