Serum zinc levels in hepatic encephalopathy.

BACKGROUND

Zinc is essential for various metabolic processes of the body. Since serum zinc levels are lowered in liver diseases, it has been postulated to be a precipitating factor for hepatic encephalopathy.

METHODS

We prospectively studied serum zinc levels in consecutive patients with fulminant hepatic failure, subacute hepatic failure and chronic liver disease with encephalopathy. Serum zinc levels were correlated with various clinical and biochemical parameters and final outcome of patients. Serum zinc levels were estimated by atomic absorption spectrometry at admission and also 24 hours after recovery in survivors.

RESULTS

Of the 55 patients (age 17-65 years, 35 men) studied, 30 had acute, 5 subacute and 20 chronic liver disease. Patients with hepatic encephalopathy had significantly lower serum zinc levels as compared to 20 age and sex matched controls. High serum bilirubin levels and prothrombin time showed inverse relationship with serum zinc levels. There was no relationship of serum zinc levels with age, sex, grade and duration of encephalopathy, liver size, ascites or splenomegaly.

CONCLUSIONS

Hepatic encephalopathy is associated with low serum zinc levels. Recovery occurred in 17 patients despite persisting low serum zinc levels. Serum bilirubin > 23 mg/dL and prothrombin time prolongation > 12 seconds above control have inverse correlation with serum zinc level.