Diagnostic Accuracy of Markers of Insulin Resistance (HOMA-IR) and Insulin Sensitivity (QUICKI) in Gestational Diabetes

Objectives: To determine the diagnostic accuracy of HOMA-IR, and QUICKI in diagnosing gestational diabetes mellitus (GDM) considering oral glucose tolerance test (OGTT) as gold standard. Study Design: Cross-sectional analytical study. Place and Duration of Study: Department of Chemical Pathology, Armed Forces Institute of Pathology, Rawalpindi from September 2020 to February 2021. Methodology: Pregnant women with gestational age between 24 to 28 weeks, who reported to Endocrine Clinic of AFIP for OGTT, were included in the study. OGTT was performed by following ADA guidelines. Sample for fasting insulin was collected along with first fasting sample of OGTT. HOMA-IR and QUICKI were calculated simultaneously. Percentage was used for qualitative variable while median (IQR 25th-75th) was applied for quantitative variables. OGTT was used as gold standard for calculation of diagnostic accuracy of HOMA-IR and QUICKI. Results: Out of 182 patients, 74 (40.6%) were found to have GDM on OGTT while 108 (59.4%) had normal OGTT. Women with GDM (n=74) had median values of fasting insulin 15.9 (IQR 11.2-17.77), HOMA-IR 3.5 (IQR 2.6-4.1) and QUICKI 0.31 (IQR 0.30-0.33) as compared to median values of fasting insulin 8.0 (IQR 5.9-10.3), HOMA-IR 1.60 (IQR 1.12-2.03) and QUICKI 0.35 (IQR 0.34-0.37) in patients (n=108) with normal response to OGTT, (p <0.001). On logistic regression analysis, there was a strong association of HOMA-IR and QUICKI with gestational diabetes mellitus (p <0.001, accuracy 84.6%). HOMA-IR at cutoff of <= 2 had 94.5% sensitivity, 72.2% specificity, 70% PPV, 95.1% NPV, and 81.31% overall diagnostic accuracy with 0.913 AUC. QUICKI at cutoff of 0.34 had 86.4% sensitivity, 83.3% specificity, 78.0% PPV, 90.0% NPV, and 84.61% overall diagnostic accuracy with 0.905 AUC. Conclusion: Fasting insulin and HOMA-IR were significantly higher while QUICKI was lower in patients of GDM as compared to non-GDM pregnant patients at 24 to 28 weeks of gestation. Being more convenient for patients, it has the potential to be used as screening tool for gestational diabetes.

Automated summary

The study found that during 24 to 28 weeks of gestation, GDM patients had significantly higher levels of fasting insulin and HOMA-IR, while QUICKI levels were lower. Based on the research results, HOMA-IR and QUICKI have the potential value in diagnosing gestational diabetes.