Effect of a physical activity intervention on suPAR levels: A randomized controlled trial

Objectives: Soluble urokinase-type plasminogen activator receptor (suPAR) is a novel inflammatory marker, associated with lifestyle diseases and mortality risk. No studies have investigated whether physical activity may reduce suPAR levels using a randomized controlled design.

Design and methods: suPAR and C-reactive protein (CRP) levels were determined in blood samples from a previous randomized controlled trial with Pakistani immigrants in Norway, 2008. The study included physically inactive men that were randomized to an intervention group (supervised group exercises) or a control group and followed for 5 months. A linear regression model was used and adjusted for age, inactivity level at baseline, and mean difference in CRP levels.

Results: Overall, 80 and 53 participants were included in the intervention and control group, respectively. Obesity and smoking were associated with higher suPAR levels at baseline. The intervention group had a mean suPAR level of 2.65 (95% CI=2.48-2.78)ng/mL at baseline compared to 2.80 (95% CI=2.65-2.95)ng/mL at post-test, and thereby significantly increased suPAR levels after intervention (p=0.02). In the control group, mean suPAR level significantly increased from 2.93 (95% CI=2.68-3.16)ng/mL at baseline to 3.09 (95% CI=2.81-3.38)ng/mL at post-test (p=0.04). When comparing change from baseline to post-test in suPAR levels for the intervention group versus the control group, no significant change in the unadjusted model was found (β=-0.002, 95% CI=-0.219-0.215). Similar results were found for CRP levels.

Conclusion: There was no change in suPAR levels after regular exercise compared to a control group implying that suPAR rather reflects underlying harmful inflammatory responses associated with disease development.