Mayo Graduate School, Mayo Clinic, Rochester, Minnesota.
Division of Cardiovascular Diseases, Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota; and.
J Appl Physiol (1985). 2017 Jun 1;122(6):1425-1434. doi: 10.1152/japplphysiol.00694.2016. Epub 2017 Mar 23.
Aging is associated with deterioration in the structure and function of the pulmonary circulation. We characterized the lung diffusing capacity for carbon monoxide (DL), alveolar-capillary membrane conductance (Dm), and pulmonary-capillary blood volume (Vc) response to discontinuous incremental exercise at 25, 50, 75, and 90% of peak work (W) in four groups: ) Young [27 ± 3 yr, maximal oxygen consumption (V̇o): 110 ± 18% age predicted]; 2) Young Highly Fit (27 ± 3 yr, V̇o: 147 ± 8% age predicted); ) Old (69 ± 5 yr, V̇o: 116 ± 13% age predicted); and ) Old Highly Fit (65 ± 5 yr, V̇o: 162 ± 18% age predicted). At rest and at 90% W, DL, Dm, and Vc were decreased with age. At 90% W, DL, Dm, and Vc were greater in Old Highly Fit vs. Old adults. The slope of the DL-cardiac output (Q̇) relationship from rest to end exercise at 90% W was not different between Young, Young Highly Fit, Old, and Old Highly Fit (1.35 vs. 1.44 vs. 1.10 vs. 1.35 ml·mmHg·liter blood, = 0.388), with no evidence of a plateau in this relationship during exercise; this was also true for Dm-Q̇ and Vc-Q̇. V̇o was positively correlated with ) DL, Dm, and Vc at rest; and ) the rest to end exercise change in DL, Dm, and Vc. In conclusion, these data suggest that despite the age-associated deterioration in the structure and function of the pulmonary circulation, expansion of the pulmonary capillary network does not become limited during exercise in healthy individuals regardless of age or cardiorespiratory fitness level. Healthy aging is a crucial area of research. This article details how differences in age and cardiorespiratory fitness level affect lung diffusing capacity, particularly during high-intensity exercise. We conclude that highly fit older adults do not experience a limit in lung diffusing capacity during high-intensity exercise. Interestingly, however, we found that highly fit older individuals demonstrate greater values of lung diffusing capacity during high-intensity exercise than their less fit age-matched counterparts.
衰老是与肺循环的结构和功能恶化有关的。我们描述了在 25%、50%、75%和 90%的峰值工作（W）下，连续递增运动时一氧化碳的肺弥散能力（DL）、肺泡毛细血管膜传导率（Dm）和肺毛细血管血容量（Vc）的变化，分为四组：1）年轻组[27±3 岁，最大摄氧量（V̇o）：110±18%预测年龄]；2）年轻健康组[27±3 岁，V̇o：147±8%预测年龄]；3）老年组[69±5 岁，V̇o：116±13%预测年龄]；4）老年健康组[65±5 岁，V̇o：162±18%预测年龄]。在休息和 90%的 W 时，DL、Dm 和 Vc 随着年龄的增长而降低。在 90%的 W 时，老年健康组的 DL、Dm 和 Vc 大于老年组。从休息到 90%的 W 运动结束时，DL-心输出量（Q̇）关系的斜率在年轻、年轻健康、老年和老年健康组之间没有差异（1.35 对 1.44 对 1.10 对 1.35 ml·mmHg·liter blood，=0.388），在运动过程中没有出现此关系的平台；Dm-Q̇和 Vc-Q̇也是如此。V̇o 与休息时的）DL、Dm 和 Vc 呈正相关；和）休息到运动结束时 DL、Dm 和 Vc 的变化呈正相关。总之，这些数据表明，尽管与年龄相关的肺循环结构和功能恶化，但在健康个体中，无论年龄或心肺功能适应水平如何，在运动过程中，肺毛细血管网络的扩张并不会受到限制。健康老龄化是一个重要的研究领域。本文详细介绍了年龄和心肺功能适应水平的差异如何影响肺弥散能力，特别是在高强度运动期间。我们得出的结论是，高适应能力的老年成年人在高强度运动中不会出现肺弥散能力的限制。有趣的是，然而，我们发现，在高强度运动中，高适应能力的老年个体表现出比他们适应能力较差的同龄个体更高的肺弥散能力值。
