Meta-analysis on association between the ATP-binding cassette transporter A1 gene (ABCA1) and Alzheimer's disease.

Purpose: In the past decade, a number of case-control studies have been carried out to investigate the relationship between ABCA1 polymorphisms and Alzheimer's disease (AD). However, these studies have yielded contradictory results. To investigate this inconsistency, a meta-analysis was performed.

Methods: Databases including PubMed, Web of Science, EMBASE and CNKI were searched to find relevant studies. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of association.

Results: A total of 13 case-control studies, involving 6214 patients and 6034 controls for ABCA1 polymorphisms were included. In a combined analysis, the summary per-allele odds ratio for AD of the 219K was 1.03 (95% CI: 0.93-1.14, p=0.56). A meta-analysis of studies on the 883M and 1587K variant showed no significant overall association with AD, yielding a per-allele odds ratio of 1.10 (95% CI: 0.96-1.26, p=0.16), and 1.09 (95% CI: 0.97-1.24, p=0.16) respectively. Similar results were also found for heterozygous and homozygous. In the subgroup analysis by ethnicity, sample size, APOE status and onset type, no significant associations were found in almost all genetic models.

Conclusions: In summary, there was no significant association detected between ABCA1 R219K, I883M and R1587K polymorphisms and risk for AD.