FGF21 and diabetes mellitus: In the case of the serum FGF21 levels, however, there were no statistically significant differences across the three groups [T2D-R: 540.55 pg/mL, T2D-NoR: 842.24 pg/mL, No-T2D: 393.28 pg/mL, (Kruskal-Wallis Chi Square Test: 4.39, P-value = 0.1111)] despite the fact that the two diabetes groups had higher FGF21 serum levels.