Table 1.
Study Sample Characteristics for Those With Actigraphy, Complete BMI Data, and No History of Bariatric Surgery (n = 612), the CARDIA Sleep Study, 2000–2006
| Total | Average Sleep Duration, hours |
Ptrend | ||||
| <4.5 | 4.5–<6 | 6–<7.5 | ≥7.5 | |||
| No. (%) | ||||||
| 612 | 51 (8.3) | 211 (34.5) | 306 (50.0) | 44 (7.2) | ||
| Mean (SD) | ||||||
| Age, years | 45.2 (3.6) | 44.5 (3.6) | 45.4 (3.7) | 45.2 (3.6) | 45.2 (3.4) | 0.66 |
| Physical activity, exercise units | 334 (264) | 306 (209) | 323 (277) | 350 (258) | 309 (300) | 0.39 |
| Physical activity 5 years prior, exercise units | 365 (296) | 402 (319) | 350 (309) | 375 (285) | 323 (282) | 0.66 |
| Sleep fragmentation, score | 19.2 (8.0) | 28.1 (11.6) | 21.0 (7.6) | 17.0 (6.2) | 15.2 (5.5) | <0.001 |
| Frequencies, % | ||||||
| Race-sex groupsa | <0.001b | |||||
| White women | 29.7 | 1.1 | 17.0 | 65.4 | 16.5 | |
| Black women | 27.8 | 7.7 | 48.2 | 40.0 | 4.1 | |
| White men | 26.8 | 7.3 | 29.9 | 58.5 | 4.3 | |
| Black men | 15.7 | 25.0 | 51.0 | 24.0 | 0 | |
| Educationa | <0.001b | |||||
| Less than high school | 5.1 | 16.1 | 61.3 | 19.4 | 3.2 | |
| High school | 16.5 | 13.9 | 34.7 | 44.6 | 6.9 | |
| Some college | 25.7 | 12.7 | 41.4 | 27.6 | 8.3 | |
| College degree | 24.5 | 4.0 | 28.0 | 60.0 | 8.7 | |
| Postgraduate | 28.3 | 3.5 | 28.9 | 61.9 | 5.8 | |
| Smoking groups | ||||||
| Smoker | 16.3 | 15.0 | 44.0 | 30.0 | 11.0 | <0.001 |
| Smoker 5 years prior | 19.8 | 16.5 | 41.3 | 35.5 | 6.6 | 0.01 |
| Apnea symptoms | ||||||
| Snoring | 12.9 | 13.9 | 31.7 | 48.1 | 6.3 | 0.24 |
| Tiredness | 31.7 | 9.3 | 34.0 | 48.5 | 8.3 | 0.93 |
Abbreviations: BMI, body mass index; CARDIA, Coronary Artery Risk Development in Young Adults; SD, standard deviation.
a
Column 1 displays the frequency distribution across race-sex and education groups, and columns 2–5 display sleep distribution for race-sex or education group.
b
P values for race-sex groups and education are not trend tests but global tests of association.