Assessment of systemic inflammation in osteoarthritis patients by testing fatty-acid-binding protein 4 and adiponectin in plasma

Abstract

Introduction: Obesity not only increases risk of osteoarthritis (OA) in weight-bearing but also non–weight-bearing joints, indicating systemic mediators involved. It was recently reported that inflammation is involved in the pathogenesis of OA. Fatty-acid-binding protein 4 (FABP-4) has been described as a novel adipokine, playing a pro-inflammatory role in inflammatory pathways. Adiponectin has been widely reported with an anti-inflammatory function. This study aimed to evaluate the relationship of plasma levels of FABP4 and adiponectin and the presence of OA. Materials and Methods: For FABP4 concentration determination, a total of 231 Chinese subjects (77 males and 154 females) were recruited, including 141 OA cases and 90 community-based controls. Circulating levels of FABP4 and adiponectin were determined using enzyme-linked immunosorbent assay (AIS, HKU). Results: The mean (± standard deviation) FABP4 levels in OA patients (16.6 ± 15.5 ng/mL) were significantly higher than non-OA subjects (12.6 ± 10.1 ng/mL, p = 0.0453). Female subjects had significantly higher mean circulating levels of FABP4 than male counterparts both in case group (16.1 ± 14.9 ng/mL vs. 8.6 ± 7.3 ng/mL, p < 0.0001) and control group (17.1 ± 11.6 ng/mL vs. 7.9 ± 5.2 ng/mL, p < 0.0001). There were no significant differences of circulating levels of FABP4 neither between male cases and male controls (p = 0.765) nor female cases and female controls (p = 0.261). Discussion and Conclusion: Female subjects had significantly higher concentrations of FABP-4 in plasma.