Table 2.
Mean and standard errors of the polysomnographic variables of Alzheimer’s disease (AD) patients, amnesic mild cognitive impairment (MCI) patients and healthy controls (HCs). The results of the one-way ANOVAs (F and p values) were also reported, with post hoc unpaired t-test (p values) when ANOVAs were significant (p ≤ 0.05). Significant differences between groups are indicated in bold.
| Variables | AD | MCI | HC | F2,57 | p | AD vs. MCI | AD vs. HC | MCI vs. HC |
|---|---|---|---|---|---|---|---|---|
| Mean (SE) | Mean (SE) | Mean (SE) | ||||||
| Stage 1 latency (min) | 51.02 (13.43) | 31.02 (4.69) | 21.45 (4.96) | 3.01 | 0.06 | - | - | - |
| Stage 2 latency (min) | 42.88 (13.21) | 31.97 (4.57) | 14.15 (3.79) | 3.01 | 0.06 | - | - | - |
| Stage 1 (%) | 11.59 (2.39) | 8.54 (1.24) | 6.71 (1.04) | 2.19 | 0.12 | - | - | - |
| Stage 2 (%) | 74.90 (2.65) | 74.33 (2.13) | 76.76 (1.78) | 0.33 | 0.72 | - | - | - |
| SWS (%) | 0.14 (0.07) | 0.13 (0.06) | 0.95 (0.37) | 4.43 | 0.01 | 0.87 | 0.04 | 0.04 |
| REM (%) | 13.58 (2.54) | 16.98 (1.98) | 15.93 (1.28) | 0.76 | 0.47 | - | - | - |
| WASO (min) | 86.38 (11.37) | 105.78 (11.97) | 83.86 (8.24) | 1.26 | 0.29 | - | - | - |
| Awakenings (#) | 17.25 (3.05) | 19.25 (1.90) | 20.30 (1.81) | 0.44 | 0.64 | - | - | - |
| Arousals (#) | 35.70 (7.41) | 28.65 (5.28) | 32.25 (6.09) | 0.31 | 0.73 | - | - | - |
| TST (min) | 260.67 (18.74) | 261.67 (14.45) | 300.12 (14.88) | 1.94 | 0.15 | - | - | - |
| TBT (min) | 389.07 (16.79) | 418.13 (21.21) | 397.18 (11.97) | 0.77 | 0.47 | - | - | - |
| SEI % (TST/TBT) | 66.74 (3.66) | 63.94 (3.71) | 75.23 (2.68) | 3.02 | 0.06 | - | - | - |
Abbreviations: SWS: slow-wave sleep; REM: rapid eye movement; WASO: wake after sleep onset; TST: total sleep time; TBT: total bed time; SEI: sleep efficiency index.