Table 1.
Sample characteristics
| Total sample (n = 103) | Alzheimer’s disease pathology (n = 62) | Non-Alzheimer’s disease pathology (n = 41) | P-value (effect size) | |
|---|---|---|---|---|
| Demographics | ||||
| Sex, n (%) female | 47 (45.6) | 28 (45.2) | 19 (46.3) | 0.91 |
| Age at blood draw, mean (SD) | 78.77 (8.21) | 77.97 (8.46) | 79.98 (7.76) | 0.23 |
| Age at death, mean (SD) | 84.40 (8.25) | 83.27 (8.26) | 86.10 (8.02) | 0.09 |
| Race, n (%) | 0.19 | |||
| American Indian/Alaska Native | 2 (1.9) | 2 (3.2) | 0 | |
| Asian | 1 (1.0) | 0 | 1 (2.4) | |
| Black or African American | 4 (3.9) | 1 (1.6) | 3 (7.3) | |
| White | 95 (92.2) | 59 (95.2) | 36 (87.8) | |
| Other | 1 (1.0) | 0 | 1 (2.4) | |
| Ethnicity, n (%) | – | |||
| Hispanic | 0 | 0 | 0 | |
| Diagnosis at death, n (%) | <0.01 (OR = 7.53) |
|||
| Normal cognition | 10 (9.7) | 0 (0) | 10 (24.4) | |
| MCI/non-MCI cognitively impaired | 20 (19.4) | 7 (11.3) | 13 (31.7) | |
| Dementia | 73 (70.9) | 55 (88.7) | 18 (43.9) | |
| Dementia severity | ||||
| Global CDR score at death, mean (SD) | 1.22 (1.13) | 1.59 (1.14) | 0.66 (0.85) | <0.01 (d = 0.90) |
| Global CDR score at death, n (%) | <0.01 (OR = 4.91) | |||
| <1 | 55 (53.4) | 24 (38.7) | 31 (75.6) | |
| ≥1 | 48 (46.6) | 38 (61.3) | 10 (24.4) | |
| Global CDR score at blood draw, mean (SD) | 0.83 (0.93) | 1.11 (0.97) | 0.39 (0.68) | <0.01 (d = 0.84) |
| Global CDR score at blood draw, n (%) | <0.01 (OR = 5.26) | |||
| <1 | 57 (55.3) | 25 (40.3) | 32 (78.0) | |
| ≥1 | 46 (44.7) | 37 (59.7) | 9 (22.0) | |
| Vascular risk factors, n (%) | ||||
| Hypertension | 61 (59.2) | 34 (54.8) | 27 (65.8) | 0.27 |
| Diabetes | 13 (12.6) | 8 (12.9) | 5 (12.2) | 0.92 |
| Obstructive sleep apnoea | 9 (8.7) | 3 (4.8) | 6 (14.6) | 0.10 |
| Genetic | ||||
| APOE ε 4 allele status, n (%) carrier | 47 (45.6) | 33 (53.2) | 14 (34.1) | 0.06 (OR = 2.20) |
| Plasma biomarker | ||||
| P-tau181, mean (SD)/range, pg/ml | 27.19 (16.52)/3–95 | 31.28 (15.67)/9–90 | 20.99 (16.00)/3–95 | <0.01 (d = 0.65) |
The 1997 NIA–Reagan criteria were used for the neuropathological diagnosis of Alzheimer’s disease and those with sparse neuritic plaques and Braak stage 5 or 6 were classified as Alzheimer’s disease. Binary logistic regression was used to compare donors with and without autopsy-confirmed Alzheimer’s disease on binary outcomes; independent samples t-test was used for continuous outcomes. For race, White and non-White were compared and coded as 1 (White) and 0 (non-White). Sex was coded as 0 (male) and 1 (female). Sample size for ethnicity was 101 as two were unknown.