Table 1.
Summary of Sleep Staging and REM Latency by Demographic/Lifestyle Characteristics, Mean ± SD
| Characteristic | % of time spent in Stage 1 sleep | % of time spent in Stage 2 sleep | % of time spent in slow wave sleep | % of time spent in REM sleep | REM latency (min) |
|---|---|---|---|---|---|
| Age, years | |||||
| <72 (n = 657) | 6.02 ± 3.23 | 62.15 ± 8.80 | 11.49±8.31 | 20.33 ± 6.05 | 73.65±41.78 |
| 72 to <76 (n = 745) | 6.69 ± 4.03 | 61.92 ± 9.56 | 11.47±8.88 | 19.92 ± 6.35 | 73.60±41.23 |
| 76 to <80 (n = 650) | 6.82 ± 4.22 | 62.91 ± 10.10 | 11.14±9.06 | 19.13 ± 6.84 | 72.89±41.80 |
| 80+ (n = 801) | 7.58 ± 5.12 | 63.49 ± 9.77 | 10.95±9.56 | 17.99 ± 6.71 | 77.77±47.83 |
| p Value | <.0001 | .0052 | .5828 | <.0001 | .1124 |
| BMI, kg/m2 | |||||
| <20 (n =27) | 8.95 ± 4.71 | 62.12±9.51 | 11.31 ± 10.21 | 17.61±6.03 | 83.44 ± 51.46 |
| 20 to <25 (n = 837) | 6.59 ± 4.34 | 62.20±9.49 | 12.08 ± 9.31 | 19.13±6.36 | 72.42 ± 43.99 |
| 25 to <30 (n = 1,411) | 6.85 ± 4.16 | 62.54±9.66 | 11.04 ± 8.76 | 19.57±6.66 | 74.15 ± 42.46 |
| 30+ (n = 576) | 6.97 ± 4.47 | 63.52±9.57 | 10.61 ± 8.95 | 18.90±6.61 | 78.47 ± 44.41 |
| p Value | .0198 | .0782 | .0126 | .0746 | .0471 |
| Race/ethnicity | |||||
| White (n = 2,585) | 6.79±4.26 | 62.56 ± 9.60 | 11.45 ± 9.06 | 19.20 ± 6.55 | 75.00±43.28 |
| Black (n = 97) | 6.63±5.31 | 65.02 ± 10.21 | 7.84 ± 7.73 | 20.52 ± 7.28 | 71.75±57.16 |
| Other (n = 171) | 7.33±3.93 | 62.45 ± 8.98 | 10.19 ± 8.10 | 20.04 ± 6.19 | 70.61±36.65 |
| p Value | .2503 | .045 | .0001 | .0455 | .3555 |
| Education | |||||
| <High school (n = 149) | 7.62 ± 4.85 | 64.34 ± 10.57 | 10.86±10.60 | 17.17 ± 7.03 | 82.73 ± 52.93 |
| High school (n = 466) | 7.64 ± 4.98 | 63.09 ± 9.99 | 10.52±8.44 | 18.76 ± 6.89 | 77.92 ± 47.23 |
| Some college or more (n = 2,238) | 6.59 ± 4.06 | 62.43 ± 9.43 | 11.43±8.98 | 19.54 ± 6.43 | 73.40 ± 41.84 |
| p Value | <.0001 | .0342 | .1187 | <.0001 | .008 |
| PASE score | |||||
| Quartile 1 (n = 711) | 7.14±4.46 | 63.06±10.01 | 11.47±9.64 | 18.33 ± 6.89 | 79.12 ± 49.10 |
| Quartile 2 (n = 713) | 6.72±4.09 | 62.55±10.02 | 11.26±9.17 | 19.47 ± 6.51 | 74.17 ± 45.76 |
| Quartile 3 (n = 715) | 6.75±3.98 | 62.71±9.22 | 10.94±8.53 | 19.59 ± 6.62 | 73.22 ± 39.41 |
| Quartile 4 (n = 714) | 6.65±4.57 | 62.24±9.09 | 11.34±8.59 | 19.77 ± 6.12 | 72.01 ± 38.43 |
| p Value | .1301 | .4342 | .7259 | .0001 | .0117 |
| Alcohol use (drink/week) | |||||
| <1 (n = 1,326) | 6.71±4.14 | 62.89±9.72 | 11.30±9.14 | 19.11±6.87 | 74.60±44.78 |
| 1–13 (n = 1,361) | 6.88±4.37 | 62.48±9.42 | 11.24±8.88 | 19.4±6.26 | 74.50±42.72 |
| 14+ (n = 154) | 7.19±4.81 | 61.69±10.12 | 11.27±8.93 | 19.84±6.36 | 75.70±39.46 |
| p Value | .3209 | .2526 | .9861 | .2865 | .9487 |
| Smoking status | |||||
| Never (n = 1,127) | 6.87±4.28 | 62.88±9.17 | 11.00±8.60 | 19.25±6.51 | 74.26±45.16 |
| Past (n = 1,669) | 6.77±4.30 | 62.45±9.80 | 11.46±9.20 | 19.33±6.57 | 74.86±42.34 |
| Current (n = 57) | 7.23±4.12 | 63.56±11.47 | 10.31±10.09 | 18.9±7.39 | 74.93±41.93 |
| p Value | .6418 | .3849 | .3112 | .8631 | .9373 |
Notes. BMI = body mass index; PASE = Physical Activity Scale for the Elderly; REM = rapid eye movement. p Value from analysis of variance. Bold values indicate p < .05.