Abstract 10127: Persistent Insulin Resistance After Optimized Therapy for Atherosclerotic Risk Factors is a Predictor of an Adverse Outcome in Non-Diabetic Patients with Coronary Artery Disease
Insulin resistance (IR) is a strong predictor of cardiovascular (CV) events even before the onset of diabetes. IR is reversible after a reduction in atherosclerotic risk factor burden by medications and life-style modifications in non-diabetic subjects. It is unclear whether changes in IR after reduction of atherosclerotic burden may have a predictive value for future CV events in patients with coronary artery disease (CAD). This study examined whether the reversibility of IR after optimized therapy for atherosclerotic risk factors provides prognostic information of future CV events in non-diabetic patients with CAD.
Methods: This study consisted of 175 non-diabetic patients with newly diagnosed CAD and presence of IR at entry. IR was defined as the homeostasis model assessment of IR (HOMA-IR) ≥ 2.5. After enrollment, all patients had individualized, optimized therapy including medications and life style changes based on AHA guidelines to reduce atherosclerotic risk factors. Evaluation of HOMA-IR was repeated at entry and 6 months after therapies were initiated (2nd test). After the 2nd test, all patients were prospectively followed-up for 3 years or until the occurrence of one of the following events: CV death, nonfatal myocardial infarction, unstable angina requiring coronary revascularization or ischemic stroke.
Results: IR was improved (HOMA-IR < 2.5) after 6 months in 71 (41%) patients, while IR was persistently present in 104 (59%) patients. HOMA-IR at entry was similar between patients with improved IR and persistent IR (3.6 ± 0.1 vs. 3.6 ± 0.2%, respectively). During a follow-up period, events occurred 21 (20%) of the 104 patients with persistent IR and 3 (4%) of the 71 patients with improved IR (p < 0.01). In multivariate stepwise Cox proportional hazards analysis, persistent IR was a predictor of future CV events that was independent of HOMA-IR at entry, fasting plasma glucose, HbA1c, use of medications and the Framingham risk score variables (HR 3.8, 95%CI 1.1 - 11.2, p < 0.01).
Conclusions: Persistent IR despite optimized therapies to reduce atherosclerotic risk burden represents an adverse outcome in non-diabetic patients with CAD. Periodic measurement of IR may be useful for risk stratification in non-diabetic patients with CAD.
- © 2011 by American Heart Association, Inc.