Rizzo Nico S, Ruiz Jonatan R, Oja Leila, Veidebaum Tomas, Sjöström Michael
Unit for Preventive Nutrition, Department of Biosciences and Nutrition, NOVUM, Karolinska Institutet, Huddinge, Sweden.
Am J Clin Nutr. 2008 Mar;87(3):586-92. doi: 10.1093/ajcn/87.3.586.
More and better data are needed to understand the action of physical activity (PA) on insulin resistance and the concomitant relation with body fat in adolescence.
We examined the relation between total PA and intensity levels with insulin resistance under special consideration of waist circumference and skinfold thickness.
This was a cross-sectional study of 613 adolescents (352 girls, 261 boys) with a mean (+/-SD) age of 15.5 +/- 0.5 y from Sweden and Estonia. Total, low, moderate, and vigorous PA was measured by accelerometry. Body fat estimators included waist circumference and the sum of 5 skinfold thicknesses. Fasting insulin and glucose were measured, and insulin resistance was calculated according to the homeostasis model assessment (HOMA). Linear regression analysis and analysis of covariance were used to determine the association between PA and insulin resistance while considering body fat. All estimates were adjusted for sex, country, pubertal status, and indicators of body fat when applicable.
Total, moderate, and vigorous PA were inversely correlated with HOMA. Body fat estimators were positively correlated with HOMA. Significant contrasts in HOMA concentrations were seen when comparing the lower 2 tertiles with the upper tertile of PA indicators. Repeating the analysis with body fat estimators showed significant contrasts in HOMA concentrations when comparing the lower tertiles with the upper tertile.
In view of an increase in obesity in young people, the results accentuate the role of PA in sustaining metabolic balance in adolescence and the potential benefit of an increase of time spent at higher PA levels for youth with relatively elevated amounts of body fat.
需要更多更好的数据来了解体育活动（PA）对胰岛素抵抗的作用以及与青少年体脂的伴随关系。
我们特别考虑腰围和皮褶厚度，研究了总PA和强度水平与胰岛素抵抗之间的关系。
这是一项对613名青少年（352名女孩，261名男孩）的横断面研究，他们来自瑞典和爱沙尼亚，平均（±标准差）年龄为15.5±0.5岁。通过加速度计测量总PA、低强度PA、中等强度PA和高强度PA。体脂评估指标包括腰围和5个皮褶厚度之和。测量空腹胰岛素和血糖，并根据稳态模型评估（HOMA）计算胰岛素抵抗。使用线性回归分析和协方差分析来确定PA与胰岛素抵抗之间的关联，同时考虑体脂。所有估计值在适用时均根据性别、国家青春期状态和体脂指标进行了调整。
总PA、中等强度PA和高强度PA与HOMA呈负相关。体脂评估指标与HOMA呈正相关。当比较PA指标的下三分位数与上三分位数时，HOMA浓度存在显著差异。在对体脂评估指标重复分析时，当比较下三分位数与上三分位数时，HOMA浓度也存在显著差异。
鉴于年轻人肥胖率上升，研究结果强调了PA在维持青少年代谢平衡中的作用，以及对于体脂相对较高的年轻人增加在较高强度PA水平上花费时间的潜在益处。
