Background

Low muscle strength (dynapenia) is a primary characteristic of sarcopenia, the age-related loss of muscle mass and strength or low walking speed. New evidence suggests that muscle strength positively affects blood pressure (BP) responses to exercise. As older adults with lowest handgrip strength also have lowest BP at rest, those with dynapenia may experience attenuated BP responses during physical activity. The purpose of this study was to test the hypothesis that dynapenic older adults would exhibit lower BP response to post-exercise muscle ischemia (PEMI).

Methods

Brachial and aortic systolic BP (SBP), diastolic BP (DBP), and mean arterial pressure (MAP) were measured in older adults (age, 80 ± 5 y) with dynapenia (n = 16) and non-dynapenia (n = 9) at rest and during PEMI following 2 min of isometric handgrip exercise at 30% maximal voluntary contraction. Walking speed was assessed by an 8-foot (2.44 m) walk course.

Results

Increases in aortic SBP (11 ± 2 vs. 23 ± 6 mm Hg, p = .03), DBP (6 ± 2 vs.14 ± 4 mm Hg, p = .04), and MAP (8 ± 1 vs. 17 ± 5 mm Hg, p = .02) were lower in dynapenic compared to non-dynapenic adults. Aortic MAP (r = 0.52, p < .05) response to PEMI was correlated with MVC in dynapenic adults. Gait speed was correlated with aortic DBP response to PEMI (r = 0.698, p = .05) in non-dynapenic adults.

Conclusions

Our findings indicate that aortic DBP response to muscle metaboreflex activation is attenuated in older adults with dynapenia. Normal aortic DBP response during metaboreflex activation may positively affect walking performance in non-dynapenic older adults.

中文翻译：

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老年人活动障碍的主动脉血压对代谢反射激活的反应减弱。

背景

肌肉力量低下（运动障碍）是肌肉减少症的主要特征，是与年龄相关的肌肉质量和力量的丧失或步行速度低。新证据表明，肌肉力量会积极影响血压（BP）对运动的反应。由于握力最低的老年人在休息时的血压也最低，患有运动障碍的人在体育锻炼过程中可能会减弱BP反应。这项研究的目的是检验运动障碍的老年人对运动后肌肉缺血（PEMI）表现出较低的BP反应的假设。

方法

在患有运动障碍（n  = 16）和非运动障碍（n  = 9 ）的老年人（年龄80±5岁）中测量了肱和主动脉收缩压（SBP），舒张压（DBP）和平均动脉压（MAP））在等距手握运动后2分钟以30％最大主动收缩的静息时间和PEMI期间进行。通过8英尺（2.44 m）的步行路线评估步行速度。

结果

主动脉SBP（11±2 vs. 23±6 mm Hg，p  = .03），DBP（6±2 vs.14±4 mm Hg，p  = .04）和MAP（8±1 vs. 17）增加 与非动态性成人相比，动态性儿童中±5 mm Hg，p = .02）低。 在动力异常成人中，对PEMI的主动脉MAP（r  = 0.52，p <.05）与MVC相关。 在非活动性成人中 ，步态速度与主动脉DBP对PEMI的反应相关（r = 0.698，p = .05）。

结论

我们的研究结果表明，老年人的运动障碍患者对肌肉代谢反射激活的主动脉DBP反应减弱。代谢异常激活过程中正常的主动脉DBP反应可能会积极影响非运动障碍老年人的行走性能。