TABLE 2.

Univariable and multivariable mixed models for the circadian and sleep effects on the cortisol awakening response (CAR) in two distinct protocols.

	Protocol 1			Protocol 2
	β	SE	P	β	SE	P
Univariable analyses
Circadian	0.129	0.0220	P < 0.001	0.060	0.0191	P = 0.002
Total sleep time	0.002	0.0005	P < 0.001	0.0002	0.0002	P = 0.437
Sleep efficiency	0.003	0.0008	P < 0.001	0.001	0.0001	P = 0.512
Time awake before lights on	–0.002	0.0007	P = 0.003	–0.0004	0.0003	P = 0.115
% NREM	–0.002	0.0014	P = 0.232	0.0000	0.0002	P = 0.916
% REM	0.003	0.0019	P = 0.101	–0.001	0.002	P = 0.530
Arousal index	–0.004	0.0016	P = 0.011	–0.001	0.002	P = 0.582
Multivariable analyses
Circadian + total sleep time
Circadian	0.075	0.0268	P = 0.005	0.058	0.020	P = 0.004
Total sleep time	0.002	0.0006	P = 0.005	0.0000	0.0002	P = 0.872
Circadian + sleep efficiency
Circadian	0.076	0.0267	P = 0.005	0.058	0.020	P = 0.004
Sleep efficiency	0.003	0.0009	P = 0.006	–0.0001	0.001	P = 0.886
Circadian + time awake before lights on
Circadian	0.086	0.0264	P = 0.001	0.055	0.020	P = 0.007
Time awake before lights on	–0.002	0.0007	P = 0.031	–0.0002	0.0003	P = 0.482
Circadian + arousal index
Circadian	0.086	0.0270	P = 0.001	0.058	0.020	P = 0.004
Arousal index	–0.003	0.0016	P = 0.101	0.0002	0.002	P = 0.931