Back to Bibliography
Page
Power Spectral Analysis of Electroencephalographic Activity during Sleep in Cigarette
Smokers.
ABSTRACT
Background: Research on the effects of cigarette smoking on sleep architecture
is limited. The objective of this investigation was to examine differences in the sleep electroencephalogram
(EEG) between smokers and nonsmokers.
Methods: Smokers and nonsmokers free of all medical co-morbidities were matched on factors including
age, gender, race, body mass index, and other measures of body composition. Home polysomnography was conducted
using a standard recording montage. Sleep architecture was assessed using visual sleep stage scoring. The
discrete Fast Fourier Transform (FFT) was used to calculate the EEG power spectrum for the entire night within
contiguous 30-second epochs of sleep for the following frequency bandwidths: (0.8-4.0Hz), (4.1-8.0Hz),
(8.1-13.0Hz), and ß (13.1-20.0Hz).
Results: Conventional sleep stages were similar between the two groups. However, spectral analysis of
the sleep EEG showed that, compared to nonsmokers, smokers had, on average, 15.1% lower EEG power in the
-bandwidth (p<0.01) and 58.3% higher EEG power in -bandwidth (p<0.0002). Differences in the EEG power spectrum
between smokers and nonsmokers were greatest in the early part of the sleep period and decreased towards the
end. Subjective complaints of lack of restful sleep were also more prevalent in smokers than nonsmokers
(22.5% vs. 5.0%, 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 non-restorative sleep.
Keywords: Cigarette smoking • sleep architecture • power spectral analysis
