Statin and Ezetimibe Combination Therapy Decreases Mean Platelet Volume Compared to Statin Monotherapy

permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. When platelets are activated, they increase in size and change from a quiescent disc to a swollen sphere. Large platelets are more reactive and likely aggregate more than small ones. 1 Mean platelet volume (MPV), an indicator of platelet size and activation , has been shown to predict ischemic stroke, myocardial in-farction, and overall vascular mortality. The IMProved Reduction of Outcomes: Vytorin Efficacy International Trial (IMPROVE-IT) study showed that ezetimibe added to statin therapy further decreases low density lipoprotein cholesterol (LDL-C) levels and prevented acute coronary syndromes. 4 In this study, we investigated the lowering effect of LDL-C and MPV changes in patients who are on statin-ezetimibe combination therapy and those who receive statin monotherapy. Patients with acute ischemic cerebral infarctions (n = 120) were divided into those who were on statin therapy (n= 60) and those on statin plus ezetimibe (n= 60). The statin group received either atorvastatin (20 mg; n = 13) or rosuvastatin (10 mg; n = 48). The statin plus ezetimibe group received ezetimibe (10 mg) on top of the same dose of statin (atorvastatin plus ezeti-mibe, n = 14; rosuvastatin plus ezetimibe, n = 47). Student's t-tests showed that MPV and serum LDL-C levels were more significantly decreased (MPV: P< 0.001; LDL-C: P= 0.017) by statin plus ezetimibe combination therapy (MPV: from 7.] mg/ dL). Total cholesterol and triglycerides, but not high-density lipo-protein-cholesterol, were more significantly altered with combination therapy than with statin monotherapy (Table 1). A multi-variate regression analysis showed that only LDL-C in the lipid profile correlated significantly with the MPV change. A Pearson correlation analysis showed a positive correlation between the post-treatment MPV and post-treatment LDL-C levels (r= 0.230, P= 0.012). Statin has pleiotrophic effects and modulates platelet function by direct interactions with platelet membranes or by influencing signaling pathways, irrespective of the cholesterol-lowering effects. Aydin et al. reported that high doses of statin decrease MPV and LDL-C levels in patients with diabetes, but the changes in LDL-C and MPV did not correlate. 5 Nevertheless, Marek et al. reported that MPV was correlated with small dense LDL-C. 6 The possible mechanisms through which small dense LDL-C increases MPV include easier oxidation and glycation, which enhances the mobilization of arachidonic acid from phospholipids and decreases membrane fluidity. However, small dense-LDL-C measurements are time consuming and expensive …