Table 2.
Multilevel linear mixed models reveal the relationship between menstrual phase, covariates, and wrist skin temperature.
| Predictors | Model 1a | Model 2a | Model 3a | Model 4a | Model 5a | Model 6a | Model 7a | Model 8a | Model 9a | |
| Intercept | 34.12b (0.08) | 35.40b (0.36) | 34.09b (0.08) | 34.09b (0.08) | 34.09b (0.08) | 34.09b (0.08) | 33.32b (0.48) | 34.24b (0.10) | 35.01b (0.64) | |
| Cycle phase | ||||||||||
|
|
Menstrual | Reference group | Reference group | Reference group | Reference group | Reference group | Reference group | Reference group | Reference group | Reference group |
| Follicular | –0.24b (0.03) | –0.23b (0.03) | –0.24b (0.03) | –0.24b (0.03) | –0.24b (0.02) | –0.24b (0.03) | –0.24b (0.03) | –0.24b (0.03) | –0.23b (0.03) | |
| Fertile | –0.26b (0.03) | –0.25b (0.03) | –0.26b (0.03) | –0.26b (0.03) | –0.25b (0.03) | –0.26b (0.03) | –0.26b (0.03) | –0.26b (0.03) | –0.24b (0.03) | |
| Early luteal | 0.00 (0.02) | 0.01 (0.03) | 0.00 (0.02) | 0.00 (0.02) | 0.01 (0.02) | 0.00 (0.02) | 0.00 (0.03) | 0.00 (0.02) | 0.02 (0.03) | |
| Late luteal | 0.19b (0.02) | 0.20b (0.02) | 0.19b (0.02) | 0.19b (0.02) | 0.19b (0.02) | 0.19b (0.02) | 0.20b (0.02) | 0.19b (0.02) | 0.20b (0.02) | |
| Mealc | ||||||||||
|
|
Small or no food | Reference group | —d | — | — | — | — | — | — | Reference group |
|
|
Medium meal | –0.03b (0.01) | — | — | — | — | — | — | — | –0.03b (0.01) |
|
|
Large meal | –0.05b (0.01) | — | — | — | — | — | — | — | –0.05b (0.01) |
| Body mass index (kg/m2) | — | –0.06b (0.02) | — | — | — | — | — | — | –0.05b (0.02) | |
| Coffeec | — | — | 0.00 (0.01) | — | — | — | — | — | 0.01 (0.01) | |
| Exercisec | ||||||||||
|
|
No exercise | — | — | — | Reference group | — | — | — | — | Reference group |
| <60 min | — | — | — | 0.01 (0.01) | — | — | — | — | 0.01 (0.01) | |
| >60 min | — | — | — | 0.02 (0.01) | — | — | — | — | 0.01 (0.01) | |
| Sexual intercoursec | — | — | — | — | –0.02e (0.01) | — | — | — | –0.02e (0.01) | |
| Alcoholc | ||||||||||
|
|
No alcohol | — | — | — | — | — | Reference group | — | — | Reference group |
| 1-4 units | — | — | — | — | — | –0.01 (0.01) | — | — | 0.00 (0.01) | |
| ≥5 units | — | — | — | — | — | 0.05e (0.02) | — | — | 0.07d (0.02) | |
| Age (years) | — | — | — | — | — | — | 0.02 (0.01) | — | 0.02 (0.01) | |
| Cycle duration | — | — | — | — | — | — | — | –0.01e (0.00) | –0.01e (0.00) | |
aUnstandardized b-coefficient values reported, with SEs in parentheses.
bP<.001 with a Bonferroni correction.
cWithin the 3 hours preceding the onset of sleep.
dIndicates a predictor was not considered in a given model.
eP<.05 with a Bonferroni correction.