Hopkins N D, Stratton G, Tinken T M, McWhannell N, Ridgers N D, Graves L E F, George K, Cable N T, Green D J
Research Institute for Sport and Exercise Science, Liverpool John Moore's University, Liverpool, United Kingdom.
Atherosclerosis. 2009 May;204(1):244-9. doi: 10.1016/j.atherosclerosis.2008.09.004. Epub 2008 Sep 9.
The prevalence of obesity and physical inactivity in Western countries has increased rapidly. Both are modifiable risk factors for cardiovascular disease. Atherosclerosis begins in childhood and endothelial dysfunction is its earliest detectable manifestation.
We assessed flow-mediated dilation (FMD) in 129 children (75 female; 10.3+0.3 yrs; 54 male; 10.4; 0.3 yrs). FMD was normalised for differences in the eliciting shear rate stimulus between subjects (SR(AUC)). Fitness was assessed as peak oxygen uptake during an incremental treadmill exercise test (V O(2)peak). Body composition was measured using a dual-energy X-ray absorptiometry (DEXA) scan. Physical activity (PA) was assessed using Actigraph accelerometers. The cohort was split into tertiles according to FMD% and also FMD% corrected for SR(AUC) to gain insight into the determinants of vascular function.
Across the cohort, significant correlations were observed between FMD%/SR(AUC) and DEXA percentage fat (r=-0.23, p=0.009) and percentage lean mass (r=0.21, p=0.008), and also with PA performed at moderate-to-high intensity (r=0.363, p=0.001). For children in the lowest FMD%/SR(AUC) tertile, a stronger relationship with all PA measures was observed, particularly with high intensity PA (r=0.572, P=0.003). Regression analysis revealed that high intensity PA was the only predictor of impaired FMD%/SR(AUC).
These data suggest that traditional risk factors for CHD in adult populations impact upon vascular function in young people. Furthermore, it appears that individuals with impaired FMD may benefit from performing high intensity PA, whereas no relationships exist between FMD and lower intensities of PA or between PA and FMD in those subjects who possess preserved vascular function a priori.
西方国家肥胖和缺乏身体活动的患病率迅速上升。两者都是心血管疾病的可改变风险因素。动脉粥样硬化始于儿童期，而内皮功能障碍是其最早可检测到的表现。
我们评估了129名儿童（75名女性；年龄10.3±0.3岁；54名男性；年龄10.4±0.3岁）的血流介导的血管舒张（FMD）。FMD根据受试者之间引发切变率刺激的差异进行标准化（SR(AUC)）。通过递增式跑步机运动试验中的峰值摄氧量（VO₂峰值）评估体能。使用双能X线吸收法（DEXA）扫描测量身体成分。使用Actigraph加速度计评估身体活动（PA）。根据FMD%以及校正SR(AUC)后的FMD%将队列分为三分位数，以深入了解血管功能的决定因素。
在整个队列中，观察到FMD%/SR(AUC)与DEXA脂肪百分比（r=-0.23，p=0.009）和瘦体重百分比（r=0.21，p=0.008）之间存在显著相关性，并且与中高强度的PA也存在显著相关性（r=0.363，p=0.001）。对于FMD%/SR(AUC)处于最低三分位数的儿童，观察到与所有PA指标的关系更强，尤其是与高强度PA（r=0.572，P=0.003）。回归分析显示，高强度PA是FMD%/SR(AUC)受损的唯一预测因素。
这些数据表明，成年人群中冠心病的传统风险因素会影响年轻人的血管功能。此外，FMD受损的个体可能从进行高强度PA中受益，而在先验血管功能正常的受试者中，FMD与较低强度的PA之间或PA与FMD之间不存在关联。
