Smokers are four times more likely than nonsmokers to report sleep problems, and researchers say that nicotine may disrupt sleep patterns and prevent smokers from experiencing deep sleep, the Baltimore Sun reported Feb. 5.

Researcher Naresh M. Punabi and colleagues at Johns Hopkins School of Medicine found that smokers spent more time in light sleep and less time in deep sleep than nonsmokers. Punabi said that nicotine's stimulant effect along with resulting withdrawal symptoms in the middle of the night are likely to blame. "Some of the heaviest smokers will actually reach for a cigarette during the night when they wake up," Punjabi said. "Then, they may not be able to get back to sleep."

The researchers drew their conclusions from electroencephalograms (EEG) scans on 40 smokers and 40 nonsmokers and interviews on sleep and fatigue.

The study was published in the February 2008 issue of the journal Chest.