TABLE 2.
Correlations among biomarkers and demographic factors.
| P‐tau181 | NfL | GFAP | Aβ42/Aβ40 | p‐tau181/Aβ42 | PCA1 | PCA2 | Age | |
|---|---|---|---|---|---|---|---|---|
| P‐tau181 | 1.00 | 0.34 | 0.21 | −0.18 | 0.60 | 0.47 | −0.31 | 0.18 |
| NfL | 0.34 * | 1.00 | 0.50 | 0.00 | 0.24 | 0.85 | 0.02 | 0.39 |
| GFAP | 0.21 * | 0.50 * | 1.00 | 0.00 | 0.13 | 0.81 | 0.08 | 0.33 |
| Aβ42/Aβ40 | −0.18 * | 0.00 | 0.00 | 1.00 | −0.04 | 0.03 | 0.96 | 0.01 |
| p‐tau181/ Aβ42 | 0.60 * | 0.24 * | 0.13 * | −0.04 | 1.00 | 0.48 | −0.30 | 0.20 |
| PCA1 | 0.47 * | 0.85 * | 0.81 * | 0.03 | 0.48 * | 1.00 | 0.00 | 0.44 |
| PCA2 | −0.31 * | 0.02 | 0.08 | 0.96 * | −0.30 * | 0.00 | 1.00 | 0.00 |
| Age | 0.18 * | 0.39 * | 0.33 * | 0.01 | 0.20 * | 0.44 * | 0.00 | 1.00 |
| BMI | 0.01 | −0.06 | 0.00 | −0.01 | 0.11 | 0.00 | −0.04 | 0.11 |
Notes: PCA1 and PCA2 were derived from principal component analysis (PCA) using log‐transformed values of Aβ42/Aβ40, p‐tau181/ Aβ42, NfL, and GFAP, with PCA1 having positive loadings on p‐tau181/ Aβ42, NfL, GFAP, and PCA2 having positive loading on Aβ42/Aβ40 and negative loading on p‐tau181/ Aβ42.
Abbreviations: Aβ, amyloid beta; BMI, body mass index; GFAP, glial fibrillary acidic protein; NfL, neurofilament light chain; p‐tau181, phosphorylated tau‐181;
* P < 0.01. The log‐transformed values of biomarkers were used in the Pearson correlation analyses. Values in the table show the Pearson correlation coefficients.