Table 3

Selected sleep stage variables in healthy controls and chronic fatigue syndrome patients who were either less sleepy or sleepier after polysomnography

Healthy
 CFS a.m. less sleepya
 CFS a.m. sleepiera
Number
 26
 14
 12
Age, years
 37 ± 8
 39 ± 8
 39 ± 8
Body mass index, kg/m2
 24.0 ± 4.4
 24.1 ± 5.7
 25.8 ± 4.7
CES-D score
 8 ± 7
 20 ± 8b
 14 ± 7b,c
Sleep structure


Time in bed, minutes
 453 ± 33
 433 ± 41
 445 ± 44
Total sleep time, minutes
 385 ± 38
 350 ± 50b
 353 ± 61b
Sleep efficiency, percentage
 85 ± 8
 81 ± 9
 79 ± 10b
Number of arousals per hour
 8.3 ± 5.2
 4.8 ± 3.7
 6.7 ± 6.1
Wakefulness, minutes
 52 ± 38
 64 ± 33
 61 ± 35
Stage 1, minutes
 45 ± 19
 32 ± 12
 34 ± 22
Wakefulness plus stage 1, minutes
 96 ± 44
 96 ± 34
 95 ± 37
Stage 2, minutes
 222 ± 34
 195 ± 29b
 202 ± 38
Stage 3, minutes
 30 ± 22
 50 ± 20b
 41 ± 26
Stage 4, minutes
 5 ± 11
 13 ± 15
 7 ± 15
Slow-wave sleep (stage 3 + 4), minutes
 35 ± 26
 63 ± 30b
 48 ± 37
Stage REM, minutes
 83 ± 24
 60 ± 18b
 69 ± 33
Sleep latency, minutes
 16 ± 19
 20 ± 20
 32 ± 31b
REM latency, minutes
 107 ± 49
 128 ± 64
 126 ± 69
Median duration of sleep runs, minutes
 15.6 ± 18.4
 10.0 ± 6.7
 7.9 ± 3.3b
Likert scale (0–15.5)


     Sleepiness


          Evening
 6 ± 4
 12 ± 2b
 6 ± 5c
          Morning
 1 ± 2d
 7 ± 4b,d
 10 ± 2b-d
     Fatigue


          Evening
 4 ± 4
 11 ± 3b
 10 ± 3b
          Morning
 1 ± 2d
 8 ± 4b,d
 11 ± 3b,c
     Pain


          Evening
 1 ± 2
 8 ± 4b
 7 ± 5b
          Morning
 0 ± 1
 6 ± 4b,d
 9 ± 4b,c
     Feeling blue


          Evening
 1 ± 2
 2 ± 3
 1 ± 1
          Morning
 0 ± 0d
 1 ± 3
 1 ± 3

Values are presented as mean ± standard deviation. aData dichotomized based on difference between daytime and nighttime self-reported ratings of sleepiness (P < 0.05, analysis of variance [ANOVA]). bSignificantly different from healthy controls. cSignificantly different from CFS in the a.m. less sleepy group (P < 0.05, ANOVA). dSignificantly different from evening (P < 0.05, paired t test). CES-D, Centers for Epidemiological Study-Depression; CFS, chronic fatigue syndrome; REM, rapid eye movement.

Togo et al. Arthritis Research & Therapy 2008 10:R56   doi:10.1186/ar2425

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