Table 1.
Model results.
| Predicted marginal means (S.E.) at age = 69.9 y | Correlation coefficient with age | |||||
|---|---|---|---|---|---|---|
| Amyloid negative (N = 58) | Amyloid positive (N = 38) | P valuea | Amyloid negative (N = 58) | P value | ||
| CSF leak | Qleak > 0? | 20/58 | 10/38 | 0.40* | ||
| Qleak (mL/h) | 2.6 (0.6) | 2.6 (0.8) | 0.92 | −0.36 | 0.0050 | |
| Aβ clearance | kBPD38 (h−1) | 0.31 (0.02) | 0.22 (0.03) | 0.015 | −0.68 | <0.0001 |
| kBPD40 (h−1) | 0.37 (0.03) | 0.24 (0.03) | 0.0024 | −0.59 | <0.0001 | |
| kBPD42 (h−1) | 0.53 (0.06) | 0.96 (0.07) | <0.0001 | −0.27 | 0.044 | |
| kBPD42/kBPD38 | 2.1 (0.4) | 5.3 (0.5) | <0.0001 | 0.24 | 0.069 | |
| kBPD42/kBPD40 | 1.7 (0.3) | 4.8 (0.4) | <0.0001 | 0.13 | 0.33 | |
| kBPD40/kBPD38 | 1.36 (0.08) | 1.1 (0.1) | 0.10 | 0.21 | 0.11 | |
| Aβ production (w/o mutation carriers) | Vmax,γ42/Vmax,γ38 | 1.02 (0.04)b | 1.07 (0.06)c | 0.52 | 0.28b | 0.039 |
| Vmax,γ42 (μg/(mL·h)) | 125 (5)b | 139 (8)c | 0.15 | 0.34b | 0.013 | |
| APP production (w/o mutation carriers) | kf (ng/h) | 3500 (300)b | 3400 (500)c | 0.79 | −0.58b | <0.0001 |
| Total gray volume (mL) | 590 (8)b | 570 (10)c | 0.15 | −0.42b | 0.0014 | |
| Exchange | kex42 (h−1) | 0.06 (0.02) | 0.17 (0.02) | <0.0001 | 0.087 | 0.52 |
| CSF fluid flow | QCSF = Qglymph (mL/h) | 23 (1) | 26 (2) | 0.31 | −0.0062 | 0.99 |
| Qosc (mL/h) | 8.8 (0.8) | 11 (1) | 0.16 | 0.47 | <0.0001 | |
| [Aβ40]ISF/[Aβ40]lumbar | 10.1 (0.8) | 10 (1) | 0.85 | −0.51 | <0.0001 | |
| Predicted cisternography half-life (h) | 20.7 (0.6) | 19.8 (0.7) | 0.32 | −0.30 | 0.021 | |
| VCSF (mL) | 300 (10) | 310 (10) | 0.47 | 0.38 | 0.0030 | |
| Flux Aβ38 | CSF-based (ng/min) | 3.1 (0.4) | 3.4 (0.5) | 0.54 | −0.24 | 0.070 |
| BBB + proteolysis (ng/min) | 4.9 (0.4) | 3.2 (0.5) | 0.0082 | −0.81 | <0.0001 | |
| % CSF-based | 43 (3) | 52 (3) | 0.037 | 0.47 | <0.0001 | |
| Flux Aβ40 | CSF-based (ng/min) | 14 (2) | 17 (2) | 0.29 | −0.33 | 0.011 |
| BBB + proteolysis (ng/min) | 28 (2) | 16 (3) | 0.0037 | −0.76 | <0.0001 | |
| % CSF-based | 39 (2) | 50 (3) | 0.0042 | 0.45 | <0.0001 | |
| Flux Aβ42 | CSF-based (ng/min) | 2.2 (0.2) | 1.7 (0.3) | 0.19 | −0.30 | 0.021 |
| BBB + proteolysis (ng/min) | 4.1 (0.4) | 1.6 (0.5) | <0.0001 | −0.70 | <0.0001 | |
| Deposition (ng/min) | 1.4 (0.4) | 4.6 (0.5) | <0.0001 | −0.21 | 0.11 | |
| % CSF-based | 33 (2) | 22 (3) | 0.0014 | 0.33 | 0.012 | |
*Chi-square statistic = 0.71.
at test of predicted marginal means (least-squares means) except where noted by *. See Supplementary Table 5 for interactions between age and amyloid status; italic values signify: P < 0.05; bold italic values signify: P < 0.01.
bN = 54.
cN = 33.