Association between Circulating Adiponectin Levels and Osteoarthritis: A Meta-analysis

ABSTRACT

OBJECTIVE: The aim of this study was to analyze the relationship between the circulating adiponectin levels and osteoarthritis (OA). METHODS: Meta-analysis was conducted on the serum/plasma adiponectin levels in patients with OA and controls, and subgroup analysis was performed based on ethnicity, sex, OA site, and adjustment for age, sex, and/or body mass index (BMI). RESULTS: Seven studies with eleven comparisons including 538 patients with OA and 366 controls were selected, which showed that the adiponectin levels were significantly higher in the OA group than in controls (standardized mean difference [SMD]=0.745, 95% confidence interval [CI]=0.316~1.174, p=0.001). Stratification according to ethnicity showed significantly elevated adiponectin levels in Caucasian individuals with OA (SMD=0.769, 95% CI=0.218~1.319, p=0.006). Stratification according to sex revealed significantly higher adiponectin levels in women with OA, but not in men (SMD=0.861, 95% CI=0.099~1.623, p=0.027; SMD=1.177, 95% CI=−0.911~3.316, p=0.281). Stratification by an adjustment for age, sex, or BMI showed significantly higher adiponectin levels in the OA group (SMD=0.837, 95% CI=0.326~ 1.349, p=0.001). Stratification according to the OA site showed significantly higher adiponectin levels in patients with knee OA (SMD=0.938, 95% CI=0.456~1.419, p < 0.001). CONCLUSION: The significantly higher levels of circulating adiponectin in patients with OA than in healthy controls indicates that adiponectin likely plays a role in the pathogenesis of OA.