HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 294/4/E645    most recent 00720.2007v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Bergouignan, A. Articles by Blanc, S. PubMed PubMed Citation Articles by Bergouignan, A. Articles by Blanc, S.

The acetate recovery factor to correct tracer-derived dietary fat oxidation in humans

¹Institut Pluridisciplinaire Hubert Curien-Département d'Ecologie, Physiologie, Ethologie Université Louis Pasteur Centre National de la Recherche Scientifique 7178, Strasbourg, France; ²Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, Wisconsin; ³Obesity and Diabetes Research Section-National Institutes of Health/National Institute of Diabetes and Digestive and Kidney Diseases, Phoenix, Arizona; and ⁴Département de Nutrition-Hôpital d'Hautepierre, Université Louis Pasteur, Strasbourg, France

Submitted 14 November 2007 ; accepted in final form 16 January 2008

When using ¹³C tracer to measure plasma fat oxidation, an acetate recovery factor should be determined in every subject to correct for label sequestration. Less is known regarding the acetate recovery factor for dietary fatty acid oxidation. We compiled data from six studies to investigate the determinants of the dietary acetate recovery factor (dARF) at rest and after physical activity interventions and compared the effects of different methods of dARF calculation on both the fat oxidation and its variability. In healthy lean subjects, dARF was 50.6 ± 5.4% dose (n = 56) with an interindividual coefficient of variation of 10.6% at rest and 9.2% after physical activity modifications. The physical activity interventions did not impact dARF, and the intraindividual coefficient of variation was 4.6%. No major anthropological or physiological determinants were detected except for resting metabolic rate, which explains 7.4% of the dARF variability. Applying an individual or an average group dARF did not affect the mean and the variability of the derived dietary lipid oxidation at rest or after physical activity interventions. Using a mean dARF for a group leads to over- or underestimation of fat oxidation of less than 10% in individual subjects. Moreover, the use of a group or individual correction did not affect the significant relationship found between fasting respiratory exchange ratio and dietary fat oxidation. These data indicate that an average dARF can be applied for longitudinal and cross-sectional studies investigating dietary lipid metabolism.

exogenous fatty acid oxidation; stable isotopes; mass spectrometry