title: Effects of enteral carbohydrates on de novo lipogenesis in critically ill patients.
abstract: BACKGROUND
  Conversion of glucose into lipid (de novo lipogenesis; DNL) is a possible fate of carbohydrate administered during nutritional support. It cannot be detected by conventional methods such as indirect calorimetry if it does not exceed lipid oxidation.
  
  
  OBJECTIVE
  The objective was to evaluate the effects of carbohydrate administered as part of continuous enteral nutrition in critically ill patients.
  
  
  METHODS
  This was a prospective, open study including 25 patients nonconsecutively admitted to a medicosurgical intensive care unit. Glucose metabolism and hepatic DNL were measured in the fasting state or after 3 d of continuous isoenergetic enteral feeding providing 28%, 53%, or 75% carbohydrate.
  
  
  RESULTS
  DNL increased with increasing carbohydrate intake (f1.gif" BORDER="0"> +/- SEM: 7.5 +/- 1.2% with 28% carbohydrate, 9.2 +/- 1.5% with 53% carbohydrate, and 19.4 +/- 3.8% with 75% carbohydrate) and was nearly zero in a group of patients who had fasted for an average of 28 h (1.0 +/- 0.2%). In multiple regression analysis, DNL was correlated with carbohydrate intake, but not with body weight or plasma insulin concentrations. Endogenous glucose production, assessed with a dual-isotope technique, was not significantly different between the 3 groups of patients (13.7-15.3 micromol * kg(-1) * min(-1)), indicating impaired suppression by carbohydrate feeding. Gluconeogenesis was measured with [(13)C]bicarbonate, and increased as the carbohydrate intake increased (from 2.1 +/- 0.5 micromol * kg(-1) * min(-1) with 28% carbohydrate intake to 3.7 +/- 0.3 micromol * kg(-1) * min(-1) with 75% carbohydrate intake, P: < 0. 05).
  
  
  CONCLUSIONS
  Carbohydrate feeding fails to suppress endogenous glucose production and gluconeogenesis, but stimulates DNL in critically ill patients.
authors.affiliation: Department of Nutritional Sciences, University of California, Berkeley.
authors.forename: J M
authors.initials: JM
authors.lastname: Schwarz
authors.forename: R
authors.initials: R
authors.lastname: Chioléro
authors.forename: J P
authors.initials: JP
authors.lastname: Revelly
authors.forename: C
authors.initials: C
authors.lastname: Cayeux
authors.forename: P
authors.initials: P
authors.lastname: Schneiter
authors.forename: E
authors.initials: E
authors.lastname: Jéquier
authors.forename: T
authors.initials: T
authors.lastname: Chen
authors.forename: L
authors.initials: L
authors.lastname: Tappy
mesh_terms: D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000032:analysis; D002153:Calorimetry, Indirect; D050260:Carbohydrate Metabolism; D002241:Carbohydrates / Q000008:administration & dosage; D002851:Chromatography, High Pressure Liquid; D003422:Critical Care / Q000379:methods; D004750:Enteral Nutrition / Q000379:methods*; D005227:Fatty Acids / Q000097:blood; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry; D005934:Glucagon / Q000097:blood; D005943:Gluconeogenesis; D005947:Glucose / Q000096:biosynthesis / Q000378:metabolism; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D007328:Insulin / Q000032:analysis; D007700:Kinetics; D008055:Lipids / Q000096:biosynthesis*; D008099:Liver / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011446:Prospective Studies; D011863:Radioimmunoassay; D011897:Random Allocation; D012044:Regression Analysis; D014280:Triglycerides / Q000097:blood
chemical_list: D001786:Blood Glucose; D002241:Carbohydrates; D005227:Fatty Acids; D007328:Insulin; D008055:Lipids; D014280:Triglycerides; D005934:Glucagon; D005947:Glucose; D006854:Hydrocortisone