Fig. 3
Correlation between leptin and matrix metalloproteinase-1 (MMP-1) and MMP-3 in non-obese (a) and obese (b) patients with osteoarthritis. Leptin and MMPs were measured in synovial fluid (SF) by immunoassay. Natural logarithms (LN) were formed of the SF levels of leptin and MMPs in order to have normally distributed variables for the Pearson correlation analysis. Correlation coefficients (r) and p values are indicated. Samples were collected from 90 patients (non-obese, BMI <30 kg/m2, n = 44; obese, BMI >30 kg/m2, n = 46)