Cytokine Polymorphisms and Predisposition to Diabetic Nephropathy: A Meta-Analysis

Background: Cytokine polymorphismsmight influence the predisposition to diabetic nephropathy (DN), but the results of already published related studies are still controversial and ambiguous. Objectives: The authors designed this meta-analysis to more precisely estimate relationships between TNF-α/IL-1/IL-4/IL-8/IL-18polymorphisms and DN by pooling the results of already published related studies. Methods: The authors searched Pubmed, Embase, Web of Science and CNKI for already published studies. Thirty already published studies were pooled and analyzed in this meta-analysis. Results: The overall pooled meta-analysis results showed that distributions of TNF-α –238 G/A, TNF-α –308 G/A, TNF-α –1031 C/T, IL-1A −889 C/T, IL-1B −511 C/Tand IL-18 –137 G/C polymorphisms among patients and controls differed significantly. Additionally, we also found that distributions of TNF-α –308 G/A, IL-1B −511 C/T and IL-18 –137 G/C polymorphisms among patients and controls from Asians differed significantly, and the distribution of the IL-1B −511 C/T polymorphism among patients and controls from Caucasians also differed significantly. Conclusion: The meta-analysis results demonstrated that TNF-α –238 G/A, TNF-α –308 G/A, TNF-α –1031 C/T, IL-1A −889 C/T, IL-1B −511 C/Tand IL-18 –137 G/Cpolymorphisms might influence predisposition to DN in the overall pooled population. Moreover, TNF-α –308 G/A, IL-1B −511 C/T and IL-18 –137 G/C polymorphisms might influence predisposition to DN in Asians, whereas the IL-1B −511 C/T polymorphism might also influence predisposition to DN in Caucasians.