The Association between Volume Status and Plasma Brain Natriuretic Peptide in Hemodialysis Patients

Park, Moo Yong; Choi, Soo Jeong; Kim, Jin Kuk; Hwang, Seung Duk

Abstract

BACKGOUND: Brain natriuretic peptide (BNP, b-type natriuretic peptide) is released into circulation in response to ventricular dilatation and pressure overload. In the general population, the plasma concentration of BNP are useful to predict left ventricular hypertrophy (LVH) and LV systolic dysfunction. Whether these cardiac hormone have correlation with hydration state in hemodialysis (HD) patients is unclear.
METHODS
We measured the pre-HD and post-HD plasma BNP level in 36 HD patients and evaluated their cardiac state with echocardiography and their fluid overload state with chest X-ray. We checked intradialytic HD weight gain and ultrafiltration volume, as a marker of hydration status.
RESULTS
Mean pre-HD BNP level of 36 HD patients was 545.79 pg/mL and mean post-HD BNP level was 503.64 pg/mL. And mean BNP level of 10 healthy adults was 13.46 pg/mL. In 29 patients, BNP level was decreased after HD. But BNP levels of 7 patients were paradoxically increased after HD. Ultrafiltration volume was smaller in these patients (p=0.03) and post-HD blood pressure was higher (p=0.048). Plasma BNP level was significantly increased in 17 patients with pulmonary congestion or cadiomegaly (p=0.005). But pre-HD BNP level did not correlated with pre-HD blood pressure. BNP reduction ratio was higher in larger ultrafiltration (UF) volume (>3 L) group than in smaller UF volume group (p=0.02). There were no difference in BNP levels between DM and non-DM group.
CONCLUSION
Plasma BNP level seems to be a limited but useful, marker of volume status in HD patients.