The effects of running on systemic inflammatory markers in chronic low back pain: a secondary analysis of the ASTEROID randomised controlled trial

Background Exercise is a well-established treatment for chronic low back pain (LBP), yet its effects on inflammation remain unclear. Objective Examine the effects of running on inflammatory markers in chronic LBP and its associations with pain intensity, and mental health as an a priori secondary analysis. Methods An a priori secondary analysis of a 12-week, two-arm, parallel-group randomised controlled trial was conducted. Forty adults with chronic LBP were randomised to a run-walk program or waitlist control. The intervention was a digitally delivered, remotely supervised run-walk program, prescribed three times per week for 30 min. Outcomes assessed included systemic inflammatory markers (C-reactive protein [CRP], interleukin-8 [IL-8], and tumour necrosis factor alpha [TNF-α] as well as pain intensity (Visual Analogue Scale), and mental health (21-item Depression, Anxiety, and Stress Scale). Results No significant between-group differences were observed in CRP ( ß [95% CI] = 0.34 [-0.07, 0.74] (log-transformed scale), p = 0.109), TNF-α (−1.29 [-6.15, 3.58] pg/mL, p = 0.595), or IL-8 (−0.36 [-1.30, 0.58] (log-transformed scale), p = 0.443) over the 12 weeks. The associations between changes in inflammatory markers and pain intensity or mental health were not different between groups (all p > 0.05). Conclusions A 12-week run-walk training did not alter systemic CRP, TNF-α, or IL-8 in adults with chronic LBP. Improvements in pain intensity were not associated with changes in these inflammatory markers. Clinically, this intervention offers a low-cost and accessible approach that provides meaningful improvements in chronic LBP without observed changes in systemic CRP, IL-8, and TNF-α.