Relationships between CETP genetic polymorphisms and Alzheimer's disease risk: a meta-analysis

This meta-analysis was performed to evaluate the relationships between single-nucleotide polymorphisms in the CETP gene and the risk of Alzheimer's disease (AD). The PubMed, CISCOM, CINAHL, Web of Science, Google Scholar, EBSCO, Cochrane Library, and CBM databases were searched from inception through October 1, 2013, without language restrictions. Nine case-control studies with a total of 2172 AD patients and 8017 healthy controls were involved in this meta-analysis. Two common polymorphisms (rs708272 T>C and rs5882 A>G) in the CETP gene were assessed. Our meta-analysis results showed that CETP rs5882 A>G polymorphism might increase the risk of AD (A allele vs. G allele: odds ratio [OR]=1.11, 95% confidence interval [95% CI]=1.02-1.21, p=0.014; AA+AG vs. GG: OR=1.28, 95% CI=1.07-1.52, p=0.006; AA vs. GG: OR=1.32, 95% CI=1.10-1.70, p=0.003; AA vs. AG: OR=1.25, 95% CI=1.03-1.50, p=0.020; respectively). However, we found no correlations of CETP rs708272 T>C polymorphism with AD risk (all p>0.05). Subgroup analysis by ethnicity suggested positive associations between CETP rs5882 A>G polymorphism and an increased risk of AD among Caucasians (A allele vs. G allele: OR=1.10, 95% CI=1.01-1.21, p=0.014; AA+AG vs. GG: OR=1.34, 95% CI=1.06-1.69, p=0.015; AA vs. GG: OR=1.35, 95% CI=1.07-1.70, p=0.011; respectively), but not among Asians (all p>0.05). No associations were found between CETP rs708272 T>C polymorphism and AD risk among both Asians and Caucasians (all p>0.05). Our findings provide empirical evidence that CETP rs5882 A>G polymorphism may contribute to susceptibility to AD, especially among Caucasians. However, CETP rs708272 T>C polymorphism does not seem to be an important determinant in the pathogenesis of AD.