Table 1. Baseline Characteristics of Participants.
| Characteristic | Participants (N = 1159) |
|---|---|
| Age, mean (SD), y | 77.4 (6.0) |
| Educational level, mean (SD), y | 12.6 (3.5) |
| Sex, No. (%) | |
| Female | 728 (63) |
| Male | 431 (37) |
| African American, No. (%) | 696 (60) |
| Chronic medical conditions, mean (SD), No. | 1.3 (1.0) |
| APOE4, No. (%) | 393 (34) |
| Composite physical activity score, mean (SD), min/wk | 170.6 (4.5) |
| Composite physical activity score by activity level, min/wk | |
| Little activity (response to at least 4 items on physical activity measure is 0 min/wk) | |
| No. participants | 357 |
| Median (range) | 0 |
| Mean (SD) | 0 |
| Medium activity (<150 min/wk) | |
| No. participants | 400 |
| Median (range) | 62.5 (2 to 150) |
| Mean (SD) | 71 (42) |
| High activity (≥150 min/wk) | |
| No. participants | 402 |
| Median (range) | 327.5 (153 to 2940) |
| Mean (SD) | 422 (330) |
| Total tau, geometric, mean (95% CI), pg/mL | |
| Low total tau (≤0.40 pg/mL) | 0.48 (0.47 to 0.50) |
| High total tau (>0.40 pg/mL) | 0.48 (0.47 to 0.50) |
| Global cognitive function score | |
| Mean (SD) | 0.209 (0.680) |
| Range | (–3.026 to 1.456) |
| Episodic memory score | |
| Mean (SD) | 0.189 (0.827) |
| Range | (–2.462 to 1.418) |
| Mini-Mental State Examination score | |
| Mean (SD) | 0.257 (0.609) |
| Range | (–4.143 to 0.810) |
| Perceptual speed score | |
| Mean (SD) | 0.245 (0.902) |
| Range | (–1.747 to 2.800) |
Abbreviation: APOE4, apolipoprotein e4.