Susceptibility of Coronary Heart Disease Is Associated with Interleukin-18 Gene Polymorphisms

OBJECTIVE: To investigate the proposed associations between interleukin-18 (IL-18) polymorphisms and coronary heart disease (CHD) susceptibility among the human population. STUDY DESIGN: A comprehensive search was conducted to retrieve published studies relevant to IL-18 polymorphisms and CHD susceptibility. Odds ratios (ORs) of CHD with 95% confidence interval (95% CI) were used to compare effects of IL-18 mutations on CHD susceptibility in 5 different inheritance models. Statistical software was utilized for all data analyses. RESULTS: A sum of 9 published studies containing 5,394 CHD patients and 6,008 healthy controls in total were enrolled in our study. Both rs187238 G>C and rs549908 A>C polymorphisms were correlated with an elevated risk of CHD in the allele model (rs187238 G>C: OR=1.23, 95% CI 1.10 similar to 1.37, p<0.001; rs549908 A>C: OR=1.31, 95% CI 1.04 similar to 1.64, p=0.022), and the rs1946519 C>T polymorphism was associated with an increased risk of CHD in both the allele model and dominant model (both p<0.05). Ethnicity subgroup analysis clarified that rs187238 G>C, rs1946519 C>T, and rs549908 A>C were associated with CHD risk in Caucasians (all p<0.05), while only rs549908 A>C was associated with CHD risk in Asians (OR=1.62, 95% CI 1.07 similar to 2.46, p=0.024). CONCLUSION: Results of our metaanalysis suggested that 3 IL-18 polymorphisms, rs1946519 C>T, rs187238 G>C, and rs549908 A>C, were related to increased risk of CHD, and these polymorphisms may contribute to our understanding of mechanisms underlying CHD.