FGF21 and type 2 diabetes mellitus: Futhermore, an evidently higher of serum FGF21 levels was also observed in these T2DM patients with both CAS and HP as compared to those with one of these VDs [550.5 (312.6-711.3) vs. 305.9 (177.2-508.4) pg/mL, p < 0.001] (multiple comparisons’ data not shown) (Table 2; Fig. 1), suggesting that elevated serum FGF21 levels during diabetes may be related to the progress of VDs.