Metabolic factors in osteoarthritis: obese people do not walk on their hands.

Obesity is an important risk factor for the development and progression of osteoarthritis (OA). Recently, the paradigm that obesity predisposes people to OA because of extra-mechanical loading only has shifted to the paradigm that metabolic factors (adipokines) are also involved in the pathophysiology of OA. In a cross-sectional study in the previous issue of Arthritis Research & Therapy, Massengale and colleagues investigated the association between one of the adipokines - leptin - and hand OA. Hand joints are an ideal target to investigate the role of adipokines since they are not weight-bearing. Interestingly, no association with OA was found, bringing into question a metabolic, rather than a mechanical, explanation for the association between obesity and OA.