Inflammatory Myopathies
Conditions
Keywords
Inspiratory muscle training, Diaphragm ultrasound, Respiratory muscle strength, Exercise tolerance
Brief summary
Inflammatory myopathies are rare autoimmune diseases leading to progressive muscle weakness, often including the respiratory muscles. This study aims to investigate whether inspiratory muscle training (IMT) using a threshold device can improve functional status in patients with inflammatory myopathy. Thirty-three patients will undergo a 3-month home-based IMT program with progressive resistance. Functional capacity, inspiratory muscle strength, lung function, diaphragmatic mobility, fatigue, and quality of life will be assessed at baseline and during follow-up. The primary hypothesis is that IMT will enhance inspiratory muscle strength and translate into better functional performance and quality of life.
Detailed description
Idiopathic inflammatory myopathies (IIM) are rare autoimmune disorders characterized by progressive, symmetrical proximal muscle weakness, frequently affecting the respiratory muscles. Diaphragmatic dysfunction and reduced inspiratory muscle strength contribute to impaired ventilation, fatigue, and reduced exercise tolerance. While exercise training has proven beneficial in patients with various neuromuscular conditions, evidence regarding inspiratory muscle training (IMT) in IIM is lacking. This pilot interventional study will prospectively evaluate the impact of a 3-month IMT program on respiratory and functional outcomes in patients with IIM. The intervention consists of daily inspiratory resistance training (30 breaths/day, 7 days/week) using the Threshold IMT device (Philips Respironics, USA). Training intensity is set at 30% of maximal inspiratory pressure (MIP) and adjusted progressively based on patient-reported exertion. Participants receive individualized instruction, follow-up phone consultations every 2 weeks, and record adherence in exercise diaries. Assessments include inspiratory muscle strength (measured with Powerbreathe KH2), spirometry (Forced Expiratory Volume in 1 Second, Forced Vital Capacity, Forced Inspiratory Vital Capacity, Inspiratory Reserve Volume), diaphragm ultrasound (mobility and thickness fraction), six-minute walk test (6MWT), fatigue assessment (Borg Rating of Perceived Exertion Scale, Fatigue Severity Scale), and quality of life (36-Item Short Form Health Survey). Outcomes will be measured 3 months before training, at baseline, after 3 months of training, and during extended follow-up (up to 6-12 months). The primary endpoint is change in MIP. Secondary endpoints include pulmonary function parameters, diaphragmatic function, exercise tolerance, fatigue, and health-related quality of life. The study will be conducted in the Neurology Clinic of the Medical University of Warsaw (WUM). A total of 33 patients with IIM, diagnosed according to European Alliance of Associations for Rheumatology / American College of Rheumatology criteria, will be recruited. Inclusion requires age ≥18 and written informed consent. Exclusion criteria include cognitive impairment, acute respiratory infection, prior respiratory training, pneumothorax, pulmonary hypertension, or contraindications to IMT. This trial is expected to provide the first structured evidence on the role of IMT in improving functional status in patients with inflammatory myopathy, potentially guiding individualized rehabilitation strategies for this patient population.
Interventions
BEHAVIORALInspiratory Muscle Training (IMT)
Inspiratory muscle training performed with a threshold loading device (Threshold IMT, Philips Respironics). Participants perform 30 breaths once daily, 7 days per week, for 3 months. The training load is set at 30% of maximal inspiratory pressure (MIP) and increased by 10% if the perceived exertion decreases on two consecutive training days. Participants receive individualized instruction and regular follow-up consultations (every 2 weeks) to adjust load and verify adherence.
Sponsors
Józef Piłsudski University of Physical Education
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
SUPPORTIVE_CARE
Masking
NONE
Intervention model description
This is a single-group, prospective pilot intervention study evaluating the effects of inspiratory muscle training on functional status in patients with inflammatory myopathy. All participants receive the same inspiratory muscle training program and are followed for 12 months
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Diagnosis of inflammatory myopathy according to European Alliance of Associations for Rheumatology / American College of Rheumatology criteria * Age ≥ 18 years * Stable clinical condition allowing participation in physical activity * Ability to understand and follow instructions * Written informed consent to participate in the study
Exclusion criteria
* Cognitive impairment preventing proper exercise performance * Current respiratory tract infection * Previous respiratory muscle training within the last 12 months * History of spontaneous pneumothorax * Pulmonary hypertension * Tympanic membrane rupture or other middle ear pathology * Lack of voluntary and informed consent
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in maximal inspiratory pressure (MIP) | 3 months before training, baseline, 3 months (end of training), 6 months, 9 months, 12 months | Maximal inspiratory pressure (MIP) measured at the mouth using Powerbreathe KH2 devices. Results are expressed in cmH₂O. Higher values indicate greater inspiratory muscle strength. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in Forced Vital Capacity (FVC) | 3 months before training, baseline, 3 months (end of training), 6 months, 9 months, 12 months | Forced Vital Capacity (FVC) assessed by spirometry using the EasyOne spirometer (NDD Medical Technologies). Results are expressed in liters (L) and as percent of predicted values (% predicted). Higher values indicate better pulmonary function. |
| Change in Forced Expiratory Volume in 1 Second (FEV1) | 3 months before training, baseline, 3 months (end of training), 6 months, 9 months, 12 months | Forced Expiratory Volume in 1 Second (FEV1) assessed by spirometry using the EasyOne spirometer (NDD Medical Technologies). Results are expressed in liters (L) and as percent of predicted values (% predicted). Higher values indicate better pulmonary function. |
| Change in diaphragm thickness | 3 months before training, baseline, 3 months (end of training), 6 months, 9 months, 12 months | Diaphragm thickness assessed by ultrasound using a Philips Lumify linear probe. Thickness is measured in millimeters (mm) at end-expiration and end-inspiration. Diaphragm thickening fraction (%) may be calculated from inspiratory and expiratory thickness measurements. |
| Change in 6-Minute Walk Distance (6-Minute Walk Test) | 3 months before training, baseline, 3 months (end of training), 6 months, 9 months, 12 months | Functional exercise capacity assessed by the 6-Minute Walk Test (6MWT), conducted on a 30 m corridor. The total distance walked in 6 minutes is recorded in meters. Greater distance indicates better functional exercise capacity. |
| Change in perceived exertion (Borg Rating of Perceived Exertion) | 3 months before training, baseline, 3 months (end of training), 6 months, 9 months, 12 months | Perceived exertion assessed using the Borg Rating of Perceived Exertion Scale (modified 0-10 scale). The scale ranges from 0 (no exertion) to 10 (maximal exertion), with higher scores indicating greater perceived exertion and fatigue. |
| Change in fatigue severity (Fatigue Severity Scale) | 3 months before training, baseline, 3 months (end of training), 6 months, 9 months, 12 months | Fatigue assessed using the Fatigue Severity Scale (FSS), a 9-item questionnaire in which each item is scored from 1 (strongly disagree) to 7 (strongly agree). The total score is calculated as the mean of the 9 items (range 1-7), with higher scores indicating greater fatigue severity. |
| Change in quality of life (36-Item Short Form Health Survey) | 3 months before training, baseline, 3 months (end of training), 6 months, 9 months, 12 months | Health-related quality of life assessed using the 36-Item Short Form Health Survey (SF-36). The questionnaire includes eight domains scored from 0 to 100, with higher scores indicating better health status and quality of life. |
Countries
Poland
Contacts
CONTACTJan Sznajder, PhD
CONTACTAgnieszka Lewińska, PhD
Outcome results
None listed