AUTHOR=Luo Jian-Quan , Ren Huan , Banh Hoan Linh , Liu Mou-Ze , Xu Ping , Fang Ping-Fei , Xiang Da-Xiong 

TITLE=The Associations between Apolipoprotein E Gene Epsilon2/Epsilon3/Epsilon4 Polymorphisms and the Risk of Coronary Artery Disease in Patients with Type 2 Diabetes Mellitus

JOURNAL=Frontiers in Physiology

VOLUME=8

YEAR=2017

URL=https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2017.01031

DOI=10.3389/fphys.2017.01031

ISSN=1664-042X

ABSTRACT=<p><bold>Background and Objective:</bold> Apolipoprotein E (APOE) plays important roles in lipoprotein metabolism and cardiovascular disease. Evidence suggests the <italic>APOE</italic> gene epsilon2/epsilon3/epsilon4 (ε2/ε3/ε4) polymorphisms might be associated with the susceptibility of coronary artery disease (CAD) in patients with type 2 diabetes mellitus (T2DM). However, no clear consensus has yet been established. Therefore, the aim of this meta-analysis is to provide a precise conclusion on the potential association between <italic>APOE</italic> ε2/ε3/ε4 polymorphisms and the risk of CAD in patients with T2DM based on case-control studies.</p><p><bold>Methods:</bold> Pubmed, Embase, Chinese National Knowledge Infrastructure (CNKI), and Wanfang databases were searched for all relevant studies prior to August 2017 in English and Chinese language. The pooled odds ratios (ORs) and their corresponding 95% confidence intervals (CIs) were used to assess the strength of the relationships. The between-study heterogeneity was evaluated by Cochran's Q-test and the I<sup>2</sup> index to adopt fixed- or random- effect models.</p><p><bold>Results:</bold> A total of 13 studies were eligible for inclusion. There was evidence for significant associations between <italic>APOE</italic> ε4 mutation and the risk of CAD in patients with T2DM (for ε3/ε4 vs. ε3/ε3: OR = 1.69, 95% CI = 1.38–2.08, <italic>P</italic> &lt; 0.001; for ε4/ε4 vs. ε3/ε3: OR = 2.72, 95% CI = 1.61–4.60, <italic>P</italic> &lt; 0.001; for ε4/ε4+ε3/ε4 vs. ε3/ε3: OR = 1.83, 95% CI = 1.52–2.22, <italic>P</italic> &lt; 0.001; for ε4 allele vs. ε3 allele: OR = 1.64, 95% CI = 1.40–1.94, <italic>P</italic> &lt; 0.001). In contrast, no significant associations were found in genetic model of <italic>APOE</italic> ε2 mutation (for ε2/ε2 vs. ε3/ε3: OR = 1.67, 95% CI = 0.90–3.09, <italic>P</italic> = 0.104; for ε2/ε3 vs. ε3/ε3: OR = 1.18, 95% CI = 0.93–1.51, <italic>P</italic> = 0.175; for ε2/ε2+ε2/ε3 vs. ε3/ε3: OR = 1.26, 95% CI = 0.88–1.82, <italic>P</italic> = 0.212; for ε2 allele vs. ε3 allele: OR = 1.34, 95% CI = 0.98–1.84, <italic>P</italic> = 0.07).</p><p><bold>Conclusions:</bold> The <italic>APOE</italic> gene ε4 mutation is associated with an increased risk of CAD in patients with T2DM, while the ε2 variation has null association with this disease.</p>