Sleep-related deglutition and respiratory phase patterns in the aged with obstructive sleep apnea under CPAP therapy

Background: Respiratory phase patterns associated with deglutition and clearance of pharynx by deglutition are important in protecting airways and lungs against aspiration.Aims/objectives: Sleep-related deglutition and respiratory phase patterns in the aged with obstructive sleep apnea (OSA) before and under CPAP therapy were investigated.Materials and methods: Ten aged adults with severe OSA under CPAP therapy were examined by polysomnography and surface electromyography of the muscles related to swallowing and compared with the same patients before CPAP therapy.Results: Under CPAP therapy, swallowing was also infrequent and absent for long periods. The deeper the sleep stage, the lower the deglutition frequency. The median number of swallows per hour during total sleep time was 1.5 and the median longest deglutition-free period was 74.5 min. Swallows following and/or followed by inspiration, which were observed a great deal before CPAP therapy, were markedly reduced. On the other hand, swallows following and/or followed by expiration markedly increased. Approximately, 73.5% of swallows occurred after expiration and approximately 66.8% were followed by expiration. Respiratory phase patterns associated with sleep-related deglutition improved under CPAP.Conclusions/significance: CPAP therapy improved sleep-related deglutition and respiratory phase patterns in the aged with OSA.