Table 1.
Clinical, polysomnographic, and respiratory variables for healthy control subjects and OSA groups.
| Variables | Controls [A] | Mild OSA [B] | Moderate OSA [C] | Severe OSA [D] | p-value | Post-hoc tests |
|---|---|---|---|---|---|---|
| AHI criteria for groups | <5 | ≥5 to < 15 | ≥15 to < 30 | ≥30 | n/a | |
| Number of subjects | 16 | 37 | 20 | 23 | n/a | |
| Sex (#; %Male) | 10; 62.5% | 24; 64.9% | 17; 85.0% | 20; 87.0% | ns | |
| Age (years) | 64.4 (6.7) | 64.4 (5.9) | 64.6 (6.3) | 67.0 (7.0) | ns | |
| Body mass index (kg/m2) | 25.9 (3.4) | 26.7 (3.6) | 28.9 (3.6) | 28.6 (2.5) | <0.05 | A < C |
| Vascular burden index | 0.9 (1.1) | 1.3 (1.4) | 1.3 (1.0) | 1.4 (1.3) | ns | |
| Epworth sleepiness scale | 7.8 (5.7) | 7.5 (4.6) | 9.1 (5.2) | 8.4 (4.8) | ns | |
| Beck depression inventory II | 5.4 (5.4) | 6.4 (5.4) | 7.1 (5.4) | 7.0 (5.2) | ns | |
| Beck anxiety inventory | 4.7 (4.7) | 4.0 (4.0) | 5.2 (5.7) | 4.1 (4.1) | ns | |
| Montreal cognitive assessment | 27.4 (2.2) | 27.6 (2.0) | 27.2 (2.4) | 26.5 (3.0) | ns | |
| Polysomnographic variables | ||||||
| TST (min) | 367.0 (54.9) | 358.7 (74.0) | 347.1 (49.1) | 370.5 (62.6) | ns | |
| Sleep efficiency (%) | 78.4 (8.8) | 79.1 (12.5) | 78.7 (11.2) | 79.2 (11.0) | ns | |
| MAI (MA/h) | 11.1 (4.0) | 13.5 (5.4) | 17.0 (6.6) | 23.8 (10.8) | <0.001 | A, B, C < D |
| NREM 1 (min) | 58.5 (28.1) | 62.4 (23.3) | 78.3 (30.5) | 121.0 (51.7) | <0.001 | A, B, C < D |
| NREM 2 (min) | 209.7 (44.2) | 197.7 (61.6) | 196.7 (47.6) | 180.8 (57.5) | ns | |
| NREM 3 (min) | 40.3 (31.7) | 41.4 (39.0) | 21.1 (24.5) | 16.3 (18.7) | <0.01 | B > D |
| NREM (min) | 308.5 (52.9) | 301.4 (60.1) | 296.0 (42.7) | 318.1 (54.6) | ns | |
| NREM (%) | 83.9 (4.6) | 84.5 (5.5) | 85.5 (5.7) | 86.0 (5.7) | ns | |
| REM (min) | 58.5 (16.5) | 57.2 (24.0) | 51.0 (20.5) | 52.3 (24.3) | ns | |
| REM duration < 30 (%) | 0.0% | 13.5% | 20.0% | 13.0% | ns | |
| REM (%) | 16.1 (4.6) | 15.5 (5.5) | 14.5 (5.7) | 14.0 (5.7) | ns | |
| Respiratory variables | ||||||
| AHI (AH/hour) | 2.0 (1.3) | 9.3 (2.8) | 22.3 (4.6) | 46.6 (17.9) | <0.001 | A < B < C < D |
| AH duration (s) | 20.3 (5.2) | 22.3 (4.6) | 20.7 (3.6) | 25.9 (5.2) | <0.001 | A, B, C < D |
| NREM-AHI (AH/h) | 1.4 (1.2) | 7.5 (3.5) | 20.3 (5.9) | 46.5 (18.2) | <0.001 | A, B < C < D |
| #NREM-AH | 6.8 (5.5) | 37.0 (18.8) | 101.1 (37.1) | 246.0 (107.7) | <0.001 | A, B < C < D |
| REM-AHI (AH/h) | 5.4 (5.1) | 22.7 (22.2) | 40.1 (28.2) | 49.5 (30.2) | <0.001 | A < C, D; B < D |
| #REM-AH | 5.3 (5.4) | 18.0 (14.1) | 28.2 (17.0) | 38.0 (22.4) | <0.001 | A < B, C, D; B<D |
| Minimal SpO2 (%) | 90.4 (2.9) | 87.0 (4.5) | 82.9 (5.6) | 82.5 (5.5) | <0.001 | A, B > C, D |
| Minimal NREM SpO2 (%) | 91.3 (2.9) | 88.2 (4.6) | 84.1 (5.8) | 83.9 (4.8) | <0.001 | A, B > C, D |
| Minimal REM SpO2 (%) | 91.4 (2.3) | 89.6 (3.5) | 85.2 (6.3) | 84.7 (6.1) | <0.001 | A, B > C, D |
| TST SpO2 < 90% (min) | 0.1 (0.2) | 2.1 (5.1) | 6.0 (5.1) | 16.1 (18.9) | <0.001 | A, B, C < D |
Note: Results are presented as mean (SD).
OSA: obstructive sleep apnea; AHI: apnea–hypopnea index; N/A: not applicable; TST: Total sleep time; MAI: micro-arousal index; NREM: non-rapid eye movement sleep; REM: rapid eye movement sleep; AH: apneas and hypopneas; SpO2: oxygen desaturation.