Insulin resistance in nondiabetic patients with acute myocardial infarction.

BACKGROUND: Recent studies have shown that insulin resistance (IR) is an independent predictor of early restenosis after coronary stenting. The aim of this study was to examine the effects of IR and its linkage to late loss with bare metal stenting in nondiabetic patients with acute myocardial infarction (AMI).
MATERIALS AND METHODS: We enrolled 61 nondiabetic patients with AMI who have undergone coronary stenting. Quantitative analyses of coronary angiographic data before and after the procedure and at 4 months were performed. Fasting plasma glucose (FPG) and insulin were measured every week until the subjects' hospital discharge. Stress hormones, endothelial nitric oxide synthase, tumor necrosis factor alpha, interleukin-6, leptin, and adiponectin were measured on admission and at 4 months after coronary stenting.
RESULTS: Simple linear regression analyses showed a relationship between FPG and insulin [IR group: r=0.297, P=.0428; no insulin resistance (NIR) group: r=0.539, P=.0466] and that late loss was associated with the homeostasis model assessment of IR (HOMA-IR) at 4 months (r=0.435, P=.03). At multiple regression analyses, HOMA-IR on admission in the IR group significantly correlated with thyroid-stimulating hormone, glucagon, and cortisol. The HOMA-IR at 4 months correlated with leptin.
CONCLUSIONS: Nondiabetic patients with AMI can be classified into two groups: the IR group and the NIR group. The IR consisted of the transient IR, which correlated with stress hormones, and the continuous IR, which correlated with leptin and contributed to restenosis after coronary stenting.