An oral glucose tolerance test in pregnancy and its association with future cardiovascular diseases

Gestational diabetes and abnormal 100-g oral glucose tolerance test (OGTT) results in pregnancy are associated with type 2 diabetes, but their relationship with cardiovascular disease (CVD) is less clear. We evaluated the risk of CVD according to the number of abnormal OGTT values during pregnancy.

This retrospective cohort study used data from a major Israeli healthcare provider. Pregnant individuals aged 20-50 years without a prior diagnosis of type 2 diabetes and CVD who had a complete 100-g OGTT during their last pregnancy between January 2000 and December 2022 were included. The primary outcome was the development of a composite of CVD by September 2024. Risk was assessed using Cox proportional hazards models based on the number of abnormal OGTT values.

The study included 103 389 individuals with a mean age of 34 ± 5.2 years. Overall, the median follow-up was 6.8 years (IQR, 3.4-12.9), totalling 886 955 person-years. A composite of CVD developed in 641 individuals (a cumulative incidence of 0.62%). When compared to individuals with all OGTT values normal, individuals with one to three abnormal values had an adjusted hazard ratio (HR) of 1.2 (95% CI: 1.02-1.4) for CVD, reaching 2.41 (95% CI 1.44-4.05) in those with four abnormal OGTT values.

A history of abnormal 100-gram OGTT results during pregnancy, and specifically having four abnormal values, is associated with an elevated risk of CVD. These results underscore the need for early post-partum identification and prevention strategies in this high-risk population.