Relationship between baseline NFL level, GBA and APOE status and change in motor, cognitive and functional scores using linear mixed effects models
| Variable | Main effect, coefficient – Intercept (95% CI), p value | Interaction with time–slope coefficient (95% CI), p value | ||||
| NfL | GBA | APOE | NfL | GBA | APOE | |
| H&Y | −0.11 (–0.23 to 0.01), 0.061 | 0.02 (–0.18 to 0.21, 0.880 | −0.12 (–0.28 to 0.04), 0.151 | 0.06 (0.02 to 0.08), 0.001 | 0.00 (–0.06 to 0.06), 0.967 | 0.02 (–0.02 to 0.07), 0.335 |
| MDS-UPDRS 3 Total | −3.55 (–5.68 to –1.43), 0.001 | −0.25 (–1.03 to 0.92), 0.218 | −2.48 (–5.46 to 0.51), 0.104 | 0.79 (0.17 to 1.43), 0.012 | −0.05 (–1.03 to 0.92), 0.912 | 0.69 (–0.17 to 1.56), 0.116 |
| MDS-UPDRS Rigidity | −0.82 (–1.38 to –0.25), 0.004 | −0.71 (–1.65 to 0.23), 0.140 | −0.74 (–1.52 to 0.04), 0.062 | 0.20 (0.04 to 0.36), 0.016 | 0.10 (–0.18 to 0.37), 0.491 | 0.19 (–0.04 to 0.42), 0.104 |
| MDS-UPDRS Bradykinesia | −1.87 (–3.14 to –0.60), 0.004 | −1.46 (–3.57 to 0.65), 0.175 | 0.29 (–1.52 to 2.10), 0.752 | 0.42 (0.07 to 0.77), 0.019 | 0.03 (0.54 to 0.60), 0.912 | 0.00 (–0.47 to 0.48), 0.989 |
| MDS-UPDRS Axial | −1.20 (–1.94 to –0.46), 0.002 | 0.57 (–0.62 to 1.75), 0.348 | −0.96 (–1.98 to 0.06), 0.065 | 0.38 (0.06 to 0.70), 0.018 | −0.38 (–0.06 to 0.12), 0.138 | 0.41 (–0.03 to 0.85), 0.07 |
| MDS-UPDRS Tremor | −0.79 (–1.54 to –0.01), 0.046 | −0.09 (–1.20 to 1.38), 0.894 | −1.11 (–2.21 to 1.38), 0.048 | 0.05 (–0.13 to 0.22), 0.588 | −0.28 (–0.56 to 0.01), 0.060 | 0.15 (–0.10 to 0.40), 0.241 |
| MoCA | 0.07 (–0.56 to 0.69), 0.839 | −0.14 (–1.11 to 0.83), 0.775 | −0.47 (–1.27 to 0.34), 0.258 | −0.17 (–0.34 to 0.01), 0.062 | 0.14 (–1.32 to 0.41), 0.312 | −0.43 (–0.66 to –0.19), <0.001 |
| Semantic Fluency | −0.61 (–1.68 to 0.46), 0.263 | 2.26 (0.54 to 3.98), 0.010 | −0.90 (–2.41 to 0.61), 0.243 | −0.03 (–0.31 to 0.24), 0.803 | −0.37 (–0.81 to 0.07), 0.100 | −0.34 (–0.71 to 0.04), 0.077 |
| SEADL | 3.36 (1.08 to 5.64), 0.004 | −0.02 (–3.82 to 3.78), 0.991 | 1.55 (–1.59 to 4.68), 0.333 | −1.51 (–2.30 to –0.72), <0.001 | 0.09 (−1.26 to –1.44), 0.899 | −0.49 (–1.58 to 0.59), 0.373 |
| PDQ8 | 0.02 (–0.86 to 0.89), 0.970 | −0.46 (–1.87 to 0.96), 0.527 | −0.14 (–1.38 to 1.10), 0.824 | 0.06 (–0.16 to 0.284), 0.616 | −0.02 (–0.37 to 0.33), 0.910 | −0.05 (–0.36 to 0.27), 0.762 |
Linear mixed effects analysis on baseline NfL levels, GBA and APOE status with clinical outcomes in PD patients over time adjusted for age at diagnosis and gender. The main effect indicates the effect of the assessed baseline variable on the intercept and the interaction with time indicates the effect on the slope (change in value per year) of the model. The GBA group includes GD causing and non-GD causing mutation carriers; the APOE group includes APOEe4 heterozygous and homozygous carriers.
Values in bold demarcate statistical significance
APOE, apolipoprotein E; GBA, Glucocerebrosidase; GD, Gaucher disease; H&Y, Hoehn and Yahr stage; MDS-UPDRS, Movement Disorders Society Unified Parkinson’s Disease Rating Scale; MoCA, Montreal Cognitive Assessment; NfL, Neurofilament light protein; PD, Parkinson’s disease; PDQ8, Parkinson’s Disease Questionnaire-8; SEADL, Schwab and England scale.