The associations between the MCP-1 -2518 A/G polymorphism and ischemic heart disease and ischemic stroke: a meta-analysis of 28 research studies involving 21,524 individuals.

Epidemiologic studies have been performed to explore the relationship between MCP-1 polymorphism and ischemic heart disease (IHD) and ischemic stroke (IS). But, the results are not consistent. Because of the poor effect of each individual study, we've performed a systematic review and a meta-analysis. A comprehensive search was carried out from PubMed, Embase, Foreign Medical Journal Service (FMJS), China National Knowledge Infrastructure and Wanfang Data. Odds ratios (OR) with 95% confidence interval (CI) were used to evaluate the strength of associations between the MCP-1 A-2518G polymorphism (rs1024611) and IHD and IS susceptibilities. The pooled OR was calculated by the allelic model (G vs A), the additive model (GG vs AA), the dominant model (GG+GA vs AA) and the recessive model (GG vs AA+GA), respectively. The homogeneity among studies was checked using Cochrane Q statistic. The stability of results was checked by one-way sensitivity analysis. The publication bias between studies was examined by Begg's funnel plots and Egger's test. 28 eligible case-control studies met all the criteria and were involved in the present meta-analysis, including a total of 8,901 cases and 12,623 controls. Overall, the MCP-1 A-2518G polymorphism was significantly associated with the IHD susceptibility. The pooled OR was 1.27 (95% CI 1.09-1.48, P = 0.002) in the dominant model, 1.20 (95% CI 1.07-1.35, P = 0.001) in the allelic model, 1.25 (95% CI 1.05-1.50, P = 0.015) in the recessive model and 1.39 (95% CI 1.10-1.75, P = 0.005) in the additive model. At the same time, the MCP-1 A-2518G polymorphism was significantly associated with the IS susceptibility. The pooled OR was 1.72 (95% CI 1.12-2.65, P = 0.013) in the dominant model, 1.39 (95% CI 1.12-1.74, P = 0.003) in the allelic model, 1.59 (95% CI 1.30-1.93, P = 0.000) in the recessive model, and 2.33 (95% CI 1.76-3.08, P = 0.000) in the additive model, respectively. No significant publication bias was found in the present meta-analysis. The results of the present meta-analysis suggest that MCP-1 gene A-2518G polymorphism may be associated with the IHD and IS susceptibilities. But the positive result exists in relatively small sample size subgroup.