Very high 50-gram Glucose Challenge Test results and the risk for future cardio-metabolic morbidities


      50-gram Glucose Challenge Test (GCT) results > 180 or 200 mg/dL are considered diagnostic for Gestational Diabetes Mellitus. We sought to look at the incidence of endo-metabolic (EM) and cardio-vascular (CV) morbidities among women with very high GCT results.

      Study Design

      This was a population-based retrospective cohort study, including all pregnant women aged 17-55 who underwent GCT between the years 2005 and 2020 at a large HMO. EM morbidities were defined as pre-diabetes, type 2 diabetes or impaired lipid profile. CV morbidities were defined as hypertension, ischemic heart disease or vascular diseases. Study population was divided into the following groups: High (180-199 mg/dL) and very high ( >200 mg/dL) based on their highest GCT result, and the reference category was GCT< 120 mg/dL. Cox proportional survival analysis models were used to calculate the Hazard Ratios for EM and CV morbidities among the study groups, while adjusting for clinical and demographic characteristics.


      During the study period 77,568 women met inclusion criteria, 850 (3.9%) had high GCT and 527 (2.4%) had very high GCT (Table). The incidence of EM diseases among women with high and very high GCT were 50.9% and 73.4% respectively, while incidence of CV diseases were 5.3% and 6.6% respectively. The differences between the groups can also be seen in the Kaplan Meier Survival curves, demonstrating a significant difference in cumulative survival (p, log rank< 0.001). The multivariable analysis, which adjusted for socio-demographic characteristics and maternal age, revealed an adjusted HR=3.25 (95%CI 2.92-3.61) and 2.13 (1.54-2.93) for EM and CV diseases, respectively, among women with high GCT and among women with very high GCT an adjusted HR = 5.26 (95%CI 4.71-5.88) and 2.00 (1.40-2.87) for EM and CV diseases respectively.