Table 3.
Descriptive characteristics of the study population.
| Feature | Mean ±std |
|---|---|
| Sociodemographic data | |
| Gender (women) | 31 (50.8%) |
| Age (years) | 75.0 [72.0; 78.0] |
| BMI, kg/m2 | 28.0 [24.4; 31.1] |
| Comorbidities | |
| Hypertension | 39 (63.9%) |
| Diabetes mellitus | 10 (16.4%) |
| Dyslipidemia | 30 (49.2%) |
| Heart diseases | 12 (19.7%) |
| Hypertension | 3 (4.9%) |
| OSA | 26 (42.6%) |
| Alzheimer's disease parameters | |
| Mini-mental state examination | 23.0 [21.0; 25.0] |
| Aβ42 (pg/ml) | 515.0 [404.25; 614.25] |
| t-tau (pg/ml) | 555.0 [327.5; 712.0] |
| p-tau (pg/ml) | 82.0 [52.0; 98.75] |
| Polysomnographic parameters | |
| Epworth sleepiness scale | 5.0 [3.0; 8.0] |
| Time in bed (minutes) | 420.1 [391.0; 446.1] |
| Total sleep time (minutes) | 262.1 [203.5; 326.1] |
| Sleep efficiency (%) | 66.4 [49.7; 79.4] |
| N1 stage (% TST) | 11.96 [7.7; 18.4] |
| N2 stage (% TST) | 23.1 [16.0; 35.1] |
| N3 stage (% TST) | 13.6 [7.1; 22.4] |
| REM stage (% TST) | 6.6 [3.3; 11.2] |
| REM sleep (% TST) | 6.6 [3.3; 11.2] |
| Latency to N1 stage (minutes) | 23.1 [11.9; 57.7] |
| Latency to REM sleep (minutes) | 126.7 [85.1; 179.9] |
| AHI (events/hour) | 27.0 [15.4; 52.5] |
| AI (events/hour) | 36.1 [23.2; 49.5] |
| Mean SaO2 (%) | 93.0 [92.0; 94.0] |
| CT90 (%) | 1.9 [0.7; 7.2] |
| ODI (events/h) | 18.3 [12.6; 44.0] |
AHI, apnoea-hypopnea index; AI, arousal index; ApoE, apolipoprotein E; Aβ42, amyloid-beta protein; BMI, body mass index; ESS, Epworth sleepiness scale; IQR, interquartile range; ODI, oxygen-hemoglobin desaturation index; SaO2, oxygen-hemoglobin saturation; TST, total sleep time; CT90, percent of TST spent below 90% oxygen-hemoglobin desaturation; p-tau, phospho-tau; t-tau, total-tau.