TABLE 3.
Comparison of Circadian Activity Variables by Level of Depressive Symptoms
| Circadian Activity Rhythm Parameters | Mean (95% Confidence Interval)
|
|||||
|---|---|---|---|---|---|---|
| Normal (GDS 0–2) | Some Depressive Symptoms (GDS 3–5) | Depressed (GDS ≥ 6) | p trend | t | df | |
| Time of rhythm peak (acrophase; hours:minutes) | ||||||
| Age and site adjusted (N = 3,020) | 14.38 (14.33–14.44) | 14.44 (14.35–14.53) | 14.44 (14.31–14.57) | 0.262 | 1.12 | 3,014 |
| Multivariate (2,764) | 14.41 (14.35–14.46) | 14.37 (14.27–14.46) | 14.30 (14.16–14.44) | 0.191 | −1.31 | 2,740 |
| Height (amplitude) | ||||||
| Age and site adjusted (N = 3,020) | 2,005.28 (1,981.40–2,029.17) | 1,796.79 (1,756.96–1,836.63) | 1,714.94 (1,658.68–1,771.20) | <0.001 | −11.31 | 3,014 |
| Multivariate (2,764) | 1,980.92 (1,957.68–2,004.17) | 1,885.36 (1,845.29–1,925.43) | 1,898.08 (1,838.05–1,958.10) | <0.001 | −3.55 | 2,740 |
| Mean modeled activity (mesor) | ||||||
| Age and site adjusted (N = 3,020) | 2,520.28 (2,496.14–2,544.42) | 2,354.16 (2,313.90–2,394.42) | 2,233.77 (2,176.90–2,290.63) | <0.001 | −10.36 | 3,014 |
| Multivariate (2,764) | 2,498.15 (2,473.64–2,522.66) | 2,414.53 (2,372.28–2,456.78) | 2,384.53 (2,321.24–2,447.81) | <0.001 | −3.88 | 2,740 |
| Robustness (pseudo F-statistic) | ||||||
| Age and site adjusted (N = 3,020) | 918.88 (897.64–940.12) | 777.64 (742.22–813.07) | 740.94 (690.91–790.98) | <0.001 | −8.07 | 3,014 |
| Multivariate (2,764) | 901.13 (879.48–922.79) | 837.77 (800.45–879.09) | 834.39 (778.48–890.30) | 0.005 | −2.83 | 2,740 |
| Time becoming active in morning (hours:minutes) | ||||||
| Age and site adjusted (N = 3,020) | 7:21 (7:19–7:25) | 7:29 (7:23–7:35) | 7:33 (7:25–7:41) | 0.003 | 2.97 | 3,014 |
| Multivariate (2,764) | 7:24 (7:20–7:28) | 7:24 (7:18–7:30) | 7:23 (7:14–7:31) | 0.836 | −0.21 | 2,740 |
| Time evening settling (hours:minutes) | ||||||
| Age and site adjusted (N = 3,020) | 22:01 (21:56–22:06) | 21:58 (21:49–22:06) | 21:52 (21:40–22:03) | 0.116 | −1.57 | 3,014 |
| Multivariate (2,764) | 22:02 (21:57–22:01) | 21:55 (21:47–22:04) | 21:47 (21:33–22:00) | 0.028 | −2.19 | 2,740 |
Notes: A comparison of mean circadian activity rhythm parameters, estimated by linear regression and least-squared means, for groups of women with different levels of depressive symptoms is shown. Multivariate models adjusted for age, race, site, smoking status, body mass index, self-reported health status, education, exercise, number of reported medical conditions, impairments in activities of daily living, cognitive impairment, and use of antidepressants, benzodiazepines, nonbenzodiazepine anxiolytics, or medications for sleep. p trend: p value for linear trend.