Impaired metabolism of fatty acids is associated with obesity and type 2 diabetes (T2D). Based
on evidence in lean adults, the expected response of skeletal muscle to aerobic training is an
increase in the oxidation of fatty acids. However, considerably less is known about the response
of fat oxidation to aerobic training in those with obesity and/or T2D. PURPOSE: 1) To
determine if sedentary overweight adults with and without type 2 diabetes exhibit significant
improvements in fatty acid metabolism at rest and during physical activity due to endurance
training. 2) To compare changes in the oxidation of intramuscular triacylglycerols (IMTG)
during sub-maximal exercise between those with and without T2D. METHODS: 13 (10
without T2D, 3 with T2D) overweight (BMI: 28-40 kg/m2) men and women aged 28-55
completed an 8-week aerobic exercise intervention. Pre and post intervention, all subjects
underwent a DEXA, maximal graded exercise test, and indirect calorimetry with non-radioactive
labeled isotopes palmitate and acetate to determine energy expenditure, fat oxidation, and source
of fatty acids for oxidation at rest and during exercise. RESULTS: VO2max improved by an
average of 14% (40.8+1.6 to 46.5+1.7ml/kg LBM/min) in the OW group (p<0.01) and 13.4%
(34.8+4.5 to 38.0+1.7 ml/kg/LBM/min) in the T2D group (p=0.10). A non-significant increase
in whole body fat oxidation during exercise was measured in both the OW (6.2%) and T2D
(5.1%) group. There were no changes in whole body fat oxidation at rest in either group. Before
and after intervention, IMTG oxidation during exercise was 4.13 + 1.7 and 5.5 + 2.3 uMol/kg
Changes in Fat Oxidation with Endurance Activity in
Adults with and without Type 2 Diabetes
Anne Mathews, RD, PhD
University of Pittsburgh, 2008
v
LBM/min in OW and 3.42 + 1.9 and 2.41 + 2.8 uMol/kg LBM/min in T2D. These changes were
not significant due to the intervention (p=0.62). CONCLUSIONS: Eight weeks of moderate
intensity aerobic exercise results in increased cardiorespiratory fitness but not a significant
increase in whole body fatty acid oxidation during rest and exercise in overweight adults with or
without type 2 diabetes. Moreover, oxidation of fatty acids from IMTG was not enhanced by the
8-week intervention.
| Identifer | oai:union.ndltd.org:PITT/oai:PITTETD:etd-07222008-110748 |
| Date | 29 September 2008 |
| Creators | Mathews, Anne |
| Contributors | John Jakicic, PhD, Amy Otto, PhD, RD, Frederico Toledo, MD, Bret Goodpaster, PhD |
| Publisher | University of Pittsburgh |
| Source Sets | University of Pittsburgh |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.library.pitt.edu/ETD/available/etd-07222008-110748/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to University of Pittsburgh or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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