Objective: Although obesity is widely accepted as a risk factor for knee osteoarthritis, whether weight per se or the specific components of body composition are the major determinants of articular knee cartilage properties is unclear. The aim of this study was to examine the associations between anthropometric and body composition measures and knee cartilage properties in healthy adults.
Methods: 297 healthy adults with no clinical knee osteoarthritis were recruited from an existing community- based cohort. Anthropometric measures and body composition including fat-free mass and fat mass assessed using bioelectrical impedance analysis, were measured at baseline (1990-4) and current follow-up (2003-4). Tibial cartilage volume and tibiofemoral cartilage defects were assessed using magnetic resonance imaging at follow-up.
Results: After adjustment for potential confounders, baseline and current fat-free mass, independent of fat mass, were positively associated with tibial cartilage volume (all P < 0.001). Increase in fat- free mass over the time period was positively associated with tibial cartilage volume (P < 0.001). Current fat mass was negatively associated with tibial cartilage volume (P = 0.004). Baseline and current fat mass were weakly associated with increased tibiofemoral cartilage defects (P = 0.06 and P = 0.07, respectively), independent of fat-free mass.
Conclusion: Our findings suggest a beneficial effect of fat-free mass, but a deleterious effect of fat mass on knee cartilage properties in healthy adults. This suggests that weight-loss programs aimed at reducing fat mass but maintaining muscle mass may be important in preventing the onset and/or progression of knee osteoarthritis.
- cartilage defects
- fat mass
- fat-free mass