The association between three promoter polymorphisms of IL-1 and stroke: A meta-analysis

Aim: The association between Interleukin-1 (IL-1) gene polymorphism and stroke remains controversial. The present study was designed to clarify this relationship through a pooled analysis of the numerous epidemiological studies focusing on this association. Methods: Published data addressing the association between polymorphism of the IL-1 gene and stroke were selected from electronic databases. A total of 21 studies froth 19 publications including 5280 stroke patients and 5699 controls were included in this meta-analysis which detect whether IL-1 alpha-889C/T, IL-1 beta-511C/T and IL-1 RN polymorphism were associated with stroke susceptibility. Result: The combined results of overall analysis revealed that there was a significant association between IL-1 alpha-889C/T polymorphism and stroke (allele model: OR = 139, 95% CI = 1.14-1.68, P <0.001; recessive model: OR = 1.56,95% CI = 1.27-1.90, P < 0.001; dominant model: OR = 1.45,95% CI = 1.13-1.87, P = 0.004; additive model: OR = 1.70, 95% CI = 1.37-2.10, P < 0.001). On a subgroup analysis by ethnicity of study population, significant association was found in Asians (allele model: OR = 1.25 95% CI = 1.12-1.39, P < 0.001; recessive model: OR = 1.36, 95% CI = 1.09-1.69, P = 0.007; dominant model: OR = 1.29, 95% CI = 1.12-1.48, P < 0.001; additive model: OR = 1.42, 95% CI = 1.13-1.80, P = 0.003). There are no associations of IL-1 beta-511C/T and IL-RN polymorphisms on stroke risk were identified. Conclusion: In conclusion, our results suggested that IL-1 alpha-889C/T polymorphism is associated with stroke risk, especially in Asians. However, no associations of IL-1 beta-511C/T and IL-RN polymorphisms on stroke risk in overall analysis or subgroup analysis. (C) 2015 Elsevier B.V. All rights reserved.