C-type natriuretic peptide expression in patients with chronic heart failure: effects of aerobic training

BACKGROUND: C-type natriuretic peptide (CNP) is structurally related to cardiac natriuretic peptides and is currently considered as an endothelium-derived hyperpolarizing factor. Endothelial dysfunction, commonly observed in chronic heart failure (HF) patients is positively affected by physical training. METHODS: To evaluate the effect of aerobic physical training on the expression of CNP, 90 HF patients on optimal pharmacological treatment (age 62+/-2 years, mean+/-SEM), randomly assigned in a 3 : 1 ratio to either control group (C, 19 patients) or home-based aerobic exercise-training program group (T, 71 patients), completed the protocol. Plasma assay of CNP, brain natriuretic peptide or B-type natriuretic peptide (BNP), and norepinephrine; echocardiogram; and cardiopulmonary-stress test were performed in all patients at enrollment and after 9 months. RESULTS: At baseline, in both groups, CNP plasma level was significantly related to BNP (R=0.50), ejection fraction (R=0.43), and peak oxygen uptake (VO2, R=0.43, all P<0.001). After 9 months, trained patients showed an improvement in peak VO2 (P<0.001) and ejection fraction (P<0.05), whereas norepinephrine (P<0.05), BNP (P<0.001), and CNP (P<0.001) decreased. No changes occurred in group C. In group T, the decrease in CNP was significantly related to the increase in peak VO2 (R=0.31, P<0.01), and the relation between CNP and BNP was preserved at the end of the program (R=0.41, P<0.001). CONCLUSION: Clinical and functional improvement after physical training in HF patients is associated with a decrease in adrenergic activation and in both CNP and BNP concentration. Changes in CNP plasma concentration after physical training might reflect an improvement in endothelial function.