Table 1. Comparison of Key Characteristics of White and African American Study Participantsa.
| Characteristic | African American participants (n = 300) | White participants (n = 317) | P value |
|---|---|---|---|
| Demographic characteristics | |||
| Age, mean (SD), y | 63.60 (6.83) | 67.40 (8.48) | <.001 |
| Sex | |||
| Female | 194 (64.7) | 183 (57.7) | .08 |
| Male | 106 (35.3) | 134 (42.3) | |
| Social determinants | |||
| Educational attainment, mean (SD), y | 14.62 (2.53) | 16.18 (2.58) | <.001 |
| Salary level | |||
| <25 000 | 128 (57.1) | 100 (40.2) | <.001 |
| 25 000-50 000 | 60 (26.8) | 55 (22.1) | |
| 50 000-80 000 | 26 (11.6) | 40 (16.1) | |
| >80 000 | 10 (4.5) | 54 (21.7) | |
| ADI score, mean (SD) | 5.43 (1.9) | 3.22 (1.9) | <.001 |
| Clinical characteristics | |||
| Hypertension | |||
| No | 55 (19.3) | 148 (51.4) | <.001 |
| Yes | 230 (80.7) | 140 (48.6) | |
| Diabetes | |||
| No | 208 (73.0) | 257 (89.6) | <.001 |
| Yes | 77 (27.0) | 30 (10.4) | |
| GFR, mean (SD), mL/min/1.73 m2 | 85.57 (18.92) | 77.24 (14.36) | <.001 |
| CRP, mean (SD), mg/dL | 0.54 (0.66) | 0.43 (1.64) | .38 |
| BMI, mean (SD) | 31.64 (7.26) | 27.52 (5.98) | <.001 |
| Cognitive characteristics | |||
| Consensus diagnosis | |||
| MCI | 220 (74.1) | 209 (66.1) | .04 |
| Normal | 77 (25.9) | 107 (33.9) | |
| Test scores | |||
| MoCA, mean (SD) | 21.77 (3.82) | 23.99 (3.58) | <.001 |
| Logical Memory, mean (SD) | |||
| Story score 1 | 12.08 (4.07) | 12.05 (4.85) | .94 |
| Story score 2 | 10.44 (4.20) | 10.32 (5.94) | .80 |
| CDR, total score | |||
| 0 | 88.00 (47.06) | 113.00 (43.97) | .56 |
| 0.5 | 99.00 (52.94) | 144.00 (56.03) | |
| HVLT-R delayed recall, mean (SD) | 7.12 (3.02) | 7.69 (3.72) | .04 |
| Trail Making Test, mean (SD) | |||
| Part A test completion time | 41.26 (16.59) | 37.29 (17.61) | .006 |
| Part B test completion time | 144.69 (80.52) | 111.51 (75.64) | <.001 |
| Boston Naming Test total correct | 13.18 (1.70) | 14.17 (1.22) | <.001 |
| Digit span forward score (maximum span) | 9.04 (2.13) | 9.76 (2.27) | <.001 |
| Digit span backward score (maximum span) | 5.35 (2.17) | 6.20 (2.55) | <.001 |
| WRAT-4 total correct score | 97.10 (16.74) | 113.38 (13.72) | <.001 |
| Neuroimaging | |||
| Hippocampal volume, mean (SD), mm3 | 7246.60 (847.94) | 7260.30 (1147.60) | .89 |
| WML volume, mean (SD), mm3 | 3570.40 (5749.20) | 3950.40 (5902.90) | .50 |
| Genetic characteristics | |||
| APOE4 | |||
| E4 | 112 (42.1) | 121 (43.5) | .79 |
| Non-E4 | 154 (57.9) | 157 (56.5) | |
| Genetic ancestry, mean (SD) | |||
| East Asian | 0.01 (0.04) | 0.01 (0.03) | .20 |
| African | 0.79 (0.11) | 0.01 (0.02) | <.001 |
| European | 0.19 (0.10) | 0.98 (0.04) | <.001 |
Abbreviations: ADI, Area Deprivation Index; BMI, body mass index (calculated as weight in kilograms divided by height in meters squared); CDR, Clinical Dementia Rating; CRP, C-reactive protein; GFR, glomerular filtration rate; HVLT-R, Hopkins Verbal Learning Test–Revised; MCI, mild cognitive impairment; MoCA, Montreal Cognitive Assessment; WML, white matter lesion; WRAT-4, Wide Range Achievement Test–Fourth Edition.
SI conversion factors: To convert CRP to milligrams per liter, multiply by 10.
a
Data are presented as number (percentage) of study participants unless otherwise indicated.