Adiponectin levels in plasma and those released by cultured cartilage were higher in patients with radiologically more severe osteoarthritis. Adiponectin levels in plasma (A) and the amount of adiponectin released by osteoarthritis (OA) cartilage samples into culture media (B) in OA patients classified according to the severity of knee OA evaluated using the Ahlbäck grading scale. Horizontal solid and dashed bars within the boxes represent the median and mean, respectively. Boxes represent the interquartile range. Lines outside boxes represent minimums and maximums. Outliers are indicated.