The body composition of patients with knee osteoarthritis: relationship with clinical parameters and radiographic severity.

Background And Aims: We investigated body composition in knee osteoarthritis (OA) patients and evaluated its relationship with clinical parameters and radiographic severity.

Methods: Sixty-four patients with knee OA (52 females and 12 males with a mean age of 57.7 ± 8.6 years) and thirty healthy volunteers (20 females and 10 males with a mean age of 56.3 ± 9.5 years) were evaluated. Controls were selected among similar to demographic and hematologic characteristics of patients. Body compositions were assessed via bioelectrical impedance analysis (BIA). Each patient was clinically evaluated by the Western Ontario and McMaster University Osteoarthritis Index (WOMAC). In addition, radiographic severity was classified according to Kellgren-Lawrence's criteria.

Results: Phase angle, body capacitance, resistance, reactance, lean body mass, and intracellular water values of the patients with knee OA were found to be significantly lower than those of the controls (p < 0.05). Furthermore, fat mass and extracellular water levels were significantly higher in the patients compared to the controls (p < 0.05). Lean body mass was inversely correlated with WOMAC score (r = -0.716, p < 0.001), whereas fat mass was moderately correlated with WOMAC score (r = 0.281, p < 0.05) in bivariate analysis. However, with respect to the body composition, there was no significant difference between early grades and late grades in the knee OA with patients (p > 0.05).

Conclusion: Body composition assessed using BIA might be associated with knee OA, and be a noninvasive tool for diagnosis of knee OA. However, body composition may not be predictive of the progression of knee OA.