AMONG PATIENTS undergoing total knee arthroplasty (TKA) for knee osteoarthritis (OA), sarcopenic obesity is associated with greater central sensitization-related symptoms and poorer physical function, according to a cross-sectional study.
Sarcopenic obesity is associated with poor physical function in knee OA, but its links with pain sensitivity and central sensitization-related symptoms remain unclear. This study compared pain characteristics and physical function across body composition phenotypes in end-stage knee OA.
Patients undergoing TKA were categorised using the Japanese Working Group on Sarcopenic Obesity criteria into four phenotypes: no obesity/sarcopenia, obesity, sarcopenia, and sarcopenic obesity.
Primary outcomes were pain intensity at rest and during movement, pressure pain thresholds (PPTs) at the affected knee and forearm, and central sensitization-related symptoms measured by the Central Sensitization Inventory-9 (CSI-9). Secondary outcomes were physical function and disability, assessed using quadriceps strength, Timed Up and Go, and Oxford Knee Score.
Of 636 patients, 55 had sarcopenic obesity. Compared with the no obesity/sarcopenia and obesity groups, respectively, this group had higher CSI-9 scores (adjusted mean differences: 3.89 and 3.47) and lower affected-knee PPTs (−0.64 and −0.52 kgf/cm²).
Differences versus the sarcopenia group were smaller and not clearly distinguishable from zero for CSI-9 (1.28) and PPTs (−0.33 kgf/cm²). Compared with the no obesity/sarcopenia group, patients with sarcopenic obesity had lower quadriceps strength (−0.06 kgf/kg) and slower Timed Up and Go performance (2.14 s).
In this study, sarcopenic obesity was associated with greater central sensitization-related symptoms and lower pain thresholds than the no obesity/sarcopenia phenotype in patients with knee OA. However, the mechanisms remain unclear because neuropathic-like pain was not assessed in this study.
Reference
Tanaka S et al. Sarcopenic obesity and pain sensitivity, central sensitization–related symptoms, and physical function among patients undergoing total knee arthroplasty: a cross-sectional study. Osteoarthritis and Cartilage. 2026;DOI:10.1016/j.joca.2026.10.013.
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