ABSTRACT

　The purpose of this study was to clarify the possibility of intramuscular fat (IMF) could be the risk factor of metabolic syndrome in obese children. Thirty-seven obese boys and girls participated in this study (age, 10.4 ± 2.1 year-old; height, 146.2 ± 13.4 cm; weight, 56.1 ± 16.5 kg; percentage of overweight, 41.1 ± 16.8%). The subjects were divided into three groups based on percentage of overweight, i.e. mild obesity group, moderate obesity group, and sever obesity group. This study was conducted a part of obesity treatment for the subjects and was approved by the institutional review board of local committees. Computed tomography (CT) images were taken at the midby thigh and umbilicus levels. Using the CT images, IMF index of the quadriceps femoris (QF), hamstrings(HM) and adductor (AD) muscle groups based on mean grey scale level of the interested muscle groups and visceral fat cross-sectional area (CSA) was calculated. For the mid-thigh CT image, skeletal muscle CSA and subcutaneous fat was also calculated. Plasma triglyceride, FFA, HDL-cholesterol, total-cholesterol, glucose, and HbA1c were measured from fasting blood drop. IMF index of QF, HM and AD was significantly different in all comparisons: HM was the lowest (1066 ± 6 a.u.), meaning largest IMF depot, and QF was the highest (1080 ± 3 a.u.), meaning smallest IMF depot. Stepwise multiple regression analysis revealed that none of independent variables were extracted to predict IMF index in QF. For IMF index in HM, visceral fat CSA per body weight and FFA were extracted (R=0.483, P < 0.05). Interestingly, visceral fat CSA per body weight was the only extracted variable to predict IMF index in AD (R=0.531, P < 0.05). These results suggest that IMF in hamstring and adductor could be a risk factor of metabolic syndrome in obese children.

DESCENTE SPORTS SCIENCE Vol.37/THE DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE