The Association Between the Serum Sodium Level and the Severity of Complications in Liver Cirrhosis

BACKGROUND/AIMS Dilutional hyponatremia associated with liver cirrhosis is caused by impaired free water clearance. Several studies have shown that serum sodium levels correlate with survival in cirrhotic patients. Little is known, however, regarding the relationship between the degree of dilutional hyponatremia and development of cirrhotic complications. The aim of this study was to evaluate the association between the serum sodium level and the severity of complications in liver cirrhosis. METHODS Data of inpatients with cirrhotic complications were collected retrospectively. The serum sodium levels and severity of complications of 188 inpatients were analyzed. RESULTS The prevalence of dilutional hyponatremia, classified as serum sodium concentrations of <or=135 mmol/L, <or=130 mmol/L, and <or=125 mmol/L, were 20.8%, 14.9%, and 12.2%, respectively. The serum sodium level was strongly associated with the severity of liver function impairment as assessed by Child-Pugh and MELD scores (p<0.0001). Even a mild hyponatremia with a serum sodium concentration of 131-135 mmol/L was associated with severe complications. Sodium levels less than 130 mmol/L indicated the existence of massive ascites (OR, 2.685; CI, 1.316-5.477; p=0.007), grade III or higher hepatic encephalopathy (OR, 5.891; CI, 1.490-23.300; p=0.011), spontaneous bacterial peritonitis (OR, 2.562; CI, 1.162-5.653; p=0.020), and hepatic hydrothorax (OR, 5.723; CI, 1.889-17.336; p=0.002). CONCLUSIONS Hyponatremia, especially serum levels <or=130 mmol/L, may indicate the existence of severe complications associated with liver cirrhosis.