Table. Study Demographicsa.
| Group | No. | Male- Female Ratio |
Age, Mean (SD), y |
Education, Mean (SD), y |
Positive APOE ε4 Genotype Status, No. |
WM Hyperin- tensities, Mean (SD), mL |
WM Hypoin- tensities, Mean (SD), mL |
History of Hyper- tension, No. |
Cognitive Subscale of the Alzheimer Disease Assessment Scale, Mean (SD) |
Aβ42 Level, Mean (SD) |
T-tau Level, Mean (SD) |
P-tau Level, Mean (SD) |
||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Baseline Score |
Slope, Units/y |
Baseline, ng/L |
Slope, ng/L*y |
Baseline, ng/L |
Slope, ng/L*y |
Baseline, ng/L |
Slope, ng/L*y |
|||||||||
| CN Aβ-s | 13 | 10:3 | 76.2 (4.8) | 16.7 (2.5) | 0 | 0.24 (0.17) | 3.8 (1.3) | 6 | 5.2 (0.9) | −0.19 (0.31) | 258 (25) | −2.1 (−1.3) | 58 (23) | 1.8 (0.13) | 21 (5.6) | 1.8 (1.0) |
| CN Aβ-d | 13 | 5:8 | 78.1 (6.8) | 15.2 (2.5) | 1 | 1.61 (3.67) | 7.9 (9.8) | 5 | 5.5 (1.6) | 0.15 (0.82) | 256 (29) | −6.7 (−2.9)b | 71 (24) | 1.7 (0.15) | 23 (6.6) | 2.0 (1.0) |
| CN Aβ+ | 21 | 12:9 | 76.0 (3.4) | 16.1 (3.3) | 10 | 1.07 (2.21) | 6.6 (5.2) | 11 | 6.4 (1.6) | 0.52 (0.89)c | 151 (26)b | −3.3 (−1.5)d | 86 (33)d | 1.6 (0.21) | 31 (10)d | 3.4 (1.8) |
| AD Aβ+ | 15 | 6:9 | 73.0 (6.3) | 15.0 (2.9) | 12 | 0.35 (0.33) | 7.6 (9.2) | 6 | 15.4 (5.1)b,e | 5.10 (2.80)b,e | 126 (20)b,f | 0.1 (1.2) | 114 (57)d,f | 1.5 (0.31) | 36 (9.1)b,f | 4.2 (1.5)c,f |
Abbreviations: Aβ, β-amyloid; AD, Alzheimer disease; AD Aβ+, Aβ-positive AD group; APOE, apolipoprotein E; CN, cognitively normal; CN Aβ+, Aβ-positive CN group; CN Aβ-d, declining Aβ-negative CN group; CN Aβ-s, stable Aβ-negative CN group; ng/L*y, change in concentration per year; WM Hyperintensities, white matter hyperintensities (volume in standardized space, corrected for head size).
For group comparisons of demographic factors, Kruskal-Wallis test was used for age (P = .10), education (P = .20), white matter hyperintensities (P = .81), and white matter hypointensities (P = .41), and χ2 test was used for sex (P = .15), APOE ε4 genotype status (P < .001), and history of hypertension (P = .84). Data for Aβ42 level, T-tau level, P-tau level, and cognitive subscale score on the Cognitive Subscale of the Alzheimer Disease Assessment Scale are modeled intercepts (baseline levels) and slopes from linear mixed-effects models, adjusted for age and sex (Aβ42 levels were modeled separately for cognitively normal control subjects and patients with Alzheimer disease dementia because of different distributions). Group comparisons for Aβ42 level, T-tau level, P-tau level, and cognitive subscale score on the Cognitive Subscale of the Alzheimer Disease Assessment Scale were performed by comparing every group with the CN Aβ-s group and comparing the AD Aβ+ group with the CN Aβ+ group in the linear mixed-effects models.
P < .001 vs the CN Aβ-s group.
P < .05 vs the CN Aβ-s group.
P < .01 vs the CN Aβ-s group.
P < .001 vs the CN Aβ+ group.
P < .05 vs the CN Aβ+ group.