Cyclic alternating pattern and sleep quality in healthy subjects--is there a first-night effect on different approaches of sleep quality?
OBJECTIVE
Cyclic alternating pattern (CAP) is defined as periodic EEG activity during NREM sleep that reflects unstable sleep and represents a marker of instability of the sleep process. The aim of the present investigation was to analyze sleep quality of 28 healthy subjects (mean age 53.3+/-21.3 years) over two consecutive nights and determine potential differences between them ("first-night effect").


METHODS
Evaluations comprised objective and subjective sleep variables as well as macrostructural and microstructural variables of sleep.


RESULTS
Macrostructural analysis showed significant differences between the first and the second sleep laboratory night in REM latency (122.39+/-60.46 min vs. 95.43+/-36.60 min; T=3.431; p=0.002) and the amount of sleep stage 1 (42.60+/-21.80 min vs. 39.70+/-18.95 min; T=2.223; p=0.035). Microstructural analysis revealed a significant decrease in the CAP rate (1st night: 33.29%; 2nd night: 26.34%; T=3.288; p=0.003) and in the amount of subtype A2 (74.79+/-43.47 vs. 58.50+/-23.22; T=2.185; p=0.038). Subjective variables also demonstrated a significant increase of drive (T=2.564; p=0.016).


CONCLUSIONS
Healthy subjects show hardly any macrostructural differences between the first and the second night in the sleep laboratory. On the microstructural level differences in CAP variables were found.


CONCLUSIONS
Microstructural analysis can be seen as a further approach to the classification of sleep and CAP turned out to be sensitive to environmental influences on sleep.
Department of Neurology, Medical University of Vienna, Waehringer Guertel 18-20, Vienna, Austria. doris.c.moser@meduniwien.ac.at
Doris
D
Moser
Gerhard
G
Kloesch
Florian Ph
FP
Fischmeister
Herbert
H
Bauer
Josef
J
Zeitlhofer
D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D016208:Databases, Factual / Q000706:statistics & numerical data; D004569:Electroencephalography; D004576:Electromyography / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D010507:Periodicity; D017286:Polysomnography / Q000379:methods; D012016:Reference Values; D012649:Self Concept; D012890:Sleep / Q000502:physiology*; D014851:Wakefulness / Q000502:physiology*; D055815:Young Adult