PURPOSE: Obesity is often associated with dyslipidemia and insulin resistance. L-carnitine supplementation has been shown to increase fatty acid oxidation, which may lead to decreased dyslipidemia and insulin resistance. Therefore, the purpose of this study was to evaluate the effects of exercise and L-carnitine supplementation on lipid profiles and insulin levels in obese female high school students.
METHODS: Subjects were obese (BMI = 30±3) female Korean high school students (age 16±1yrs, height 163±3.4 cm, bodymass 68±6.4 kg). Subjects were assigned to either a control group (Con, n=10), an exercise group (Ex, n=10), or an exercise combined with L-carnitine supplementation group (ExCar, n=10). Exercise consisted of brisk walking or jogging for 30 minutes at a moderate intensity (65-70% HRmax, RPE 10-13), 3 times/wk, for 12 wks. Supplementation consisted of a 2 g L-carnitine pill (L-carnitine 100%, GNC, U.S.A) once a day after dinner for 12 wks. Resting blood samples were taken before and after the 12 wk period (Con after 2 wks). Body composition was measured by electro impedance (Biospace, In body 3.0, Korea).
RESULTS: Weight, BMI, waist/hip ratio and percent body fat were significantly decreased only in the ExCar group (p<0.05). There were no significant changes in LDL in any group, and HDL significantly increased only in the ExCar group (p<0.05). There were no changes in glucose or leptin levels for any group, however, insulin levels were significantly decreased within Ex and ExCar (p<0.05) compared to the Con group.
CONCLUSIONS: Moderate exercise and L-carnitine treatment had positive effects on several risk factors for these obese subjects; weight, BMI, WHR, HDL, and insulin levels. Furthermore, treatment with 2 g/day L-carnitine had additional beneficial effects beyond exercise alone on the blood lipid profile. This study shows that L-carnitine supplementation in conjunction with moderate aerobic exercise can improve many risk factors in young obese females.