Natriuretic peptides in chronic kidney disease and during renal replacement therapy: an update.

Natriuretic peptides play a major role in sodium and body volume homeostasis in patients with adequate kidney function. Circulating B-type natriuretic peptide (BNP) and its amino-terminal fragment NT-proBNP provide important information on cardiac dysfunction, hypervolemia, and risk for hospitalization or death even in patients with severe impairment of kidney function. NT-proBNP acts also as significant independent predictor of progression of chronic kidney disease (CKD). Differences in elimination and degradation as well as molecular weight and half-life between BNP and NT-proBNP are responsible for different plasma levels, different membrane-dependent removal during hemodialysis, and different diagnostic and prognostic power to predict morbidity and mortality in patients at different stages of CKD and in those on hemodialysis or peritoneal dialysis. Serial estimations of natriuretic peptides will help in the identification of potential complications in CKD patients with or without renal replacement therapies and probably improve outcome of these patients.