Inspiratory Muscle Training on Balance, Falls and Diaphragm Thickness in the Elderly

The Effect of Inspiratory Muscle Training on Balance, Falls and Diaphragm Thickness in the Elderly: A Randomized Controlled Trial

Decreases in body muscle mass, function and strength occur with ageing and this condition is called "sarcopenia". It is known that sarcopenic elderly people fall more than non-sarcopenic elderly people, their balance is negatively affected, their diaphragm thickness decreases and their quality of life may decrease due to their lower functional capacity. Although exercise training, which is considered among the approaches in the treatment of sarcopenia, has been shown to be an effective method, the effects of inspiratory muscle training applied at different intensities are relatively limited. Therefore, in this study, we are investigating the effects of low [30% of maximal inspiratory pressure (MIP)] and moderate (50% of MIP) inspiratory muscle training on respiratory and peripheral muscle strength, physical performance, functional capacity, balance, fear of falling, quality of life, diaphragm thickness and stiffness in sarcopenic elderly. In this study, participants are randomly divided into 3 groups: a low-intensity inspiratory muscle training group, a moderate-intensity inspiratory muscle training group and control (sham) group by simple random method after being evaluated for respiratory and peripheral muscle strength, physical performance, functional capacity, balance, fear of falling, quality of life, diaphragm thickness and stiffness.

INTRODUCTION

The proportion of the elderly population compared to the total population is increasing worldwide. While this rate was 8.3% in 2015, it is predicted to reach 17.8% by 2060. Decreases in body muscle mass, function and strength occur with ageing and this condition is called "sarcopenia". The European Working Group on Sarcopenia in Older People (EWGSOP) defined sarcopenia as a syndrome characterized by a loss not only in muscle mass but also in muscle strength or physical performance, leading to movement disorders, hospitalization and falls. In studies, it was found that the frequency of falls in sarcopenic participants was higher than in non-sarcopenic participants. In addition, it has been shown that sarcopenia negatively affects balance in the elderly, sarcopenic participants have shorter standing times on one leg compared to non-sarcopenic participants, their diaphragm thickness decreases and their quality of life decreases due to their lower functional capacity.

In order to make a diagnosis of sarcopenia, the current situation of the participant should be analyzed in terms of "muscle mass", "muscle strength" and "physical performance". Methods such as Magnetic Resonance, Dual Energy X-ray Absorptiometry (DEXA), Computed Tomography, Bioimpedance Analysis (BIA), and circumference measurement are preferred in the evaluation of muscle mass; dynamometer is preferred in the evaluation of muscle strength; and tests such as walking speed, timed get up and go test, sit up and stand test from a chair are preferred in the evaluation of physical performance. Important approaches in the prevention and treatment of sarcopenia are exercise, physical activity and nutritional support. Exercise training in the treatment of sarcopenia has been shown to be an effective method to increase muscle mass and strength in the elderly. Both aerobic and resistance exercises have been shown to decrease the rate of decline in muscle mass and increase endurance with age. The literature shows that studies have focused especially on exercises involving peripheral muscles. However, sarcopenia may affect respiratory muscles in addition to peripheral muscles.

Respiratory muscle training is a specific exercise training applied to respiratory muscles using skeletal muscle training principles in order to increase respiratory muscle strength and endurance, correct the length-tension relationship of respiratory muscles and increase respiratory capacity. The most common approach to respiratory muscle training is the inspiratory threshold pressure loading method. In the only study in the literature to our knowledge that examined the effect of inspiratory muscle training in sarcopenic elderly, the authors compared the effect of peripheral and respiratory exercises on isometric knee extension and arm flexion strength, hand grip strength, inspiratory and expiratory muscle strength and walking speed, but did not examine the effect of training on functional capacity, balance, fear of falling, quality of life, diaphragm thickness and stiffness.

