Association of plasma leptin levels and complexity of the culprit lesion in patients with unstable angina

Background: Angiographically visible complex lesions which are associated with plaque vulnerability have been shown to correlate strongly with clinical severity of unstable angina (UA). By activating different immune/inflammatory cells or directly acting on the vessel wall leptin has been shown to play a potential role in the development of acute coronary syndrome. However, the relationship between leptin and simple or complex lesion morphology in UA has not been investigated. Therefore, we designed this study to determine the association between plasma leptin level and simple or complex lesions in patients with UA and to see any correlation between leptin and other inflammatory markers in these patients. Methods: Plasma concentrations of leptin, interleukin (IL)-6, IL-10 and high-sensitivity C-Reactive Protein (hsCRP) were analyzed in 47 patients with UA. These patients were also angiographically studied and divided into two groups: simple lesion (n = 18) and complex lesion (n = 29) based on the coronary plaque morphology. We further compared them with 20 control subjects having no evidence of coronary artery diseases. Results: Plasma leptin concentrations were higher in patients having complex lesions compared to those having simple lesions as well as normal controls. Similarly IL-6 and hsCRP were also higher in complex lesion group compared to simple lesion group and controls, and leptin was positively correlated with IL-6 and hsCRP. Concentrations of IL-10 were lower in simple and complex lesion groups compared to the controls and leptin was negatively correlated with IL-10, but no significant difference between simple and complex lesions was found. Furthermore, leptin was found to be an independent predictor for the complex lesion morphology in UA patients. Conclusion: These findings suggested that angiographically visible complex lesions are associated with increased concentrations of leptin, and thus leptin can be a useful biomarker for risk stratification in UA. (c) 2007 Elsevier Ireland Ltd. All rights reserved.