Genetic polymorphism of interleukin 1β -511C/T and susceptibility to sporadic Alzheimer's disease: a meta-analysis.

A large number of epidemiological studies have been performed to investigate the association between Alzheimer's disease (AD) risk and interleukin-1β -511C/T genetic polymorphism, however, inconsistent results have been reported. The effect of the IL-1β -511C/T polymorphism on AD susceptibility was evaluated by a meta-analysis. Series of databases were researched. 14 studies involving 2640 AD case and 3493 control subjects were identified. The pooled results showed there were no statistical associations of interleukin-1β -511C/T genetic polymorphism with susceptibility to AD for five analysis models in all subjects. However, obvious heterogeneity among studies was detected. When stratifying for age at onset, ethnicity and geographic distribution of population to explore the original source of heterogeneity, the meta-analysis results based on geographic distribution of population showed the significant difference (CC vs CT, OR 1.26, 95 % CI: 1.03, 1.54, z = 2.25, P = 0.025; CC vs CT+TT, OR 1.24, 95 % CI: 1.03, 1.50, z = 2.24, P = 0.025) only in non-Europe. These findings indicate that the IL-1β -511C/T polymorphism might be associated with AD risk, and individuals with IL-1β -511C/C genotype might be at higher risk of AD in non-Europe. Further larger sample research would be warranted to confirm these conclusions.