David M. MacDonald, MD, MS; Sarah Samorodnitsky, PhD; Eric F. Lock, PhD; Vincent Fan, MD, MPH; Zijing Chen, PhD, RN; Huong Q. Nguyen, PhD, RN; Chris H. Wendt, MD
Individuals with chronic obstructive pulmonary disease (COPD) have high levels of inflammation measured in their blood. Compared to individuals without COPD, on average, they also have decreased physical activity, strength, and lung function. Inflammation may affect physical activity, strength, and lung function in individuals with COPD, but prior studies have been undecided about this.
In this study, we used data from 302 participants in the COPD Activity: Serotonin Transporter, Cytokines, and Depression (CASCADE) study to test whether higher levels of 14 different blood biomarkers of inflammation predicted changes in physical activity, grip strength, and lung function over 2 years of follow-up.
Individuals with higher measures of inflammation (C-reactive protein and interleukin-6) on their first visit/blood test, had lower activity at that visit and over 2 years of follow-up. However, higher levels of inflammation were not associated with changes in physical activity, strength, or lung function.
These findings do not support targeting inflammation to improve physical activity, strength, or lung function. Some links between inflammation and physical activity may be due to instances where lower physical activity leads to more inflammation.