Background
Methods
Ethics, consent, and permission
Subjects
Clinical and neuropsychological characterization
Overall | Normal cognition | MCI | AD | |||||
---|---|---|---|---|---|---|---|---|
African American (n = 65) | Caucasian (n = 70) | African American (n = 27) | Caucasian (n = 29) | African American (n = 27) | Caucasian (n = 25) | African American (n = 11) | Caucasian (n = 16) | |
Age, years (SD) | 69.1 (7.4) | 70.8 (7.7) | 67.5 (6.2) | 71.4 (8.1) | 67.7 (7.6) | 71.5 (5.8) | 71.4 (9.1) | 68.5 (9.4) |
Male sex, n (%) | 29 (45%) | 29 (41%) | 10 (37%) | 12 (41%) | 15 (56%) | 10 (40%) | 4 (36%) | 7 (44%) |
Education, years (SD) | 16.1 (2.8) | 16.4 (2.7) | 15.8 (2.7) | 17.0 (2.6) | 16.3 (2.9) | 17.1 (2.6) | 16.7 (3.4) | 14.2 (1.9) |
MMSE (SD) | 26.1 (4.0) | 26.7 (3.6) | 28.0 (1.8) | 28.9 (0.8) | 26.6 (2.4) | 27.6 (1.7) | 20.5 (5.9) | 21.4 (3.4) |
Hypertension | 47 (72%)a
| 32 (46%) | 17 (63%) | 13 (45%) | 21 (78%) | 14 (56%) | 9 (82%) | 5 (31%) |
Diabetes | 22 (34%)a
| 4 (6%) | 9 (33%) | 2 (7%) | 8 (30%) | 0 | 5 (45%) | 2 (12%) |
Average number of vascular risk factors (SD) | 1.9 (1.2)a
| 1.3 (1.1) | 1.5 (1.1) | 1.3 (1.3) | 2.2 (1.3) | 1.4 (0.9) | 2.2 (1.2) | 1.0 (1.0) |
Having at least one APOE ε4 allele, n (%) | 31/60 (52%) | 35/70 (50%) | 7/25 (29%) | 11 (38%) | 15/26 (58%) | 13 (52%) | 9/10 (90%) | 11 (69%) |
Having ABCA7 risk allele, n (%) | 28/60 (47%)a
| 16/70 (23%) | 12/25 (48%) | 8 (27%) | 13/25 (52%) | 6 (24%) | 3/10 (30%) | 2 (12%) |
Completed LP, n (%) | 58 (89%) | 68 (97%) | 23 (85%) | 28 (97%) | 25 (93%) | 25 (100%) | 10 (91%) | 15 (94%) |
CSF | ||||||||
Aβ42, pg/ml (SD) | 212.3 (118) | 207.2 (148) | 273 (110) | 250 (131) | 178 (110) | 226 (172) | 158 (105) | 96 (61) |
Aβ40, ng/ml (SD) | 7.89 (2.92) | 9.29 (3.32) | 7.21 (1.96)a
| 10.03 (3.65) | 7.83 (3.21) | 9.38 (3.18) | 9.49 (3.61) | 7.91 (2.54) |
t-Tau, pg/ml (SD) | 47.0 (31.1)a
| 71.5 (47.8) | 36.3 (12.0)a
| 58.6 (29.0) | 46.4 (38.6) | 66.6 (38.4) | 72.8 (27.5) | 103.8 (72.9) |
p-Tau181, pg/ml (SD) | 17.9 (9.3)a
| 25.6 (12.6) | 13.8 (5.1)a
| 22.5 (9.8) | 18.8 (10.2) | 24.0 (12.0) | 25.3 (10.3) | 34.2 (14.9) |
CSF t-Tau/Aβ42 > 0.39 | 17/58 (29%) | 31/68 (46%) | 2/23 (9%) | 7/28 (25%) | 9/25 (36%) | 13/25 (52%) | 6/10 (60%) | 11/15 (73%) |
Log10(NfL), ng/ml (SD) | 2.87 (0.27) | 2.97 (0.19) | 2.76 (0.23) | 2.96 (0.22) | 2.87 (0.26) | 2.96 (0.15) | 3.14 (0.23) | 3.02 (0.22) |
Log10(WMH), cm3 (SD) | 0.367 (0.453) | 0.437 (0.364) | 0.238 (0.337) | 0.355 (0.365) | 0.401 (0.515) | 0.483 (0.308) | 0.607 (0.466) | 0.514 (0.431) |
MRI acquisition and analysis
CSF collection and analysis
DNA extraction and analysis
Statistical analysis
Results
Baseline and genetic characteristics
Relationship between race and CSF biomarkers for amyloid and tau
CSF neurodegenerative and endothelial markers do not account for race-associated AD biomarker differences
Race modifies the impact of WMH on cognition
Variables | B (95% CI) |
p Value |
---|---|---|
Intercept | −3.08 (−4.70, −1.45) | < 0.001 |
Log(WMH) | −0.35 (−0.89, 0.19) | 0.206 |
Male sex | 0.54 (0.21, 0.87) | 0.002 |
Having at least one APOE ε4 allele | −0.36 (−0.71, −0.01) | 0.042 |
Having ABCA7 risk allele | 0.38 (0.04, 0.72) | 0.03 |
Aβ42 | 0.003 (0.001, 0.004) | < 0.001 |
t-Tau | −0.006 (−0.010, −0.002) | 0.003 |
Age | 0.039 (0.015, 0.063) | 0.002 |
African American race × log(WMH) | −0.496 (−1.074, 0.081) | 0.091 |