Metabolic syndrome and knee osteoarthritis: associations with disease stage and pain

Abstract Objectives Metabolic syndrome (MetS) has been associated with osteoarthritis (OA) progression and pain, however, its relationship with outcomes in early-stage disease remains unclear. We assessed associations between MetS, radiographic stage, and knee pain in individuals with early- and late-stage knee OA. Methods We analyzed cross-sectional baseline data from 251 participants in the Western Ontario Registry for Early Osteoarthritis. Associations between MetS and radiographic stage were assessed using modified Poisson regression. Associations with knee pain, measured by the Knee Injury and Osteoarthritis Outcome Score (KOOS), were evaluated using multivariable linear regression accounting for within-participant correlation. Analyses were stratified by OA stage and adjusted for body mass index (BMI). Results MetS was associated with a higher prevalence of late-stage knee OA (aPR 1.45, 95% CI 1.16, 1.81). After BMI adjustment, hypertension and HbA1C remained associated with late-stage disease. Participants with MetS reported worse knee pain, with lower KOOS pain scores (β -14.70 95% CI -20.92, -8.47), particularly in early-stage disease (β-14.15; 95% CI -20.37, -7.93). Dyslipidaemia (elevated triglycerides and reduced HDL cholesterol were also associated with worse pain in early-stage disease. Conclusion MetS and its components are associated with greater radiographic severity and clinically meaningful worsening of pain, especially in early-stage knee OA, independent of BMI. These findings suggest that early identification and management of metabolic risk factors may represent a modifiable target to improve OA outcomes.