Definition of insulin resistance using HOMA-IR in correlation with metabolic syndrome for population of Rawalpindi/ Islamabad

Abstract

Objective: To determine mean optimal cut off of HOMA IR in correlation with metabolic syndrome for population of Rawalpindi/Islamabad.

Study Design: Crossectional study

Place and Duration of the study: Department of Chemical Pathology & Endocrinology, Armed Forces Institute of Pathology (AFIP) Rawalpindi, from July to Dec 2014.

Material and Methods: 100 subjects of age between 18 to 40 years including both genders were inducted. Pregnant females, subjects suffering from mental or physical disabilities, CLD, CCF, CKD were excluded. Subjects were considered to have hypertension if they had a mean systolic blood pressure (SBP) ≥140 mmHg and/or diastolic blood pressure (DBP) ≥90 mmHg or used antihypertensive medications. Waist circumference and body weight and height were measured according to a standard protocol. The body mass index (BMI) was calculated as the weight (kg) divided by the square of the height (meters). A blood sample was drawn after an overnight fast of >8 h. Plasma glucose levels were measured using a hexokinase enzymatic reference method. Fasting insulin levels were measured using chemiluminescent method on Immulite 2000. Fasting Triglyceride and HDL C were analyzed on Modular P 800. HOMA-IR was calculated using formula fasting serum insulin (μU/ml) × fasting plasma glucose (mmol l-1)/22.5). Metabolic syndrome (MetSATPIII) was defined as the presence of three or more of the following: HDL- cholesterol <1.03 mmol l-1 (males) and <1.30 mmol l-1 (females) or specific treatment for this lipid abnormality; blood pressure ≥130/85 mm Hg or treatment of previously diagnosed hypertension; fasting plasma glucose ≥5.6 mmol l-1, or previously diagnosed type 2 diabetes; triglycerides ≥1.7 mmol l-1 or specific treatment for this lipid abnormality; waist circumference ≥102 cm for males and ≥88 cm for females.

Results: We studies 104 subjects out of which 47 had metabolic syndrome and 57 did not have. Using ROC, area under the curve (AUC) (95%CI) was 0.791 (0.705-0.877) with the ATPIII definition. The optimal HOMA-IR cut-off for the diagnosis of ATPIII-defined MetS was 1.84 (sensitivity: 93 specificity: 36%).

Conclusion: The optimal cut- off point of HOMA-IR for MetS diagnosis found in our study was 1.69 .Use of this cut off values can help in early determination of metabolic syndrome which will be helpful in clinical management in such individuals to reduce risk for clinical atherosclerotic cardiovascular disease. In our study we found a new emergent group of premetabolics, persons not fulfilling the entire criteria of diagnosis of metabolic syndrome but still having one or two risk factors. They should also undergo investigation of HOMAIR for early active intervention. Our study shows an increase in prevalence that can be the result of shift from a traditional to a Western-like way of life.

Keywords: HOMA IR, Insulin resistance, Metabolic syndrome.