Association between pain catastrophizing and sarcopenia in patients with knee osteoarthritis: A cross-sectional study

Sarcopenia and pain catastrophizing(PC) are prevalent physiological and psychological comorbidities in knee osteoarthritis(KOA). They may collectively burden patients' quality of life. Nevertheless, their potential association remains inadequately explored.

To explore the association between PC and sarcopenia in KOA patients, adjusting for demographic, lifestyle, and disease-related covariates (e.g., sex, BMI, affected site, disease duration, physical activity and other relevant factors.) To examine whether this association varies across subgroups defined by age and sedentary behavior.

Cross-sectional study.

This study recruited 390 KOA patients aged ≥45 years from orthopedic surgery departments. PC was assessed using the PC scale. Sarcopenia was defined by concurrent low muscle mass and muscle strength, measured via bioelectrical impedance analysis and electronic handgrip dynamometry. Logistic regression was used to describe the relationship between PC and sarcopenia, adjusting for covariates.

Among the patients, 24.9 % were diagnosed with sarcopenia and 21.5 % with PC, with 10.3 % had both. Adjusted analyses showed PC was independently associated with sarcopenia (OR = 1.036; 95 % CI: 1.012, 1.061; P = 0.003). Subgroup analyses revealed stronger associations in patients aged 60-69 years (aOR = 1.036; 95 % CI: 1.001, 1.073; P = 0.045), those aged ≥70 years (aOR = 1.095; 95 % CI: 1.050, 1.143; P < 0.001), and individuals with prolonged sedentary time (aOR = 1.051; 95 % CI: 1.016, 1.086; P = 0.004).

PC was significantly associated with higher odds of sarcopenia in KOA patients, and this association was stronger in older individuals and those with prolonged sedentary behavior. Comprehensive management of elderly KOA patients should address both psychological and physical comorbidities.