Monahan K D, Dinenno F A, Seals D R, Clevenger C M, Desouza C A, Tanaka H
Human Cardiovascular Research Laboratory, Department of Kinesiology and Applied Physiology, University of Colorado at Boulder, 80309, USA.
Am J Physiol Heart Circ Physiol. 2001 Jul;281(1):H284-9. doi: 10.1152/ajpheart.2001.281.1.H284.
Cardiovagal baroreflex sensitivity (BRS) declines with advancing age in humans, but the underlying mechanism has not been established. Using two different approaches, we determined the relation between age-associated decline in cardiovagal BRS and the compliance of an artery in which arterial baroreceptors are located. First, we measured carotid artery compliance (via the simultaneous application of ultrasonography and arterial applanation tonometry) and cardiovagal BRS (phase IV of the Valsalva maneuver) in 47 healthy sedentary men that varied widely in age (19--76 yr). Cardiovagal BRS declined progressively with age (r = -0.69; P < or = 0.001) and was positively related to carotid artery compliance (r = 0.71; P < or = 0.001). Stepwise multiple-regression analysis revealed that carotid artery compliance was the strongest independent physiological correlate of cardiovagal BRS and that it explained 51% of the total variance. Second, we studied 13 middle-aged and older previously sedentary men (age 56 +/- 2 yr) before and after 13 wk of aerobic exercise intervention. Regular exercise increased both cardiovagal BRS and carotid artery compliance (P < 0.05) and the two events were strongly and positively related (r = 0.72; P < 0.01). We conclude that reduced carotid artery compliance may play an important mechanistic role in age-associated decrease in cardiovagal BRS in healthy sedentary humans.
在人类中，心血管迷走神经压力反射敏感性（BRS）会随着年龄的增长而下降，但其潜在机制尚未明确。我们采用两种不同的方法，确定了与年龄相关的心血管迷走神经BRS下降与动脉压力感受器所在动脉顺应性之间的关系。首先，我们在47名年龄跨度较大（19 - 76岁）的健康久坐男性中测量了颈动脉顺应性（通过同时应用超声和动脉压平式眼压计）和心血管迷走神经BRS（瓦尔萨尔瓦动作的第四阶段）。心血管迷走神经BRS随年龄逐渐下降（r = -0.69；P≤0.001），且与颈动脉顺应性呈正相关（r = 0.71；P≤0.001）。逐步多元回归分析显示，颈动脉顺应性是心血管迷走神经BRS最强的独立生理相关因素，它解释了总方差的51%。其次，我们研究了13名年龄较大的中年久坐男性（年龄56±2岁）在进行13周有氧运动干预前后的情况。规律运动增加了心血管迷走神经BRS和颈动脉顺应性（P < 0.05），且这两个变化密切正相关（r = 0.72；P < 0.01）。我们得出结论，在健康久坐人群中，颈动脉顺应性降低可能在与年龄相关的心血管迷走神经BRS下降中起重要的机制性作用。
