Table 1.
Descriptive characteristics. Descriptive characteristics in the total population and split into two age groups by the median age (73.3 years). Mean (SD) if not otherwise specified. ***p < 0.001, **p < 0.01, *p < 0.05. Abbreviations: CSF, cerebrospinal fluid; Aβ40, amyloid-β 40; Aβ42, amyloid-β 42; MRI, magnetic resonance imaging; WML, white matter lesion; ctx, cortex; ADAS, Alzheimer's disease assessment scale; AQT, A quick test of cognitive speed; SDMT, symbol digit modalities test; TMT-A, trailmaking test A.
| All (n = 300) | Younger (n = 150) | Older (n = 150) | |
|---|---|---|---|
| Demographics | |||
| Age (years) | 73.8 (5.0) | 69.7 (2.1) | 77.9 (3.5)*** |
| Sex (% female) | 59.7 | 52.0 | 67.3** |
| Education (years) | 12.3 (3.7) | 13.1 (3.8) | 11.5 (3.5)*** |
| APOE ε4 allele carrier (%; n = 297) | 27.9 | 28.4 | 27.5 (ns) |
| CSF Measures | |||
| Aβ40 (pg/l) | 18 418 (5 638) | 17 602 (5 283) | 19 234 (5 877)* |
| Aβ42 (pg/l) | 1 429 (648) | 1 379 (626) | 1 478 (667; ns) |
| Aβ42/40 | 0.081 (0.064) | 0.078 (0.023) | 0.084 (0.087; ns) |
| Aβ status (% positive) | 18.0 | 13.3 | 22.7* |
| P-tau (ng/l) | 20.1 (7.85) | 18.2 (6.6) | 22.0 (8.5)*** |
| T-tau (ng/l) | 234 (84.1) | 213 (71.1) | 255 (90.8)*** |
| YKL-40 (ng/l; n = 299) | 196 053 (67 789) | 180 181 (64 993) | 212 032 (66 992)*** |
| MRI Measures | |||
| WML volume (cm3) | 10.6 (13.7) | 7.43 (11.1) | 13.8 (15.2)*** |
| Total intracranial volume (cm3) | 1 557 (158) | 1 582 (150) | 1 531 (162)** |
| Hippocampal volume (cm3) | 7.37 (1.02) | 7.77 (0.94) | 6.96 (0.93)*** |
| Entorhinal/parahippocampal ctx (mm) | 2.64 (0.33) | 2.76 (0.27) | 2.53 (0.34)*** |
| Temporal ctx (mm) | 2.48 (0.21) | 2.56 (0.17) | 2.41 (0.23)*** |
| Frontal ctx (mm) | 2.24 (0.19) | 2.29 (0.16) | 2.19 (0.20)*** |
| Parietal ctx (mm) | 2.06 (0.15) | 2.09 (0.13) | 2.02 (0.16)*** |
| Occipital ctx (mm) | 1.86 (0.11) | 1.88 (0.10) | 1.84 (0.11)** |
| Cognitive Measures | |||
| ADAS Cog delayed recall (correct answers) | 8.0 (2.0) | 8.3 (1.5) | 7.6 (2.2)** |
| AQT (seconds; n = 299) | 66.4 (13.0) | 64.1 (12.1) | 68.7 (13.4)** |
| SDMT (correct answers; n = 298) | 36.8 (8.43) | 39.9 (8.04) | 33.6 (7.58)*** |
| TMT A (seconds) | 46.2 (16.9) | 41.5 (13.8) | 51.0 (18.3)*** |