Association between patatin-like phospholipase domain-containing 3 gene (PNPLA3) polymorphism and overweight/obesity: a meta-analysis

Background: The patatin-like phospholipase domain-containing 3 (PNPLA3, rs738409) gene polymorphism has been implicated in susceptibility to overweight and obesity, but study results are still controversial. Objective: The present meta-analysis was performed to evaluate the relationship between PNPLA3 polymorphism and overweight/obesity among adults, children or adolescents. Methods: A literature search was conducted in PubMed, Medline, Embase, EBSCO and Web of Science databases up to December 2015. Statistical analysis of qualified studies was performed with Stata 12.0 software. Results: Ten studies comprising 14,220 participants (7,120 cases and 7,100 controls) were included in the analysis. A total of 6,963 patients had the rs738409 GG+CG genotype, whereas 7,257 patients had the CC genotype. No evidence of an association between the rs738409 polymorphism and overweight/obesity risk was observed in incorporated patients (OR = 0.929, 95% CI: 0.863-1.000; P = 0.051). Ethnicity stratification analyses revealed that the G allele (GG+CG) did not show an unfavorable effect compared to CC genotype in Caucasians (OR = 0.960, 95% CI: 0.885-1.042; P = 0.327) and Asians (OR = 0.707, 95% CI: 0.575-0.869; P = 0.001). Also, no significant association was found between the PNPLA3 gene polymorphism and the risk of overweight/obesity when the population was stratified by age (children or adolescents, adults) and non-alcoholic fatty liver disease (NAFLD). Conclusion: Our meta-analysis revealed that the PNPLA3 gene rs738409 polymorphism was not associated with an enhanced risk of overweight/obesity among Caucasians, neither adults nor children or adolescents. This conclusion accredits confirmation by more case-control and cohort studies.