Department of Human Services, Curry School of Education, University of Virginia, Charlottesville, VA, USA.
Med Sci Sports Exerc. 2012 May;44(5):786-92. doi: 10.1249/MSS.0b013e31823cef5e.
Obesity in adolescence increases the risk for early adult cardiovascular disease. We recently showed that 6 months of diet, exercise, and metformin resulted in reductions in adiposity and that diet/exercise alone reduced proinflammatory factors and intrahepatic fat in pubertal children with uncomplicated obesity. The purpose of the present study was to determine whether changes in cardiorespiratory fitness (CRF) after 6 months of structured diet and exercise (DE) or DE plus metformin are related to the previously observed changes in adiposity, markers of inflammation, and intrahepatic fat.
Sixteen obese pubertal adolescents between the ages of 10 and 17 were randomized into a structured lifestyle program consisting of DE or DE plus metformin. Subjects performed aerobic and resistance exercise 3 d·wk⁻¹, 30 min per session. Cycle ergometer maximal oxygen consumption (V˙O2max), body composition, blood markers (glucose, insulin, homeostatic model assessment-insulin resistance, interleukin-6, hsCRP), and intrahepatic fat were measured at baseline and 6 months.
In the cohort, as whole-body weight decreased by 4.0% (P = 0.009), body mass index decreased by 4.9% (P = 0.003), percent body fat decreased by 8.8% (P < 0.001), and V˙O2max improved in 10 of 16 subjects. The addition of metformin provided no further effect on body composition, CRF, or inflammatory factors. More favorable changes in adiposity, adiponectin, and a trend toward blood glucose and interleukin-6 concentrations (P = 0.07) were observed in subjects who increased V˙O2max at 6 months (n = 10) compared with no change in these variables in those who did not improve V˙O2max.
Metformin did not provide benefits above lifestyle modification for improving CRF in obese adolescents. Improvements in V˙O2max seem to be associated with more favorable metabolic outcomes.
青少年肥胖会增加成年早期心血管疾病的风险。我们最近的研究表明，经过 6 个月的饮食、运动和二甲双胍治疗，可以减少肥胖，而单纯的饮食/运动可以减少青春期单纯性肥胖儿童的促炎因子和肝内脂肪。本研究的目的是确定经过 6 个月的结构化饮食和运动（DE）或 DE 加二甲双胍治疗后，心肺功能（CRF）的变化是否与之前观察到的脂肪量、炎症标志物和肝内脂肪的变化有关。
16 名年龄在 10 至 17 岁之间的肥胖青春期青少年被随机分为结构化生活方式计划，包括 DE 或 DE 加二甲双胍。受试者每周进行 3 天、每次 30 分钟的有氧运动和抗阻运动。在基线和 6 个月时测量了自行车测功计最大摄氧量（V˙O2max）、身体成分、血液标志物（血糖、胰岛素、稳态模型评估-胰岛素抵抗、白细胞介素-6、高敏 C 反应蛋白）和肝内脂肪。
在整个队列中，全身体重下降了 4.0%（P = 0.009），体重指数下降了 4.9%（P = 0.003），体脂百分比下降了 8.8%（P < 0.001），16 名受试者中有 10 名的 V˙O2max 得到了改善。二甲双胍的添加对身体成分、CRF 或炎症因子没有进一步的影响。与 V˙O2max 没有改善的受试者相比，在 6 个月时 V˙O2max 增加的 10 名受试者中，观察到脂肪量、脂联素的更有利变化，以及血糖和白细胞介素-6 浓度的趋势（P = 0.07）。
二甲双胍对改善肥胖青少年的 CRF 没有比生活方式改变带来更多益处。V˙O2max 的改善似乎与更有利的代谢结果有关。
