Barnard Christopher R, Peters Matthew, Sindler Amy L, Farrell Emily T, Baker Kim R, Palta Mari, Stauss Harald M, Dagle John M, Segar Jeffrey, Pierce Gary L, Eldridge Marlowe W, Bates Melissa L
Department of Health and Human Physiology, University of Iowa, Iowa City, IA, USA.
Department of Pediatrics, University of Wisconsin, Madison, WI, USA.
Physiol Rep. 2020 Jun;8(12):e14462. doi: 10.14814/phy2.14462.
Adults born prematurely have an increased risk of early heart failure. The impact of prematurity on left and right ventricular function has been well documented, but little is known about the impact on the systemic vasculature. The goals of this study were to measure aortic stiffness and the blood pressure response to physiological stressors; in particular, normoxic and hypoxic exercise.
Preterm participants (n = 10) were recruited from the Newborn Lung Project Cohort and matched with term-born, age-matched subjects (n = 12). Aortic pulse wave velocity was derived from the brachial arterial waveform and the heart rate and blood pressure responses to incremental exercise in normoxia (21% O ) or hypoxia (12% O ) were evaluated.
Aortic pulse wave velocity was higher in the preterm groups. Additionally, heart rate, systolic blood pressure, and pulse pressure were higher throughout the normoxic exercise bout, consistent with higher conduit artery stiffness. Hypoxic exercise caused a decline in diastolic pressure in this group, but not in term-born controls.
In this first report of the blood pressure response to exercise in adults born prematurely, we found exercise-induced hypertension relative to a term-born control group that is associated with increased large artery stiffness. These experiments performed in hypoxia reveal abnormalities in vascular function in adult survivors of prematurity that may further deteriorate as this population ages.
早产出生的成年人早期心力衰竭风险增加。早产对左心室和右心室功能的影响已有充分记录，但对全身血管系统的影响知之甚少。本研究的目的是测量主动脉僵硬度以及对生理应激源的血压反应；特别是常氧和低氧运动时的反应。
从新生儿肺部项目队列中招募早产参与者（n = 10），并与足月出生、年龄匹配的受试者（n = 12）进行匹配。通过肱动脉波形得出主动脉脉搏波速度，并评估在常氧（21% O₂）或低氧（12% O₂）状态下递增运动时的心率和血压反应。
早产组的主动脉脉搏波速度较高。此外，在整个常氧运动期间，心率、收缩压和脉压均较高，这与较高的传导动脉僵硬度一致。低氧运动导致该组舒张压下降，但足月出生的对照组未出现这种情况。
在关于早产出生的成年人运动时血压反应的首份报告中，我们发现相对于足月出生的对照组，运动诱发的高血压与大动脉僵硬度增加有关。在低氧状态下进行的这些实验揭示了早产成年幸存者的血管功能异常，随着该人群年龄增长，这种异常可能会进一步恶化。
