Serum sodium concentration is associated with increased risk of mortality in patients with compensated liver cirrhosis

Abstract

Although hyponatremia is associated with a poor prognosis in liver cirrhosis, little is known about the clinical significance of serum sodium concentration in cirrhosis in Japan. This study investigated associations of mortality in Japanese cirrhosis patients taking conventional diuretics with serum sodium concentration and other clinical characteristics. A total of 171 consecutive patients with cirrhosis who were taking diuretic medication were enrolled retrospectively. We determined the prevalence of low serum sodium concentration and searched for associations with age, sex, etiology, complications of cirrhosis, liver function tests and Model for End-Stage Liver Disease (MELD) and MELD-Na scores. The predictive ability of sodium level on mortality was also investigated. Median serum sodium concentration was 139 mEq/L (interquartile range, 137-141). Only eight of 171 (4.7%) patients had low serum sodium (<130 mEq/L). Median MELD-Na score was 10.5 (interquartile range, 8.0-14.3). Cumulative survival rates were significantly lower in patients with Na of less than 139 mEq/L or MELD-Na score of 10.5 or more (log-rank test, P = 0.017 and P = 0.0002, respectively). Several liver function tests, MELD and MELD-Na scores, and the incidence of ascites were all significantly associated with patients having Na of less than 139 mEq/L. Serum sodium concentration below 139 mEq/L and MELD-Na score above 10.5 may be predictive markers for mortality in patients with cirrhosis despite being within normal ranges. These markers may help to better assess and manage the prognosis of patients with cirrhosis in Japan.