Effect of concurrent training on risk factors and hepatic steatosis in obese adolescents

OBJECTIVE To analyze the effects of a 20-week concurrent training on the variables of body composition, lipid profile, and fatty liver diagnosis in obese adolescents. METHODS An open clinical trial was carried out with 34 obese adolescents aged between 12 and 15 years. Total body fat, trunk fat mass, total cholesterol and its fractions (HDL, LDL and VLDL), and triglycerides were analyzed; an upper abdominal ultrasound was performed in order to diagnose fatty liver. The participants underwent concurrent training (association of weight training with aerobic training) three times per week, lasting one hour for 20 weeks. Statistical analysis included paired Studentâ€(tm)s t-test and frequency analysis in order to verify the relative and absolute reductions of fatty liver diagnosis, being significant p<0.05. RESULTS The studied adolescents showed statistically significant improvement in body composition, with a decrease of total body fat percentage, total fat mass, trunk fat, and an a increase in the lean body mass. They also presented reduced size of liver lobes, decrease in total cholesterol and in LDL-cholesterol, with a lower prevalence of fatty liver. CONCLUSIONS The concurrent training was effective for promoting significant improvements in body fat composition and lipid profile variables, besides reducing fatty liver prevalence rate.

【研究目的】分析为期20周的联合训练（抗阻训练与有氧训练相结合）对肥胖青少年身体成分、血脂谱及脂肪肝诊断相关指标的影响。
【研究方法】本研究纳入34名年龄介于12至15岁的肥胖青少年，开展一项开放临床试验。检测指标包括总体脂、躯干脂肪量、总胆固醇及其组分（高密度脂蛋白胆固醇（HDL）、低密度脂蛋白胆固醇（LDL）、极低密度脂蛋白胆固醇（VLDL））以及甘油三酯；并通过上腹部超声检查完成脂肪肝诊断。受试者每周接受3次联合训练，每次时长1小时，持续20周。统计学分析采用配对t检验与频数分析，以验证脂肪肝诊断的相对与绝对改善情况，以p<0.05为差异具有统计学意义。
【研究结果】受试青少年的身体成分出现具有统计学意义的改善：体脂百分比、总脂肪量、躯干脂肪量均下降，瘦体重（lean body mass）升高。同时，受试者肝叶体积缩小，总胆固醇与低密度脂蛋白胆固醇水平降低，脂肪肝患病率下降。
【研究结论】联合训练可有效改善肥胖青少年的体脂组成与血脂谱指标，同时降低脂肪肝患病率。