Introduction:
Patients with advanced cirrhosis are susceptible to hyponatremia due to impaired kidney function. Recent studies have shown that hyponatremia can be an independent predictor of hepatic encephalopathy (HE) in these patients.

Aim:
The present study performed to evaluate the relationship between serum sodium concentration and HE in patients with cirrhosis.

Material and methods:
This cross-sectional study was conducted on 65 cirrhotic patients admitted to the internal ward of Shariati Hospital in Esfahan, Iran. Patients were divided into two groups based on serum sodium concentration: (1) hyponatremic patients with serum sodium less than 135 meq/L and (2) those with serum sodium not less than 135 meq/L. Groups were compared regarding demographic characteristics, causes of cirrhosis, diuretics consumption, prevalence of HE, and severity of cirrhosis assessed using MELD and Child–Pugh scores, as well as biochemical measurements.

Results:
Based on serum sodium levels, 21 patients (32.3%) had hyponatremia. Thirty (46.2%) individuals had HE. Comparing hyponatremic patients with those without low serum sodium, there were no statistically significant differences in gender, causes of cirrhosis, and MELD score between groups (P > 0.05); however, hyponatremic patients had more prevalence of HE (P < 0.001), diuretic intake (P < 0.001), lower levels of albumin (P = 0.003), and were older (P = 0.017). Severity of cirrhosis in patients with hyponatremia was mostly in groups B and C of Child–Pugh (P = 0.002).

Discussion:
In summary, HE is frequent in cirrhotic patients with hyponatremia.

Conclusions:
It is suggested to monitor serum sodium level in patients with cirrhosis to prevent HE and other complications, especially among those who are taking diuretics.