Aims: To compare the incidence of myocardial infarction and death in non-diabetic subjects with and without insulin resistance.
Methods: Population-based prospective cohort study, in Malmö, Sweden, of 4748 non-diabetic subjects (60% women), aged 46-68 years, with no history of myocardial infarction or stroke. The prevalence of insulin resistance was established by the homeostasis model assessment (HOMA) and defined as values above the sex-specific 75th percentile (1.80 for women and 2.12 for men). Incidence of myocardial infarction and death is based on record linkage with local and national registers. Cox's proportional hazards model was used to assess the influence of insulin resistance after adjustment for age, sex, hyperglycaemia, raised arterial blood pressure, dyslipidaemia, central obesity, smoking and leisure-time physical activity.
Results: Sixty-two subjects suffered a coronary event, and 93 subjects died during the 6-year follow-up period. Insulin resistance was after adjustment for other factors included in the insulin resistance syndrome and other potential confounders, associated with an increased incidence of coronary events (relative risk (RR) 2.18; 95% confidence interval (CI) 1.22-3.87; P = 0.008) and deaths (RR 1.62; 1.03-2.55; P = 0.038).
Conclusions: Insulin resistance, as assessed by the HOMA method, was in this cohort of middle-aged non-diabetic subjects associated with an increased incidence of myocardial infarction and death. This risk remained when smoking, low physical activity and factors included in the insulin resistance syndrome were taken into account in a stepwise regression model.