Peterson Linda R, Rinder Morton R, Schechtman Kenneth B, Spina Robert J, Glover Kathryn L, Villareal Dennis T, Ehsani Ali A
Claude D. Pepper Older Americans Independence Center, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
J Appl Physiol (1985). 2003 Mar;94(3):1108-14. doi: 10.1152/japplphysiol.00397.2002. Epub 2002 Nov 8.
One of the most debilitating effects of primary aging is the decline in aerobic exercise capacity. One of its causes is an age-related decline in peak exercise stroke volume. This study's main purpose was to determine the cardiovascular adaptations to aging that most influence peak exercise stroke volume in the elderly. We hypothesized that increased left ventricular (LV) filling and mild concentric LV remodeling would be associated with an increase in peak exercise stroke volume corrected for lean body mass (LBM) and that an increased augmentation index (AI), which is a marker of arterial stiffness, would be associated with a decrease. A second aim was to determine the adaptations to aging that most influence LV concentric remodeling in the elderly. We hypothesized that AI would be a predictor of LV mass/LBM and the LV posterior wall thickness-to-LV radius ratio (h/r). We performed a cross-sectional study of cardiac and vascular adaptations to aging in 52 sedentary, elderly subjects. LV filling [as measured by the early-to-late transmitral flow velocity ratio (E/A)] was inversely correlated with and was an independent predictor of peak exercise stroke volume/LBM and was also a predictor of LV remodeling. AI was a predictor of LV remodeling (LV mass/LBM) but not of peak exercise stroke volume/LBM. We conclude that 1) maintenance of LV filling (E/A <1) is associated with a higher peak exercise stroke volume/LBM in very elderly subjects and thus may be a useful adaptation that enhances stroke volume during peak exercise, 2) LV remodeling and AI are less influential on peak exercise stroke volume/LBM, and 3) AI was the most important predictor of LV remodeling.
自然衰老最具损害性的影响之一是有氧运动能力下降。其原因之一是与年龄相关的运动高峰时每搏输出量下降。本研究的主要目的是确定对衰老的心血管适应性变化中，哪些对老年人运动高峰时每搏输出量影响最大。我们假设，左心室（LV）充盈增加和轻度向心性LV重塑与经去脂体重（LBM）校正后的运动高峰时每搏输出量增加有关，而作为动脉僵硬度标志物的增强指数（AI）增加则与之降低有关。第二个目的是确定对衰老的适应性变化中，哪些对老年人LV向心性重塑影响最大。我们假设AI将是LV质量/LBM和LV后壁厚度与LV半径之比（h/r）的预测指标。我们对52名久坐不动的老年受试者进行了一项关于心脏和血管对衰老适应性变化的横断面研究。LV充盈[通过二尖瓣血流速度早期与晚期比值（E/A）测量]与运动高峰时每搏输出量/LBM呈负相关，并且是其独立预测指标，也是LV重塑的预测指标。AI是LV重塑（LV质量/LBM）的预测指标，但不是运动高峰时每搏输出量/LBM 的预测指标。我们得出结论：1）在高龄受试者中，维持LV充盈（E/A<1）与较高的运动高峰时每搏输出量/LBM相关，因此可能是一种在运动高峰时增加每搏输出量的有益适应性变化；2）LV重塑和AI对运动高峰时每搏输出量/LBM的影响较小；3）AI是LV重塑最重要的预测指标。
