NPPB and heart failure: In addition, serum NE and BNP levels, markers of heart failure progression, were higher in the METH group than in the control group (NE, ng/mL: 564 ± 23 vs. 324 ± 21, p < 0.01; BNP, ng/mL: 283 ± 19 vs. 118 ± 14, p < 0.01) and lower in the DAPA + METH group than in the METH group (NE, ng/mL: 439 ± 20 vs. 564 ± 23, p < 0.01; BNP, ng/mL: 189 ± 23 vs. 283 ± 19, p < 0.01) (Figures 2D,E).