High synovial fluid resistin levels are associated with radiographic severity in female patients with knee osteoarthritis

Abstract

Purpose: Osteoarthritis (OA) is one of the ten disabling diseases affecting predominantly women worldwide. Resistin is an adipocytokine which has been related with inflammation and insulin resistance. Although the resistin level of knee OA patients comparing to healthy controls has been investigated in previous studies, there were limited data regarding the association between synovial fluid resistin levels and severity of knee OA. We examined the relationship between the synovial fluid resistin level and radiographic severity in female knee OA patients. We also investigated the association between the synovial resistin and those of factors involved in inflammation and cartilage maintenance. Methods: Thirty five female patients with primary knee OA grade 1∼4 Kellgren Lawrence (KL) score were included in this study. Patients with traumatic OA or all systemic autoimmune diseases were excluded. The patients were divided into two groups according to radiographic severity (Group I: KL score 1∼2, Group II: KL score 3∼4). Synovial levels of resistin, Interlukin (IL)-6, matrix metalloproteinase (MMP)-1, MMP-3 were measured by enzyme-linked immunosorbent assay. Results: The patients had a mean age of 69.7 ± 5.5 years and mean body mass index (BMI) was 27.5 ± 3.3 (kg/m2). There were 13 and 21 patients in group I and group II, respectively. Mean age and BMI were not significantly different between two groups. Synovial resistin level was significantly higher in group II compared to group I (p = 0.028) (Figure). However the synovial levels of IL-6, MMP-1 and MMP-3 showed no difference between the two groups. Synovial resistin level tend to be positively correlated with synovial IL-6 level, but did not showed statistical significance (r=0.053, p = 0.076). Conclusions: The result showed that resistin is produced within knee OA joints, and it is associated with the radiographic severity in female knee OA patients. This finding proposed a specific role of resistin in the pathogenesis of OA and as a target for disease modifying osteoarthritis drugs.