Table 1.
Descriptive Characteristics of the Sample
| Characteristics | Full sample (n = 203) |
CSF subsample (n = 100) |
|---|---|---|
| Age, years | 68.25 (5.41) | 67.45 (5.46)* |
| Sex, n men (%) | 78 (38.4) | 29 (29.0) |
| Education, years | 15.16 (3.37) | 15.13 (3.17) |
| Retirement, n (%) | 143 (70.4) | 61 (61.0)* |
| Body mass index, kg/m2 | 27.08 (4.83) | 27.50 (4.28) |
| Geriatric Depression Scale, score | 1.50 (2.14) | 1.21 (1.79) |
| Geriatric Anxiety Inventory, score | 2.17 (3.63) | 1.77 (3.02) |
| Hypertension or usage of antihypertensive, n (%) | 61 (30.1) | 30 (30.0) |
| Usage of statins, n (%) | 49 (24.1) | 26 (26.0) |
| History of atrial fibrillation, n (%) | 23 (11.3) | 8 (8.0) |
| Years remaining before estimated expected onset (EYO), years** | 5.64 (7.56) | 5.81 (7.41) |
| Up to 5 years before expected onset, n (%) | 79 (38.9) | 36 (36.0) |
| 5 to 10 years before expected onset, n (%) | 56 (27.6) | 31 (31.0) |
| More than 10 years before expected onset, n (%) | 54 (26.6) | 26 (26.0) |
| MCI progressors, n (%) | 34 (16.8) | 17 (17.0) |
| MCI at the time of actigraphy, n (%) | 10 (4.9) | 6 (6.0) |
| Delayed memory, RBANS score | 105.27 (10.54) | 104.96 (11.24) |
| APOE4 allele carrier status, n (%) | 78 (38.4) | 40 (40.0) |
| CSF IL-6 levels, npx | — | 3.04 (0.55) |
| CSF MCP-1 levels, npx | — | 13.85 (0.48) |
| CSF t-tau/Aβ42 | — | 0.24 (0.22) |
| CSF p-tau181/Aβ42 | — | 0.049 (0.031) |
| Sleep characteristics, weekly average | ||
| Time of sleep onset, hh:mm | 23:18 (00:58) | 23:22 (00:58) |
| Time of last morning awakening, hh:mm | 07:11 (01:06) | 07:01 (01:07)* |
| Time in bed, min | 504.22 (55.11) | 492.23 (50.98)* |
| Sleep efficiency, % | 86.97 (5.95) | 86.69 (6.75) |
| Sleep duration, min | 438.79 (52.98) | 426.34 (50.93)* |
CSF, cerebrospinal fluid; EYO, expected years remaining before clinical onset; MCI, mild cognitive impairment; RBANS, Repeatable Battery for the Assessment of Neuropsychological Status; APOE4, carriers with > 1 ε4 allele; IL-6, interleukin-6; MCP-1, monocyte chemoattractant protein 1; npx, normalized protein expression levels.
*Significant difference between the full and CSF subsample.
**EYO for those with a history of parental sporadic AD (n = 189), excluding those with a multiple-sibling history of AD. The group “up to 5 years before expected onset” include those with an EYO score between 0 and 5 that are proximal to age of parental onset, as well as those with a negative EYO score that exceeded age of parental onset while remaining dementia-free.