Table 1:
Sample characteristics stratified by the two independent study cohorts. Cohort comparisons for brain volume controlled for age, sex, total intracranial volume, and scanner type. Cognition comparisons controlled for age, sex, and education. Effect size estimates are presented as Cramer’s V (chi-square), Cohen’s d (independent samples t-test), or partial eta squared (analysis of covariance).
| Cohort 1 | Cohort 2 | Sig. (p) | Effect Size | |
|---|---|---|---|---|
| N | 50 | 71 | - | - |
| Age, years | 71.6 (6.9) | 72.2 (9.2) | .70 | |
| Sex, %Female | 52% | 51% | .89 | V=0.01 |
| Education, years | 17.5 (1.9) | 17.3 (2.9) | .58 | d=0.08 |
| Race, %White | 92% | 90% | .64 | V=0.04 |
| APOE, %e4 carriers | 42% | 43% | .93 | V=0.01 |
| MMSE | 29 (28, 30) | 28 (24, 29) | <.001 | d=0.73 |
| CDR-SB | 0.0 (0.0, 0.0) | 2.0 (0.0, 4.5) | - | - |
| Clinical Diagnosis, N(%) | ||||
| Normal | 39 (78%) | 32 (45%) | <.001 | V=0.45 |
| MCI | 11 (22%) | 18 (25%) | ||
| Dementia | 0 (0%) | 21 (30%) | ||
| Plasma Biomarkers | ||||
| GFAP, pg/mL | 190 (143, 241) | 153 (95, 219) | ||
| Normal | 183 (140, 242) | 110 (75, 184) | [not comparable between cohorts] | - |
| MCI | 213 (168, 254) | 172 (151, 233) | ||
| Dementia | - | 167 (137, 265) | ||
| NfL, pg/mL | 19.6 (16.4, 27.4) | 23.6 (17.3, 31.1) | ||
| Normal | 21.7 (16.4, 29.2) | 20.5 (15.2, 25.8) | [not comparable between cohorts] | - |
| MCI | 19.4 (18.3, 25.6) | 28.8 (22.1, 33.4) | ||
| Dementia | - | 24.3 (20.0, 31.3) | ||
| Brain Volume (L or mL) | ||||
| Total GM | 0.60 (0.05) | 0.57 (0.06) | .008 | η2=.08 |
| Total WM | 0.44 (0.06) | 0.43 (0.05) | .73 | η2<.01 |
| Frontal GM | 40.9 (4.1) | 38.6 (5.3) | .02 | η2=.06 |
| Frontal WM | 36.8 (5.4) | 36.1 (4.8) | .31 | η2=.01 |
| Temporal GM | 44.0 (4.9) | 41.3 (5.4) | .004 | η2=.09 |
| Temporal WM | 20.8 (2.9) | 20.0 (2.8) | .13 | η2=.03 |
| Parietal GM | 34.8 (3.3) | 32.2 (4.3) | .001 | η2=.11 |
| Parietal WM | 36.7 (5.0) | 35.5 (5.1) | .18 | η2=.02 |
| Cognition (Z-scores) | ||||
| Executive Function | −0.02 (0.80) | −0.73 (1.45) | .002 | η2=.09 |
| Memory | −0.53 (1.40) | −1.26 (2.02) | .04 | η2=.04 |
| Language | −0.04 (0.85) | −0.76 (1.55) | .004 | η2=.08 |
| Visuospatial | −0.25 (0.94) | −1.42 (2.77) | .004 | η2=.08 |
Abbreviations: APOE = apolipoprotein E gene, CDR-SB = Clinical Dementia Rating Sum of Boxes score, GFAP = glial fibrillary acidic protein, GM = grey matter, L = liters, MCI = mild cognitive impairment, mL = milliliters, MMSE = Mini Mental State Exam, NfL = neurofilament light chain, pg/mL = picograms per milliliter, Sig. = statistical significance