The yield of early-pregnancy HOMA-IR index for predicting gestational diabetes mellitus in different BMI and age groups

Abstract

Background: Gestational diabetes (GDM) is a highly prevalent disorder with maternal and neonatal complications. Early prediction of GDM can be beneficial for lifestyle modifications to prevent GDM. Method: This study is part of the Qazvin Maternal and Neonatal Metabolic Study (QMNMS) in Iran in which pregnant women with gestational age ≤14 weeks were enrolled and followed until delivery to investigate the risk factors for maternal and neonatal complications. The predictive value and best cut-off of early-pregnancy Homeostasis of Model Assessment -Insulin Resistance (HOMA-IR) to predict GDM in BMI and age categories were evaluated using logistic regression analysis and receiver operating characteristic analysis, respectively. Results: GDM was developed in 16.7% of 772 participants who completed the study. In the logistic regression analysis, the third HOMA-IR tertile was independently associated with 3.7 times higher GDM development (95% CI:1.9-7.3, P<0.001). Despite the high prevalence of GDM in advanced maternal age (GDM rate=30.9%), HOMA-IR had no association with GDM occurrence in this high-risk group. In both normal BMI and overweight/obese groups, HOMA-IR was a moderate predictor of GDM development (AUC=0.638, P=0.005 and AUC=0.622, P=0.008, respectively). However, the best cut-off for predicting GDM was 2.06 (sensitivity 67.5%, specificity 61.1%) in normal BMI and 3.13 (sensitivity 64.6%, specificity61.8%) in overweight/obese BMI. Conclusion: The present study revealed the necessity of considering the baseline GDM risk group when using the HOMA-IR index to predict GDM. Using lower cut-offs is more accurate for women with a normal BMI. In the advanced maternal age, there is no yield of HOMA-IR for predicting GDM.