Background/Aims. Gestational diabetes mellitus (GDM) and milder gestational impaired glucose tolerance (GIGT) identify women who are at risk of developing cardiovascular disease. Endothelial dysfunction, as indicated by impaired flow-mediated dilatation (FMD) on brachial artery ultrasound, is an early marker of vascular disease. Thus, we sought to evaluate endothelial function in women with and without recent glucose intolerance in pregnancy. Methods. One-hundred and seventeen women underwent oral glucose tolerance testing (OGTT) in pregnancy, enabling stratification into those with normal gestational glucose tolerance (n = 59) and those with GDM or GIGT (n = 58). 6 years postpartum, they underwent a repeat of OGTT and brachial artery FMD studies, enabling assessment of FMD and 4 secondary vascular measures: FMD after 60 seconds (FMD60), baseline arterial diameter, peak shear rate, and reactive hyperemia. Results. There were no differences between the normal gestational glucose tolerance and GDM/GIGT groups in FMD (mean 8.5 versus 9.3%, P = 0.61), FMD60 (4.1 versus 5.1%, P = 0.33), baseline diameter (3.4 versus 3.4 mm, P = 0.66), peak shear rate (262.6 versus 274.8 s−1, P = 0.32), and reactive hyperemia (576.6 versus 496.7%, P = 0.07). After covariate adjustment, there were still no differences between the groups. Conclusion. Despite their long-term cardiovascular risk, women with glucose intolerance in pregnancy do not display endothelial dysfunction 6 years postpartum.

The development of gestational diabetes and even milder forms of dysglycemia during pregnancy represents a maternal phenotype at increased subsequent risk for developing type 2 diabetes mellitus, metabolic syndrome, and, with time, overt cardiovascular disease. A careful and systematic dissection of the hormonal, metabolic, and vascular changes occurring in such women during pregnancy and over the postpartum years provides a unique opportunity to identify conventional and novel conditions and biomarkers whose modification may attenuate adverse long-term outcomes, particularly cardiovascular risk. The purpose of this review is to summarize current understanding of the magnitude of such risk and its potential causes, with a particular focus on postpartum alterations in endothelial and vascular smooth muscle responsiveness.