Impact of pregnancy on the trajectories of cardiovascular risk factors in women with and without gestational diabetes

Aims — The elevated lifetime risk of cardiovascular disease in women who develop gestational diabetes (GDM) has been attributed to adverse life-course trajectories of cardiovascular risk factors that arise before pregnancy and continue thereafter. We hypothesized that pregnancy may differentially impact these trajectories in women who develop GDM and those who do not.

Methods — With population-based administrative databases, we identified all nulliparous women in Ontario, Canada, who had singleton pregnancies between Jan/2011 and Dec/2016 and ≥ 2 measurements of the following analytes both before and after pregnancy: A1c, glucose, lipids, and transaminases. 39 581 women (4373 with GDM) had 3.9 ± 3.4 tests before and 4.6 ± 5.4 tests after pregnancy.

Results — Both before and after pregnancy, women who developed GDM had higher A1c, fasting glucose, LDL-cholesterol and triglycerides than their peers, with lower HDL-cholesterol (all p < 0.0001). Before pregnancy, women who went on to GDM had higher annual increases than their peers in A1c, fasting glucose, and triglycerides (all p ≤ 0.01); lesser annual decrease in LDL (p = 0.0003); and greater annual decrease in HDL (p = 0.0006). Compared to pre-pregnancy, the postpartum differences in annual rates of change in A1c and fasting glucose were 6.9-fold and 3.3-fold higher, respectively, in women with GDM. Conversely, the respective postpartum differences in annual rates of change in triglycerides, LDL and HDL were 1.2-times, 1.6-times and 0.3-times lower than before pregnancy.

Conclusion — After pregnancy, differences in pregravid trajectories of glycemic measures are amplified between women with GDM and their peers. In contrast, pregravid differences in lipid measures persist but do not differentially worsen after pregnancy. This article is protected by copyright. All rights reserved.