Table 2.
Comparison of sleep parameters between the participants with and without MCI.
| Categorical Variable | Non-MCI Group (n = 31) | MCI Group (n = 37) | P |
|---|---|---|---|
| Sleep architecture | |||
| Sleep efficiency (%) | 72.20 ± 12.19 | 67.92 ± 20.18 | .67 |
| Wake (% of SPT) | 22.63 ± 11.77 | 26.98 ± 18.51 | .61 |
| NREM (% of SPT) | 69.30 ± 10.98 | 63.88 ± 16.28 | .30 |
| REM (% of SPT)a | 8.09 ± 6.15 | 9.67 ± 5.08 | .26 |
| WASO (min) | 76.24 ± 38.55 | 87.84 ± 56.42 | .74 |
| TST (min) | 261.69 ± 45.37 | 247.29 ± 72.69 | .76 |
| Oximetry parameter | |||
| Mean SpO2 (%) | 95.41 ± 1.69 | 95.76 ± 1.42 | .59 |
| Minimum SpO2 (%) | 83.55 ± 7.72 | 85.32 ± 7.75 | .13 |
| ODI-3% (events/h) | 23.55 ± 16.76 | 22.41 ± 16.42 | .83 |
| Sleep disorder index (events/h) | |||
| AHI | 24.61 ± 17.53 | 22.81 ± 16.43 | .73 |
| AI | 3.25 ± 3.88 | 6.05 ± 10.66 | .80 |
| AINREM | 2.84 ± 3.46 | 6.02 ± 11.11 | .71 |
| AIREMa | 6.40 ± 11.99 | 6.27 ± 11.62 | .33 |
| HI | 21.35 ± 16.87 | 16.76 ± 13.08 | .35 |
| HINREM | 21.13 ± 17.65 | 16.22 ± 13.44 | .38 |
| HIREMa | 22.97 ± 20.96 | 22.04 ± 19.19 | .45 |
Data are expressed as mean ± SD. Differences between groups were assessed using the Mann-Whitney U test. aTwo participants with MCI did not have a REM stage during the polysomnography. AHI = apnea-hypopnea index, AI = apnea index, AINREM = apnea index in the non–rapid eye movement stage, AIREM = apnea index in the rapid eye movement stage, HI = hypopnea index, HINREM = hypopnea index in the non–rapid eye movement stage, HIREM = hypopnea index in the rapid eye movement stage, MCI = mild cognitive impairment, NREM = non–rapid eye movement, ODI-3% = oxygen desaturation index ≥ 3%, REM = rapid eye movement, SpO2 = peripheral arterial oxygen saturation measured by pulse oximetry, SPT = sleep period of time, TST = total sleep time, WASO = wake time after sleep onset.