Increase in skeletal muscle fatty acid binding protein (FABPC) content is directly related to weight loss and to changes in fat oxidation following a very low calorie diet.
OBJECTIVE
There is increasing evidence that intracellular fatty acid binding proteins (FABPc's; 15 kD) function as vehicles of cytosolic fatty acid transport. We studied skeletal muscle cytosolic FABPc, and enzymes reflecting beta-oxidation and oxidative capacity (3-hydroxyacyl-CoA dehydrogenase, HAD, and citrate synthase, CS) in relation to weight loss and changes in substrate utilisation in a group of 35 obese women and obese men with Type II (non-insulin-dependent) diabetes mellitus (women = 27, men = 8).


METHODS
Muscle biopsies (vastus lateralis), and measurements of body composition, resting energy expenditure and respiratory exchange ratio were taken before and after dietary intervention (by means of a very low calorie diet).


RESULTS
Muscle FABPc tended to increase after diet (178 +/- 13 vs 204 +/- 12 mg x gww(-1), p = 0.06), whereas there were no changes in CS (10.5 +/- 0.7 vs 11.1 +/- 0.6 U x gww(-1)) and HAD (11.2 +/- 0.7 vs 11.7 +/- 0.6 U x gww(-1)). There was a positive relation between the increase in FABPc as result of diet and the amount of weight lost (p < 0.01; adjusted R2, 15.4 %), even when adjusted for mean body weight, and changes in CS and in HAD by partial regression analysis. Interestingly, the increase in FABPc was positively related to increases in resting fat oxidation (adjusted R2, 24 %), even when adjusted for mean resting fat oxidation, and changes in CS and in HAD.


CONCLUSIONS
In conclusion, the ability to increase muscle FABPc could be directly related to weight loss and to changes in fat oxidation following dietary intervention in obesity and Type II (non-insulin-dependent) diabetes mellitus.
Blaak
E E
EE
Department of Human Biology, Nutrition Research Centre, Maastricht University, Maastricht, The Netherlands. E.Blaak@HB.Unimaas.nl
Glatz
J F
JF
Saris
W H
WH
D000328:Adult; D001823:Body Composition; D015992:Body Mass Index; D002352:Carrier Proteins / Q000378:metabolism*; D003920:Diabetes Mellitus / Q000378:metabolism*; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism*; D004038:Diet, Reducing; D004734:Energy Metabolism; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D005227:Fatty Acids / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism*; D009363:Neoplasm Proteins; D009765:Obesity; D010084:Oxidation-Reduction; D012044:Regression Analysis; D025521:Tumor Suppressor Proteins; D015431:Weight Loss
D002352:Carrier Proteins; C107608:FABP7 protein, human; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D005227:Fatty Acids; D009363:Neoplasm Proteins; D025521:Tumor Suppressor Proteins