FGF21 (AUC = 0.70, 95% CI: 0.60−0.79) and NT-proBNP (AUC = 0.73, 95% CI: 0.63–0.82) demonstrated significant predictive value to discriminate T2DM patients with advanced HF from those with mild HF. Here, FGF21 is linked to type 2 diabetes mellitus.