The longitudinal relationship between body composition and patella cartilage in healthy adults.

BACKGROUND: Although obesity is a risk factor for patellofemoral osteoarthritis (OA), it is unclear whether the components of body composition, such as muscle and fat mass, are major determinants of articular cartilage properties at the patella.
OBJECTIVE: The aim of this study was to determine whether anthropometric and body composition measures, assessed over 10 years, were related to articular patella cartilage volume and defects in healthy adults with no clinical knee OA. METHODS AND PROCEDURES: Two hundred and ninety-seven healthy, community-based adults aged 50-79 years with no clinical history of knee OA were recruited. Anthropometric and body composition (fat-free mass and fat mass) data were measured at baseline (1990-1994) and follow-up (2003-2004). Patella cartilage volume and defects were assessed at follow-up (2003-2004) using magnetic resonance imaging (MRI).
RESULTS: After adjustment for potential confounders, increased measures of obesity (weight, BMI, waist circumference, and fat mass) at baseline and follow-up were associated with an increased risk for the presence of patella cartilage defects at follow-up for both men and women (all P < or = 0.03). Increased baseline values for these variables tended to be associated with reduced patella cartilage volume at follow-up for women (all P < or = 0.11), but not men (all P < or = 0.87). DISCUSSION: We have demonstrated that increased anthropometric measures of obesity, as well as fat mass, are associated with an increased risk for the presence of patella cartilage defects in both men and women. Women, but not men, with greater baseline body mass, particularly adipose-derived mass, appear to have an associated reduction in their patella cartilage volume. Interventions targeting a reduction in adipose tissue may help reduce the risk for the onset and progression of patellofemoral OA, particularly in women.