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

Abstract

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.

Keywords: Diabetic nephropathy; Gene polymorphisms; Interleukin-1; Interleukin-18; Interleukin-4; Interleukin-8; Meta-analysis; Tumor necrosis factor-α.