Long H, Xie D, Zeng C, et al. - An extensive literature review was carried out in order to examine the relationship between body composition and OA. Nineteen studies were involved. The combined mean difference exhibited the fat mass of the individuals with knee OA was higher compared with the control group. Both fat mass and fat mass percentages were positively related to knee OA. In hip and hand joints as well, comparable findings were noted, and such results were also validated via most cohort studies of the knee and hip OA. Lean mass was also positively related to knee OA. Nevertheless, the lean mass percentage was negatively correlated with knee OA. Therefore, both fat mass and fat mass percentage were expected to be risk factors for knee, hip and hand OA. Likewise, lean mass also appeared to be a risk factor for knee OA, whereas lean mass percentage appeared to be a protective factor.