Specialized pro-resolving mediator (SPM)-enriched supplementation modulates inflammatory biomarkers in patients with symptomatic knee osteoarthritis: Blood plasma analysis from the GAUDI study.
BACKGROUND: Osteoarthritis (OA) is a leading cause of chronic pain and functional impairment, associated with persistent inflammation, potentially due to impaired resolution. Specialized pro-resolving lipid mediators (SPMs) regulate inflammation resolution and restore homeostasis. The GAUDI study previously demonstrated that SPM supplementation reduces pain and improves quality of life (QoL) in patients with knee OA. This analysis assesses the impact of SPM supplementation on inflammatory biomarkers (IB) and SPM levels and their relationship with clinical outcomes. METHODS: This is a secondary analysis of the GAUDI trial, a randomized, multicenter, double-blind, placebo-controlled study conducted in Spain in adults with symptomatic knee OA who received daily supplementation with SPMs or placebo for 12 weeks. Endpoints included changes in plasma IB and SPM levels and their correlation with clinical outcomes. RESULTS: Changes in IL-1 (15.9 vs. -1.1 pg/ml, p-value: 0.051) and IL-18 (10.3 vs. -1.4 pg/ml, p-value: 0.29) showed a tendency toward reduction in the SPM group compared to the placebo group. Changes in IL-1 and IL-8 positively correlated (r = 0.707, p-value: 0.005 and r = 0.551, p-value: 0.04; respectively) with changes in WOMAC score and negatively correlated (r = -0.797, p-value <0.001 and r = -0.804, p-value <0.001; respectively) with changes in EuroQoL-5 VAS score. Changes in IL-1 (r = 0.554, p-value: 0.048) and IL-6 (r = 0.631, p-value: 0.014 and r = 0.572, p-value: 0.031) correlated with changes in OMERACT-OARSI pain score. No significant differences in IB levels were observed between groups during the intervention. Minor changes in SPM levels point to metabolic pathways at work with SPM supplementation. In patients with a BMI ≥25 kg/m², most IB tended to decrease following SPM consumption. CONCLUSIONS: This analysis suggests a potential association between SPM supplementation, decreased inflammation, and improved pain and QoL in patients with knee OA. Subtle changes in blood plasma SPM levels were detected that indicate, through bioinformatics analysis, a pathway-specific metabolome activation induced by SPM supplementation. TRIAL REGISTRATION: NCT05633849. Registered December 1st, 2022. Retrospectively registered, https://clinicaltrials.gov/ct2/show/study/NCT05633849.