Notably, we found that FGF21/adiponectin ratio provided an improvement in diabetes risk prediction, compared with the use of FGF21 (NRI = 23.5%, p = 0.002; IDI = 0.3%, p = 0.014) or adiponectin (NRI = 18.3%, p = 0.016; IDI = 0.3%, p = 0.161) alone. This evidence concerns the gene FGF21 and diabetes mellitus.