Genetic polymorphism of apolipoprotein A5 gene and susceptibility to type 2 diabetes mellitus: a meta-analysis of 15,137 subjects.

Background: Several studies have investigated whether the polymorphism in the apolipoprotein A5 (APOA5) is associated with type 2 diabetes mellitus (T2DM) risk. However, those studies have produced inconsistent results. The purpose of this study was to investigate whether the APOA5 -1131T/C polymorphism (rs662799) confers significant susceptibility to T2DM using a meta-analysis.

Methods: PubMed, Embase, Web of Science, Cochrane database, CBMdisc, CNKI and Google Scholar were searched to get the genetic association studies. All statistical analyses were done with Stata 11.0.

Results: A total of 19 studies included 4,767 T2DM cases and 10,370 controls (four studies involving 555 T2DM cases and 2958 controls were performed among Europeans and 15 studies involving 4212 T2DM cases and 7412 controls were performed among Asians) were combined showing significant association between the APOA5 -1131T/C polymorphism and T2DM risk (for C allele vs. T allele: OR = 1.28, 95% CI = 1.17-1.40, p<0.00001; for C/C vs. T/T: OR = 1.57, 95% CI = 1.35-1.83, p<0.00001; for C/C vs. T/C+T/T: OR = 1.36, 95% CI = 1.18-1.57, p<0.0001; for C/C+T/C vs. T/T: OR = 1.32, 95% CI = 1.16-1.51, p<0.0001). In the subgroup analysis by ethnicity, significant association was also found among Asians (for C allele vs. T allele: OR = 1.31, 95% CI = 1.22-1.40, p<0.00001; for C/C vs. T/T: OR = 1.61, 95% CI = 1.38-1.88, p<0.00001; for C/C vs. T/C+T/T: OR = 1.39, 95% CI = 1.20-1.61, p<0.0001; for C/C+T/C vs. T/T: OR = 1.42, 95% CI = 1.25-1.62, p<0.00001). However, no significant association was found between the APOA5 -1131T/C polymorphism and T2DM risk among Europeans.

Conclusions: The present meta-analysis suggests that the APOA5 -1131T/C polymorphism is associated with an increased T2DM risk in Asian population.