Differential expression of adipokines in knee osteoarthritis patients with and without metabolic syndrome

The purpose of this study was to compare adipokines levels in plasma and synovial fluid (SF) between knee osteoarthritis (OA) patients with and without metabolic syndrome (MetS), and to evaluate the associations between adipokines levels and clinical severity of knee osteoarthritis.

Eighty female patients with knee osteoarthritis were enrolled in the study. These patients were divided into two groups: patients with and without MetS. Clinical severity was evaluated according to visual analogue scale (VAS) pain scores and Western Ontario McMaster University Osteoarthritis Index (WOMAC) scores. Adipokines and soluble leptin receptor levels in plasma and SF were determined by a sandwich enzyme-linked immunosorbent assay.

Forty-three (54%) osteoarthritis patients with MetS and 37 (46%) osteoarthritis patients without MetS were enrolled as MetS-OA group and nMetS-OA group, respectively. VAS pain and WOMAC scores were higher in MetS-OA group compared with those in nMets-OA group (p < 0.01). The leptin and free leptin levels in plasma and SF were significantly higher in MetS-OA group than those in nMetS-OA group, while the adiponectin levels were lower (All p < 0.01). Significant differences existed even after adjustment for body mass index (BMI) (p < 0.05). There were no significant associations between adipokines levels and the clinical severity of OA in MetS-OA group and nMetS-OA group respectively (p > 0.05).

Leptin was higher and adiponectin was lower in knee osteoarthritis patients with MetS compared to those without MetS, independent of BMI. The higher SF and plasma levels of leptin in MetS-OA patients may need further studies to delineate their pathophysiological relationships.