Cameron J D, Rajkumar C, Kingwell B A, Jennings G L, Dart A M
Department of Biomedical Engineering, La Trobe University, Melbourne, Australia.
J Am Geriatr Soc. 1999 Jun;47(6):653-6. doi: 10.1111/j.1532-5415.1999.tb01585.x.
Arterial compliance is an important therapeutic target in older individuals in whom stiffening of the proximal arterial circulation is thought to underlie systolic hypertension and increased cardiac work. We have shown previously that arterial compliance is related to aerobic fitness and that it is increased in young (20 to 35 years old), previously sedentary individuals by a 4-week period of moderate aerobic training. The extent to which compliance relates to exercise performance in a random selection of young older patients has not been reported previously. Therefore, we examined the interrelationship between systemic arterial compliance (SAC) and time to cessation of exercise during a standard treadmill exercise test in an older population.
A cross-sectional survey.
SAC was estimated at rest using simultaneous recordings of ascending aortic flow and carotid applanation tonometry in 43 subjects aged 67 +/- 7 years (mean +/- SD; 24 men and 19 women). Treadmill exercise testing was performed using a modified Bruce protocol. Aerobic capacity was assessed as Heart Rate-Blood Pressure product and exercise tolerance as total treadmill time.
SAC and exercise tolerance were related to gender, with men exhibiting greater exercise reserve and higher SAC than women. There was a significant positive correlation between SAC and time to cessation of exercise (r = .34; P = .03), with a negative correlation between SAC and resting heart rate-blood pressure product (r = -.66; P < .001). SAC was correlated with height and blood pressure. Exercise tolerance was related to height (P < .02).
These data indicate a positive association between SAC and fitness level in healthy older people and an inverse association between SAC and systolic blood pressure. Our findings are consistent with either (1) acquisition of a more compliant circulation and lower blood pressure through more physical activity or (2) that a more compliant arterial circulation and lower blood pressure permit greater athletic performance.
动脉顺应性是老年个体的一个重要治疗靶点，近端动脉循环硬化被认为是收缩期高血压和心脏做功增加的基础。我们之前已经表明，动脉顺应性与有氧适能相关，并且通过为期4周的适度有氧训练，年轻（20至35岁）、之前久坐不动的个体的动脉顺应性会增加。在随机选择的年轻老年患者中，顺应性与运动表现之间的关系程度此前尚未见报道。因此，我们在老年人群中，研究了标准跑步机运动试验期间全身动脉顺应性（SAC）与运动停止时间之间的相互关系。
横断面调查。
对43名年龄为67±7岁（均值±标准差；24名男性和19名女性）的受试者，通过同步记录升主动脉血流和颈动脉压平式眼压测量法在静息状态下估算SAC。使用改良的布鲁斯方案进行跑步机运动试验。将心率-血压乘积评估为有氧能力，将总跑步机时间评估为运动耐量。
SAC和运动耐量与性别有关，男性比女性表现出更大的运动储备和更高的SAC。SAC与运动停止时间之间存在显著正相关（r = 0.34；P = 0.03），SAC与静息心率-血压乘积之间存在负相关（r = -0.66；P < 0.001）。SAC与身高和血压相关。运动耐量与身高有关（P < 0.02）。
这些数据表明，在健康老年人中，SAC与体能水平呈正相关，与收缩压呈负相关。我们的研究结果与以下两种情况之一一致：（1）通过更多的体力活动获得更顺应的循环和更低的血压；（2）更顺应的动脉循环和更低的血压允许有更好的运动表现。
