Leptin, soluble interleukin-6 receptor, C-reactive protein and soluble vascular cell adhesion molecule-1 levels in human coronary atherosclerotic plaque

The aim of the present study was to explore the relationship between tissue levels of leptin, soluble interleukin-6 receptor (sIL-6R), high-sensitive-C-reactive protein (hs-CRP) and soluble vascular cell adhesion molecule-1 (sVCAM-1) in atherosclerotic plaques, and traditional risk factors. Coronary artery specimens were obtained from 35 consecutive patients (26 men and nine women) who underwent coronary artery bypass grafting procedure. The mean tissue levels of leptin, hs-CRP and sIL-6R were significantly higher in patients with diabetes mellitus than without diabetes mellitus. When patients were classified according to the smoking status, the mean tissue levels of leptin, hs-CRP and sIL-6R were significantly higher in current smokers than both former smokers and non-smokers. In addition, the mean tissue levels of leptin and sIL-6R were significantly higher in former smokers than non-smokers. There was a positive association between leptin and hs-CRP, sIL-6R and plasma glucose in all patients. Plasma HDL levels were associated negatively with atherosclerotic tissue levels of leptin. Tissue levels of sIL-6R were associated significantly in a positive manner with leptin, hs-CRP and plasma glucose, while tissue levels of hs-CRP were associated with both leptin and sIL-6R. In conclusion, it is attractive to speculate that hs-CRP, sIL-6R and leptin could act synergistically in course of local inflammatory activity and those molecules may not be just markers of inflammation and cardiovascular risk but are also likely to play a pathogenic role in atheromatous plaque. In addition, atherosclerotic tissue levels of CRP, sIL-6R and leptin were significantly higher in current smokers and patients with diabetes.