Relationships Between Social Determinants of Health and Pain Outcome Changes After Exercise in Adults with Knee Osteoarthritis

Background: Knee osteoarthritis (KOA) is a common musculoskeletal disease with pain as the primary symptom. KOA pain is a major contributor to disability and reduced quality of life and has been associated with social determinants of health (SDOH) variables. As for treatments of KOA pain, exercise such as stationary cycling is a first-line and recommended treatment. However, limited research has examined how SDOH influence pain outcomes following such interventions. Objective: This study investigated whether income level, education level, employment status, acculturative stress, and perceived ethnic discrimination are associated with changes in pain following a standardized cycling ergometer exercise in adults with KOA. Methods: A quasi-experimental pre-post design was used with 28 adults in El Paso, Texas. Participants completed two SDOH questionnaires, the Perceived Ethnic Discrimination Questionnaire-Community Version (PEDQ-CV) and the Social, Attitudinal, Familial, and Environmental Acculturative Stress Scale (SAFE), and underwent quantitative sensory testing before and after a 30-minute cycling intervention. Exposures included income level, education level, employment status, acculturative stress, and perceived ethnic discrimination. Outcomes included change in self-reported knee pain following a 20-meter walk (PRW), temporal summation (TS), pressure pain threshold (PPT), and conditioned pain modulation (CPM). Linear regression models were used to assess associations between each SDOH exposure and each pain outcome. Results: Employment status showed a near-significant association with change in PPT (β = 0.48, p = 0.0539), suggesting employed participants may have experienced greater pain relief following exercise. None of the other SDOH exposures were associated with any of the outcomes. Conclusion: These findings suggest that employment status may influence how individuals with KOA respond to exercise-related pain modulation, which may identify patients vi more likely to achieve better pain outcomes through exercise. In contrast, none of the other SDOH exposures were associated with any changes in the pain outcomes following exercise. Larger, more diverse samples are needed to clarify these relationships and to better understand how social context contributes to pain and treatment response in individuals with KOA.