Table 1.
WRAP participant characteristics at each study visit (2,324 samples total)
| Characteristic | Visit 1 | Visit 2 | Visit 3 |
|---|---|---|---|
| (N = 1,200) | (N = 912) | (N = 212) | |
| Age, mean y (SD, range) | 60.8 (6.7, 40–78) | 63.1 (6.7, 43–81) | 63.8 (7.0, 45–77) |
| Female, N (%) | 830 (69.2) | 628 (68.9) | 141 (66.5) |
| Years of education, mean (SD) | 16.3 (2.9) | 16.3 (2.9) | 16.6 (3.0) |
| Non-Hispanic White, N (%) | 1,125 (93.8) | 873 (95.7) | 211 (99.5) |
| APOE ε4 carrier, N (%) | 457 (38.1) | 354 (38.8) | 84 (39.6) |
| Cholesterol lowering medication, N (%) | 381 (31.8) | 298 (32.7) | 69 (32.6) |
| Sample storage, mean days, (SD) | 1,518.8 (403.9) | 718.5 (294.3) | 219.4 (147.6) |
| Executive Function Composite Score, mean (SD)* | −0.10 (0.85) | −0.09 (0.83) | 0.04 (0.84) |
| Delayed Recall Composite Score, mean (SD)* | 0.02 (0.81) | 0.16 (0.77) | 0.31 (0.70) |
Study visits indicate when the first, second, and third metabolomic samples were available, which do not correspond with the first, second, and third WRAP study visits (analyses did not include the baseline WRAP visit due to subsequent protocol changes regarding sample collection procedures and tests included in the neuropsychological battery).
*
An increase in cognitive scores is observed over time within individuals likely due to practice effects and self-selection bias (i.e., non-random return patterns for longitudinal visits). See Supplementary Figure 1 for details regarding cognitive scores across age within and across individuals.