Abstract
BACKGROUND: the deleterious changes in body composition that occur during the year after hip fracture are associated with increased disability, recurrent fracture, and mortality. While the majority of these unfavourable changes have been shown to occur during the first 2 months after fracture, potential changes in body composition occurring earlier than 2 months post-fracture have not been studied. Accordingly, the aim of this study was to rigorously assess short-term changes in body composition after hip fracture. METHODS: total body mass, lean mass, fat mass and total hip and femoral neck bone mineral density (BMD) were assessed via dual energy X-ray absorptiometry at 3 days, 10 days and 2 months post-fracture among 155 hip fracture patients from the Baltimore Hip Studies. Longitudinal regression analysis using mixed models was conducted to model short-term changes in body composition. RESULTS: no significant changes in body composition were revealed from 3- to 10 days post-fracture. However, significant decreases from 10 days to 2 months post-fracture were noted in the total body mass (-1.95 kg, P < 0.001), lean mass (-1.73 kg, P < 0.001), total hip BMD (-0.00812 g/cm(2), P = 0.04) and femoral neck BMD (-0.015 g/cm(2), P = 0.03). No meaningful changes in fat mass were uncovered. CONCLUSIONS: the adverse changes in body composition during the first 2 months after hip fracture appear to have occurred primarily between 10 days and 2 months post-fracture. More research is needed to determine how these findings might help inform the optimal timing of interventions aimed at improving body composition and related outcomes after hip fracture.