Table 2.
Least squared means and standard errors for each sleep stage, stratified by sex and cool vs. warm temperatures for Pod OFF as a reference compared to Pod ON.
| Variable | Men | Women | Effect Modification by Sex: Cool | Effect Modification by Sex: Warm | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| OFF (Ref) | Cool | Warm | OFF (Ref) | Cool | Warm | |||||||
| lsmean ± SE | p-Value | lsmean ± SE | p-Value | lsmean ± SE | lsmean ± SE | p-Value | lsmean ± SE | p-Value | p-Value | p-Value | ||
| Bedtime | ||||||||||||
| SOL | 28.5 ± 4.1 | 28.7 ± 5.1 | 0.965 | 26.0 ± 4.6 | 0.452 | 31.5 ± 3.9 | 33.0 ± 5.3 | 0.756 | 24.2 ± 4.5 | 0.079 | 0.756 | 0.079 |
| Deep SOL | 16.8 ± 2.2 | 10.0 ± 3.2 | 0.045 | 11.5 ± 2.7 | 0.066 | 18.4 ± 4.3 | 8.5 ± 6.2 | 0.124 | 23.1 ± 5.0 | 0.377 | 0.654 | 0.100 |
| Early Phase | ||||||||||||
| Deep (min) | 64.3 ± 4.9 | 78.6 ± 5.7 | 0.003 | 70.9 ± 6.3 | 0.205 | 68.5 ± 6.5 | 63.6 ± 7.1 | 0.305 | 61.8 ± 7.3 | 0.194 | 0.005 | 0.071 |
| Deep (%) | 17.3 ± 1.5 | 20.1 ± 1.7 | 0.051 | 18.7 ± 1.9 | 0.389 | 17.4 ± 1.7 | 16.8 ± 1.9 | 0.669 | 15.9 ± 1.9 | 0.292 | 0.089 | 0.178 |
| REM (min) | 37.2 ± 3.34 | 30.5 ± 4.0 | 0.072 | 35.3 ± 4.5 | 0.628 | 35.0 ± 4.2 | 44.3 ± 4.9 | 0.033 | 35.5 ± 5.1 | 0.924 | 0.005 | 0.702 |
| REM (%) | 10.0 ± 0.9 | 7.8 ± 1.1 | 0.061 | 9.1 ± 1.3 | 0.476 | 9.3 ± 1.1 | 11.7 ± 1.3 | 0.028 | 8.8 ± 1.4 | 0.686 | 0.004 | 0.823 |
| Light (min) | 113.0 ± 5.9 | 105.0 ± 6.6 | 0.075 | 108.0 ± 7.0 | 0.341 | 115.0 ± 6.7 | 108.0 ± 7.4 | 0.169 | 109.0 ± 7.6 | 0.301 | 0.843 | 0.923 |
| Light (%) | 30.5 ± 1.9 | 27.0 ± 2.2 | 0.047 | 28.4 ± 2.4 | 0.291 | 29.8 ± 1.9 | 28.4 ± 2.1 | 0.326 | 28.8 ± 2.2 | 0.527 | 0.401 | 0.664 |
| Wake (min) | 22.8 ± 2.2 | 22.0 ± 2.8 | 0.754 | 21.7 ± 3.1 | 0.713 | 20.6 ± 3.1 | 23.5 ± 3.6 | 0.375 | 24.7 ± 3.8 | 0.236 | 0.412 | 0.236 |
| REM SOL | 111.0 ± 45.9 | 116.6 ± 51.2 | 0.694 | 132.6 ± 81.1 | 0.443 | 122.4 ± 64.5 | 101.8 ± 75.2 | 0.181 | 144.6 ± 52.4 | 0.202 | 0.200 | 0.634 |
| Late Phase | ||||||||||||
| Deep (min) | 7.3 ± 1.4 | 7.3 ± 1.6 | 0.993 | 4.6 ± 2.0 | 0.181 | 9.2 ± 2.1 | 10.4 ± 2.7 | 0.654 | 7.1 ± 2.7 | 0.460 | 0.700 | 0.902 |
| Deep (%) | 1.8 ± 0.3 | 1.8 ± 0.4 | 0.957 | 1.1 ± 0.5 | 0.188 | 2.3 ± 0.5 | 2.6 ± 0.6 | 0.622 | 1.8 ± 0.6 | 0.499 | 0.692 | 0.771 |
| REM (min) | 55.6 ± 5.6 | 48.7 ± 6.5 | 0.257 | 66.5 ± 7.9 | 0.142 | 45.6 ± 4.3 | 48.0 ± 5.5 | 0.678 | 47.8 ± 5.5 | 0.706 | 0.219 | 0.328 |
| REM (%) | 13.4 ± 1.2 | 11.6 ± 1.4 | 0.159 | 15.2 ± 1.7 | 0.252 | 11.4 ± 0.9 | 11.8 ± 1.2 | 0.792 | 11.4 ± 1.2 | 0.990 | 0.221 | 0.346 |
| Light (min) | 94.4 ± 6.9 | 105.0 ± 8.2 | 0.204 | 117.8 ± 10.2 | 0.023 | 105.0 ± 7.1 | 106.0 ± 8.7 | 0.967 | 113.0 ± 8.9 | 0.405 | 0.378 | 0.242 |
| Light (%) | 23.1 ± 1.3 | 25.5 ± 1.6 | 0.166 | 28.2 ± 2.0 | 0.016 | 26.1 ± 1.4 | 26.1 ± 1.7 | 0.983 | 27.5 ± 1.8 | 0.403 | 0.300 | 0.190 |
| Wake (min) | 21.0 ± 2.4 | 18.3 ± 2.8 | 0.216 | 24.2 ± 3.4 | 0.046 | 18.7 ± 3.2 | 24.0 ± 4.0 | 0.186 | 26.9 ± 4.0 | 0.044 | 0.082 | 0.377 |
Note: OFF indicates all nights of Pod OFF as a reference for comparing with Pod ON at cool or warm temperatures for Bedtime, Early, and Late Phases for women and men. See Section 2 for the description of cool vs. warm bins. Bolded values indicate significance at p < 0.05. lsmeans: least squared means; SE: standard error; SOL: sleep onset latency; Early Phase: first four hours of sleep after sleep onset; Late Phase: end of Early Phase until waking; Cool: those who slept at cool Pod temperatures during Early or Late Phase (see Section 2 for details); warm: those who slept at warm Pod temperatures during Early or Late Phases (see Section 2 for details).