Table 1.
Summary of participant characteristics
| Characteristic | Value | n |
|---|---|---|
| Age, yr | 63.2 ± 11.3 | 5,655 |
| Race | ||
| White | 4,781 (84.5%) | 5,655 |
| Black | 504 (8.9%) | |
| Other | 370 (6.6%) | |
| Sex | ||
| Male | 2,666 (47.1%) | 5,655 |
| Female | 2,989 (52.9%) | |
| Body mass index, kg/m2 | 28.1 ± 5.0 | 5,615 |
| Smoking | ||
| Never | 2,644 (46.7%) | 5,616 |
| Current | 549 (9.7%) | |
| Former | 2,423 (42.8%) | |
| Diabetes | 392 (6.9%) | 5,393 |
| History of COPD | 62 (1.1%) | 5,599 |
| EDS | 1,335 (24.5%) | 5,441 |
| Hypertension* | 2,384 (42.5%) | 5,655 |
| Apnea–Hypopnea Index† | 12.9 (6.7–23.2) | 5,655 |
| T90 | 0.18 (0.0–1.7) | 5,650 |
| Wakefulness SpO2‡ | 97.3 (96.1–98.0) | 5,655 |
| HB, % min/h | 34.4 (18.4–59.8) | 5,655 |
| HBOxi, % min/h | 34.5 (21.7–53.8) | 5,655 |
Definition of abbreviations: COPD = chronic obstructive pulmonary disease; EDS = excessive daytime sleepiness (Epworth Sleepiness Scale score >10); HBOxi = oximetry-derived hypoxic burden; SpO2 = oxygen saturation as measured by pulse oximetry; T90 = total time arterial oxygen saturation is <90%.
Data presented as mean ± standard deviation for continuous variables. Ranges in parentheses are interquartile ranges.
Hypertension status was defined based on the average of the second and third sitting blood pressure readings of >140 mm Hg in systolic blood pressure and >90 mm Hg in diastolic blood pressure or being treated with hypertension medications.
All apneas and hypopneas with ⩾30% nasal cannula reduction and ⩾3% oxygen desaturation or with arousal per hour of sleep.
Wakefulness SpO2 was the average of local SpO2 maxima during the wakefulness period before the start of the first sleep period.