Sodium handling is associated with liver function impairment and renin-aldosterone axis activity in patients with preascitic cirrhosis without hyponatremia

Background: In cirrhotic patients awaiting liver transplantation, serum sodium concentration is related to prognosis. However, abnormalities in sodium homeostasis are evident even in the early preascitic stage of cirrhosis. We aimed to investigate whether parameters of renal sodium handling (serum sodium, urinary sodium and fractional exertion of sodium (FeNa%) correlate with markers of liver function and renin-aldosterone axis activity in patients with preascitic cirrhosis without hyponatremia.

Methods: Patients with preascitic cirrhosis without hyponatremia underwent routine blood and urine laboratory tests, including markers of liver function impairment and sodium homeostasis.

Results: Thirty eight cirrhotic patients (22 men) with mean age of 57.3±12.2 (SD) years were included. Twenty six and twelve patients were at Child-Pugh stage A and B cirrhosis respectively. Eighteen patients had a Model for End-stage Liver Disease (MELD) score of ≤9 and twenty had MELD >9. Serum sodium was found to differ significantly between Child-Pugh stage A and B cirrhotics (mean 142.8±2.0 mmol/L vs. 140.5±3.3 mmol/L, p<0.05). Serum sodium was also found to differ significantly between patients with MELD score ≤9 and >9 (mean 143.3±2.0 mmol/L vs. 140.9±2.8 mmol/L, respectively, p<0.01). Serum sodium correlated negatively with the international normalized ratio (INR) (r=-0.51, p<0.01), aldosterone (r=-0.40, p<0.05), Child-Pugh and MELD scores (r=-0.34, p<0.05 and r=-0.45, p<0.05 respectively). FeNa% correlated negatively with renin and aldosterone (r=-0.56, p<0.001 and r=-0.50, p<0.01 respectively).

Conclusion: Serum sodium concentration is a good surrogate marker of liver function impairment not only in late-stage liver cirrhosis before transplantation but also in the early preascitic stage.