Does inspiratory muscle training improve lung function and quality of life in people with inclusion body myositis? A pilot study.

Inclusion body myositis is the most common acquired myositis in adults, predominantly weakening forearm flexor and knee extensor muscles. Subclinical respiratory muscle weakness has recently been recognised in people with inclusion body myositis, increasing their risk of respiratory complications. Inspiratory muscle training, a technique which demonstrates efficacy and safety in improving respiratory function in people with neuromuscular disorders, has never been explored in those with inclusion body myositis. In this pilot study, six adults with inclusion body myositis (age range 53 to 81 years) completed eight weeks of inspiratory muscle training. Measures of respiratory function, quality of life, sleep quality and a two-minute walk test were performed pre and post-intervention. All participants improved their respiratory function, with maximal inspiratory pressure, sniff nasal inspiratory pressure and forced vital capacity increasing by an average of 50 % (p = .002), 43 % (p = .018) and 13 % (p = .003) respectively. No significant change was observed in quality of life, sleep quality or two-minute walk test performance. No complications occurred due to inspiratory muscle training This pilot study provides the first evidence that inspiratory muscle training may be safe and effective in people with Inclusion Body Myositis, potentially mitigating the complications of poor respiratory function.

Respiratory muscle training in neuromuscular disease: a systematic review and meta-analysis.

BACKGROUND: Neuromuscular disease causes a progressive decline in ventilatory function which respiratory muscle training may address. Previous systematic reviews have focussed on single diseases, whereas this study systematically reviewed the collective evidence for respiratory muscle training in children and adults with any neuromuscular disease. METHODS: Seven databases were searched for randomised controlled trials. Three reviewers independently reviewed eligibility, extracted characteristics, results, determined risk of bias and combined results using narrative synthesis and meta-analysis. RESULTS: 37 studies (40 publications from 1986-2021, n=951 participants) were included. Respiratory muscle training improved forced vital capacity (standardised mean difference (SMD) 0.40 (95% confidence interval 0.12-0.69)), maximal inspiratory (SMD 0.53 (0.21-0.85)) and maximal expiratory pressure (SMD 0.70 (0.35-1.04)) compared to control (usual care, sham or alternative treatment). No impact on cough, dyspnoea, voice, physical capacity or quality of life was detected. There was high degree of variability between studies. DISCUSSION: Study heterogeneity (children and adults, different diseases, interventions, dosage and comparators) suggests that the results should be interpreted with caution. Including all neuromuscular diseases increased the evidence pool and tested the intervention overall. CONCLUSIONS: Respiratory muscle training improves lung volumes and respiratory muscle strength in neuromuscular disease, but confidence is tempered by limitations in the underlying research.