This Article Full Text Full Text (PDF) All Versions of this Article: chest.07-1190v1 133/2/427    most recent Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Add to My Personal Article Archive Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Zhang, L. Articles by Punjabi, N. M. Search for Related Content PubMed PubMed Citation Articles by Zhang, L. Articles by Punjabi, N. M.

Power Spectral Analysis of EEG Activity During Sleep in Cigarette Smokers^*

^* From the Departments of Epidemiology (Drs. Zhang, Samet, and Punjabi) and Biostatistics (Dr. Caffo), and Applied Physics Laboratory (Dr. Bankman), Johns Hopkins University, Baltimore, MD.

Correspondence to: Naresh M. Punjabi, MD, PhD, FCCP, Johns Hopkins University Asthma and Allergy Center, 5501 Hopkins Bayview Circle, Baltimore, MD 21224; e-mail: npunjabi{at}jhmi.edu

Abstract

Background: Research on the effects of cigarette smoking on sleep architecture is limited. The objective of this investigation was to examine differences in sleep EEG between smokers and nonsmokers.

Methods: Smokers and nonsmokers who were free of all medical comorbidities were matched on different factors, including age, gender, race, body mass index, and anthropometric measures. Home polysomnography was conducted using a standard recording montage. Sleep architecture was assessed using visual sleep-stage scoring. The discrete fast Fourier transform was used to calculate the EEG power spectrum for the entire night within contiguous 30-s epochs of sleep for the following frequency bandwidths: (0.8 to 4.0 Hz); (4.1 to 8.0 Hz); (8.1 to 13.0 Hz); and β (13.1 to 20.0 Hz).

Results: Conventional sleep stages were similar between the two groups. However, spectral analysis of the sleep EEG showed that, compared to nonsmokers, smokers had a lower percentage of EEG power in the -bandwidth (59.7% vs 62.6%, respectively; p < 0.04) and higher percentage of EEG power in -bandwidth (15.6% vs 12.5%, respectively; p < 0.001). Differences in the EEG power spectrum between smokers and nonsmokers were greatest in the early part of the sleep period and decreased toward the end. Subjective complaints of lack of restful sleep were also more prevalent in smokers than in nonsmokers (22.5% vs 5.0%, respectively; p < 0.02) and were explained, in part, by the differences in EEG spectral power.

Conclusions: Cigarette smokers manifest disturbances in the sleep EEG that are not evident in conventional measures of sleep architecture. Nicotine in cigarette smoke and withdrawal from it during sleep may contribute to these changes and the subjective experience of nonrestorative sleep.

Key Words: cigarette smoking • power spectral analysis • sleep architecture