Sleep Apnea: New Insights

Sleep apnea is the most common disorder of breathing during sleep. It is defined as repeated episodes of obstructive apnea and hypopnea during sleep, together with daytime sleepiness or altered cardiopulmonary function [1]. There are three syndromes of upper airway closure during sleep: obstructive sleep apnea (OSA), obstructive sleep hypopnea, and upper airway resistance. These three syndromes share two features: excessive daytime sleepiness and arousal associated with increased ventilatory effort in response to upper airway closure. The specific sites of narrowing or closure and upper airway dysfunction are influenced by the underlying neuromuscular tone, upper airway muscle synchrony, an…