Table 1.
Patient characteristics
| Characteristic | All Subjects (N = 42) |
|---|---|
| Demographics | |
| Age, yr | 57.4 ± 9.6 |
| Sex | |
| Male | 27 |
| Female | 15 |
| Race | |
| Black | 12 |
| White | 29 |
| Asian | 0 |
| Other | 1 |
| Body mass index, kg/m2 | 32.8 ± 6.4 |
| Neck circumference, cm | 41.7 ± 4.8 |
| Polysomnography* | |
| OSA severity | |
| Mild | 13 |
| Moderate | 8 |
| Severe | 21 |
| Apnea–hypopnea index, total (events/h) | 26 (13–44) |
| Fraction of hypopneas | 52 (34–87) |
| Fraction of central events | 0 (0–0) |
| Fraction of events ending in arousal | 89 (77–96) |
| Mean event duration, s | 22 ± 6 |
| Sleep time, spontaneous breathing off CPAP, min | 193 (88–283) |
| N1, % sleep off CPAP | 40 (23–63) |
| N2, % sleep off CPAP | 41 (32–58) |
| N3, % sleep off CPAP | 1 (0–11) |
| REM sleep, % sleep off CPAP | 4 (0–11) |
Definition of abbreviations: CPAP = continuous positive airway pressure; N = non–rapid eye movement sleep stage; OSA = obstructive sleep apnea; REM = rapid eye movement.
Values are mean ± SD, n, or median (interquartile range) as determined by normality.
*
Polysomnographic respiratory event data refer to the period off CPAP. OSA severity categories are as follows: mild (5–15 events/h), moderate (15–30 events/h), and severe (⩾30 events/h).