GPT and type 2 diabetes mellitus: Yan Liu et al. [7,8] showed that the concentration of serum RA determined by enzyme-linked immunosorbent assay (ELISA) was significantly lower in T2DM subjects than in normal glucose tolerance subjects; furthermore, it was inversely associated with ALT, AST, GGT, total cholesterol (TC), and TG, which are traditionally considered T2DM risk factors.