Skeletal muscle metabolic characteristics before and after energy restriction in human obesity: fibre type, enzymatic beta-oxidative capacity and fatty acid-binding protein content.
BACKGROUND
Skeletal muscle has the ability to adapt as result of dietary, hormonal or pharmacological interventions affecting energy metabolism. The aim of the present study was to investigate the effects of energy restriction on skeletal muscle metabolic characteristics in obese women.


METHODS
The effects of 8 weeks' energy restriction on body composition, energy expenditure and skeletal muscle characteristics were investigated in 28 healthy obese women. Subjects were aged 37.9 +/- 1.5 years and had a body mass index of 32.0 +/- 0.8 kg m-2.


RESULTS
Energy restriction (2800 kJ day-1) resulted in a 10.8 +/- 0.5 kg weight loss consisting of 8. 6 +/- 0.5 kg of fat mass and 2.2 +/- 0.3 kg of fat-free mass. Basal respiratory exchange ratio, sleeping metabolic rate and exercise-induced thermogenesis significantly declined in response to the diet. These changes were accompanied by an increase (P = 0.038) in the skeletal muscle content of cytosolic fatty acid-binding protein (H-FABP), whereas no changes occurred in fibre type distribution or activities of enzymes reflecting beta-oxidation and mitochondrial density (3-hydroxyacyl-CoA dehydrogenase and citrate synthase respectively).


CONCLUSIONS
The results suggest that increased capacity of intracellular fatty acid transport in skeletal muscle cells is involved in the physiological adaptations of fat metabolism to energy restriction in obese female subjects.
Kempen
K P
KP
University of Maastricht, Maastricht, The Netherlands.
Saris
W H
WH
Kuipers
H
H
Glatz
J F
JF
Van Der Vusse
G J
GJ
D015094:3-Hydroxyacyl CoA Dehydrogenases / Q000378:metabolism; D000328:Adult; D000943:Antigens, Differentiation / Q000378:metabolism; D002352:Carrier Proteins / Q000378:metabolism*; D002950:Citrate (si)-Synthase / Q000378:metabolism; D002149:Energy Intake; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D005227:Fatty Acids / Q000378:metabolism; D005260:Female; D006801:Humans; D008875:Middle Aged; D018485:Muscle Fibers, Skeletal / Q000166:cytology / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000378:metabolism*; D018996:Myelin P2 Protein / Q000378:metabolism*; D009363:Neoplasm Proteins; D009765:Obesity / Q000378:metabolism*; D025521:Tumor Suppressor Proteins
D000943:Antigens, Differentiation; D002352:Carrier Proteins; C107608:FABP7 protein, human; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D005227:Fatty Acids; D018996:Myelin P2 Protein; D009363:Neoplasm Proteins; D025521:Tumor Suppressor Proteins; D015094:3-Hydroxyacyl CoA Dehydrogenases; D002950:Citrate (si)-Synthase