Fig. 1: Associations of baseline physical activity with longitudinal Aβ, tau and cognition.
From: Physical activity as a modifiable risk factor in preclinical Alzheimer’s disease
a, Linear mixed effects model revealed no association between baseline physical activity and longitudinal Aβ burden (β = −0.0006 [−0.01 to 0.01], P = 0.92; n = 241). b–d, By contrast, there were significant interactions between baseline physical activity and Aβ burden on longitudinal ITC tau burden (b), longitudinal cognition measured with PACC5 (c) and longitudinal functional decline measured with CDR-SOB scores (d). Individuals with high baseline physical activity and elevated Aβ (solid red line) showed slower ITC tau accumulation (β = −0.13 [−0.19 to −0.06], P < 0.001; n = 172) (b), slower PACC5 decline (β = 0.10 [0.05 to 0.16], P < 0.001; n = 296) (c) and slower CDR-SOB progression (β = −0.14 [−0.22 to −0.05], P = 0.001; n = 296) (d). Statistical significance was assessed using two-tailed t-tests, with P < 0.05 considered statistically significant without adjustment for multiple comparisons. Baseline physical activity (mean steps per day) and Aβ burden were modeled as continuous variables. To visualize the model results, the estimated trajectories based on representative levels of low versus high baseline physical activity and (for tau, PACC5 and CDR-SOB models) low versus high baseline Aβ burden are presented, with error bands representing 95% confidence intervals for the estimated trajectories. Low and high physical activity are represented by −1 and +1 s.d. relative to the mean (low, 2,800 steps per day; high, 8,700 steps per day). Low and high Aβ are represented, for illustration purposes, by the mean Aβ burden of Aβ-negative (PiB PVC-DVR = 1.17) and Aβ-positive (PiB PVC-DVR = 1.85) participants, respectively. The numbers of participants contributing longitudinal data to each 2.5-year segment for the respective statistical models are summarized in Extended Data Table 5.
