Background: To establish the reference intervals of GIR, HOMA, and QUICKI index and to identify the clinical value of the three indexes for newly diagnosed diabetes mellitus.
Methods: The results of fasting glucose and insulin were acquired for 123 healthy individuals using Roche cobas-8000 to establish reference intervals of GIR, HOMA, and QUICKI based on Clinical and Laboratory Standards Institute (CLSI) EP28-A3. Meanwhile, 36 newly diagnosed type 1 and type 2 diabetes mellitus (DM) patients were enrolled to judge the effect of insulin resistance/insufficiency using the three indexes based on clinical initial treat-ment procedures. All the data were acquired from Wangjing Hospital, China Academy of Traditional Chinese Medicine.
Results: The reference intervals of GIR, HOMA, and QUICKI were 5.83 - 21.15, 0.87 - 4.22, and 0.309 - 0.392, respectively. Concerning to GIR, HOMA, and QUICKI, there were 57.7% (15/26), 80.8% (21/26), and 80.8% (21/26) outside of the reference limit among type 2 DM patients, respectively; The area under the curve (AUC) of the GIR > 10.937, HOMA < 5.436, and QUICKI > 0.299 were 0.937 (95% CI 0.681 - 1.000), 0.689 (95% CI 0.510 - 0.868), and 0.689 (95% CI 0.510 - 0.868) by ROC curves when insulin insufficiency was judged based on whether insulin was included in initial treatment procedures. There concordance rates were 77.8% (28/36), 50% (18/36), and 50% (18/36) using the three indexes, GIR, HOMA, and QUICKI, respectively.
Conclusions: We established reference intervals for GIR, HOMA, and QUICKI. HOMA and QUICKI were more reliable indexes to identify insulin resistance among type 2 DM patients, but GIR was a more reliable index to identify insulin relatively or absolutely insufficiency than HOMA and QUICKI among DM patients.