The effect of inspiratory muscle training on the quality of life, immune response, inspiratory and lower limb muscle strength of older adults: a randomized controlled trial

Abstract Objective: To evaluate the impact of inspiratory muscle training (IMT) on the quality of life, immune response, inspiratory and lower limb muscle strength of older adults. Method: A randomized clinical trial was conducted with 30 institutionalized older adults. They were allocated into two groups: the IMT group (n=15), which underwent IMT with PowerBreathe Classic, using a load of 60% of maximal inspiratory pressure (MIP). This was performed using a 30 repetition protocol, three times a week, for six weeks. The second group was the control group (n=15) which did not perform any type of therapeutic intervention. In both groups, MIP, lower limb strength by sit-up test, quality of life by the SF-36 questionnaire and C-reactive protein (CRP) were evaluated. Results: The results demonstrated the homogeneity between the groups regarding the demographic and clinical variables. The IMT group showed an increase in the variation of MIP (9.20±7.36 cmH2O) compared to the control (0.93±8.79 cmH2O). Improvement was also observed in the sitting and standing test (p<0.05) (Tukey Test) in the difference between the values before and after the IMT. In terms of quality of life, two of the eight SF-36 domains were influenced by the IMT, namely: functional capacity and limitations due to physical factors. There were no changes in CRP in either group. Conclusion: IMT improved the inspiratory muscle strength, lower limb strength and quality of life of institutionalized older adults. These findings reinforce the contribution of this therapy to reducing the deleterious effects of aging.

摘要
目的：评估呼吸肌训练（inspiratory muscle training, IMT）对老年人群的生活质量、免疫应答、呼吸肌与下肢肌力的影响。
方法：本研究针对30名机构养老老年人开展随机对照试验。将受试者分为两组：呼吸肌训练组（n=15），采用PowerBreathe Classic设备进行呼吸肌训练，训练负荷设置为最大吸气压（maximal inspiratory pressure, MIP）的60%，采用30次重复训练方案，每周训练3次，持续6周；对照组（n=15）未接受任何治疗性干预。两组均完成以下检测与评估：最大吸气压、通过仰卧起坐测试评估下肢肌力、采用SF-36量表评估生活质量，以及C反应蛋白（C-reactive protein, CRP）水平。
结果：两组的人口学与临床变量均具有组间均衡性。与对照组（0.93±8.79 cmH₂O）相比，呼吸肌训练组的最大吸气压变化量显著升高（9.20±7.36 cmH₂O）。坐立试验结果显示，呼吸肌训练组干预前后的指标差值具有统计学意义（p<0.05，Tukey检验（Tukey Test））。在生活质量方面，呼吸肌训练对SF-36量表的2个维度产生了显著影响，分别为躯体功能维度与躯体活动受限维度。两组的C反应蛋白水平均未出现明显变化。
结论：呼吸肌训练可提升机构养老老年人的呼吸肌肌力、下肢肌力并改善其生活质量。本研究结果进一步证实该疗法可缓解衰老带来的不良影响。