Leptin Levels in the Synovial Fluid of Patients With Temporomandibular Disorders

Abstract

This study was conducted to measure concentrations of leptin and interleukin-6 (IL-6) in the synovial fluid (SF) of 38 patients with temporomandibular disorders (TMDs) and 7 healthy controls and to analyze the correlation between leptin and IL-6. Patients with TMDs were divided into 3 subgroups according to imaging and clinical findings: displaced disc with reduction (DDR; n=12), displaced disc without reduction (DDNR; n=13), and osteoarthritis (OA; n=13). SF samples were collected, and leptin and IL-6 levels were measured by enzyme-linked immunosorbent assay. No relevant difference in leptin level was found between the control group and the DDR or DDNR group, whereas the OA group presented a higher leptin concentration than all other groups. IL-6 concentrations were markedly higher in all patient groups than in the control group. Levels were markedly higher in the OA group than in the DDR or DDNR group, but no relevant differences were found between the DDR and DDNR groups. No relevant correlation was found between leptin and IL-6 concentrations. Distinct changes in leptin and IL-6 concentrations in the SF occurred at different stages of TMDs, suggesting their potential role in the pathogenesis of TMDs.