NPPB and diabetes mellitus: RCT: randomized controlled trial; T2DM: type 2 diabetes mellitus; HF: heart failure; LVEF: left ventricular ejection fraction; NT-proBNP: N-terminal pro-brain natriuretic peptide; NYHA: New York Heart Association; eGFR: estimated glomerular filtration rate; LVEDV: left ventricular end-diastolic volume; ESV: end-systolic volume.