Impact of inflammatory mavkevs on cardiovascular mortality in patients with metabolic syndrome

Background Recent investigations suggest the inclusion of inflammatory markers in the definition of the metabolic syndrome (MS).The aim of this study was to address the role of C-reactive protein, fibrinogen, interieukin-6 (IL-6) and IL-18 (IL-18) on cardiovascular prognosis in accordance to MS. Methods A total of 1263 patients with documented coronary artery disease were prospectively included. We defined MS (MS yes: N= 533, 42.2%) as the presence of at least three of the following criteria: triglycerides >= 150 mg/dl; low high-density lipoprotein cholesterol (men: < 40mg/dl women: < 50mg/dl); body mass index greater than 30kg/m(2); blood pressure >= 130/85 mmHg; fasting glucose >= 100mg/dl. In addition, we determined C-reactive protein, fibrinogen, IL-6 and IL-18 levels. Results Follow-up data (median 6.1 years) were available for 1257 patients (99.5%). 139 patients (11.1%) died from cardiovascular causes. Cardiovascular mortality was related to MS (MS yes: 15.1% versus MS no: 8.1%, P < 0.0001) and was further increased by elevation of each inflammatory marker. To address whether elevation of inflammatory markers provides additional prognostic information, a subgroup analysis was performed including patients with MS. In a multivariate-adjusted model including all four inflammatory markers, only IL-18 could be identified as an independent predictor of cardiovascular mortality. Conclusion The measurement of inflammatory markers, especially IL-18, adds important prognostic information with regard to the long-term prognosis of patients with MS.