Table 1.
Sample characteristics for the total sample analyzed and stratified by mean weekday sleep duration
| Subject Characteristics | Total sample analyzeda (n = 240) | Sample according to mean weekday sleep durationb |
P Value | |
|---|---|---|---|---|
| < 8 h (n = 159) | ≥ 8 (n = 81) | |||
| Age, y | 17.7 ± 0.4 | 17.6 ± 0.4 | 17.7 ± 0.4 | 0.18 |
| Sex | ||||
| Male | 115 (47.9) | 88 (76.5) | 27 (23.5) | 0.001 |
| Female | 125 (52.1) | 71 (56.8) | 54 (43.2) | |
| Race | ||||
| African American | 50 (20.8) | 37 (74.0) | 13 (26.0) | 0.19 |
| Non-African American | 190 (79.2) | 122 (64.2) | 68 (35.8) | |
| Term status | ||||
| Preterm | 102 (42.5) | 66 (64.7) | 36 (35.3) | 0.66 |
| Full term | 138 (57.5) | 93 (67.4) | 45 (32.6) | |
| BMI, kg/m2 | 23.1 (21.1, 27.1) | 23.3 (21.4, 28.3) | 22.8 (20.6, 25.9) | 0.09 |
| Obesityc | ||||
| Obese | 44 (18.3) | 35 (79.6) | 9 (20.4) | 0.04 |
| Nonobese | 196 (81.7) | 124 (63.3) | 72 (36.7) | |
| Socioeconomic Status | ||||
| Highest parent education level | ||||
| ≤ High-school diploma | 38 (15.8) | 27 (71.1) | 11 (28.9) | |
| Some college | 79 (32.9) | 51 (64.6) | 28 (35.4) | 0.78 |
| College degree | 123 (51.3) | 81 (65.9) | 42 (34.1) | |
Data are presented as number (%) except age, which is mean ± SD, and body mass index (BMI), which is mean (interquartile range).
a
Column percentages shown;
b
Row percentages shown;
c
Obesity is defined as a BMI ≥ 95th percentile or BMI ≥ 30.