Abstract
BACKGROUND: Frozen shoulder (FS), or adhesive capsulitis, is a disabling condition characterized by pain and restricted shoulder mobility. AIMS: This study investigates the relationship between metabolic biomarkers-liver enzymes and thyroid function-and pain and shoulder functionality in patients with FS. METHODS: A total of 32 patients (22 women and 10 men) were included in this cross-sectional study. Participants underwent clinical evaluations and blood tests to assess metabolic biomarkers, including aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyl transferase (GGT), and thyroid-stimulating hormone (TSH). Pain and functionality were measured using the Shoulder Pain and Disability Index (SPADI). Correlation and multiple regression analyses were performed to assess the associations between biomarkers, pain, and functionality. RESULTS: Significant negative correlations were found between AST (r = -0.528, p = 0.029), ALT (r = -0.533, p = 0.027), GGT (r = -0.602, p = 0.011), and TSH (r = -0.556, p = 0.017) with total pain scores. A significant negative correlation was also observed between TSH and SPADI scores (r = -0.511, p = 0.039). Multiple regression analysis showed that GGT (β = -0.335, p = 0.008) and TSH (β = -0.298, p = 0.014) were the strongest predictors of pain. These findings suggest that metabolic biomarkers, particularly liver enzymes and thyroid function, play a significant role in the pathophysiology of frozen shoulder. The results highlight the importance of assessing these biomarkers for better understanding and managing pain and functionality in patients with FS. CONCLUSIONS: Further research is needed to explore the underlying mechanisms and potential therapeutic targets.