The Relationship Between Plasma B-type Natriuretic Peptide Level And Liver Function In Patients With Cirrhosis

The systemic circulation in patients with cirrhosis is hyperdynamic with an increased cardiac output and heart rate and a reduced systemic vascular resistance as the most pronounced alterations. And the subsequent activation of sympathetic nervous system and renin-angiotensin- aldosterone system (RAAS) may aggravate heart afterload and preload leading to latent cardiac dysfunction. B-type or brain natriuretic peptide (BNP), a cardiac hormone belonging to the natriuretic peptide family ( NPF) play a major role in the regulation of volume homeostasis. They increase diuresis and natriuresis, relax vascular smooth muscle and inhibit the sympathetic nervous system and the RAAS. These physiologic effects result in decreased water-sodium retention, causing arterial and venous dilation and leading to reduce blood pressure and ventricular preload so as to lessen heart failure. Therefor BNP can inhibit haemodynamic and neuroendocrine changes in patients withcirrhosis. Previous studies have shown increased plasma levels of BNP in some patients with cirrhosis. But it is rare in our country. The objective of this study is to investigate the associations between the plasma BNP level and Child Pugh grade, curative effect as well as prognosis of cirrhosis.Materials and MethodsPlasma BNP levels, liver and kidney function and QTc intervals of 50 patients with cirrhosis were measured and evaluated. Plasma BNP levels of the patients with cirrhosis were compared among different Child Pugh grade groups and with those of controls. Correlation analysis between the plasma BNP level and the Child-pugh score, the serum albumin level as well as QTc interval were made. Plasma BNP levels in different groups of curative effect and QTc intervals between study group and controls were evaluated by t-test.ResultsPlasma BNP levels of study group were significantly higher than those of controls (P<0.01). What is more, the associations between plasma BNP levels of the Child A group and those of controls are borderline significant (P=0.092). The plasma BNP concentrations of child B and child C groups were significantly higher than those of controls (P<0.01). The plasma BNP levels were elevated according to the grade of Child-pugh classification. And the associations among these three groups are significant (P<0.05). Furthermore, the plasma concentrations of BNPwere significantly related to Child-pugh score (P<0.01) and inversely related to serum albumin levels (P<0.01) while exhibit no correlation to QTc intervals. Liver function of 37 patients was improved after treatment while 13 patients showed no improvement, and the plasma BNP levels between these two groups demonstrated significant difference (P<0.01) . QTc interval was longer in patients with cirrhosis than in controls ( P<0 .01) and prolonged (>440 ms) in 20 patients (40%) and 1 controls (2.70%, PO.01).ConclusionThe elevated plasma BNP levels in patients with cirrhosis may reflect the severity of disease and help evaluate the liver function.