Zócalo Yanina, Marotta Marco, García-Espinosa Victoria, Curcio Santiago, Chiesa Pedro, Giachetto Gustavo, Bia Daniel
Physiology Department, School of Medicine, Centro Universitario de Investigación, Innovación y Diagnóstico Arterial (CUiiDARTE), Republic University, General Flores 2125, 11800, Montevideo, Uruguay.
Basic Medicine Department, School of Medicine, Clinical Hospital, Republic University, Avenida Italia w/n, 11600, Montevideo, Uruguay.
High Blood Press Cardiovasc Prev. 2017 Dec;24(4):371-386. doi: 10.1007/s40292-017-0207-2. Epub 2017 May 15.
The existing evidence indicates that primary prevention of atherosclerotic disease should begin in childhood. Detection of children and adolescents at risk for atherosclerosis may allow early intervention to decrease the atherosclerotic process, thereby preventing or delaying cardiovascular disease. Vascular reactivity (VR) is altered even by early atherosclerosis. Obesity is a main cardiovascular risk factor (CVRF) observed in childhood. If childhood obesity associates impaired macro and/or micro VR is controversial.
To characterize macro and micro VR analyzing the stimulus and vascular response temporal profiles in children and adolescents considering their body mass index (BMI); and to assess potential associations between subjects' characteristics and the hyperemic stimulus and/or VR.
Healthy subjects (n = 99, age 5-17 years, female 46%) were included. Considering the BMI, normal, overweight and obese groups were defined. CVRF exposure was assessed. Brachial flow-mediated dilation and reactive hyperemia, associated with transient ischemia (forearm cuff-inflation) were evaluated. Diameter, flow velocities, resistive indexes and shear-stress were determined before, during and after cuff-release. Complimentary VR indexes were computed. Aortic stiffness and aortic and brachial blood pressure were determined.
Obese showed the lowest and slowest macrovascular response (p < 0.05). Micro VR was not associated with obesity. Higher aortic stiffness levels were associated with slower macrovascular responses (p < 0.05).
Childhood obesity associates not only reduced, but also slowed macrovascular reactivity. Microvascular response to transient ischemia is preserved in obese children. Macro and microvascular responses would be non-associated phenomena in childhood. During childhood, VR dynamics would depend on the arterial stiffness.
现有证据表明，动脉粥样硬化疾病的一级预防应始于儿童期。识别有动脉粥样硬化风险的儿童和青少年，可能有助于早期干预以减缓动脉粥样硬化进程，从而预防或延缓心血管疾病。即使早期动脉粥样硬化也会改变血管反应性（VR）。肥胖是儿童期观察到的主要心血管危险因素（CVRF）。儿童肥胖是否伴有宏观和/或微观VR受损存在争议。
通过分析儿童和青少年的刺激和血管反应时间曲线，并考虑其体重指数（BMI）来表征宏观和微观VR；评估受试者特征与充血刺激和/或VR之间的潜在关联。
纳入健康受试者（n = 99，年龄5 - 17岁，女性占46%）。根据BMI定义正常、超重和肥胖组。评估CVRF暴露情况。评估肱动脉血流介导的舒张和反应性充血，以及与短暂性缺血（前臂袖带充气）相关的情况。在袖带松开前、期间和之后测定直径、流速、阻力指数和剪切应力。计算补充VR指数。测定主动脉僵硬度以及主动脉和肱动脉血压。
肥胖者表现出最低且最慢的大血管反应（p < 0.05）。微观VR与肥胖无关。较高的主动脉僵硬度水平与较慢的大血管反应相关（p < 0.05）。
儿童肥胖不仅伴有大血管反应性降低——而且反应减慢。肥胖儿童对短暂性缺血的微血管反应得以保留。在儿童期，宏观和微血管反应可能是不相关的现象。在儿童期，VR动态变化可能取决于动脉僵硬度。
