Figure 2.

Brain natriuretic peptides in patients with CKD. In response to increased stretch or tension, left ventricular myocytes release brain natriuretic peptide (BNP) and N-terminal-pro-BNP (NT-pro-BNP) from precursors. BNP is an active molecule with a short plasma half-life and is degraded in the circulation by enzymatic action. NT-pro-BNP is the inactive form of BNP, with a longer half-life. It is primarily cleared by the kidneys. Reduced eGFR correlates to a greater extent with elevated plasma NT-pro-BNP than to BNP levels. Increased NT-pro-BNP/BNP ratio correlates with advancing CKD stages, especially if the eGFR is <30 ml/min per 1.73 m². However, both BNP and NT-pro-BNP are associated with surrogate and hard clinical outcomes in asymptomatic patients with CKD.