title: Validation of deuterium-labeled fatty acids for the measurement of dietary fat oxidation during physical activity.
abstract: Measurement of 13C-labeled fatty acid oxidation is hindered by the need for acetate correction, measurement of the rate of CO2 production in a controlled environment, and frequent collection of breath samples. The use of deuterium-labeled fatty acids may overcome these limitations. Herein, d31-palmitate was validated against [1-13C]palmitate during exercise. Thirteen subjects with body mass index of 22.9 +/- 3 kg/m2 and body fat of 19.6 +/- 11% were subjected to 2 or 4 h of exercise at 25% maximum volume oxygen consumption (VO2max). The d31-palmitate and [1-13C] palmitate were given orally in a liquid meal at breakfast. The d3-acetate and [1-13C]acetate were given during another visit for acetate sequestration correction. Recovery of d31-palmitate in urine at 9 h after dose was compared with [1-13C] palmitate recovery in breath. Cumulative recovery of d31-palmitate was 10.6 +/- 3% and that of [1-13C]palmitate was 5.6 +/- 2%. The d3-acetate and [1-13C]acetate recoveries were 85 +/- 4% and 54 +/- 4%, respectively. When [1-13C]acetate recovery was used to correct 13C data, the average recovery differences were 0.4 +/- 3%. Uncorrected d31-palmitate and acetate-corrected [1-13C]palmitate were well correlated (y=0.96x + 0; P <0.0001) when used to measure fatty acid oxidation during exercise. Thus, d31-palmitate can be used in outpatient settings as it eliminates the need for acetate correction and frequent sampling.
authors.affiliation: Interdepartmental Program in Nutritional Sciences, University of Wisconsin-Madison, Madison, WI, USA.
authors.forename: Aarthi
authors.initials: A
authors.lastname: Raman
authors.forename: Stephane
authors.initials: S
authors.lastname: Blanc
authors.forename: Alexandra
authors.initials: A
authors.lastname: Adams
authors.forename: Dale A
authors.initials: DA
authors.lastname: Schoeller
mesh_terms: D019342:Acetic Acid / Q000378:metabolism; D003903:Deuterium / Q000378:metabolism*; D004041:Dietary Fats / Q000378:metabolism*; D015444:Exercise / Q000502:physiology*; D005227:Fatty Acids / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D010084:Oxidation-Reduction; D019308:Palmitic Acid / Q000378:metabolism
chemical_list: D004041:Dietary Fats; D005227:Fatty Acids; D019308:Palmitic Acid; D003903:Deuterium; D019342:Acetic Acid