Fig. 1.

Mediation analysis in obese children for HIF3A SNP, methylation and plasma ALT. ALT: alanine aminotransferase; HIF3A: Hypoxia Inducible Factor 3 Alpha Subunit; SNP: Single Nucleotide Polymorphism. In order to distinguish among the three linear regression models constructed in the mediation analysis, the coefficients in the model were represented by ‘a’,’ b’, ‘c’ and ‘c _r ’. The first regression model used ‘c’ as the coefficient of SNP in association with ALT; the second model used ‘a’ as the coefficient of SNP in association with methylation; the third model put methylation and SNP as independent variables simultaneously, and used ‘b’ and ‘c _r ’ as the coefficients in association with ALT. ‘X’, ‘Y’ and ‘M’ were used to represent the independent variable, the dependent variable and the mediator in the mediation analysis model