Table 1.
Demographic and polysomnography variables grouped by severity of cognitive status; mean scores (SD)
| Total N = 59 | Mild MMSE 21-30 (n = 29) | Moderate MMSE 11-20 (n = 23) | Severe MMSE 1-10 (n = 7) | F | P | |
|---|---|---|---|---|---|---|
| Age | 79.1 (6.0) | 78.1 (6.4) | 79.7 (5.0) | 80.4 (8.1) | 0.66 | 0.52 |
| Gender | 3.83 | 0.02* | ||||
| Male | 41 | 24 | 15 | 2 | ||
| Female | 18 | 5 | 8 | 5 | ||
| Sleep Architecture: | ||||||
| Minutes of latency to first epoch of sleep | 43.2 (91.2) | 25.7 (25.0) | 49.5 (104.8) | 98.1 (182.3) | 1.94 | 0.15 |
| Minutes of latency to first 10 min of sleep | 87.4 (144.6) | 43.3 (36.6) | 92.9 (143.9) | 258.1 (281.5) | 7.73 | ≤ 0.01* |
| Minutes of latency to REM sleep | 147.9 (89.83) | 131.8 (71.4) | 161.5 (106.6) | 173.8 (102.4) | 0.95 | 0.39 |
| NREM Sleep | ||||||
| Minutes | 292.7 (96.1) | 293.1 (80.7) | 287.7 (95.21) | 307.3 (160.4) | 0.11 | 0.89 |
| % of TIB | 57.5 (15.3) | 58.6 (12.4) | 57.0 (15.5) | 54.69 (25.7) | 0.20 | 0.82 |
| % of TST | 85.9 (10.5) | 86.2 (7.6) | 85.9 (10.7) | 85.2 (19.4) | 0.04 | 0.96 |
| REM Sleep | ||||||
| Minutes | 45.6 (28.9) | 48.6 (27.9) | 44.7 (30.4) | 35.6 (29.8) | 0.58 | 0.56 |
| % of TIB | 9.0 (5.9) | 10.0 (6.1) | 8.7 (5.6) | 6.2 (5.0) | 1.29 | 0.28 |
| % of TST | 12.5 (7.43) | 13.8 (7.55) | 12.2 (7.2) | 7.6 (6.6) | 2.03 | 0.14 |
| TST | ||||||
| Minutes | 338.3 (109.2) | 341.7 (89.0) | 332.4 (113.3) | 342.9 (177.9) | 0.05 | 0.94 |
| Total Wake Time | ||||||
| Minutes | 151.6 (71.8) | 152.8 (68.6) | 154.7 (77.3) | 136.5 (76.1) | 0.17 | 0.84 |
| Awakenings, No. | 34.7 (16.3) | 39.6 (19.8) | 31.8 (10.4) | 23.3 (5.4) | 3.75 | 0.02* |
| Spontaneous | 14.6 (8.5) | 14.6 (9.6) | 14.4 (7.8) | 15.2 (7.4) | 0.02 | 0.97 |
| Bathroom | 1.9 (1.8) | 2.2 (1.4) | 1.8 (2.3) | 0.9 (0.7) | 1.54 | 0.22 |
| Respiratory | 18.2 (16.1) | 22.8 (19.0) | 15.5 (11.6) | 7.1 (6.0) | 3.44 | 0.03* |
| Sleep efficiency | 66.6 (18.0) | 68.6 (14.7) | 65.8 (18.6) | 60.8 (28.5) | 0.57 | 0.57 |
| TIB | 490.0 (78.5) | 494.6 (59.3) | 487.3 (82.8) | 479.4 (134.8) | 0.12 | 0.88 |
| Stage shifts, No. | 83.2 (36.5) | 99.2 (40.3) | 71.6 (23.0) | 53.1 (22.0) | 7.90 | ≤ 0.01* |
| PLMI | 15.3 (19.2) | 13.6 (18.1) | 15.4 (19.2) | 25.3 (26.9) | 0.89 | 0.41 |
| PLMI with arousals | 4.8 (6.9) | 3.9 (6.1) | 4.7 (6.9) | 9.5 (9.2) | 1.73 | 0.18 |
| AHI | 19.5(14.9) | 21.6 (16.9) | 18.5 (12.8) | 13.0 (12.1) | 0.90 | 0.41 |
| SpO2 nadir, % | 86.7 (4.8) | 86.3 (4.3) | 86.7 (5.2) | 89.7 (6.2) | 1.05 | 0.35 |
NREM, non-rapid eye movement; REM, rapid eye movement; TIB, time in bed; TST, total sleep time; PLMI, periodic limb movement in sleep index; AHI, apnea hypopnea index.
*
significant χ2