Kalfon Roy, Campbell Jeremiah, Alvarez-Alvarado Stacey, Figueroa Arturo
Department of Nutrition, Food and Exercise Sciences, Florida State University, Tallahassee, FL, USA; Department of Molecular Genetics, The Rappaport Family Institute for Research in the Medical Sciences, Technion-Israel Institute of Technology, Haifa, Israel.
Department of Nutrition, Food and Exercise Sciences, Florida State University, Tallahassee, FL, USA;
Am J Hypertens. 2015 Nov;28(11):1332-8. doi: 10.1093/ajh/hpv043. Epub 2015 Apr 22.
Overweight/obese young men have increased sympatho-excitation to cold and pain stress-induced by the cold pressor test (CPT) that may lead to abnormal hemodynamic responses. Concurrent CPT and exercise may augment the sympathetic-induced increases in aortic blood pressure (BP), pressure wave reflection (augmentation index, AIx), and arterial stiffness (pulse wave velocity, PWV). Since obesity is related with hypertension and sympathetic activity, we evaluated the aortic hemodynamic and PWV responses to muscle metaboreflex activation imposed by postexercise muscle ischemia (PEMI) concurrent with CPT in overweight/obese men.
In 16 healthy (body mass index >25 and <40kg/m(2)) men (24±2 years), heart rate (HR), brachial BP, aortic BP, augmented pressure (AP), AIx, AIx adjusted to 75 beats/min (AIx@75), reflection time (Tr), first (P1) and second systolic peak (P2, wave reflection magnitude), and PWV (brachial-ankle PWV, baPWV) were evaluated at baseline, during isometric-handgrip exercise (IHG), and PEMI with (PEMI + CPT) and without CPT.
During IHG, brachial BP, aortic BP, AP, AIx, AIx@75, P1, and P2 increased ( P < 0.01) while Tr decreased ( P < 0.05) compared with baseline. During PEMI, all hemodynamic parameters remained elevated ( P < 0.05) and baPWV increased (P < 0.05) while Tr and HR returned to baseline. Compared with PEMI, the increases in HR, brachial BP, aortic BP, AIx@75, P1, P2, and baPWV were greater ( P < 0.05) during PEMI + CPT. During PEMI + CPT, Tr remained lower ( P < 0.05) than baseline.
Cold exposure with concurrent metaboreflex activation induces a significant increase in aortic hemodynamics and arterial stiffness, which may explain the high risk of adverse cardiovascular events during physiological stress.
Trial Number NCT02104375.
超重/肥胖的年轻男性对冷刺激和冷加压试验（CPT）诱导的疼痛应激的交感神经兴奋性增加，这可能导致异常的血流动力学反应。同时进行CPT和运动可能会增强交感神经引起的主动脉血压（BP）、压力波反射（增强指数，AIx）和动脉僵硬度（脉搏波速度，PWV）的升高。由于肥胖与高血压和交感神经活动有关，我们评估了超重/肥胖男性在CPT同时进行运动后肌肉缺血（PEMI）引起的肌肉代谢反射激活时的主动脉血流动力学和PWV反应。
对16名健康（体重指数>25且<40kg/m²）男性（24±2岁），在基线、等长握力运动（IHG）期间、以及有CPT（PEMI + CPT）和无CPT的PEMI期间，评估心率（HR）、肱动脉血压、主动脉血压、增强压（AP）、AIx、调整至75次/分钟的AIx（AIx@75）、反射时间（Tr）、第一个（P1）和第二个收缩期峰值（P2，波反射幅度）以及PWV（肱踝PWV，baPWV）。
与基线相比，在IHG期间，肱动脉血压、主动脉血压、AP、AIx、AIx@75、P1和P2升高（P < 0.01），而Tr降低（P < 0.05）。在PEMI期间，所有血流动力学参数均保持升高（P < 0.05），baPWV升高（P < 0.05），而Tr和HR恢复到基线水平。与PEMI相比，在PEMI + CPT期间，HR、肱动脉血压、主动脉血压、AIx@75、P1、P2和baPWV的升高幅度更大（P < 0.05）。在PEMI + CPT期间，Tr仍低于基线水平（P < 0.05）。
同时进行代谢反射激活的冷暴露会导致主动脉血流动力学和动脉僵硬度显著增加，这可能解释了生理应激期间发生不良心血管事件的高风险。
试验编号NCT02104375。
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