However, only about 60% of the women with gestational diabetes had a check-up a year later that included screening for type 2 diabetes (as recommended). And few women with or without gestational diabetes received 1-year screening for other CVD risk factors such as high body mass index (BMI), hypertension, dyslipidemia, and smoking.
Gestational diabetes is increasing because of the obesity epidemic and older pregnant mothers, Daly and colleagues note, and it is well established that gestational diabetes greatly increases the lifetime risk of type 2 diabetes. Researchers conducted a retrospective cohort study using The Health Improvement Network (THIN), a nationally representative data base of women seen in primary care practices in the United Kingdom.
They matched these women with 37 281 women of the same age who became pregnant around the same time but did not develop gestational diabetes, to identify the risk of developing coronary artery disease (CAD) that did not require hospitalization. The women were a median age of 33 years (range, 14–47) and were followed for a median of 2.9 years (up to 25 years).
Women who developed gestational diabetes were more likely to have an economically deprived background, be overweight or obese (BMI ≥25 kg/m2; 63% vs 35% of normal weight women) or have hypertension, but were less likely to be current smokers (16% vs 19%). During follow-up, about 1 in 10 women with gestational diabetes (9.8%) vs only 0.38% of other women developed type 2 diabetes.
Women with gestational diabetes were also more likely than other women to develop CAD (0.15% vs 0.06%, respectively) or hypertension (3.2% vs 1.3%, respectively). After adjusting for confounders, gestational diabetes was associated with a 21-fold higher risk of developing type 2 diabetes, and about a 2- to 3-fold higher risk of developing hypertension or CAD, but no increased risk of stroke.
The risk for type 2 diabetes was greatest in the first year following delivery but persisted for 25 years. Only 58% of the women with gestational diabetes had a test for glycemia at 1 year, which dropped to less than 40% at 2 years postpartum. "The findings add an important insight into the trajectory of the development of type 2 diabetes, hypertension, and cardiovascular disease in the early and latter post-partum periods," Daly and colleagues note.
Authors conclude that the value of preventing cardiovascular outcomes requires further studies. There is some evidence that targeting the subgroup of young women with gestational diabetes for prevention programs may yield benefits in reducing conversion to type 2 diabetes.