Notably, the multivariate analysis showed that T2DM was an independent predictor of the lowered peak VO2 in both the CHF patients with non-reduced LVEF and those with reduced LVEF after the adjustment for age-squared, gender, hemoglobin, eGFR, LVEF, and log BNP, all of which may influence exercise capacity. This evidence concerns the gene NPPB and type 2 diabetes mellitus.