TABLE 1.
Participant characteristics
| Cognitively normal | Alzheimer's disease | P | |
|---|---|---|---|
| Participants (n) | 19 | 45 (mild dementia: 28, MCI: 17) | – |
| Sex (M/F) | 9/10 | 23/22 | 0.78 |
| Age (years) | 70.84 (7.78) (59–82) | 70.82 (7.48) (50–83) | 0.99 |
| Education (years) | 17.74 (2.00) (12–20) | 16.13 (2.31) (12–20) | 0.0093 |
| CDR‐global | 0 (0) (0) | 0.76 (.25) (0.5–1) | < 0.00001 |
| CDR‐SB | 0.00 (0.00) (0) | 4.11 (1.81) (0.5–9.0) | < 0.00001 |
| MMSE | 29.21 (1.06) (27–30) | 23.64 (3.37) (14–30) | < 0.00001 |
| Global cognition | 0.93 (0.25) (0.44–1.25) | –0.41 (0.62) (–1.68–0.69) | < 0.00001 |
| Executive functions | 0.85 (0.40) (0.20–1.71) | –0.42 (0.77) (–1.74–1.00) | < 0.00001 |
| Processing speed | 0.75 (0.28) (0.38–1.41) | –0.32 (0.87) (–2.32–1.00) | < 0.00001 |
| Language | 0.89 (0.32) (0.29–1.90) | –0.38 (0.79) (–2.16–0.85) | < 0.00001 |
| Visuospatial ability | 0.85 (0.41) (–0.15–1.54) | –0.37 (0.78) (–2.05–1.07) | < 0.00001 |
| Verbal memory | 1.29 (0.52) (0.29–2.01) | –0.54 (0.42) (–1.19–0.51) | < 0.00001 |
| Amyloid ± | 0/19 | 45/0 | < 0.00001 |
| Composite synaptic density (DVR) | 1.57 (0.08) (1.44–1.73) | 1.45 (0.11) (1.27–1.70) | 0.00004 |
| Hippocampal synaptic density (DVR) | 1.03 (0.08) (0.86–1.20) | 0.88 (0.12) (0.66–1.17) | < 0.00001 |
| APOE ε4 copy number (n) | |||
| 2 copies | 0 | 12 (26.7%) | – |
| 1 copy | 4 (21%) | 23 (51.1%) | – |
| 0 copies | 15 (79%) | 10 (22.2%) | – |
Abbreviations: APOE, apolipoprotein E: CDR‐global, Clinical Dementia Rating global score; CDR‐SB, Clinical Dementia Rating Sum of Boxes; DVR, distribution volume ratio of [11C]UCB‐J calculated with a whole cerebellum reference region; MMSE, Mini‐Mental State Examination; SD, standard deviation.
Notes: Data are mean (SD) (range). Scores for cognitive measures are z‐scores. P‐values are for unpaired t‐tests (continuous variables) or χ2 (categorical variables).