Role of infrapatellar fat pad in knee osteoarthritis Lipid lowering drugs as potential therapeutic strategy

The association between obesity and osteoarthritis (OA) exists due to different etiological mechanisms. Next to increased joint loading, metabolic and inflammatory pathways related to adipose tissue could explain the increased incidence and progression of OA in obese people.;Adipose tissue contains immune cells and adipocytes. These cells produce cytokines, adipokines and growth factors that may induce or inhibit inflammatory and catabolic processes in cartilage.;In this thesis, we reviewed some significant points that are evidence for a role of the infrapatellar fat pad (IPFP) in the disease process of knee-OA. We describe our in vitro experiments that indicate that cytokines produced by IPFP influence cartilage metabolism. We also found that the inflammatory environment in an osteoarthritic joint may influence the cytokine production by the IPFP itself. Therefore, we concluded that the infrapatellar fat pad could be regarded as a joint tissue contributing to the osteoarthritis process.;Then, we investigated the effect of lipid lowering drugs, such as fibrates, on cartilage, synovium and IPFP, and found that these drugs exert anti-inflammatory and anti-destructive effects in vitro.;Statins are other lipid lowering drugs. Studies indicate that these drugs have similar effects on joint tissues. In a large prospective cohort study, the Rotterdam Study, we found a decreased incidence and progression of knee-OA in the group of statin use.