Association between APOC1 Polymorphism and Alzheimer's Disease: A Case-Control Study and Meta-Analysis

Background: Previous association studies examining the relationship between the APOC1 polymorphism and susceptibility to Alzheimer's disease (AD) have shown conflicting results, and it is not clear if an APOC1 variant acts as a genetic risk factor in AD etiology across multiple populations. Methods: To confirm the risk association between APOC1 and AD, we designed a case-control study and also performed a meta-analysis of previously published studies. Results: Seventy-nine patients with AD and one hundred fifty-six unrelated controls were included in case-control study. No association was found between the variation of APOC1 and AD in stage 1 of our study. However, our meta-analysis pooled a total of 2092 AD patients and 2685 controls. The APOC1 rs11568822 polymorphism was associated with increased AD risk in Caucasians, Asians and Caribbean Hispanics, but not in African Americans. APOE epsilon 4 carriers harboring the APOC1 insertion allele, were more prevalent in AD patients than controls (chi(2) = 119.46, OR = 2.79, 95% CI = 2.31-3.36, P<0.01). Conclusions: The APOC1 insertion allele, in combination with APOE epsilon 4, likely serves as a potential risk factor for developing AD.