Association between ApoE Polymorphism and Type 2 Diabetes: A Meta-Analysis of 59 Studies.

ABSTRACT

OBJECTIVE: To identify the important risk factors for type 2 Diabetes Mellitus (T2DM) and develop effective strategies to address the problem of T2DM. Our study aimed to evaluate the association between apolipoprotein E (ApoE) genetic polymorphism and type 2 diabetes, and to provide clues for the etiology of T2DM. METHODS: Based on the criteria of inclusion and exclusion, we extracted, pooled, analyzed and assessed the case-control studies of ApoE polymorphism and T2DM published in PubMed, Web of Science, Medline, WanFang, VIP, and CNKI databases by R soft-ware (version 3.4.3). We used Random-effect models when heterogeneity was present in between-study, and fixed-effect models otherwise. RESULTS: We had 59 studies covering 6,872 cases with T2DM and 8,250 controls, and compared the alleles and genotypes of ApoE between cases and controls. When we conducted a comparison between ApoE ε4 and ε3 alleles, we produced a pooled OR of 1.18 (95% CI 1.09-1.28; P < 0.001). ApoE ε2/ε2 genotype displayed a possible association with T2DM (OR = 1.46; 95% CI 1.11-1.93; P = 0.007), ε3/ε4 genotype showed a 1.11-fold risk (OR = 1.11; 95% CI 1.01-1.22; P = 0.039) and ε4/ε4 genotype had a 1.71-fold risk of developing T2DM (OR = 1.71; 95% CI 1.33-2.19; P < 0.001) when they were compared with ε3/ε3 genotype. CONCLUSION: There is an association between ApoE polymorphism and T2DM allele ε4 and genotypes (ε2/ε2, ε3/ε4, and ε4/ε4) are associated with the increased risk for the development of T2DM, and they may be risk factors for T2DM.