title: Sleep disordered breathing and subclinical impairment of respiratory function are common in sporadic inclusion body myositis.
abstract: 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 <80% predicted normal in 7; sniff nasal inspiratory pressure was reduced in 3; daytime hypoxemia was present in 9 and hypercapnia in one. Sleep study was performed in 15 and revealed sleep disordered breathing (apnoea-hypopnoea index 23.4±12.8 (range 7-50.3)events/h) in all. There were no consistent relationships between respiratory function impairment, occurrence of sleep disordered breathing, and severity of peripheral muscle weakness. Thus, asymptomatic impairment of respiratory function was common and sleep disordered breathing observed in all patients tested, irrespective of daytime respiratory function. This suggests respiratory function testing, including sleep study, should be performed routinely in IBM, irrespective of peripheral muscle function or other disease severity parameters.
authors.affiliation: Neurology Department, Hospital General Universitario Gregorio Marañón, Madrid, Spain; Western Australia Neurosciences Research Institute and Centre for Neuromuscular and Neurological Disorders, University of Western Australia, Queen Elizabeth II Medical Centre, Perth, Australia.
authors.forename: Pedro M
authors.initials: PM
authors.lastname: Rodríguez Cruz
authors.affiliation: Western Australia Neurosciences Research Institute and Centre for Neuromuscular and Neurological Disorders, University of Western Australia, Queen Elizabeth II Medical Centre, Perth, Australia; Institute of Immunology and Infectious Diseases, Murdoch University, Perth, Australia.
authors.forename: Merrilee
authors.initials: M
authors.lastname: Needham
authors.affiliation: Department of Clinical Immunology, PathWest, Queen Elizabeth II Medical Centre, Perth, Australia.
authors.forename: Peter
authors.initials: P
authors.lastname: Hollingsworth
authors.affiliation: Western Australia Neurosciences Research Institute and Centre for Neuromuscular and Neurological Disorders, University of Western Australia, Queen Elizabeth II Medical Centre, Perth, Australia; Institute of Immunology and Infectious Diseases, Murdoch University, Perth, Australia.
authors.forename: Frank L
authors.initials: FL
authors.lastname: Mastaglia
authors.affiliation: West Australian Sleep Disorders Research Institute, Department of Pulmonary Physiology and Sleep Medicine, Sir Charles Gairdner Hospital, Perth, Australia. Electronic address: David.Hillman@health.wa.gov.au.
authors.forename: David R
authors.initials: DR
authors.lastname: Hillman
mesh_terms: D000328:Adult; D000368:Aged; D001784:Blood Gas Analysis; D003430:Cross-Sectional Studies; D003679:Deglutition; D005260:Female; D006801:Humans; D007165:Immunosuppression Therapy; D008297:Male; D008875:Middle Aged; D018979:Myositis, Inclusion Body / Q000188:drug therapy / Q000503:physiopathology*; D012120:Respiration Disorders / Q000503:physiopathology*; D012129:Respiratory Function Tests; D012891:Sleep Apnea Syndromes / Q000503:physiopathology*
keywords: Obstructive sleep apnea; Respiratory failure; Respiratory function; Sleep disordered breathing; Sporadic inclusion body myositis