Comparing the diagnostic ability of inflammatory markers in metabolic syndrome

Chronic low-grade inflammation contributes to the pathogenesis of the metabolic syndrome (MetS). Although some studies have demonstrated that several standard inflammatory markers provide diagnostic value for MetS, few studies have compared the diagnostic ability of various inflammatory markers. We demonstrated the diagnostic ability of several inflammatory markers in detecting MetS. Complement component 3 (C3), C4, high-sensitivity C-reactive protein (hs-CRP), leukocyte count, neutrophil, lymphocyte and neutrophil-to-lymphocyte ratio (NLR) concentrations were measured in 6312 participants living in Tianjin, China. MetS was defined according to American Heart Association criteria. Adjusted logistic models were used to assess associations between inflammatory markers and MetS. Receiver operating characteristic (ROC) curves were performed to determine the diagnostic values of inflammatory markers for MetS. The adjusted odds ratio (95% CI) of MetS for the highest inflammatory markers (C3, leukocyte, neutrophil, lymphocyte) quintile, when compared to the lowest quintile were 2.68 (2.12–3.38), 2.53 (2.05–3.11), 1.31 (1.06–1.62) and 1.94 (1.60–2.37), respectively. ROC analysis showed that the optimal cut-off values were 101.0 mg/dl for C3 (Area under the ROC curve (AUC) = 0.68), 5.41 × 1000 cells/mm3 for leukocyte (AUC = 0.63), 3.20 × 1000 cells/mm3 for neutrophil (AUC = 0.60) and 1.82 × 1000 cells/mm3 for lymphocyte (AUC = 0.62). No significant association was observed between the other inflammatory markers and MetS. Among the inflammatory markers assessed in this population, C3 has the strongest diagnostic value in detecting MetS. Further studies are encouraged to determine the efficacy of applying C3 to diagnosis and treatment in the clinical setting.