Table 1.
Baseline characteristics of participants from the Sleep Heart Health Study, 1995–1998 (n = 4994)
| Characteristic | No insomnia/poor sleep | Insomnia or poor sleep | Overall n = 4994 |
P* | ||
|---|---|---|---|---|---|---|
| Normal sleep duration (n=2,489, 49.8%) | Short sleep duration (n=1,801, 36.1%) | Normal sleep duration (n=350, 7.0%) |
Short sleep duration (n=354, 7.1%) |
|||
| Age (years), mean ± SD | 62.1 ± 11.1 | 66.3 ± 10.7 | 63.2 ± 11.0 | 66.1 ± 11.2 | 64.0 ± 11.1 | <.0001 |
| Race, n (%) | .83 | |||||
| White |
2179 (87.5%) | 1566 (87.9%) | 301 (86.0%) | 307 (86.7%) | 4353 (87.2%) | |
| Black/other | 310 (12.5%) | 235 (13.1%) | 49 (14.0%) | 47 (13.3%) | 641 (12.8%) | |
| Female, n (%) | 1,412 (56.7%) | 789 (43.8%) | 268 (76.6%) | 205 (57.9%) | 2,674 (53.5%) | <.0001 |
| Smoking status, n (%) | <.001 | |||||
| Current | 217 (8.7%) | 177 (9.8%) | 38 (10.9%) | 48 (13.6%) | 480 (9.6%) | |
| Former | 1,054 (42.4%) | 851 (41.3%) | 148 (42.3%) | 153 (43.2%) | 2206 (44.2%) | |
| Never | 1218 (48.9%) | 773 (42.9%) | 164 (46.8%) | 153 (43.2%) | 2308 (46.2%) | |
| Antidepressant usage, n (%) | 140 (5.6%) | 96 (5.3%) | 82 (23.4%) | 55 (15.5%) | 373 (7.5%) | <.0001 |
| Weekday,self-reported sleep duration (hr/night), mean ± SD | 7.3 ± 1.0 | 7.0 ± 1.2 | 6.4 ± 1.4 | 5.9 ± 1.5 | 7.1 ± 1.2 | <.0001 |
| Weekend, self-reported sleep duration (hr/night), mean ± SD | 7.7 ± 1.1 | 7.4 ± 1.2 | 6.7 ± 1.6 | 6.2 ± 1.6 | 7.4 ± 1.3 | <.0001 |
| AHI (events/hr), median (IQR) | 8.5 (3.5,17.2) | 11.0 (5.2, 22.0) | 7.6 (3.3,16.0) | 9.8 (4.2,19.0) | 9.4 (4.0,19.1) | <.0001 |
| BMI (kg/m2), median (IQR) | 27.4 (24.7,30.6) | 28.0 (24.9,31.2) | 27.6 (24.9,30.9) | 28.0 (24.8,31.4) | 27.6 (24.8,30.9) | <.01 |
| Hypertension, n (%) | 860 (34.6%) | 833 (46.3%) | 137 (39.1%) | 186 (52.5%) | 2,016 (40.4%) | <.0001 |
| Baseline cardiovascular disease, n (%) | 319 (12.8%) | 313 (17.4%) | 35 (10.0%) | 69 (19.5%) | 736 (14.7%) | <.0001 |
| Total cholesterol (mg/dL), mean ± SD | 205 ± 37 | 205 ± 38 | 213 ± 38 | 212 ± 40 | 207 ± 38 | .0001 |
| HDL-C (mg/dL), mean ± SD | 51.0 ± 15.3 | 49.5 ± 15.8 | 54.0 ± 17.1 | 50.3 ± 15.9 | 50.6 ± 15.7 | <.0001 |
| Diabetes, n (%) | 158 (6.3%) | 168 (9.3%) | 18 (5.1%) | 27 (7.6%) | 371 (7.4%) | <.01 |
AHI = apnea–hypopnea index; BMI = body mass index; HDL-C = high-density lipoprotein-cholesterol.
*Pearson’s chi-squared test for categorical characteristics; ANOVA for continuous characteristics.