Circulating Nampt and RBP4 levels in patients with carotid stenosis undergoing carotid endarterectomy (CEA)

Background: Obesity is a risk factor for atherosclerotic vascular disease. Altered adipokine secretion, including increased production of nicotinamide phosphoribosyltransferase (Nampt) and retinol binding protein 4 (RBP4) may link adipose tissue dysfunction to cardiovascular complications. Methods: We determined Nampt and RBP4 serum concentrations in 193 consecutive patients with carotid stenosis prior to carotid endarterectomy (CEA) in relation to recently experienced ischemic events, markers of atherosclerosis and obesity, as well as anthropometric and clinical characteristics. Results: Nampt but not RBP4 was significantly higher in symptomatic patients who experienced an ischemic event within 6 months before surgery compared to asymptomatic patients (p=0.001). In multivariate regression analysis Nampt was the only independent predictor of symptomatic carotid stenosis. Nampt correlated with peripheral leukocyte blood count (p<0.0001) and with the number of macrophages/foam cells within carotid plagues (p=0.042). However, Nampt and RBP4 serum concentrations did not correlate with the maximum percentage of carotid stenosis. Conclusion: Our data suggest circulating Nampt as an independent predictor of recently experienced ischemic events in patients with carotid stenosis despite the lack of an association between Nampt and carotid atherosclerosis severity. (C) 2011 Elsevier B.V. All rights reserved.