Table 1

Baseline Characteristics of Participants (Mean ± SD)


YOUNG ADULT
OLDER
AGE CONTRAST

Wake-up (questionnaire)
7:31 ± 1:24
5:55 ± 1:18
P < 0.001
Actigraphic wake time
8:32 ± 2:16
6:39 ± 1:07
P < 0.001
Bedtime (questionnaire)
23:48 ± 1:03
22:51 ± 1:05
P < 0.001
Bedtime (actigraph)
00:33 ± 1:31
22:41 ± 1:24
P < 0.001
Sleep log total sleep time
444 ± 65 min
406 ± 63 min
P = 0.003
Actigraphic total sleep time
404 ± 70 min
385 ± 68 min
NS
aMT6s onset
23:04 ± 1:45
22:16 ± 1:46
P = 0.02
aMT6s acrophase
3:47 ± 1:37
3:18 ± 1:58
NS
aMT6s offset
08:22 ± 1:28
08:20 ± 2:11
NS
Cortisol acrophase
9:59 ± 1:54
8:29 ± 2:51
P = 0.008
Oral Temperature bathyphase
04:04 ± 2:10
04:44 ± 3:52
NS
PSQI total score
3.8 ± 2.3
3.6 ± 2.7
NS
CESD at intake
7.0 ± 7.0
3.5 ± 3.6
P = 0.002

NS = Not Significant. Temperature bathyphase: the fitted minimum, 180° from the acrophase.

Kripke et al. Journal of Circadian Rhythms 2007 5:4   doi:10.1186/1740-3391-5-4