Interleukin-18 gene promoter 607A polymorphism, but not 137C polymorphism, is a protective factor for ischemic stroke in the Chinese population: A meta-analysis.

Some epidemiological studies have evaluated the association between interleukin (IL)-18 promoter polymorphisms and the risk of ischemic stroke (IS), but the results were inconsistent. The present meta-analysis was therefore performed to investigate the relationship between IL-18 promoter 137G/C and 607C/A polymorphisms and the risk of IS in the Chinese population. Related studies from PubMed, Embase, Web of Science, CBMdisc and CNKI databases up to November 1, 2014 were systematically searched, also the reference lists of identified articles were manually searched. Information was extracted to calculate for the allelic, genotypic, dominant and recessive models using the pooled odds ratios (ORs) along with 95% confidence intervals (CIs). Evidence of significant association between 607C/A polymorphism and risk of IS was found in four genetic models based on the overall population. However, no significant association between 137G/C polymorphism and risk of IS was found in four genetic models. In summary, the present study suggests that IL-18 gene promoter 607A polymorphism is a protective factor for IS in the Chinese population, while 137C polymorphism has weaker or no protective properties. Still, a larger number of studies with large scale and sufficient original information are required to further confirm our findings.