Abstract 9796: Association of Unrecognized Myocardial Infarctions With Impaired Fasting Glucose in the Multi-Ethnic Study of Atherosclerosis

Abstract

Background: It has been estimated that approximately 25% of initial myocardial infarctions (MI) are unrecognized (UMI). The prognostic implications of UMI’s have been shown to be as severe as those of symptomatic MI’s. Risk factors for UMI’s are not well understood. Because diabetes mellitus is known to be a risk factor for UMI, it is reasonable to investigate impaired fasting glucose (IFG) as a candidate risk factor. Additionally, it has recently been estimated that up to one-third of all adult Americans have IFG. Methods: The relationship between IFG and UMI was examined in the Multi-Ethnic Study of Atherosclerosis (MESA): a cohort of individuals aged 45 to 84 years without clinical cardiovascular disease. At baseline, participants with normal fasting glucose (NFG; n = 4955) and IFG (n=930) underwent a baseline 12-lead electrocardiogram (ECG). Using Minnesota code, an UMI was identified by the presence of pathological Q waves or minor Q waves with ST-T abnormalities. Crude and adjusted odds ratios (ORs) were calculated. Logistic regression was used to adjust for covariates in 2 models. Model 1 adjusted for age, race, gender, and body mass index. Model 2 adjusted for model 1 + systolic blood pressure, diastolic blood pressure, anti-hypertensive medication use, total cholesterol, HDL cholesterol, lipid-lowering medication use, and cigarette use. Results: The sample was 46% male, 41% white, 26% black, 20% Hispanic, and 12% Asian. There were 72 UMIs identified in the normal fasting glucose (NFG) subjects and 30 UMIs among the IFG subjects. The two corresponding prevalences (1.4% vs. 3.2%) resulted in a crude OR for UMI of 2.26 (95% Confidence Interval (CI): 1.47-3.48; p<0.001). With model 1 adjustments, the OR for UMI in IFG compared with NFG was 1.78 (95% CI: 1.12-2.8; p=0.015). With further adjustments in model 2, this relationship remained significant (OR: 1.63 (95% CI: 1.02-2.56); p=0.041). Conclusion: Unrecognized myocardial infarctions by electrocardiogram are associated with impaired fasting glucose in a population without overt cardiovascular disease. Because of the high prevalence of impaired fasting glucose, the implications of this finding may have ramifications for a large proportion of the adult population.