Table 6.
Multilevel linear mixed models reveal the relationship between menstrual phase, covariates, and skin perfusion.
| Predictors | Model 1a | Model 2a,b | Model 3a | Model 4a,b | Model 5a | Model 6a | Model 7a,b | Model 8a | Model 9a,b | |
| Intercept | 1338.17c (72.65) | 811.67d (244.86) | 1308.46c (72.58) | 1316.50c (74.72) | 1308.46c (72.59) | 1315.27c (72.86) | 1629.12c (319.49) | 1325.16c (85.35) | 1080.00d (426.30) | |
| Cycle phase | ||||||||||
|
|
Menstrual | Reference group | Reference group | Reference group | Reference group | Reference group | Reference group | Reference group | Reference group | Reference group |
| Follicular | –49.62d (15.07) | –27.30c (8.28) | –49.94d (15.20) | –30.93c (8.27) | –48.22d (15.12) | –50.23d (15.28) | –30.89c (8.32) | –49.29d (15.09) | –26.76d (8.35) | |
| Fertile | –68.23d (16.94) | –45.20c (7.69) | –68.77d (17.03) | –48.69c (7.70) | –65.00d (16.99) | –68.17d (16.74) | –48.91c (7.74) | –68.04d (16.87) | –43.89c (7.96) | |
| Early luteal | –6.37 (17.48) | –15.96d (7.50) | –7.14 (17.37) | –12.76 (7.51) | –5.64 (17.54) | –6.88 (17.56) | –14.68 (7.54) | –7.06 (17.68) | –1.53d (7.53) | |
| Late luteal | 60.82 (28.62) | 34.01c (8.09) | 60.73 (28.60) | 33.85c (8.11) | 61.94 (28.71) | 60.18 (28.75) | 33.83c (8.14) | 61.94 (29.06) | 33.43c (8.13) | |
| Meale | ||||||||||
|
|
Small or no food | Reference group | —f | — | — | — | — | — | — | Reference group |
| Medium meal | –26.43c (7.21) | — | — | — | — | — | — | — | –20.55d (7.29) | |
| Large meal | –47.36c (8.09) | — | — | — | — | — | — | — | –40.31c (8.52) | |
| Body mass index (kg/m2) | — | 22.08d (10.21) | — | — | — | — | — | — | 21.19d (10.33) | |
| Coffeee | — | — | –7.00 (9.77) | — | — | — | — | — | –0.04 (9.77) | |
| Exercisee | ||||||||||
|
|
No exercise | — | — | — | Reference group | — | — | — | — | Reference group |
| <60 min | — | — | — | –17.81d (7.46) | — | — | — | — | –18.56d (7.45) | |
| >60 min | — | — | — | 11.12 (8.03) | — | — | — | — | 7.65 (8.11) | |
| Sexual intercoursee | — | — | — | — | –11.42 (7.00) | — | — | — | –4.90 (7.03) | |
| Alcohole | ||||||||||
|
|
No alcohol | — | — | — | — | — | Reference group | — | — | Reference group |
| 1-4 units | — | — | — | — | — | –24.71c (6.01) | — | — | –16.89d (6.33) | |
| >5 units | — | — | — | — | — | –17.64 (18.50) | — | — | –13.31 (18.56) | |
| Age (years) | — | — | — | — | — | — | –9.56 (9.36) | — | –6.59 (9.49) | |
| Cycle duration | — | — | — | — | — | — | — | –0.62 (1.59) | –0.01 (1.61) | |
aUnstandardized b-coefficient values reported, with SEs in parentheses.
bThe model would not converge with the cross-classification term, so only random intercepts were included.
cP<.001 with a Bonferroni correction.
dP<.05 with a Bonferroni correction.
eWithin the 3 hours preceding the onset of sleep.
fIndicates a predictor was not considered in a given model.