Establishment of Reference Interval for Homeostasis Model Assessment of Insulin Resistance in Healthy Adult Males: a Pilot Study in Alexandria Governorate, Egypt

Objective: Homeostasis model assessment of insulin resistance (HOMA-IR) is a simple and practical method for estimation of insulin resistance (IR), but a reliable reference interval (RI) of HOMA-IR is needed to deduce the threshold level to define IR. This RI has been controversial in different populations and even more divergent when considering factors like age, gender and body mass index (BMI). This pilot study aimed to establish RI for HOMA-IR in Alexandria governorate, Egypt based on the EP28-A3c document from the Clinical and Laboratory Standards Institute (CLSI). Materials and Methods: The reference sample population included 308 healthy nondiabetic normotensive adult men aged 20-69 years with BMI 18.7-29.4 kg/m2. Serum glucose and insulin were measured by glucose oxidase method and by electrochemiluminescence immunoassay respectively, and then HOMA-IR was calculated. The data was analyzed by non-parametric statistical methods; the values were log transformed, then outliers were truncated, and finally the reference values were constructed using 2.5th and 97.5th percentiles as lower and upper reference limits. Results: There was no significant difference in HOMA-IR according to age or BMI; thus, the RI was established from the whole participants and it was 0.4-3.5, and subsequently values above 3.5 can be suggestive of IR status. Conclusions: Although the reported RIs are based on recommended standards, larger scale studies including female subjects are warranted to enable the adoption of such values in laboratories in Alexandria.