Background Some adipokines have been associated with osteoarthritis (OA) incidence and potentially its progression. Only a few studies have looked at their association with, and prediction of, structural progression of knee OA using quantitative MRI.
Objectives This study contrasted serum levels of 5 adipokines to the changes in cartilage volume and examined if they could predict the occurrence of a total knee replacement (TKR).
Methods This post hoc analysis was performed on the ATP population (n=138) of a knee OA randomized clinical trial 1,2. The serum levels of the obesity factors Adipsin/Complement Factor D (CFD), Leptin (LEP), Adiponectin (ADIPOQ), Resistin (RETN), and Serpin E1 (SERPINE1) as well as the cartilage volume were determined at baseline and at 24 month follow-up. TKR incidence of the study knee up to 4 years post trial completion was also evaluated. Univariate and multivariate analyses controlling for age, gender, BMI, and treatment allocation were performed.
Results Higher baseline BMI was associated with greater baseline CFD and LEP levels (p≤0.006) and lower baseline ADIPOQ levels (p<0.001). Greater baseline values of LEP highly correlated with more cartilage volume loss in the global knee and femur (p≤0.007), and medial compartment and femur (p≤0.033), and CFD in the lateral compartment and femur (p≤0.028). An inverse association was found for ADIPOQ in the global femur (p=0.041), and in the medial compartment and femur (p≤0.027). RETN and SERPINE1 were not associated with cartilage volume loss. Multivariate analyses revealed for CFD and LEP that, compared to all other patients, those belonging to the highest tertile at baseline had an additional 2.2% and 1.7% respectively, of cartilage volume loss in the lateral (CFD; p=0.003) and global (LEP; p=0.040) femur, and a trend for LEP (p=0.067) of 2.3% in the medial compartment. The changes at 24 months in CFD and LEP levels were also predictive of greater cartilage volume loss in the lateral femur (CFD; p=0.003) and medial compartment (LEP; p=0.038). Importantly, patients belonging to any of the “at risk” tertiles of CFD (highest), LEP (highest) or ADIPOQ (lowest) at baseline had a trend toward a greater occurrence of TKR (p=0.136, survival analysis).
Conclusions These data demonstrate that both CFD and LEP predict greater cartilage volume loss over time in the lateral femur and medial compartment, respectively. Baseline “at risk” levels of LEP, CFD and ADIPOQ are associated with a greater occurrence of TKR. These findings add further insight to the role of adipokines in knee OA structural progression and outcome.
Raynauld JP et al. Ann Rheum Dis. 2009;68:938-47.
Raynauld JP et al. Ann Rheum Dis. 2011;70:1382-8.
Acknowledgements *Equal participation in the study
Disclosure of Interest None declared