Protein Nutrition and Liver Disease after Jejunoileal Bypass for Morbid Obesity

A role for protein malnutrition in the pathogenesis of liver dysfunction after jejunoileal bypass was sought in 18 patients undergoing bypass surgery for obesity. Four months after operation, when weight loss was rapid, serum glutamic oxalacetic transaminase was elevated in 12 patients, and most had marked hepatic steatosis. Of the essential amino acids plasma valine, isoleucine, leucine, phenylalanine, threonine and lysine declined, as did the nonessential amino acids, alanine, citrulline, cystine, tyrosine, ornithine and arginine. Glycine and serine were elevated. This profile is typical of protein-calorie malnutrition. Twelve to 36 months after operation weight stabilized, transaminase was normal, and hepatic fat diminished. Concentrations of many amino acids returned toward normal though moderate depression of valine, isoleucine, leucine, lysine, tyrosine, ornithine and arginine persisted. Glycine remained elevated. Oral amino acid tolerance tests suggested that improved absorption accounted for the improved amino acid profiles. Thus, protein malnutrition contributes to hepatic dysfunction. Postoperative amino acid supplementation may be beneficial. (N Engl J Med 290:921–926, 1974)