Table 1.
Participant characteristics overall and by site.
| Measures | Total | PKU | Penn VA | P* |
|---|---|---|---|---|
| General | ||||
| n | 84 | 67 | 17 | |
| Age, y | 58.7 ± 16.3 | 56.6 ± 17.2 | 66.9 ± 7.7 | .038 |
| Sex, n (%) | ||||
| Male | 73 (86.9) | 56 (83.6) | 17 (100) | .073 |
| Female | 11 (13.1) | 11 (16.4) | 0 | |
| BMI, kg/m2 | 29.4 ± 13.0 | 27.3 ± 5.2 | 37.4 ± 26.1 | .012 |
| LVEF, % | 40.3 ± 11.5 | 39.5 ± 11.2 | 43.5 ± 12.5 | .100 |
| LVEF < 50% (% of participants) | 71 (84.5) | 59 (88.1) | 12 (70.6) | .075 |
| Epworth Sleepiness Scale score | 8.6 ± 4.2 | 8.7 ± 3.9 | 8.5 ± 4.6 | .811 |
| COPD, n (%) | 11 (13.1) | 2 (3.0) | 9 (52.9) | < .001 |
| PSG results | ||||
| n | 79 | 65 | 14 | |
| Total sleep time, min | 354.4 ± 65.5 | 367.9 ± 61.7 | 291.6 ± 42.8 | < .001 |
| Sleep efficiency, % | 74.6 ± 11.9 | 74.5 ± 12.2 | 75.0 ± 10.4 | .964 |
| Sleep stages, % | ||||
| N1 | 17.6 ± 17.0 | 18.4 ± 15.1 | 13.6 ± 24.2 | .011 |
| N2 | 51.1 ± 16.9 | 47.4 ± 13.3 | 67.9 ± 21.7 | < .001 |
| N3/N4 | 9.1 ± 9.1 | 10.2 ± 9.0 | 4.2 ± 8.5 | .003 |
| REM sleep | 15.5 ± 7.5 | 15.8 ± 6.9 | 14.3 ± 9.8 | .449 |
| AHI 4%, events/h† | 23.8 ± 21.3 | 24.2 ± 20.6 | 22.0 ± 24.9 | .590 |
| OAI, events/h | 6.9 ± 10.8 | 7.7 ± 11.6 | 2.8 ± 3.9 | .007 |
| CAI, events/h | 7.3 ± 10.9 | 7.8 ± 10.9 | 4.8 ± 11.0 | .410 |
| Total number of OSA | 41.4 ± 70.0 | 75.4 ± 9.4 | 20.0 ± 5.3 | .003 |
| Total number of CSA | 44.1 ± 70.0 | 72.5 ± 9.0 | 55.4 ± 14.8 | .240 |
| Mean SpO2 during sleep, % | 94.1 ± 3.2 | 94.4 ± 3.0 | 92.5 ± 3.4 | .028 |
| Minimum SpO2 during sleep, % | 79.9 ± 11.8 | 80.1 ± 11.5 | 78.9 ± 13.8 | .920 |
Values are presented as mean ± standard deviation for continuous variables or n (%) for categorical variables. *P values from Mann-Whitney U test or Fisher’s exact test comparing patients from PKU and Penn VA. †Scoring of hypopneas required ≥ 4% oxygen desaturation according to HSAT and ≥ 4% oxygen desaturation and/or an arousal according to PSG. AHI = apnea-hypopnea index, BMI = body mass index, CAI = central apnea index, COPD = chronic obstructive pulmonary disease, CSA = central sleep apnea, HSAT = home sleep apnea test, LVEF = left ventricular ejection fraction, OAI = obstructive apnea index, OSA = obstructive sleep apnea, Penn VA = Crescenz Veterans Affairs Medical Center, PKU = Peking University People’s Hospital, PSG = polysomnography, REM = rapid eye movement, SpO2 = oxygen saturation.