Factors associated with pain pressure threshold in both local and remote sites in knee osteoarthritis

Abstract Background Knee osteoarthritis (KOA) is a prevalent condition, and its most frequent symptom is pain that often leads to disability. Pain sensitization is a core feature of KOA, and it can be measured through quantitative sensory testing protocols such as pain pressure threshold (PPT). However, there is a lack of understanding about the factors that may influence changes in PPTs in the KOA population. Objective To explore the clinical and functional factors associated with PPTs in a sample of people with chronic KOA pain and to compare models of local (knees) and remote (thenar regions) sites. Design Cross‐sectional analysis of a prospective cohort. Setting Primary care in public institution. Participants 113 adults with KOA. Intervention N/A. Main Outcome Measures Multivariable regression analyses evaluating demographic, clinical, and functional variables that could be associated with local and remote PPTs (main outcomes) were performed. Results Both thenar region (adjusted‐ R 2 : 0.29) and knee (adjusted‐ R 2 : 0.45) models had the same significant negative association with being a female, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain levels (thenar: β : −0.15, p = .002; knee: β : −0.2, p < .001), and the 10‐Meter Walking Test (thenar: β : −0.05, p = .038; knee: β : −0.08, p = .004). A small significant positive association with depressive symptoms was identified in both models, which acted as a confounder for WOMAC pain and was likely affected by unmeasured confounders. Conclusions PPTs in KOA pain are associated with functional outcomes such as the 10‐Meter Walking Test and activity‐related pain intensity; thus more disability is associated with smaller pain thresholds. Similarity between models may suggest central sensitization.