Prediction of alterations in glucose metabolism by glucose and insulin measurements in early pregnancy.

ABSTRACT

BACKGROUND AND AIMS: Abnormal dysglycemia during pregnancy increases morbimortality in women and newborns. This study evaluated early markers for that event. We undertook this study to estimate the incidence of dysglycemic events during pregnancy and to evaluate fasting glycemia, insulin and HOMA-IR index in early pregnancy as their predictors in order to compare their predictive capability for gestational diabetes (GD). METHODS: This was a prospective cohort that included 450 women seeking prenatal care at the Mexican Social Security Institute (IMSS). Subjects were ≥19 years old, in early pregnancy, without previous dysglycemia or hypertension, and with fasting glycemia <126 mg/dL. Insulin and HOMA-IR were measured. At 24-36 weeks of gestation, a 3-h 100 g oral glucose tolerance test (OGTT) was performed, applying the modified Carpenter-Coustan criteria. Multiple logistic regression models including an offset term as indicator of time in risk allowed us to estimate the risk of developing glucose intolerance (GI), GD, or hyperglycemia 1-h after the glucose load (HG-1). Areas under the ROC curve allowed comparison of the models' predictive capability. RESULTS: Incidence of dysglycemic events was 20.7%. The risk of GD was higher for the highest glycemia (RR = 4.1, 95% CI 1.6-10.6), insulin (RR = 4.1, 95% CI 1.2-14.2), and HOMA-IR (RR = 6.4, 95% CI 1.9-21.9). A higher risk of GI was found for the highest values of glycemia (RR = 2.6, 95% CI 1.3-5.3). Higher glycemia (RR = 3.9, 95% CI 1.6-9.2), insulin (RR = 2.8, 95% CI 1.0-7.5) and HOMA-IR (RR = 3.8, 95% CI 1.4-10.2) were associated with HG-1. Areas under the ROC curve for adjusted models with glycemia, insulin, or HOMA-IR were 0.749, 0.715, and 0.747, respectively (p = 0.4). CONCLUSIONS: Fasting glycemia was the best adjusted predictor of GD in early pregnancy, having equal predictive capability compared to insulin and HOMA-IR.