Table 1.
Baseline demographic information
| AIBL |
Whole cohort n = 373 |
Cognitively unimpaired n = 240 |
Mild cognitive impairment n = 69 |
Alzheimer’s disease n = 64 |
p |
| Age, mean (SD) | 73.43 (6.99) | 72.44 (6.42) | 74.96 (7.58) | 75.52 (7.74) | 0.0003 |
| Female n (%) | 197 (52.8) | 137 (57.1) | 26 (37.7) | 34 (53.1) | 0.017 |
| Years of education n (%) | |||||
| 0–8 | 32 (8.57) | 13 (5.4) | 10 (14.5) | 9 (14.1) | 0.077 |
| 9–12 | 155 (41.55) | 100 (41.7) | 32 (46.4) | 23 (35.9) | |
| 13–15 | 75 (21.10) | 53 (22.1) | 9 (13.0) | 13 (20.3) | |
| 15 + | 108 (28.95) | 73 (30.4) | 18 (26.1) | 17 (26.6) | |
| APOE ε4 carriage n (%) | 160 (42.89) | 77 (32.08) | 34 (49.27) | 49 (76.56) | 3.254e − 09 |
| Αβ + n (%) | 171 (45.84) | 72 (30) | 42 (60.86) | 57 (89.06) | 2.2e − 16 |
| MRI n (%) | 329 (88.2) | 220 (91.66) | 57 (82.60) | 52 (81.25) | 0.485 |
| Smoking status n (%) | 138 (36.99) | 73 (30.41) | 35 (50.72) | 21 (32.81) | 0.251 |
| PACC mean (SD) [n (%)] |
− 0.88 (1.33) [358 (95.97)] |
− 0.18 (0.69) [239 (99.58)] |
− 1.61 (0.83) [68 (98.55)] |
− 3.26 (0.80) [51 (79.68)] |
0.012 |
| ADNI |
Whole cohort n = 486 |
Cognitively unimpaired n = 166 |
Mild cognitive impairment n = 256 |
Alzheimer’s disease n = 64 |
p |
| Age, mean (SD) | 73.92 (7.51) | 75.91 (6.71) | 72.05 (7.46) | 76.26 (7.84) | 0.09 |
| Female n (%) | 227 (46.70) | 86 (51.80) | 115 (44.92) | 26 (40.62) | 0.22 |
| Years of education n (%) | |||||
| 0–8 | 4 (0.8) | 2 (1.20) | 1 (0.40) | 1 (1.60) | 0.90 |
| 9–12 | 60 (12.30) | 18 (10.84) | 34 (13.28) | 8 (12.50) | |
| 13–15 | 89 (18.3) | 31 (18.67) | 45 (17.57) | 13 (20.31) | |
| 15 + | 333 (68.5) | 115 (69.27) | 176 (68.75) | 42 (65.62) | |
| APOE ε4 carriage n (%) | 204 (41.97) | 44 (26.50) | 114 (44.53) | 46 (71.87) | 1.615e − 09 |
| Αβ + n (%) | 250 (51.4) | 51 (30.72) | 143 (55.85) | 56 (87.50) | 1.372e − 14 |
| MRI n (%) | 382 (78.60) | 117 (79.48) | 229 (89.45) | 36 (56.25) | 0.47 |
| Smoking status n (%) | 193 (39.7) | 69 (41.60) | 102 (39.84) | 22 (34.37) | 0.60 |
| PACC mean (SD) [n (%)] |
− 0.11 (0.53) [469 (96.50)] |
0.10 (0.43) [164 (98.79)] |
− 0.17 (0.51) [252 (98.43)] |
− 0.54 (0.63) [53 (82.81)] |
0.352 |
Baseline demographic and clinical characteristics of all participants with available methylation data in the AIBL study. p values represent significance when comparing between classifications
Aβ + high Aβ burden, MRI magnetic resonance imaging, APOE ε4 apolipoprotein ε4 allele, PACC pre-Alzheimer’s cognitive composite