Laboratory of Cardio-circulatory, Respiratory, and Hormonal Adaptations to Muscular Exercise, Faculty of Medicine Ibn El Jazzar, Sousse, Tunisia.
Int J Obes (Lond). 2012 Jul;36(7):908-13. doi: 10.1038/ijo.2011.257. Epub 2012 Jan 17.
Obesity is associated with reduced exercise maximal fat oxidation rate (FATmax), which is generally assessed by cardiopulmonary cycling test. The six-minute walking test (6MWT) presents an alternative method in patients.
The aim of this study was to establish a practical reference equation facilitating the prediction of FATmax from the 6 MWT in obese children of both genders.
This study is a cross-sectional study using mixed linear and multiple regression models.
Anthropometric measurements were recorded and submaximal cycling test and 6 MWT conducted for 131 school-aged obese children, 68 boys and 63 girls. A multiple regression analysis for FATmax, including six-minute walking distance (6 MWD), anthropometric and cardiac parameters as the dependent variables, was performed for the two genders separately.
Mean 6 MWD and FATmax were 564.9 ± 53.7 m and 126.5 ± 12.1 mg min(-1) for boys and 506.7 ± 55.0 m and 120.7 ± 10.0 mg min(-1) for girls, respectively. The 6MWD, body mass index, Z-score, fat-free mass, waist and hip circumferences (WC and HC), rest heart rate, and systolic and diastolic blood pressures were highly correlated with FATmax for both genders. There was a significant correlation between 6 MWD and FATmax in both boys and girls (r = 0.88 and r = 0.81, P<0.001, respectively). Stepwise regression analyses revealed that the combinations of 6 MWD with HC for boys and 6MWD with WC for girls improved the predictability of the model (R(2) = 0.81 for boys and R(2) = 0.72 for girls; P<0.001).
In obese children, the 6MWT can be used to predict FATmax when formal test of exercise capacity and gas exchange analysis are unavailable or impractical. It is therefore possible to prescript targeted exercises at FATmax, without performing indirect calorimetry, just from a field test.
肥胖与运动时最大脂肪氧化率（FATmax）降低有关，通常通过心肺循环测试来评估。六分钟步行测试（6MWT）为患者提供了一种替代方法。
本研究旨在建立一种实用的参考方程，方便预测肥胖儿童的 FATmax 从 6MWT。
这是一项使用混合线性和多元回归模型的横断面研究。
对 131 名学龄肥胖儿童（68 名男孩和 63 名女孩）进行了人体测量学测量、亚最大循环测试和 6MWT。分别对男孩和女孩进行了包括 6 分钟步行距离（6MWD）、人体测量和心脏参数在内的 FATmax 的多元回归分析。
男孩的平均 6MWD 和 FATmax 分别为 564.9 ± 53.7 m 和 126.5 ± 12.1 mg min(-1)，女孩分别为 506.7 ± 55.0 m 和 120.7 ± 10.0 mg min(-1)。6MWD、体重指数、Z 分数、去脂体重、腰围和臀围（WC 和 HC）、静息心率以及收缩压和舒张压与男孩和女孩的 FATmax 高度相关。男孩和女孩的 6MWD 与 FATmax 均有显著相关性（r = 0.88 和 r = 0.81，P<0.001）。逐步回归分析显示，男孩 6MWD 与 HC 相结合，女孩 6MWD 与 WC 相结合，提高了模型的预测能力（男孩 R(2) = 0.81，女孩 R(2) = 0.72；P<0.001）。
在肥胖儿童中，当无法或不实际进行运动能力的正式测试和气体交换分析时，可以使用 6MWT 来预测 FATmax。因此，无需进行间接热量测定，仅从现场测试即可为 FATmax 开处方进行针对性锻炼。
