Association of the NQO1 C609T polymorphism with Alzheimer's disease in Chinese populations: a meta-analysis.

Several molecular genetics studies have investigated the association of NQO1 C609T polymorphism with Alzheimer's disease (AD) susceptibility in Chinese populations; however, the findings are inconclusive. To investigate the association, we performed the present meta-analysis of 5 case-control studies (including 735 AD cases and 828 controls). We searched literature from PubMed, Embase, HuGNet and CNKI databases for eligible articles that evaluated the association between NQO1 C609T polymorphism and AD risk. We used odds ratios (ORs) with 95% confidence intervals (CIs) to evaluate the strength of the association. Overall, C609T polymorphism was significantly associated with an increased AD risk (homozygote: OR = 1.87, 95% CI = 1.39-2.51, P = 0.000; heterozygote: OR = 1.93, 95% CI = 1.22-3.06, P = 0.019; dominant: OR = 1.97, 95% CI = 1.25-3.12, P = 0.004). When stratified by source of control, significant results were observed in subjects of population-based (PB), whereas no increased risk was observed among the hospital-based (HB). When stratified by APOEϵ4 carrier status, no effect of the NQO1 C609T polymorphism was seen in subjects of APOEϵ4 carriers and APOEϵ4 non-carriers. In conclusion, our results showed that NQO1 C609T polymorphism increases the risk of AD in Chinese populations. Larger studies with different ethnic populations are required to validate our findings.