Table 1.
Participants’ characteristics and biomarkers by Aβ status group.
| Total (n = 381) | A− (n = 250, 65.6%) | A+ (n = 131, 34.4%) | P‐value* | |
|---|---|---|---|---|
| Demographics, clinical characteristics | ||||
| Age, years | 61.2 (4.68) | 60.6 (4.44) | 62.3 (4.93) | 0.0007* |
| Female, n (%) | 232 (60.9) | 155 (62.0) | 77 (58.8) | 0.541 |
| Education, years | 13.4 (3.51) | 13.5 (3.48) | 13.2 (3.57) | 0.467 |
| APOE‐ε4 carriers, n (%) | 201 (52.8) | 102 (40.8) | 99 (75.6) | <0.0001* |
| MMSE | 29.1 (0.954) | 29.1 (0.935) | 29.2 (0.993) | 0.608 |
| Centiloids a | 2.82 (16.8) | −4.54 (6.37) | 16.83 (21.1) | <0.0001* |
| Aβ PET‐positive (VR), n (%) a | 42 (12.8) | 3 (1.4) | 39 (34.8) | <0.0001* |
| p‐tau‐related biomarkers | ||||
| CSF Mid‐p‐tau181 (pg/ml) | 16.3 (7.69) | 14.5 (5.23) | 19.8 (10.1) | <0.0001* |
| CSF N‐p‐tau181 (pg/ml) | 346 (216) | 278 (97.7) | 477 (304) | <0.0001* |
| CSF N‐p‐tau217 (pg/ml) | 6.29 (6.41) | 4.07 (2.28) | 10.5 (9.07) | <0.0001* |
| CSF Mid‐p‐tau231 (pg/ml) | 8.29 (6.08) | 6.11 (2.28) | 12.5 (8.46) | <0.0001* |
| Plasma N‐p‐tau181 (pg/ml) | 9.55 (3.86) | 8.83 (3.21) | 10.9 (4.57) | <0.0001* |
| Core AD biomarkers | ||||
| CSF Aβ42/40 | 0.075 (0.020) | 0.087 (0.010) | 0.051 (0.012) | <0.0001* |
| CSF t‐tau (pg/ml) | 199 (74.1) | 182 (58.8) | 230 (90.0) | <0.0001* |
| CSF NfL (pg/ml) | 82.8 (30.6) | 78.1 (28.3) | 92.0 (32.7) | 0.0006* |
| Plasma NfL (pg/ml) | 10.4 (3.71) | 9.83 (3.27) | 11.6 (4.22) | 0.0006* |
Aβ42, amyloid‐β 42; Aβ40, amyloid‐β 40; CSF, cerebrospinal fluid; Mid, mid‐region; MMSE, Mini‐Mental State Examination; N, N‐terminal; NfL, neurofilament; p‐tau, phosphorylated tau; t‐tau, total tau; PET, positron emission tomography; VR, visual read.
Participants were classified as Aβ‐negative (A−) or Aβ‐positive (A+) as defined by the CSF Aβ42/40 ratio. Data are expressed as mean (M) and standard deviation (SD) or number of participants (n) and percentage (%), as appropriate. A t‐test was used to compared age, education, MMSE and Centiloids between Aβ status groups and Pearson’s chi‐square to compare sex, APOE‐ε4 and Aβ PET visual read positivity frequency between Aβ status groups. All biomarkers were compared with a one‐way ANCOVA adjusted by age and sex. The P‐values indicated in the last column refer to the Aβ status group effect.
Aβ PET was available in 331 participants and, among them, two did not have visual read assessment.
Significant differences.