Sleep disordered breathing and subclinical impairment of respiratory function are common in sporadic inclusion body myositis

Relatively little is known about frequency and extent of respiratory problems in sporadic inclusion body myositis (IBM). To address this issue a study of peripheral muscle and respiratory function and related symptoms was performed in a cohort with biopsy-proven IBM. Dyspnoea, daytime sleepiness, dysphagia, spirometry, respiratory muscle strength, arterial blood gas tensions and ventilation during sleep were assessed. Sixteen patients were studied (10 males; age 68.1±9.9years; disease duration 11.9±5.0years; body mass index 28.5±4.0kg/m(2)). Four reported excessive daytime sleepiness; 8 had at least mild dysphagia; forced vital capacity was