Fig. 3: Physical activity levels and changes in tau and cognition in preclinical AD.
From: Physical activity as a modifiable risk factor in preclinical Alzheimer’s disease
a–c, Using extracted slopes for ITC tau (n = 172) (a), PACC5 (b) and CDR-SOB (c) (PACC5 and CDR-SOB, n = 296), we examined the interactive effects of baseline physical activity level (ordinal) and Aβ burden (continuous) using linear regression models. Levels of physical activity (ordinal) were defined as inactive (≤3,000 steps), low activity (3,001–5,000 steps), moderate activity (5,001–7,500 steps) and active (≥7,501 steps). The number of individuals in each physical activity subgroup included in the tau, PACC5 and CDR-SOB analyses are summarized in Extended Data Table 1. Aβ burden was modeled as a continuous variable. For illustration purposes, low and high Aβ are represented by the mean Aβ burden of Aβ-negative (PiB PVC-DVR = 1.17) and Aβ-positive (PiB PVC-DVR = 1.85) participants, respectively. The error bars represent the 95% confidence intervals for the estimated effects of physical activity levels on tau and cognitive slopes at representative levels of low and high Aβ burden. Results demonstrate that in individuals with elevated baseline Aβ, even low levels of physical activity (3,001–5,000 steps) were associated with substantially slower rates of tau accumulation and cognitive decline compared to inactive individuals. There were further attenuations of tau accumulation and cognitive and functional decline at moderate activity (5,001–7,500 steps per day), with similar rates in the active group (≥7,501 steps per day).
