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Journal of Nutrition and Metabolism
Volume 2017, Article ID 7832057, 7 pages
https://doi.org/10.1155/2017/7832057
Research Article

Associations of Mitochondrial Fatty Acid Oxidation with Body Fat in Premenopausal Women

1Department of Nutrition Sciences, University of Alabama at Birmingham, 1720 2nd Avenue South, Birmingham, AL 35294, USA
2Department of Human Studies, University of Alabama at Birmingham, 1720 2nd Avenue South, Birmingham, AL 35294, USA
3Department of Surgery, University of Alabama at Birmingham, 1720 2nd Avenue South, Birmingham, AL 35294, USA

Correspondence should be addressed to Gordon Fisher; ude.bau@sfndrg

Received 15 June 2017; Revised 7 September 2017; Accepted 17 September 2017; Published 24 October 2017

Academic Editor: C. S. Johnston

Copyright © 2017 Jonathan L. Warren et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Higher in vivo fatty acid (FA) oxidation rates have been reported in obese individuals compared to lean counterparts; however whether this reflects a shift in substrate-specific oxidative capacity at the level of the skeletal muscle mitochondria has not been examined. The purpose of this study was to test the hypothesis that in situ measures of skeletal muscle mitochondria FA oxidation would be positively associated with total body fat. Participants were 38 premenopausal women ( kg/m2). Total and regional fat were assessed by dual-energy X-ray absorptiometry (DXA). Mitochondrial FA oxidation was assessed in permeabilized myofibers using high-resolution respirometry and a palmitoyl carnitine substrate. We found positive associations of total fat mass with State 3 (ADP-stimulated respiration) (, ) and the respiratory control ratio (RCR, measure of mitochondrial coupling) (, ). When participants were dichotomized by high or low body fat percent, participants with high total body fat displayed a higher RCR compared to those with low body fat (). There were no associations between any measure of regional fat and mitochondrial FA oxidation independent of total fat mass. In conclusion, greater FA oxidation in obesity may reflect molecular processes that enhance FA oxidation capacity at the mitochondrial level.