Sleep-Disordered Breathing in MD-1 patients are common:obstructive sleep apnea (OSA), central apneas and nocturnal hypoventilacion Aim: To determine whether there is a relationship between sleep breathing disorders and clinical parameters such as symptoms of OSA, pulmonary function and degree of neuromuscular impairment Methods: Retrospective descriptive study of MD-1patients. We collected:symptoms of OSA and/or nocturnal hypoventilation, spirometry, arterial blood gases and muscle pressures and sleep test results. We analyzed the factors related to the presence of moderate OSA (AHI >15) Results: Patient´s characteristics in figure1.47patients(51%men /49%women), mean age 47.8 with BMI ≥30 in 27.7%. Only 36% reported any symptoms of OSA and/or nocturnal hypoventilation. 87% presented an AHI>5, with central apnea predominance in 44%. Factors related to AHI>15 are presented in figure2. A low nocturnal SATO2, with a CT90>10% was related to have an AHI >15. No differences were found in age, sex, obesity, OSA symptoms, pCO2 levels or functional parameters (FVC, MIP, MEP). Conclusions: 1)OSA is very common in MD1, with a high number of central apneas.2)It cannot be predicted on the symptoms, functional respiratory test or diurnal hypercapnia.3)Having a low nocturnal SATO2 and a CT 90> 10% are related to an IAH>15.4)So, we believe that nocturnal oximetry can have an important role in determining when to perform a sleep test, which will be preferably a PSG with capnography