Table 1.
Characteristics of Participants Overall and Stratified According to Race and Educational Level
| Characteristic | All Participants (n = 9,268) | Whites
|
Blacks
|
||||
|---|---|---|---|---|---|---|---|
| <High School (n = 1,005) | High School or Equivalent (n = 3,374) | >High School (n = 3,043) | <High School (n = 612) | High School or Equivalent (n = 535) | >High School (n = 699) | ||
| Age, mean ± SD | 56.7 ± 5.6 | 59.1 ± 5.4 | 56.9 ± 5.5 | 56.4 ± 5.6 | 57.6 ± 5.6 | 55.3 ± 5.5 | 54.6 ± 5.3 |
|
| |||||||
| Female, n (%) | 4,968 (53.6) | 470 (46.8) | 1,932 (57.3) | 1,386 (57.3) | 402 (65.7) | 351 (65.6) | 427 (61.1) |
|
| |||||||
| Hypertension, n (%) | 2,903 (31.4) | 323 (32.2) | 954 (28.3) | 723 (23.8) | 336 (55.5) | 256 (48.0) | 311 (44.8) |
|
| |||||||
| Diabetes mellitus, n (%) | 1,135 (12.3) | 161 (16.1) | 348 (10.3) | 246 (8.1) | 150 (24.6) | 114 (21.4) | 116 (16.7) |
|
| |||||||
| Cigarette smoking status | |||||||
|
| |||||||
| Current, n (%) | 1,798 (19.4) | 246 (24.5) | 657 (19.5) | 481 (15.8) | 169 (27.6) | 119 (22.2) | 126 (18.0) |
|
| |||||||
| Former, n (%) | 3,590 (38.7) | 399 (39.7) | 1,346 (39.9) | 1,304 (42.9) | 191 (31.2) | 136 (25.4) | 214 (30.6) |
|
| |||||||
| Never, n (%) | 3,880 (41.9) | 360 (35.8) | 1,371 (40.6) | 1,258 (41.3) | 252 (41.2) | 280 (52.3) | 359 (51.4) |
|
| |||||||
| Number of apolipoprotein E ε4 alleles, n (%) | |||||||
|
| |||||||
| 0 | 6,164 (69.3) | 725 (74.7) | 2,326 (72.1) | 2,054 (70.6) | 331 (55.7) | 310 (59.7) | 418 (61.3) |
|
| |||||||
| 1 | 2,512 (28.2) | 225 (23.2) | 839 (26.0) | 798 (27.4) | 241 (40.6) | 176 (33.9) | 233 (34.2) |
|
| |||||||
| 2 | 224 (2.5) | 20 (2.1) | 62 (1.9) | 56 (1.9) | 22 (3.7) | 33 (6.4) | 31 (4.6) |
|
| |||||||
| Carotid intimal medial thickness, mm, mean ± SD | 0.73 ± 0.18 | 0.77 ± 0.21 | 0.73 ± 0.18 | 0.71 ± 0.17 | 0.77 ± 0.20 | 0.73 ± 0.16 | 0.72 ± 0.14 |
|
| |||||||
| Visit 2 cognitive test scores, mean ± SD | |||||||
|
| |||||||
| Delayed word recall test (n = 9,167) | 6.73 ± 1.47 | 6.26 ± 1.40 | 6.83 ± 1.40 | 7.05 ± 1.39 | 5.76 ± 1.62 | 6.37 ± 1.48 | 6.68 ± 1.47 |
|
| |||||||
| Digit Symbol Substitution Test (n = 9,166) | 46.6 ± 13.4 | 39.8 ± 9.8 | 49.5 ± 10.4 | 53.8 ± 10.1 | 23.7 ± 9.4 | 33.1 ± 10.6 | 41.6 ± 11.9 |
|
| |||||||
| Word fluency test (n = 9,166) | 34.2 ± 12.2 | 27.1 ± 10.5 | 33.5 ± 10.5 | 40.2 ± 11.3 | 20.5 ± 9.9 | 28.5 ± 10.2 | 38.3 ± 11.6 |
|
| |||||||
| Visit 4 cognitive test scores, mean ± SD | |||||||
|
| |||||||
| Delayed word recall test (n = 8,888) | 6.61 ± 1.58 | 6.11 ± 1.54 | 6.71 ± 1.50 | 6.94 ± 1.50 | 5.54 ± 1.73 | 6.14 ± 1.60 | 6.57 ± 1.56 |
|
| |||||||
| Digit Symbol Substitution Test (n = 8,882) | 44.4 ± 13.2 | 37.7 ± 10.1 | 46.9 ± 10.5 | 51.1 ± 10.2 | 22.1 ± 10.5 | 31.4 ± 11.3 | 39.5 ± 11.8 |
|
| |||||||
| Word fluency test (n = 8,884) | 33.9 ± 12.5 | 26.8 ± 10.6 | 33.4 ± 10.9 | 39.6 ± 11.5 | 19.8 ± 10.2 | 27.8 ± 11.0 | 36.9 ± 12.3 |
|
| |||||||
| MRI visit cognitive test scores, mean ± SD | |||||||
|
| |||||||
| Delayed word recall test (n = 2,189) | 6.14 ± 1.69 | 5.93 ± 1.53 | 6.30 ± 1.58 | 6.49 ± 1.68 | 5.11 ± 1.75 | 5.70 ± 1.78 | 6.09 ± 1.63 |
|
| |||||||
| Digit Symbol Substitution Test (n = 2,184) | 38.7 ± 12.5 | 33.4 ± 9.7 | 41.5 ± 9.8 | 45.7 ± 10.3 | 21.1 ± 8.7 | 29.4 ± 10.0 | 37.0 ± 11.1 |
|
| |||||||
| Word fluency test (n = 2,191) | 32.7 ± 12.5 | 26.7 ± 10.2 | 32.6 ± 10.8 | 39.0 ± 11.6 | 18.9 ± 8.1 | 26.2 ± 10.7 | 35.9 ± 11.7 |
SD = standard deviation.