Insulin resistance and short-term mortality in patients with acute myocardial infarction

Abstract

Homeostatic Model Assessment (HOMA) is a useful model for the evaluation of insulin resistance (IR) in individuals with glucose intolerance, mild to moderate diabetes, and other insulin-resistant conditions [1]. The aim of our study was to evaluate the role of IR by means of the HOMA index in the early phase of acute myocardial infarction (AMI). This was a single-centre observational prospective study. We studied 518 subjects, 361 (75%) males, all referred to our Coronary Care Unit for AMI. All patients with no specific contraindications received the recommended drugs in the acute phase. Patients with a fasting glucose level b110 mg/dL and without a history of diabetes mellitus (DM) were classified as normoglycemic. PlasmainsulinandC-peptideconcentration were analysed in fasting samples taken on the first morning after admission. Plasma insulin was quantified using the second generation electrochemiluminescence immunoassay (ECLIA) sandwich principle, with two mouse monoclonal insulin-specific antibodies and an Elecsys analyzer (Roche Diagnostics, Mannheim, Germany). HOMA2-IR online calculator downloaded from http://www.dtu.ox.ac.uk was used to calculate IR in fasting conditions. The study was carried out according to the principles of the DeclarationofHelsinkiandwasapprovedbyourinstitutionalethicscommittee. Continuousvariableswere expressedasmean ± standarddeviation or standard error of mean, determining the differences between groups by Student's t-test. The categorical variables were compared by chisquare analysis. ROC curve analysis was used to assess the ability of various levels of HOMA2-IR to predict mortality. The model's discriminative ability was assessed with the Harrell's C statistic. A p-value of b.05 was considered statistically significant for all analyses. Data were analysed using the Statistical Package for Social Sciences, version 13.0