Inspiratory Muscle Training in Individuals With Multiple Sclerosis

Official title

Comparison of the Effects of High-Intensity and Low-Intensity Inspiratory Muscle Training in Individuals With Multiple Sclerosis

Overview

Multiple sclerosis (MS) is a chronic disease affecting the central nervous system, characterized by inflammation, demyelination, and axonal degeneration, and primarily affects young adults. Muscle weakness, sensory disturbances, spasticity, pain, visual impairment, ataxia, fatigue, cognitive dysfunction, and respiratory complications are among the most commonly reported symptoms in individuals with MS. Although inspiratory muscle training has been shown to have beneficial effects in individuals with MS, the effects of different inspiratory muscle training intensities on respiratory muscle strength and pulmonary function have not been sufficiently investigated. The primary aim of this study is to investigate the effectiveness and clinical feasibility of high-intensity interval inspiratory muscle training in individuals with MS. The secondary aim is to compare the effects of high-intensity interval inspiratory muscle training, low-intensity inspiratory muscle training, and conventional rehabilitation on respiratory muscle strength, pulmonary function, cough effectiveness, exercise capacity, lower extremity functional muscle strength, balance, fatigue, dysphagia severity, sleep quality, and quality of life in individuals with MS. Participants will be randomly assigned to one of three groups: a high-intensity interval inspiratory muscle training group, a low-intensity inspiratory muscle training group, or a conventional rehabilitation group. All three groups will receive conventional rehabilitation, while the inspiratory muscle training groups will additionally receive their respective inspiratory muscle training programs. This study aims to be the first randomized controlled trial to evaluate the effects of high-intensity interval inspiratory muscle training in individuals with MS.

Detailed description

Multiple sclerosis (MS) is a chronic autoimmune disease affecting the central nervous system. Although the pathogenesis of the disease is not fully understood, genetic and environmental factors are thought to contribute to its development. Demyelinating plaques, the primary pathological hallmark of MS, are most commonly found in the optic nerves, brainstem, spinal cord, and periventricular white matter. The clinical manifestations of the disease vary depending on the regions of the central nervous system affected and the extent of inflammation and axonal demyelination. Respiratory function and respiratory muscle strength have been shown to be lower in individuals with MS compared with healthy individuals. The risk of death due to respiratory complications is approximately 12 times higher in the MS population than in the general population, and 47% of MS-related deaths are attributed to respiratory complications. These findings highlight the critical importance of early interventions targeting respiratory function.

Although inspiratory muscle training (IMT) has been shown to improve respiratory function, its effects on functional outcomes in individuals with MS have not been sufficiently investigated. However, these functional outcomes are important for improving quality of life and optimizing rehabilitation in individuals with MS. Furthermore, because studies investigating IMT in individuals with MS are limited, the optimal training protocol in terms of training frequency, intensity, and duration has not yet been clearly established. Recent studies have demonstrated that high-intensity interval IMT is effective in improving respiratory function, respiratory muscle strength, and functional capacity in individuals with chronic obstructive pulmonary disease, bronchiectasis, and heart failure, and that it is well tolerated by patients. To the best of our knowledge, no study has investigated the effects of this approach in individuals with MS.

This study is designed as a randomized controlled trial. A total of 48 individuals diagnosed with MS will be randomly assigned to one of three groups: high-intensity interval IMT, low-intensity IMT, or conventional rehabilitation. The intervention period will last 8 weeks. All three groups will receive conventional rehabilitation consisting of aerobic and resistance exercises. In addition, the IMT groups will receive either high-intensity interval IMT or low-intensity IMT. The primary outcome measures of the study are respiratory muscle strength, pulmonary function, and cough strength. Secondary outcome measures include exercise capacity, lower extremity functional muscle strength, balance, fatigue, dysphagia severity, sleep quality, and quality of life.

Interventions

• Behavioral High intensity interval IMT
  Participants with multiple sclerosis (MS) in this group will perform high intensity interval inspiratory muscle training (IMT) for 8 weeks, three times per week (one supervised by a physiotherapist and two home-based sessions). The protocol consists of 7 cycles of 2 minutes of exercise followed by 1 minute of rest, with each session lasting 21 minutes. Training intensity will start at 30% of maximal inspiratory pressure (MIP) and progressively increase to 70% by the third week. From week 4 onwar
• Behavioral Low intensity IMT
  Participants with multiple sclerosis (MS) in this group will perform low intensity inspiratory muscle training (IMT) for 8 weeks, consisting of five sessions per week: one supervised by a physiotherapist and four home-based supervised sessions. The training will be performed as two daily sessions of 15 minutes each, totaling 30 minutes per day. Low intensity IMT will be conducted at 30% of maximal inspiratory pressure (MIP). Training intensity will be reassessed and adjusted to 30% of MIP every
• Behavioral Conventional rehabilitation
  Participants in this group will undergo a conventional rehabilitation program for 8 weeks, consisting of three sessions per week: one supervised by a physiotherapist and two home-based supervised sessions. Each session will last approximately 40 minutes. The program will include warm-up exercises, aerobic exercises, strengthening exercises, balance exercises, and cool-down exercises.

Primary outcome measures

• Maximal inspiratory pressure (MIP) [Time frame: From baseline to the end of the intervention at 8 weeks]
• Maximal expiratory pressure (MEP) [Time frame: From baseline to the end of the intervention at 8 weeks]
• Forced Vital Capacity (FVC) [Time frame: From baseline to the end of the intervention at 8 weeks]
• Forced Expiratory Volume (FEV1) [Time frame: From baseline to the end of the intervention at 8 weeks]
• Tiffeneau Index (FEV1/FVC) [Time frame: From baseline to the end of the intervention at 8 weeks]
• Peak Expiratory Flow (PEF) [Time frame: From baseline to the end of the intervention at 8 weeks]
• Cough strength [Time frame: From baseline to the end of the intervention at 8 weeks]

Secondary outcome measures (8)

• Exercise capacity [Time frame: From baseline to the end of the intervention at 8 weeks]
• Lower Extremity Functional Capacity [Time frame: From baseline to the end of the intervention at 8 weeks]
• Balance [Time frame: From baseline to the end of the intervention at 8 weeks]
• Balance [Time frame: From baseline to the end of the intervention at 8 weeks]
• Fatigue level [Time frame: From baseline to the end of the intervention at 8 weeks]
• Dysphagia severity [Time frame: From baseline to the end of the intervention at 8 weeks]
• Sleep quality [Time frame: From baseline to the end of the intervention at 8 weeks]
• The Multiple Sclerosis Quality of Life-54 (MSQOL-54) [Time frame: From baseline to the end of the intervention at 8 weeks]

Eligibility criteria

Inclusion criteria

• Diagnosis of multiple sclerosis (MS) according to the 2024 McDonald criteria
• Expanded Disability Status Scale (EDSS) score ≥2 and <6
• Age between 18 and 65 years
• Mini-Mental State Examination (MMSE) score >24
• Willingness to participate in the study

Exclusion criteria

• Experiencing an MS relapse within the past three months
• Presence of chronic cardiac or pulmonary diseases that may affect respiratory muscle strength and function, such as COPD, asthma, interstitial lung disease, or heart failure
• Presence of pulmonary infection
• Presence of orthopedic problems
• Presence of psychiatric disorders
• Pregnancy

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Open label

Primary purpose

Treatment

Study locations

Center list to be confirmed — check the primary protocol.

Identifiers

NCT: NCT07672535 · ZApaydın-1

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