Table 3.
Hierarchical Linear Regressions Showing the Contributions of Demographics, BMI, Medications, and Napping to the Prediction of Log Transformed Inflammatory Markers
| Outcome: | Actigraphy | Diary | ||
|---|---|---|---|---|
|
| ||||
| hsCRP | IL-6 | hsCRP | IL-6 | |
| Step 1 | ||||
| (Constant) | .06 (.12) | .23 (.07)* | .08 (.12) | .23 (.07)* |
| Race (−.5=white, .5=black) | .20 (.13) | .00 (.08) | .19 (.13) | .01 (.08) |
| Socioeconomic status | −.01 (.01) | −.01 (.00) | −.01 (.01) | −.01 (.003) |
| Employment (0=no, 1=part-time and/or full-time) | −.18 (.19) | .02 (.11) | −.19 (.19) | .02 (.11) |
| ln BMI (mean centered) | 2.56 (.32)* | .92 (.19)* | 2.40 (.31)* | .88 (.18)* |
| Smoker (0=no, 1=yes) | .25 (.15)† | .28 (.09)* | .22 (.15) | .28 (.09)* |
| Sleep medications (0=no, 1=yes) | .51 (.19)* | .13 (.11) | .49 (.19)* | .13 (.11) |
| Anti-inflammatory medications (0=no, 1=yes) | .44 (.38) | .37 (.23) | .27 (.37) | .35 (.21) |
| Daysleeper (0=no, 1=yes) | .12 (.29) | .20 (.17) | .10 (.30) | .15 (.17) |
| Nightshift worker (0=no, 1=yes) | −.08 (.28) | .11 (.17) | −.03 (.30) | .19 (.17) |
| Step 2 of separate models | ||||
| Proportion of days with at least 30 minutes napped | −.23 (.27) | .24 (.16) | .24 (.22) | .02 (.13) |
| Average minutes napped | −.01 (.02) | .03 (.01)† | .03 (.02) | .01 (.01) |
| Step 3 of separate models (interaction terms) | ||||
| Proportion of days with at least 30 minutes napped | ||||
| X average sleep duration | −.21 (.24) | −.29 (.14)* | −.12 (.17) | −.06 (.10) |
| X average sleep efficiency | −.01 (.04) | −.02 (.02) | −.05 (.03)† | −.03 (.02) |
| X sleep quality | .21 (.46) | −.40 (.27) | −.23 (.35) | −.02 (.20) |
| X BMI | 1.10 (1.31) | .12 (.77) | .72 (.98) | −.66 (.56) |
| X race | −.04 (.53) | .09 (.31) | −.33 (.42) | −.07 (.25) |
| Average minutes napped | ||||
| X average sleep duration | −.02 (.02) | −.04 (.01)* | −.02 (.02) | −.01 (.01) |
| X average sleep efficiency | −.003 (.003) | −.004 (.002)* | −.004 (.004) | −.003 (.002) |
| X sleep quality | .00 (.04) | −.05 (.02)* | −.02 (.03) | −.01 (.02) |
| X BMI | .09 (.12) | −.05 (.07) | .12 (.11) | −.03 (.07) |
| X race | .02 (.05) | .02 (.03) | −.01 (.05) | .001 (.03) |
Note. BMI = body mass index; hsCRP = high sensitivity C-reactive protein; IL-6 = interleukin 6.
Values reflect unstandardized coefficient (standard error); Proportion of days napped and average minutes napped (by actigraphy and diary measures) were square root transformed prior to analysis; BMI, hsCRP, and IL-6 values were natural log transformed prior to analyses.
†
p ≤ .10.
*
p ≤ .05.