Means (SD) and percentages | n (155) | SCI (n=60) | MCI (n=63) | AD dementia (n=32) | P value (X2/ANOVA) |
Age (years, ANOVA) | 155 | 60.2 (6.46) | 62.6 (7.92) | 67.9 (8.29) | <0.001*** |
Education (years, ANOVA) | 155 | 14.4 (3.24) | 14.0 (3.50) | 13.4 (3.07) | 0.380 |
Female (%, X2) | 155 | 61.7 | 54.0 | 68.8 | 0.360 |
Awakening time (hh:mm, ANOVA) | 155 | 07:11 | 06:58 | 07:18 | 0.360 |
Stress measures | |||||
Perceived Stress Scale (__ /40, ANOVA) | 145 | 17.6 (6.25) | 19.0 (8.06) | 18.0 (7.41) | 0.267 |
Cortisol | |||||
Awakening cortisol (t1) (nmol/L, ANOVA) | 155 | 8.2 (4.48) | 9.1 (5.24) | 11.0 (5.78) | 0.042* |
Bedtime cortisol (t6) (nmol/L, ANOVA) | 155 | 2.0 (2.72) | 2.7 (4.43) | 2.3 (3.60) | 0.541 |
Cortisol awakening response (ANOVA) | 155 | 0.69 (1.41) | 0.60 (1.18) | 0.27 (1.26) | 0.326 |
Daily cortisol output (ANOVA) | 155 | 75.5 (46.05) | 91.0 (79.22) | 78.3 (33.30) | 0.333 |
Cortisol AM/PM ratio (t1/t6) (ANOVA) | 155 | 9.45 (8.75) | 7.39 (5.39) | 10.02 (7.99) | 0.166 |
CSF biomarkers | |||||
Aβ42 (ng/L, ANOVA) | 135 | 867.4 (172.68) | 713.6 (229.81) | 426.7 (107.69) | <0.001*** |
Aβ42 ≤550 ng/L (%, X2) | 135 | 3.8 | 28.8 | 87.1 | <0.001*** |
T-Tau (ng/L, ANOVA) | 135 | 279.5 (112.73) | 321.8 (183.48) | 612.2 (266.71) | <0.001*** |
T-Tau >400 ng/L (%, X2) | 135 | 13.5 | 23.1 | 83.9 | <0.001*** |
P-Tau (ng/L, ANOVA) | 135 | 41.7 (14.24) | 45.4 (21.37) | 72.5 (28.84) | <0.001*** |
P-Tau >80 ng/L (%, X2) | 135 | 3.8 | 7.7 | 29.0 | 0.001** |
Cognition | |||||
Overall cognition (mean z-score, ANOVA) | 125 | −0.28 (0.86) | −0.91 (0.84) | −1.29 (0.89) | <0.001*** |
Memory (mean z-score, ANOVA) | 134 | −0.05 (0.78) | −1.46 (1.18) | −2.77 (0.88) | <0.001*** |
Processing speed (mean z-score, ANOVA) | 124 | −0.26 (1.14) | −1.00 (1.26) | −1.52 (1.02) | <0.001*** |
Working memory (mean z-score, ANOVA) | 110 | −0.25 (0.82) | −0.83 (1.11) | −1.17 (0.40) | <0.001*** |
Perceptual reasoning (mean z-score, ANOVA) | 127 | 0.05 (0.84) | −0.61 (0.96) | −0.90 (0.91) | <0.001** |
*Significant at p<0.05; **significant at p<0.01, ***significant at p<0.001.
AD, Alzheimer’s disease; ANOVA, analysis of variance; MCI, mild cognitive impairment; P-Tau, phosphorylated tau ; SCI, subjective cognitive impairment; T-Tau, total tau.