Table 1.
Sample Characteristics
| Demographics | Frequency (%) or Mean ± SD | Sleep Characteristics | Mean ± SD |
|---|---|---|---|
| Age, yr | 68.9 ± 9.2 | AHI3% (events/h) | 24.4 ± 18.4 |
| Sex, M | 780 (50.5) | NREM AHI3% (events/h) | 21.7 ± 19.6 |
| Race/ethnicity | REM AHI3% (events/h) | 36.3 ± 21.8 | |
| Non-Hispanic white | 557 (36.0) | OAI (events/h) | 5.0 ± 8.9 |
| Asian | 189 (12.2) | % Sleep time <90% oxygen saturation | 4.7 ± 9.6 |
| Black | 422 (27.3) | Oxygen desaturation index at 3% | 26.4 ± 18.4 |
| Hispanic | 378 (24.5) | Oxygen desaturation index at 4% | 17.6 ± 16.4 |
| Body mass index, kg/m2 | 29.3 ± 5.5 | Hypoxic burden | 68.39 ± 67.67 |
| Smoking use | Total sleep time (min) | 358.8 ± 80.1 | |
| Current smoker | 109 (7.1) | Sleep efficiency (%) | 75.4 ± 13.2 |
| Former smoker | 720 (46.8) | Stage N1 (%) | 15.4 ± 9.6 |
| Never smoked | 708 (46.1) | Stage N2 (%) | 57.2 ± 10.3 |
| Hypertension | 901 (58.4) | Stage N3 (%) | 9.7 ± 8.8 |
| Diabetes | 656 (42.9) | % Time in REM | 17.6 ± 6.7 |
| Heart failure | 51 (3.3) | ||
| FVC, % predicted | 96.2 ± 17.5 | Epworth sleepiness scale (0–24) | 6.2 ± 4.2 |
| FEV1, % predicted | 95.0 ± 19.2 | Women's Health Initiative Insomnia Rating scale | 7.4 ± 4.4 |
| Antidepressant use | 110 (9.8) | NREM hypopnea, seconds | 21.73 ± 5.60 |
| Sedative use | 218 (14.1) | NREM obstructive apnea, seconds | 23.87 ± 7.44 |
Definition of abbreviations: AHI3% = the sum of all apneas and hypopneas, each associated with ≥3% desaturation divided by total sleep duration; NREM = non-REM; OAI = obstructive apnea index.
Oxygen desaturation index: the average number of desaturation episodes per hour. Desaturation episodes were defined as a decrease in the mean oxygen saturation by either ≥3 or ≥4% (over the last 120 s) that lasts for at least 10 seconds. Hypoxic burden: respiratory event–associated area under the desaturation curve from preevent baseline.