The Threshold Value of Homeostasis Model Assessment for Insulin Resistance in Qazvin Metabolic Diseases Study (QMDS): Assessment of Metabolic Syndrome

Background: The homeostasis model assessment of insulin resistance (HOMA-IR) is a useful model for application at large epidemiologic studies. The aim of this study was to determine the HOMA cut off values to identify insulin resistance (IR) and metabolic syndrome (MS) in Qazvin, central Iran. Methods: Overall, 480 men and 502 women aged 20-72 yr attended in this cross sectional study from September 2010 to April 2011 . The diagnostic criteria proposed by national cholesterol education program third adult treatment panel (ATPIII), International Diabetes Federation (IDF) and new Joint Interim Societies (JIS); were applied to define MS. Lower limit of the top quintile of HOMA values in normal subjects was considered as the threshold of IR. The receiver operating characteristic (ROC) curves of HOMA for MS diagnosis were depicted. The optimal cut point to determine MS was assessed by maximum Youden index and the shortest distance from the point (0, 1) on the ROC curve. Results: The threshold of HOMA for IR was 2.48. Fifty one percent of the subjects were insulin resistant. The cut point for diagnosis of JIS, IDF, ATP III and Persian IDF defined MS was 2.92, 2.91, 2.49 and 3.21, respectively. Sensitivity and specificity of ATP III defined MS to diagnose IR was 33.95% and 84.78%, of IDF defined MS was 39.13%, 81.29% and of JIS defined MS was 43.77% and 78.11% and of Persian IDF defined MS was 27.32% and 88.76%, in that order. Conclusion: The high prevalence of IR in the present study warns about the future burden of type 2 diabetes. Only the ATP III criteria introduced more specific cut point for putative manifestations of IR.