Objectives: This study aims to investigate the effects of lumbar stabilization exercise (LSE) and graded activity exercise (GAE) on concentrations of interleukin (IL) 1A (IL1A), IL18 receptor 1 (IL18R1), IL18 receptor accessory protein (IL18RAP), IL-6, cyclooxygenase-2 (COX2), and clinical outcomes of pain intensity, disability, catastrophizing, diverting-attention, cognitivecoping and pain-reinterpretation in patients with non-specific chronic low back pain (NSCLBP).Methods: This study was a single-blind parallel trial with an adaptive trial design. Fiftyfour patients with NSCLBP were randomly assigned to LSE and GAE treatment groups. Demographic and anthropometric characteristics were measured. Treatments were administered twice a week for 10 weeks. The concentrations of IL1A, IL18R1, IL18RAP, IL-6, and COX2 of patients were assessed at four time points with enzyme-linked immunosorbent assay. Pain, disability, catastrophizing, diverting attention, cognitive coping, and pain reinterpretation were assessed at three time points with valid instruments. The responsiveness of the biochemical mediators to LSE and GAE was determined with a Bayesian one-way analysis of variance (ANOVA). Data were analyzed with descriptive and inferential statistics at P<0.05.
Results:The concentrations of IL1A, IL18R1, IL18RAP, and COX2 were unresponsive (Bayes factor [BF]<1) to LSE and GAE, while IL-6 concentrations were responsive (Bayes factor [BF]>1). The concentrations of IL-6 increased significantly (P<0.05) after LSE with a significant reduction (P<0.05) in pain, disability, and catastrophizing, while the concentration of IL-6 increased significantly (P<0.05) after GAE with a significant reduction (P<0.05) in pain, and disability. Effects of LSE and GAE on IL-6 concentrations, pain, and disability were comparable (P>0.05). Catastrophizing of patients with LSE was significantly less (P<0.05) compared to GAE.Discussion: LSE increases IL-6 concentrations in NSCLBP patients while reducing pain, disability, and catastrophizing, while GAE increases IL-6 concentrations and reduces pain and disability. IL-6 concentrations, pain, and disability of patients were similar after LSE and GAE. Patients catastrophize less with LSE compared to GAE, hence LSE shows more beneficial effects for patients with NSCLBP than GAE.