LAUSR

BACKGROUND It is plausible that gene polymorphisms in tumor necrosis factor-α (TNF-α), interleukin (IL)-1, IL-6, IL-8, and IL-18 may affect predisposition to microvascular complications of diabetes mellitus (DM), but the results of the so far published studies remain controversial. OBJECTIVES We conducted this meta-analysis to clarify relationships between TNF-α/IL-1/IL-4/IL-8/IL-18 polymorphisms and predisposition to microvascular complications of DM by pooling the findings of eligible studies. METHODS A comprehensive search of PubMed, Embase, Web of Science, and CNKI was endorsed by us to identify already published studies. Forty-nine studies were found to be eligible for the meta-analyses. RESULTS The pooled meta-analyses results showed that genotypic frequencies of TNF-α -238 G/A, TNF-α -308 G/A, TNF-α -1,031 T/C, IL-1A -889 C/T, IL-1B -511 C/T, IL-6 -572 G/C, and IL-18 -137 G/C polymorphisms among patients with diabetic nephropathy (DN) and controls differed significantly. Moreover, genotypic frequencies of TNF-α -238 G/A and IL-8 -251 A/T polymorphisms among patients with diabetic retinopathy (DR) and controls also differed significantly. CONCLUSIONS This meta-analysis suggested that TNF-α -238 G/A, TNF-α -308 G/A, TNF-α -1,031 T/C, IL-1A -889 C/T, IL-1B -511 C/T, IL-6 -572 G/C, and IL-18 -137 G/C polymorphisms may affect predisposition of DN. Moreover, TNF-α -238 G/A and IL-8 -251 A/T polymorphisms may affect predisposition of DR.