title: Randomized, controlled study evaluating effects of branched chain amino acids and alpha-ketoisocaproate on protein metabolism after surgery.
abstract: The effect of nutritional supplementation with branched chain amino acids or the ketoacid alpha-ketoisocaproate on protein metabolism after surgery was studied in 24 patients with gastrointestinal cancer. They were randomized to receive one of three nutritional regimens. All patients received a balanced amino acid solution and group 1 (n = 8) received no further supplements, group 2 (n = 8) received supplementation with alpha-ketoisocaproate (17 g day-1) and group 3 (n = 8) received a branched chain solution including leucine, isoleucine and valine, corresponding to 3.3 g nitrogen day-1. Plasma albumin, prealbumin, fibronectin and serum urea concentrations, nitrogen balance and 3-methylhistidine release from the leg and its excretion in the urine were measured. Albumin and prealbumin concentrations fell after surgery in all groups, and fibronectin levels fell in group 2 (P less than 0.001). In group 2 there was also a significant increase in serum urea concentration after operation (P less than 0.05). Cumulative nitrogen balance after 3 days was -5.6 g (group 1), -3.8 g (group 2) and -1.7 g (group 3). The release of 3-methylhistidine (nmol 100 g-1 min-1) from the leg after operation, following an overnight fast, was -0.42 (group 1), -0.51 (group 2) and -0.66 (group 3). During infusion the release was -0.56, -0.99 and -0.81, respectively. A balanced amino acid solution with an adequate energy supply has an optimal nitrogen-sparing effect. Branched chain amino acids or alpha-ketoisocaproate did not improve nitrogen balance or reduce protein degradation.
authors.affiliation: Department of Anaesthesiology, University Hospital, Linköping, Sweden.
authors.forename: S
authors.initials: S
authors.lastname: Sandstedt
authors.forename: L
authors.initials: L
authors.lastname: Jorfeldt
authors.forename: J
authors.initials: J
authors.lastname: Larsson
mesh_terms: D000597:Amino Acids, Branched-Chain / Q000627:therapeutic use*; D002208:Caproates / Q000627:therapeutic use*; D005260:Female; D005770:Gastrointestinal Neoplasms / Q000601:surgery*; D006801:Humans; D007651:Keto Acids / Q000627:therapeutic use*; D008297:Male; D008762:Methylhistidines / Q000378:metabolism; D008875:Middle Aged; D009584:Nitrogen / Q000378:metabolism; D010289:Parenteral Nutrition, Total; D011184:Postoperative Period; D011506:Proteins / Q000378:metabolism*
chemical_list: D000597:Amino Acids, Branched-Chain; D002208:Caproates; D007651:Keto Acids; D008762:Methylhistidines; D011506:Proteins; C013082:alpha-ketoisocaproic acid; C028118:3-methylhistidine; D009584:Nitrogen