Table 1. Baseline Characteristics of the Study Participants.
| Characteristic | Participants (N = 1158)a |
|---|---|
| Age, mean (SD), y | 77.4 (6.0) |
| Educational level, mean (SD), y | 12.6 (3.5) |
| Sex | |
| Female | 728 (63) |
| Male | 430 (37) |
| Race | |
| African American | 695 (60) |
| White | 463 (40) |
| APOE ε4 allele | 393 (34) |
| Composite physical activity, mean (SD), min/wk | 170.78 (269.48) |
| Physical activity category | |
| Lowb | 356 (31) |
| Mediumc | 400 (35) |
| Highd | 402 (35) |
| Serum NfL concentration, geometric mean (95% CI), pg/mL | 26.1 (25.2-27.1) |
| Serum NfL concentration category | |
| Low: ≤25.5 pg/mL | 618 (53) |
| High: >25.5 pg/mL | 540 (47) |
| Global cognitive function score, mean (SD) | 0.21 (0.68) |
| Standardized memory score, mean (SD) | 0.19 (0.83) |
| Standardized MMSE score, mean (SD) | 0.26 (0.61) |
| Standardized speed score, mean (SD) | 0.24 (0.90) |
Abbreviations: APOE, apolipoprotein E; MMSE, Mini-Mental State Examination; NfL, neurofilament light chain.
a
Data are presented as the number (percentage) of participants unless otherwise indicated.
b
Participants responded to at least 4 items on the physical activity measure and reported no activity for all responses.
c
Less than 150 minutes per week.
d
At least 150 minutes per week.