Energy expenditure and substrate utilization during eccentric exercise in obese and diabetics
Year: 2008
Type: dissertation
Abstract: Kivistö, Riikka 2008.Energy expenditure and substrate utilization during eccentric exercise in obese and diabetics.The Department of Biology of Physical Activity, the University of Jyväskylä, 92 p.The present research was a pilot study examining the effects of diabetes and obesity on energy expenditure (EE) and oxidation of energy substrates (CHO, lipid) during eccentric exercise.Exercise is an important part of treatment of diabetes, but diabetics have often increased risk of heart failure.Eccentric exercise requires lower heart rate and systolic blood pressure compared to concentric mode.Thus, it could provide a safe mode for increasing impaired glucose disposal in the skeletal muscles of diabetic patients.Subjects were males (n=28, age 52±7), of which 14 were diabetics (DM), 12 obese (OND) and 3 lean non-diabetics (LND).The OND and LND were combined to healthy controls (HC).After anthropometrical measurements, fasting blood sample, maximal VO 2max test with a bicycle ergometer and maximal isometric force measurement, the subjects had 4 weeks (2 sessions a week) adaptation period with eccentric ergometer.EE on the eccentric ergometer was measured from the respiratory gases during two intensity levels for 7 min.Muscle biopsy was obtained from the m.vastus lateralis with a Bergström biopsy needle.There were no differences in EE and substrate utilization between the DM and OND.DM (-5.0±1,3 kcal/min) had higher EE compared to HC (-4,4±1,3; p=0.037) during second intensity level.The DM (53,2±10,4 %) used higher proportion of VO 2max during eccentric exercise compared to the HC (41,2±14,7; p=0.023).DM (42,0±10,0 %) had lower fraction of type I fibres compared to OND (49,1±10,1; p=0.048) and HC (50,8±11,5; p=0.020).In the DM, the fraction of type IIb fibres correlated with CHO oxidation (r=-0.661,p=0.027).In the HC, the percentage of type IIab fibres correlated with CHO oxidation (r=0.661,p=0.038) and EE (r=-0.758,p=0.011).Also, the fraction of type IIb fibres correlated with the lipid oxidation (r=0.648,p=0.043).Obesity influences more on the EE and the oxidation of substrates than diabetes mellitus alone.Lower percentage of type I fibres in DM is showed in the higher oxidation of CHO for energy compared to HC.The diabetics used higher proportion of their oxygen consumption capacity.This could be a sign for increased glycolytic enzyme activity in diabetics compared to non-diabetics, which have been found in many previous studies.These variables could partly explain the subjects' sensitivity to develop type 2 diabetes mellitus.
Author: Riikka Kivistö
Language: English
Subfield: Physiology (medical)
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W2225752921