Sleep, lung function, and quality of life in patients with myasthenia gravis: A cross-sectional study

The purpose of this study was to investigate the physiological variables of lung function, respiratory muscle strength, and sleep in clinically stable patients with myasthenia gravis. This was a prospective cross-sectional study conducted in accordance with the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement. Patients adhering to the eligibility criteria were consecutively recruited from the Research Department of Neuromuscular Diseases at the Federal University of Sao Paulo and the Department of Neurology at Santa Casa de Misericordia of Sao Paulo and were referred to the Nove de Julho University Sleep Laboratory (Sao Paulo, Brazil). The study included 25 patients (21 female) with a mean age of 45.28 ± 12.33 years. Only one patient exhibited a restrictive ventilatory pattern. The maximum ventilatory pressures observed were considerably reduced in most patients as compared to reference values. In sleep studies, the patients exhibited significantly reduced oxygen saturation, reduced rapid eye movement sleep time, increased non-rapid eye movement stage 3 sleep, and considerable apnoea/hypopnoea indexes. Clinically stable patients with myasthenia gravis exhibit a high prevalence of sleep-disordered breathing, significant reductions in maximum ventilatory pressures, and impairment of health-related quality of life.