title: Alpha-ketoglutarate-supplemented enteral nutrition: effects on postoperative nitrogen balance and muscle catabolism.
abstract: Enteral feeding in the early postoperative phase may improve gut integrity and reduce infectious complications after trauma and surgery. The aim of the current study was to evaluate the feasibility of alpha-ketoglutarate enrichment of enteral feeding and the effect on protein metabolism after major surgery. Patients undergoing elective abdominal surgery were randomly allocated to receive a standard whole-protein-based enteral nutrition solution (n = 9) or an isonitrogenous, isocaloric solution enriched with alpha-ketoglutarate (n = 11) for 5 d postoperatively. The nutritional goals by day 4 were 25 kcal and 0.17 g of nitrogen, respectively, per kilogram of body weight every 24 h. Standard blood analysis, including prealbumin and C-peptide, was performed preoperatively and on days 1, 3, and 6. Urine was collected daily for nitrogen and 3-methylhistidine analyses. Due to restricted tolerance to enteral feeding, the nitrogen delivery reached only 0.10 g of nitrogen per kilogram of body weight. Transthyretin decreased by 25% in both groups, and albumin decreased significantly in the enriched group compared with the standard nutrition. There were no significant differences in nitrogen balance, excretion of 3-methylhistidine, or clinical outcome between groups. Enrichment of a whole-protein-based formula with alpha-ketoglutarate did not improve protein metabolism or decrease muscle catabolism after major abdominal surgery.
authors.affiliation: Center for Surgical Sciences, Karolinska Institute, Huddinge University Hospital, Stockholm, Sweden. mikael.wiren@karo.ki.se
authors.forename: Mikael
authors.initials: M
authors.lastname: Wirén
authors.forename: Johan
authors.initials: J
authors.lastname: Permert
authors.forename: Jörgen
authors.initials: J
authors.lastname: Larsson
mesh_terms: D000005:Abdomen / Q000601:surgery*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004750:Enteral Nutrition; D005260:Female; D006801:Humans; D007656:Ketoglutaric Acids / Q000627:therapeutic use*; D008297:Male; D008762:Methylhistidines / Q000652:urine; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000378:metabolism*; D009584:Nitrogen / Q000378:metabolism* / Q000652:urine; D010865:Pilot Projects; D011182:Postoperative Care / Q000379:methods; D012709:Serum Albumin / Q000032:analysis; D016896:Treatment Outcome
chemical_list: D007656:Ketoglutaric Acids; D008762:Methylhistidines; D012709:Serum Albumin; C028118:3-methylhistidine; D009584:Nitrogen