Association of apolipoprotein C3 polymorphisms with non-alcoholic fatty liver disease: an updated meta-analysis

Background The relationships between gene polymorphisms of apolipoprotein C3 (APOC3) and risk of non-alcoholic fatty liver disease (NAFLD) have been investigated, however, their findings were inconclusive. The aim of this meta-analysis is to evaluate the effects of APOC3 promoter region polymorphisms (-455T/C and − 482C/T) on the susceptibility to NAFLD. Methods A comprehensive literature search was carried out with electronic databases including MEDLINE, EMBASE, Web of Science, and Google Scholar to identify eligible studies up to June 2019. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to assess the combined effect sizes. The level of heterogeneity, sensitivity, subgroup, and publication bias analyses were subsequently conducted. Results This meta-analysis included seven studies, containing 1,318 NAFLD cases and 1,691 controls fulfilling the inclusion and exclusion criteria. The pooled analysis showed significant associations between APOC3 -455T/C polymorphism and risk of NAFLD in allelic model (OR = 1.33) and recessive model (OR = 1.67), but not in the dominant model. When stratified by ethnicity, the polymorphism − 455T/C was found to be significantly associated with risk of NAFLD in the Caucasian population, but not in the Asian population. No association was evident between the polymorphism − 482C/T and risk of NAFLD. Conclusions Our findings suggest that APOC3 promoter region polymorphism − 455T/C may associate with risk of NAFLD in Caucasian population. Further studies with other functional polymorphisms are helpful to discover the effects of APOC3 gene on the development of NAFLD.