TABLE 1.
Participant characteristics of the SLuMBER study as assessed at screening1
| Control group (n = 21) | Sleep extension participants (n = 21) | |
|---|---|---|
| Sex, n (%) | ||
| Male | 4.0 (9.5) | 3.0 (7.1) |
| Female | 17 (40.5) | 18 (41.9) |
| Age,2 y | 25.0 [22.5, 30.5] | 24.0 [21.5, 29.0] |
| Ethnicity, n (%) | ||
| White | 12 (28.6) | 11 (26.2) |
| Black | 1 (2.4) | 2 (4.8) |
| South/East Asian | 4 (9.5) | 5 (11.9) |
| Other | 4 (9.5) | 3 (7.1) |
| BMI,3 kg/m2 | 21.8 (20.9, 22.8) | 22.5 (21.3, 23.8) |
| Glucose,3,4 mmol/L | 5.0 (4.7, 5.3) | 4.7 (4.6, 4.9) |
| TC,3,4 mmol/L | 4.5 (4.2, 4.7) | 4.4 (4.0, 4.8) |
| TGs,3,4 mmol/L | 0.8 (0.6, 0.9) | 0.8 (0.6, 0.9) |
| HDL cholesterol,3,4 mmol/L | 1.7 (1.6, 1.9) | 1.6 (1.4, 1.9) |
| LDL cholesterol,3,4 mmol/L | 2.4 (2.0, 2.8) | 2.4 (2.2, 2.7) |
| Sleep score | ||
| Horne-Ostberg | 52.6 (48.6, 56.6) | 50.7 (47.5, 53.9) |
| ISI | 7.9 (6.4, 9.3) | 7.6 (6.1, 9.1) |
| ESS2 | 6.0 [5.0, 6.8] | 6.0 [4.0, 7.0] |
| Depressed mood score (CES-D) | 7.3 (5.5, 9.0) | 5.9 (3.9, 7.8) |
| Eating behavior score (DEBQ) | ||
| Restrained | 2.7 (2.3, 3.2) | 2.7 (2.4, 3.0) |
| Emotional | 2.3 (1.9, 2.7) | 2.4 (2.1, 2.8) |
| External | 3.1 (2.8, 3.4) | 3.3 (3.0, 3.7) |
Data were tested with the use of chi-square test, independent-samples t test, or Mann-Whitney U test. There were no significant differences between groups (P values not shown). CES-D, Center of Epidemiologic Studies–Depression scale; DEBQ, Dutch Eating Behavior Questionnaire; ESS, Epworth Sleepiness Scale; ISI, Insomnia Severity Index; SLuMBER, Sleep Lengthening and Metabolic health, Body composition, Energy balance and cardiovascular Risk Study; TC, total cholesterol; TG, triglyceride.
Values are medians [IQRs].
Values are geometric means (95% CIs). Data were log-transformed before analysis.
Data from 2 participants are missing from analysis due to inability to draw blood (Control group: n = 20, sleep extension participants: n = 20)