Normal protein diet for episodic hepatic encephalopathy: results of a randomized study

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Abstract

Background/Aims

Protein-restricted diets are usually prescribed for cirrhotic patients with hepatic encephalopathy. However, protein restriction may worsen the nutritional status without resulting in an improvement of hepatic encephalopathy. We designed a study to assess the effects of the amount of protein in the diet on the evolution of episodic hepatic encephalopathy.

Methods

Cirrhotics admitted to the hospital because of an episode of encephalopathy (n=30) were randomized to receive a low-protein diet with progressive increments or a normal protein diet for 14 days, in addition to standard measures to treat hepatic encephalopathy. Protein synthesis and breakdown were studied at day 2 and day 14 with the glycine-N15 infusion method.

Results

The outcome of hepatic encephalopathy was not significantly different between both groups of treatment. Protein synthesis was similar for low and normal protein diet, but those of the low-protein diet group showed higher protein breakdown.

Conclusions

Diets with a normal content of protein, which are metabolically more adequate, can be administered safely to cirrhotic patients with episodic hepatic encephalopathy. Restriction of the content of protein of the diet does not appear to have any beneficial effect for cirrhotic patients during an episode of encephalopathy.

Introduction

Hepatic encephalopathy is a common complication of cirrhosis that accounts for a large number of hospital admissions. Treatment of encephalopathy is based on the correction of precipitating factors and administration of drugs to decrease intestinal generation of ammonia [1]. Protein restriction has classically been considered a mainstay of treatment in hepatic encephalopathy [2]. However, this recommendation has been contested due to the lack of scientific proof [3]. The inclusion of protein restriction as a component of therapy for hepatic encephalopathy has been based on old uncontrolled observations, most of them anecdotal [4]. There have been no prior studies of cirrhotic patients admitted to the hospital because of an episode of hepatic encephalopathy in which patients were randomized to receive different amounts of protein in the diet.

Cirrhotic patients exhibit increased protein requirements to achieve balanced nitrogen metabolism [5]. In these patients, malnutrition has been associated with decreased survival [6]. Thus, limiting the amount of protein may worsen their clinical condition. Indeed, in severe alcoholic liver disease, high-protein diets may result in a better outcome [7]. These data have led the European Society for Parenteral and Enteral Nutrition (ESPEN) to acknowledge the importance that an adequate amount of protein may have on the outcome of cirrhotic patients [8]. The current recommendation is to limit protein restriction during an episode of hepatic encephalopathy to a moderate intake (0.5 g/kg/day) and to shortly thereafter return to a normal-to-high protein intake (1–1.5 g/kg/day). For all these reasons we designed a randomized study to assess the effects of the amount of protein in the diet on the evolution of the mental state during an episode of hepatic encephalopathy.

Section snippets

Participants

We selected our patients from subjects presenting to the emergency room of Hospital Vall d'Hebron, Barcelona, Spain. Patients were considered eligible if they were cirrhotic patients showing clear signs of episodic hepatic encephalopathy. The diagnosis of cirrhosis was based on prior liver biopsy or on a combination of clinical and imaging data demonstrating liver failure, portal hypertension and cirrhotic appearance of the liver. Episodic hepatic encephalopathy was diagnosed on the basis of a

Results

The enrolment period started on March 2001 and finished on November 2002. The flow of participants through each stage of the trial is shown in Fig. 1. During this period 62 patients were considered eligible; of them, 30 patients were randomized. The reasons for exclusion were: acute alcoholic hepatitis (n=6), gastrointestinal bleeding (n=10), hepatocellular carcinoma (n=3), previous intake of benzodiacepines (n=2), neurological comorbidities (n=3), respiratory failure requiring ventilatory

Discussion

The main finding of this study is that there is no major benefit of limiting protein intake on the evolution of episodic hepatic encephalopathy, while the administration of a low-protein diet exacerbates protein breakdown. In the short term, protein restriction did not have major consequences on liver function or plasma ammonia, as indicated by the evolution of blood tests. However, favoring protein breakdown for more prolonged periods may have detrimental consequences on the nutritional status

Acknowledgements

Study supported by FIS 99/809 and Instituto de Salud Carlos III (projects G03/155 and C03/02). Dr. Francisco Castro was supported by an educational grant of Instituto Danone.

References (27)

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