Table 2. Comparisons among obstructive sleep apnea patients as a whole, those with mild disease, and those with moderate to severe disease.a .
| Variable | OSA (n = 38) | Mild OSA (n = 20) | Moderate to severe OSA (n = 18)* | p |
|---|---|---|---|---|
| Age, years | 67.8 ± 8.6 | 64.4 ± 9.5 | 71.5 ± 5.9 | 0.008 |
| Male | 21 (55.3%) | 9 (45.0%) | 12 (66.7%) | 0.210 |
| Current or former smoker | 25 (65.8%) | 12 (60.0%) | 13 (72.2%) | 0.506 |
| ESS score | 3.0 (1.0-7.0) | 2.5 (1.0-7.0) | 3.0 (1.8-6.3) | 0.508 |
| BMI, kg/m2 | 27.2 ± 4.1 | 26.4 ± 4.7 | 28.0 ± 3.2 | 0.248 |
| ILD | ||||
| HP | 20 (52.6%) | 8 (40.0%) | 12 (66.7%) | 0.119 |
| CTD-ILD | 6 (15.8%) | 3 (15.0%) | 3 (16.7%) | 1.000 |
| Idiopathic NSIP | 6 (15.8%) | 5 (25.0%) | 1 (5.6%) | 0.184 |
| PPFE | 1 (2.6%) | 1 (5.0%) | 0 (0.0%) | 1.000 |
| Unclassifiable ILD | 3 (7.9%) | 1 (5.0%) | 2 (11.1%) | 0.595 |
| Organizing pneumonia | 1 (2.6%) | 1 (5.0%) | 0 (0.0%) | 1.000 |
| Desquamative interstitial pneumonia | 1 (2.6%) | 1 (5.0%) | 0 (0.0%) | 1.000 |
| Comorbidities | ||||
| Diabetes mellitus | 9 (23.7%) | 5 (25.0%) | 4 (22.2%) | 1.000 |
| Arterial hypertension | 17 (44.7%) | 7 (35.0%) | 10 (55.6%) | 0.328 |
| Dyslipidemia | 22 (57.9%) | 11 (55.0%) | 11 (61.1%) | 0.752 |
| Stroke | 3 (7.9%) | 0 (0.0%) | 3 (16.7%) | 0.097 |
| Coronary artery disease | 3 (7.9%) | 1 (5.0%) | 2 (11.1%) | 0.595 |
| Heart failure | 2 (5.3%) | 1 (5.0%) | 1 (5.6%) | 1.000 |
| COPD | 4 (10.5%) | 3 (15.0%) | 1 (5.6%) | 0.606 |
| Asthma | 7 (18.4%) | 4 (20.0%) | 1 (5.6%) | 1.000 |
| Pulmonary function tests | ||||
| Awake SpO2, % | 96.0 (96.0-97.5) | 96.0 (96.0-98.0) | 96.0 (95.8-97.3) | 0.593 |
| FEV1/FVC ratio, % | 82.3 ± 7.4 | 81.53 ± 8.3 | 83.3 ± 6.4 | 0.486 |
| FEV1, % | 92.8 ± 17.8 | 90.4 ± 17.3 | 95.6 ± 18.4 | 0.377 |
| FVC, % | 88.9 ± 18.2 | 89.6 ± 18.1 | 88.0 ± 18.9 | 0.791 |
| TLC, % | 84.0 ± 19.8 | 86.7 ± 20.7 | 80.8 ± 18.7 | 0.371 |
| DLCO, % | 59.0 ± 14.4 | 56.8 ± 11.9 | 61.6 ± 16.9 | 0.314 |
| KCO, % | 82.3 ± 21.4 | 76.2 ± 16.0 | 89.5 ± 25.1 | 0.059 |
| HRCT pattern | ||||
| UIP | 6 (15.8%) | 4 (20.0%) | 2 (11.1%) | 0.663 |
| Probable UIP | 8 (21.1%) | 3 (15.0%) | 5 (27.8%) | 0.438 |
| Indeterminate for UIP | 8 (21.1%) | 3 (15.0%) | 5 (27.8%) | 0.438 |
| Alternative diagnosis | 16 (42.1%) | 10 (50.0%) | 6 (33.3%) | 0.342 |
| Extent of fibrosis > 10% | 26 (68.4%) | 14 (70.0%) | 12 (66.7%) | 1.000 |
| HSAT results | ||||
| Snoring, % | 6.7 (3.2-25.5) | 5.2 (2.8-23.2) | 9.6 (4.3-34.3) | 0.105 |
| AHI, events/h | 14.3 (6.9-25.5) | 7.0 (6.6-9.7) | 25.6 (17.9-32.3) | < 0.001 |
| Apnea index, events/h | 2.0 (0.3-7.7) | 0.8 (0.1-1.9) | 7.8 (2.9-11.4) | < 0.001 |
| Hypopnea index, events/h | 9.3 (6.1-16.8) | 6.5 (5.1-8.2) | 17.0 (13.0-23.4) | < 0.001 |
| Obstructive events, events/h | 6.8 (4.9-17.0) | 6.4 (4.4-6.8) | 17 (6.9-24.5) | 0.001 |
| Central events, events/h | 0.3 (0.0-2.6) | 0.3 (0.0-1.3) | 0.9 (0.0-4.3) | 0.743 |
| ODI | 12.6 (8.2-26.0) | 8.3 (7.0-10.8) | 26.0 (20.4-35.7) | < 0.001 |
| Mean nocturnal SpO2, % | 92.3 ± 2.1 | 93.0 ± 2.1 | 91.7 ± 2.0 | 0.059 |
| Minimum nocturnal SpO2, % | 82.3 ± 5.8 | 85.0 ± 4.5 | 79.3 ± 5.8 | 0.002 |
| T90, % | 2.8 (0.3-17.2) | 0.6 (0.1-6.5) | 8.5 (2.3-29.8) | 0.007 |
| T90 scores > 20% | 8 (21.1%) | 3 (15.0%) | 5 (27.8%) | 0.438 |
OSA: obstructive sleep apnea; ESS: Epworth Sleepiness Scale; ILD: interstitial lung disease; HP: hypersensitivity pneumonitis; CTD-ILD: connective tissue disease-associated interstitial lung disease; NSIP: nonspecific interstitial pneumonia; PPFE: pleuroparenchymal fibroelastosis; KCO: carbon monoxide transfer coefficient; UIP: usual interstitial pneumonia; HSAT: home sleep apnea test; AHI: apnea-hypopnea index; ODI: oxygen desaturation index; and T90: total sleep time spent below an SpO2 of 90%. aValues expressed as mean ± SD, n (%), or median (IQR). *Moderate OSA (n = 13); severe OSA (n = 5).