Association between serum sodium level and severity of complications of cirrhosis

Abstract

Background: Dilutional hyponatremia associated with liver cirrhosis is caused by impaired free water clearance. According to several recent studies, hyponatremia occurring as a result of a reduced solute-free water clearance was a key prognostic factor in patients with liver cirrhosis when hyponatremia was incorporated into the MELD score. However few studies have evaluated the association between serum sodium levels and the occurrence and severity of complications due to liver cirrhosis. Aim: To evaluate the association between serum sodium levels and presence and severity of cirrhotic complications. Methods: Data of 250 inpatients with cirrhotic complications were collected retrospectively. Based on the serum sodium concentration measured at the time of admission, patients were divided into three groups: serum sodium ≤130 mmol/L, serum sodium between 131 and 135 mmol/L, and serum sodium ≥136 mmol/L. The occurrence and severity of various complications of cirrhosis in the three groups were compared and stasticallyanalysed. Results: The prevalence of dilutionalhyponatremia classified as serum sodium concentrations of ≤135 mmol/ was 56%. 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). Sodium levels less than 130 mmol/L was associated with the occurence of massive ascites (P =0.003), grade III or higher hepatic encephalopathy (P =0.02), spontaneous bacterial peritonitis (P =0.001), and hepatic hydrothorax (P=0.004). Conclusion: Hyponatremia, especially serum levels <or=130 mmol/L, is associated with the existence of severe complications associated with liver cirrhosis.