Table 3.
Relation of change Aβ peptide levels to incidence of AD
| Change in Aβ levels | No. at risk | AD, n (%) | Odds ratio,model A† | Odds ratio,model B‡ |
|---|---|---|---|---|
| Change as a continuous variable | ||||
| Change in Aβ 40 | 1123 | 104 (9.3) | 1.003 (0.99–1.01) | 1.002 (0.99–1.01) |
| Change in Aβ 42 | 1125 | 104 (9.2) | 0.98 (0.97–0.99)* | 0.98 (0.97–0.99)* |
| Change in Aβ 42/Aβ 40 ratio | 1123 | 104 (9.3) | 0.77 (0.55–1.08) | 0.7 (0.47–1.01) |
| Change in Aβ 40 by group | ||||
| Increasing | 626 | 59 (9.4) | 1.0 (reference) | 1.0 (reference) |
| No change | 434 | 41 (9.4) | 0.9 (0.6–1.4) | 0.7 (0.4–1.3) |
| Decreasing | 58 | 4 (6.9) | 0.6 (0.2–1.7) | 0.5 (0.2–1.7) |
| Change in Aβ 42 by group | ||||
| Increasing | 493 | 39 (7.9) | 1.0 (reference) | 1.0 (reference) |
| No change | 502 | 41 (8.2) | 1.1 (0.7–1.8) | 1.5 (0.7–2.0) |
| Decreasing | 130 | 24 (17.6) | 2.8 (1.6–5.1)*** | 2.6 (1.3–5.1)** |
| Change in Aβ 42/Aβ 40 ratio by group | ||||
| Increasing | 93 | 3 (2.9) | 1.0 (reference) | 1.0 (reference) |
| No change | 692 | 65 (9.4) | 3.1 (1.0–10.1) | 3.2 (0.9–11) |
| Decreasing | 333 | 36 (10.8) | 3.6 (1.1–12.1)* | 3.4 (1.0–11.8)* |
*, P < 0.05;
**, P < 0.01;
***, P < 0.001.
†Logistic regression model, with Aβ 42 and Aβ 40 in the model, unadjusted.
‡Logistic regression model, adjusted for age at baseline, cohort membership, sex, ethnicity, education, BMI, and the presence of the APOE ε 4 allele.