NPPB and type 2 diabetes mellitus: N-terminal prohormone brain natriuretic peptide (NT-proBNP) and age were most commonly included (n = 11 studies each), followed by T2DM and male sex (n = 10 studies each), systolic blood pressure (SBP) (n = 9 studies), blood urine nitrogen (BUN) and creatinine (n = 8 studies each), heart rate and left ventricular EF (n = 7 studies), sodium, body mass index (BMI), and New York Heart Association (NYHA) class (n = 6 studies each) (Fig 2).