Table 1.
Descriptive characteristics of study sample
| Characteristics | Mean (SD) or N (%) |
|---|---|
| Sociodemographic parameters | |
| Female, N (%) | 120 (55.6) |
| Age (year) | 60.64 (± 7.17) |
| Education (year) | 13.35 (± 2.58) |
| Sleep macroarchitecture | |
| Time in bed (min) | 462.09 (± 46.77) |
| Sleep efficiency (%) | 87.6 (± 8.5) |
| Sleep duration (min) | 303.92 (± 75.04) |
| Duration of N1 (min) | 14.34 (± 9.06) |
| Duration of N2 (min) | 159.74 (± 63.10) |
| Duration of N3 (SWS) (min) | 25.46 (± 20.62) |
| Duration of REM (min) | 34.35 (± 20.77) |
| Sleep fragmentation (number of times/h) | 2.73 (± 0.87) |
| Sleep microarchitecture | |
| Frontal SO power (μV2) | 188.21 (± 160.17) |
| Central SO power (μV2) | 134.56 (± 109.34) |
| Frontal spindle power (μV2) | 4.88 (± 4.81) |
| Central spindle power (μV2) | 5.74 (± 3.50) |
| Frontal spindle activity during SO upstate (μV2) | 0.47 (± 0.16) |
| Central spindle activity during SO upstate (μV2) | 0.56 (± 0.16) |
| Frontal coupling strength | 0.93 (± 0.01) |
| Central coupling strength | 0.94 (± 0.01) |
| Polyamines | |
| Spermidine (μM) | 0.125 (± 0.052) |
| Brain imaging measures | |
| Alzheimer’s disease scorea | − 4.076 (± 1.293) |
| Intracranial volume (L)a | 1.56 (0.15) |
| Lifestyle | |
| Alcohol consumption (ethanol in g/day)b,c | 9.01 (± 11.86) |
| Smoking status, N (%) | |
| Non-smoker | 100 (46.3) |
| Previous smoker | 99 (45.8) |
| Smoker | 17 (7.9) |
| Waist-to-hip ratio | 0.89 (± 0.084) |
| BMI (kg/m2) | 28.61 (± 4.35) |
Values are presented as mean and standard deviation or N and %. Unless indicated differently N = 216
BMI body mass index
aN = 186
bN = 214
cAlcohol consumption was calculated as alcohol consumption during the last 30 days