Device-Based Physical Activity and Low-Grade Inflammation in People With Multimorbidity: Cross-Sectional Baseline Analysis From the MOBILIZE Trial

Physical activity (PA) has anti-inflammatory effects, but its impact on individuals with multimorbidity (two or more chronic conditions) is unclear. We examined the association between device-measured (i.e., accelerometers) PA and inflammatory biomarkers in people with multimorbidity. In a, preplanned, cross-sectional analysis from the MOBILIZE trial, 214 participants with multimorbidity provided data on PA and inflammatory biomarkers including interleukin-1 receptor antagonist (IL-1ra), high-sensitivity C-reactive protein (hs-CRP), tumor necrosis factor (TNF), and interleukin-6 (IL-6). The primary outcome was minutes per day of moderate-to-vigorous physical activity (MVPA). Adjusted robust regression models were used to evaluate associations, and BMI was explored as a mediator. Higher MVPA was associated with lower IL-1ra levels, with a 2% reduction in IL-1ra for each additional minute of MVPA per day. Participants with at least 10 min/day of MVPA had 33%–45% lower IL-1ra levels compared to those with less than 1 min/day. Similar results were observed for secondary outcomes. BMI did not mediate the MVPA–IL-1ra relationship. Even small increases in MVPA appear to be associated with low-grade inflammation in individuals with multimorbidity. These findings support the promotion of PA in line with WHO guidelines for physical activity even in people with multimorbidity.