Can vigorous physical activity mitigate the effect of systemic inflammation on cognitive performance? Results from a large older community dwelling population in the Netherlands

Background: Elevated systemic inflammation is associated with poorer cognitive function, while vigorous physical activity enhances cognition.
Objective: This study examines whether physical activity moderates the relationship between systemic inflammation and
cognitive performance.
Methods: We analyzed 24,661 adults (50+) from the Dutch Lifelines cohort across two waves. Cognitive performance was
assessed via a validated composite score from the Cogstate Brief Battery, with higher scores indicating lower cognitive performance. Leukocyte count (3–11 × 109 cells/liter) served as a systemic inflammation biomarker, categorized as low (<6.5 ×
109 cells/liter) or high (≥6.5 × 109 cells/liter). We used the Short Questionnaire to Assess Health-Enhancing Physical Activity
to define moderate (0, 1–149, 150+ minutes) and vigorous (0, 1–74, 75+ minutes) physical activity. We performed linear
regression models to examine the effect of inflammation and vigorous physical activity on cognition, adjusting for moderate
physical activity and covariates. An interaction effect analyzed the potential moderation of vigorous physical activity.
Results: Individuals with high systemic inflammation (SI) levels in both waves exhibited significantly longer reaction times
(b =0.062 [95% confidence interval: 0.002; 0.122]) compared to those with low SI levels in both waves. Individuals who
engaged in 1–74 min or 75+ minutes of vigorous physical activity had significantly faster reaction times (1–74: b=−0.114
[−0.193; −0.034], 75+: b=−0.160 [−0.210; −0.111]) than those who did not. The interaction term was insignificant.
Conclusions: Although vigorous physical activity is protective, it cannot mitigate the negative association between systemic inflammation and cognition. Nevertheless, promoting vigorous physical activity in an ageing population can be an
effective strategy for preventing or delaying cognitive decline.
Keywords
Alzheimer’s disease, cognitive performance, cohort study, physical activity, systemic inflammation