Enhanced levels of soluble CD40 ligand and C-reactive protein in a total of 312 patients with metabolic syndrome

The metabolic syndrome (MS) is associated with a systemic inflammatory response that plays an important pathogenetic role in atherothrombotic disease. Increasing evidence indicates that CD40-CD40 ligand interactions constitute an important mediator for vascular inflammation. The purpose of this study was to assess whether high-sensitivity C-reactive protein (hs-CRP) and soluble CD40 ligand (sCD40L) levels were increased in patients with MS. During the study period from January 2004 to August 2004, 312 patients with MS and 98 control subjects were included. Anthropometric measurements, blood pressure assessment, electrocardiography, and blood measurements including fasting blood glucose, postprandial blood glucose, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglyceride, glycated hemoglobin, white blood cell (WBC), platelets, hs-CRP, and sCD40L were performed. Patients with MS were divided into 3 groups based upon their glucose tolerance (group 1, normal glucose tolerance; group 2, prediabetic group; and group 3, diabetes mellitus). Patients with MS showed a significant increase of WBC, hs-CRP, and sCD40L levels compared with control subjects. The levels of both hs-CRP and sCD40L were positively correlated with body mass index (BMI). High-sensitivity CRP levels were also positively correlated with waist circumferences, fasting blood glucose, postprandial blood glucose, and glycated hemoglobin, and negatively correlated with high-density lipoprotein cholesterol. In patients with MS, both hs-CRP and sCD40L levels were positively correlated with WBC count. We found a positive correlation between sCD40L and platelets. Among the subgroups of patients with MS, the mean levels of WBC, hs-CRP, and sCD40L did not show any significant differences. In conclusion, elevated levels of WBC, hs-CRP, and sCD40L in MS patients provide further insight into the relationship between MS and inflammation. In our study, positive correlations between BMI and both hs-CRP and sCD40L levels suggest that BMI is an important determinant of a chronic inflammatory state in patients with MS. Moreover, this study reports significantly increased levels of WBC, hs-CRP, and sCD40L not only in diabetic subjects with MS but also in prediabetic subjects and nondiabetic subjects with MS compared with control subjects. Our data suggest that MS patients have proinflammatory state independent of their glucose tolerance status. In our study, the positive correlation between the levels of sCD40L and platelets in patients with MS supports previous reports indicating that sCD40L are derived predominantly from platelets.