Autonomic response of older women to the submaximal effort in the six-minute walk test: a cross-sectional study

ABSTRACT This cross-sectional study aimed to evaluate the autonomic response of older women in the six-minute walk test. In total, 32 women aged 60 years or older without a diagnosed health problem were evaluated during the six-minute walk test. To monitor the autonomic response, the following variables were considered: heart rate, systolic and diastolic blood pressure, respiratory rate, and perceived exertion. These variables were compared during rest, effort, and recovery. This study also sought a correlation between autonomic function variables and performance in the test and perceived exertion. Results showed that the effort made by older women in the six-minute walk test induces an autonomic response resulting in increased heart rate and systolic and diastolic blood pressure; however, the respiratory rate remained unchanged during the test. Diastolic blood pressure remained high during recovery. No correlation was found neither between perceived exertion and cardiovascular physiological response nor between distance covered and variation of the autonomic response or level of physical conditioning. Therefore, the effort spent in the six-minute walk test promotes an autonomic response in older women, increasing cardiovascular stress without increasing ventilation. In this context, the Borg scale was not representative of cardiovascular stress during the test.

摘要 本横断面研究旨在评估老年女性在六分钟步行试验（six-minute walk test）中的自主神经反应。本研究共纳入32名年龄≥60岁、未确诊存在健康问题的女性，对其在六分钟步行试验过程中的相关指标进行评估。为监测自主神经反应，本研究选取了以下变量：心率、收缩压、舒张压、呼吸频率及自觉劳累程度（perceived exertion）。研究分别在静息状态、运动阶段及恢复期对上述变量进行对比分析。本研究同时探讨了自主神经功能变量与试验表现及自觉劳累程度之间的相关性。结果显示，老年女性在六分钟步行试验中所承受的运动负荷可诱发自主神经反应，表现为心率、收缩压及舒张压升高，但试验全程呼吸频率未发生显著变化。恢复期舒张压仍维持在较高水平。本研究未发现自觉劳累程度与心血管生理反应之间存在相关性，亦未发现步行距离与自主神经反应变化或身体活动水平之间存在相关性。综上，老年女性在六分钟步行试验中所投入的运动负荷可引发自主神经反应，加重心血管应激，但未引起通气功能的提升。在此背景下，博格量表（Borg scale）无法有效反映该试验过程中的心血管应激状态。