Studies on inspiratory muscle training in elderly participants have shown an increase in functional capacity and exercise capacity, improvement in inspiratory muscle strength and expiratory muscle strength, improvement in balance and physical performance, increase in diaphragm thickness, improvement in lower extremity muscle strength and improvement in quality of life; however, in the systematic review published in 2020 on inspiratory muscle training in the elderly, it was emphasized that the intensity of training (maximal inspiratory pressure-MIP) varies between 30% and 80%, and there is no consensus in the literature on loading. The effect of inspiratory muscle training at different intensities in a healthy elderly population was investigated for the first time by Martin-Sanchez et al. (2020), who emphasized the effectiveness of exercise performed at 20% and 40% of MIP. However, since there is no study to our knowledge on inspiratory muscle training applied at different intensities in sarcopenic elderly, our study will investigate the effects of low (30% of MIP) and moderate (50% of MIP) intensity inspiratory muscle training on respiratory and peripheral muscle strength, physical performance, functional capacity, balance, fear of falling, quality of life, diaphragm thickness and stiffness in sarcopenic elderly.

METHODS

Design:

Participants aged 65 years and over diagnosed with sarcopenia by the relevant physician in Gazi University Faculty of Medicine, Department of Internal Medicine, Geriatrics Division Outpatient Clinic are included. In this randomized controlled single-blind study, the participants are randomly divided into 3 groups: low-intensity inspiratory muscle training group, moderate-intensity inspiratory muscle training group and control (sham) group by simple random method after being evaluated. The evaluations are performed face to face at Gazi University Faculty of Medicine, Department of Internal Medicine, Division of Geriatrics. Except for respiratory muscle strength assessment, participants in the treatment group will be evaluated at baseline and at the 12th week after treatment; participants in the control group will be evaluated at baseline and at the end of the 12th week; respiratory muscle strength will be evaluated at baseline, at week 4, at week 8 and at week 12 in all groups. The Ethics Committee of Gazi University provided ethical approval (2022-19/12.12.2022). All participants included in the study will read and sign the written informed consent form prior to evaluation according to the principles of the Declaration of Helsinki. The rights of the participants are fully protected during the study procedures.

Sample Size:

In line with a similar study in the literature, using G*power software (version 3.1, Universitat Düsseldorf, Germany), the number of participants required to reach a power level of 0.80 at 5% type 1 error level with an effect size of 0.60 was determined as 30 participants.

Randomization and Blinding:

Before enrolment in the study, patients are randomly assigned to 3 groups according to an online randomization table (https://www.random.org, 2023-03-27, 11:16:08 UTC). The randomization program is computer-generated using a basic random number generator in blocks. Participants are blinded to the intervention groups that they are assigned to.

Statistical Analysis:

IBM SPSS Statistics 25 (Statistical Package for the Social Sciences) analysis program will be used for statistical analysis. Descriptive analyses will be calculated with minimum-maximum, mean±standard deviation (X±SD) and median (interquartile range-IQR) for numerical data. For categorical data, number (n) and percentage (%) values will be defined. The suitability of the data obtained from participants to normal distribution will be evaluated by Skewness, Kurtosis, Histogram Analysis, Kolmogorov-Smirnov Test and coefficient of variation ratio. The difference between the change in measurement values of participants according to the intervention programs will be calculated by ANOVA one-way analysis of variance if the data fits the normal distribution, and by Kruskal Wallis-H Test if the data does not fit the normal distribution. Post-hoc tests will be applied to investigate the differences between the groups.

Inclusion Criteria:

• being diagnosed with sarcopenia,
• 65 years of age or older,
• scoring above 21 on the Mini-Mental State Scale,
• volunteering to participate in the study.

Exclusion Criteria:

• active smoker or quit smoking in less than 5 years,
• undergone abdominal surgery, thoracic surgery or lower extremity surgery,
• fracture within the last 1 year,
• having a condition that prevents bioelectrical impedance measurement such as pacemaker, implant,
• having a disease such as pulmonary artery hypertension, glaucoma, an aneurysm that prevents the Valsalva manoeuvre,
• having hypertension that cannot be controlled with antihypertensive medication,
• having a neurological disease affecting mobility such as cerebrovascular disease, Parkinson's disease,
• having chronic inflammatory disease known to affect muscle metabolism, including uncontrolled diabetes (Hba1c>9), rheumatoid arthritis,
• presence of any acute and chronic cardiovascular disease such as unstable angina pectoris, recent myocardial infarction, uncontrolled cardiac arrhythmia, congestive heart failure, acute ischemic heart disease,
• presence of any acute and chronic pulmonary disease such as COPD, acute pulmonary embolism, pulmonary oedema,
• having a history of cancer.