Improved glucose tolerance after intensive life style intervention occurs without changes in muscle ceramide or triacylglycerol in morbidly obese subjects.
Từ khóa
trừu tượng
OBJECTIVE
This study investigated the effect of a 15-week life style intervention (hypocaloric diet and regular exercise) on glucose tolerance, skeletal muscle lipids and muscle metabolic adaptations in 14 female and 9 male morbidly obese subjects (age: 32.5±2.3 years, body mass index: 46.1±1.9 kg m(-2) ).
METHODS
Before and after the life style intervention, an oral glucose tolerance test was performed and a muscle biopsy was obtained in the fasted state. Maximal oxygen uptake was measured by an indirect test.
RESULTS
After the intervention, body weight was decreased (P<0.05) by 11±1%, maximal oxygen uptake increased (P<0.05) by 18±5% and glucose tolerance increased (P<0.05) by 12±3%. Muscle glycogen was significantly increased by 47±14%, but muscle ceramide and triacylglycerol content remained completely unchanged. No sex difference was observed for any of these parameters, but during submaximal exercise a marked decrease (P<0.05) of 15±2% in respiratory exchange ratio was seen only in females indicating an enhanced fat oxidation.
CONCLUSIONS
Despite a marked weight loss and an improved aerobic capacity muscle ceramide and triacylglycerol remained unchanged after intensive life style intervention, and muscle lipids hence do not seem to play a major role for the improved glucose tolerance in these morbidly obese subjects. Interestingly, only the females improved fat oxidation during submaximal exercise after the intervention implying the presence of a sex-dependent response to intensive life style adaptation.