Insomnia Is Linked to Trouble Breathing - NYTimes.com: ". . . . The report, published in the current issue of the journal Sleep, found that chronic insomniacs woke an average of about 30 times a night, and that a brief respiratory problem — a drop in the volume of oxygen inhaled, due to a narrowed airway, for instance — preceded about 90 percent of those interruptions. None of the people had any idea they had breathing problems during sleep. The study is hardly conclusive, experts said, because it included only 20 people and had no control group of normal sleepers for comparison. But these experts said that it was worth following up, because it challenged the predominant theory of insomnia as a problem of “hyper-arousal,”. . . . "