Smoking Increases Risks of Sleep Disturbance

5 February 2008

New research by scientists at the Johns Hopkins University School of Medicine shows that cigarette smokers are four times as likely as non-smokers to report feeling tired and not rested after a night’s sleep. The study also revealed that smokers spend less time in REM (deep) sleep and more time in lighter sleep than non-smokers. Researchers think less restful sleep pattern is due to the withdrawal effects of nicotine when the smoker sleeps.

“It is possible that smoking has time-dependent effects across the sleep period,” said study author Naresh M Punjabi, MD, PhD, FCCP, Johns Hopkins University School of Medicine, Baltimore, MD. “Smokers commonly experience difficulty falling asleep due to the stimulating effects of nicotine. As night evolves, withdrawal from nicotine may further contribute to sleep disturbance.”

Dr Punjabi and his fellow researchers compared the sleep patterns of 40 smokers and 40 non-smokers with a home polysomnography. The participants of this study were healthy (free of any significant disease) and were not taking any medication, in order to remove all health factors that could contribute to bad sleep patterns.

The study was also analysed using both a conventional method - visual classification of electroencephalogram (EEG) patterns - and a non-conventional method - power spectral analysis of the EEG, which relies on a mathematical analysis of different frequencies contained within the sleep EEG. These two methods gave a better picture of the sleep patterns of the individuals in the study.

The participants were questioned about sleep quality:

• 22.5% of smokers reported lack of restful sleep
• 5.0% of non-smokers reported lack of restful sleep

The scientific results correlated with the participants report of lack of sleep and this supports the researchers theory that nicotine's effects are strongest in the early stages of sleep and potentially decrease throughout the sleep cycle. The researchers advised that this research may have implications in ways to help people stop smoking.

“The long-term effects of smoking on respiratory and cardiovascular health are well-known,” said Alvin V. Thomas, Jr., MD, FCCP, and President of the ACCP. “However, this study is significant because it suggests that smokers may also be deprived of the much-needed restorative effects of sleep. This study provides yet one more reason to stop smoking or to never start.”

The study appears in the February issue of CHEST, the peer-reviewed journal of the American College of Chest Physicians (ACCP).



Resources
American College of Chest Physicians. Smoking linked to sleep disturbances. Accessed 8 February 2008