ABSTRACT
During the past 3 decades those interested in the interaction between sleep and breathing have focused their attention on obstructive sleep apnea (OSA). However, it is clear that sleep can alter breathing in a variety of ways that may occur independently of sleep apnea. Edward Smith reported in 1860 that ventilation is reduced during sleep in apparently healthy subjects (1). This has been confirmed multiple times in recent years, with the decrement in ventilation apparently resulting from a sleep-associated reduction in tidal volume (2,3).
