Sleep disordered breathing in a cohort of patients with sporadic inclusion body myositis

Objective: The aims of the study were: (1) to evaluate subjective sleep quality and daytime sleepiness in patients affected by sporadic inclusion-body myositis (IBM); (2) to define the sleep and sleep-related respiratory pattern in IBM patients.

Methods: Thirteen consecutive adult patients affected by definite IBM were enrolled, six women and seven men, mean age 66.2 ± 11.1 years (range: 50-80). Diagnosis was based on clinical and muscle biopsy studies. All patients underwent subjective sleep evaluation (Pittsburgh Sleep Quality Index, PSQI and Epworth Sleepiness Scale, ESS), oro-pharingo-esophageal scintigraphy, pulmonary function tests, psychometric measures, anatomic evaluation of upper airways, and laboratory-based polysomnography. Findings in IBM patients were compared to those obtained from a control group of 25 healthy subjects (13 men and 12 women, mean age 61.9 ± 8.6 years).

Results: Disease duration was >10 years in all. Mean IBM severity score was 28.8 ± 5.4 (range 18-36). Dysphagia was present in 10 patients. Nine patients had PSQI scores ≥ 5; patients had higher mean PSQI score (IBM: 7.2 ± 4.7, CONTROLS: 2.76 ± 1.45, p=0.005); one patient (and no controls) had EES>9. Polysomnography showed that IBM patients, compared to controls, had lower sleep efficiency (IBM: 78.8 ± 12.0%,

Controls: 94.0 ± 4.5%, p<0.001), more awakenings (IBM: 11.9 ± 11.0, CONTROLS: 5.2 ± 7.5, p=0.009) and increased nocturnal time awake (IBM: 121.2 ± 82.0 min.,

Controls: 46.12 ± 28.8 min., p=0.001). Seven Patients (and no controls) had polysomnographic findings consistent with sleep disordered breathing (SDB).

Conclusion: Data suggest that sleep disruption, and in particular SDB, might be highly prevalent in IBM.

Significance: Data indicate that IBM patients have poor sleep and high prevalence of SDB.