Swallowing is a vital function, and the clearance of the pharynx by deglutition, which removes matter at risk of being aspirated, and the respiratory phase patterns associated with deglutition are important for protecting the airways and lungs against aspiration.
We herein review the swallowing and respiratory phase patterns associated with deglutition during sleep in the aged.
During sleep, deglutition is extremely infrequent or absent for long periods of time in the aged. The deeper the sleep stage, the lower the mean deglutition frequency. Consequently, clearance of the pharynx and esophagus by deglutition is extremely reduced during sleep in the aged. Furthermore, respiratory phase patterns associated with deglutition display adverse patterns during sleep in the aged.
Regarding aged individuals with obstructive sleep apnea, swallowing following and/or followed by inspiration, which is observed a great deal before CPAP (continuous positive airway pressure) therapy, is markedly reduced during CPAP therapy. However, swallowing following and/or followed by expiration is markedly increased during CPAP therapy. Respiratory phase patterns associated with sleep-related deglutition are improved under CPAP therapy.
Due to the complexity of the swallowing process, many adverse health conditions can influence the swallowing functions during sleep in the aged. Sleep-related deglutition and respiratory phase patterns may adversely influence aspiration-related diseases, such as aspiration pneumonia, especially in the aged, not only in cases of primary presbyphagia but also those of secondary presbyphagia as well.
