OBJECTIVE: To investigate whether muscle mass mediates the significant association between vitamin D status and functional recovery after hip fracture in women. DESIGN: Observational study. SETTING: Rehabilitation hospital in Italy. PARTICIPANTS: We investigated white women (N=280) of 305 who were consecutively admitted to a rehabilitation hospital because of their first fracture of the hip. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: To assess muscle mass, we measured appendicular lean mass (aLM) by dual-energy x-ray absorptiometry (DXA), 21.2±6.2 (mean ± SD) days after hip fracture occurrence in the 280 women. On the same day, we assessed serum levels of 25-hydroxyvitamin D and parathyroid hormone (PTH). Ability to function in activities of daily living was evaluated by the Barthel Index both before and after acute inpatient rehabilitation. RESULTS: After adjustment for 8 confounders, including age, cognitive impairment, pressure ulcers, neurologic impairment, infections, fracture type, Barthel Index score at admission to rehabilitation, and aLM/height(2) (aLM/ht(2)), 25-hydroxyvitamin D levels were significantly associated both with Barthel Index scores after rehabilitation (P=.003) and their changes during rehabilitation (P=.008). Similar results were obtained when the 25-hydroxyvitamin D/PTH ratio was substituted for 25-hydroxyvitamin D levels. Conversely, aLM/ht(2) was not significantly correlated with Barthel Index scores and their changes during rehabilitation. Furthermore, we found no significant associations between either 25-hydroxyvitamin D levels or the 25-hydroxyvitamin D/PTH ratio and aLM/ht(2). CONCLUSIONS: The significant association between 25-hydroxyvitamin D levels (and 25-hydroxyvitamin D/PTH ratio) and the ability to function in women with hip fractures was not mediated by aLM assessed by DXA.
OBJECTIVE: To investigate whether muscle mass mediates the significant association between vitamin D status and functional recovery after hip fracture in women. DESIGN: Observational study. SETTING: Rehabilitation hospital in Italy. PARTICIPANTS: We investigated white women (N=280) of 305 who were consecutively admitted to a rehabilitation hospital because of their first fracture of the hip. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: To assess muscle mass, we measured appendicular lean mass (aLM) by dual-energy x-ray absorptiometry (DXA), 21.2±6.2 (mean ± SD) days after hip fracture occurrence in the 280 women. On the same day, we assessed serum levels of 25-hydroxyvitamin D and parathyroid hormone (PTH). Ability to function in activities of daily living was evaluated by the Barthel Index both before and after acute inpatient rehabilitation. RESULTS: After adjustment for 8 confounders, including age, cognitive impairment, pressure ulcers, neurologic impairment, infections, fracture type, Barthel Index score at admission to rehabilitation, and aLM/height(2) (aLM/ht(2)), 25-hydroxyvitamin D levels were significantly associated both with Barthel Index scores after rehabilitation (P=.003) and their changes during rehabilitation (P=.008). Similar results were obtained when the 25-hydroxyvitamin D/PTH ratio was substituted for 25-hydroxyvitamin D levels. Conversely, aLM/ht(2) was not significantly correlated with Barthel Index scores and their changes during rehabilitation. Furthermore, we found no significant associations between either 25-hydroxyvitamin D levels or the 25-hydroxyvitamin D/PTH ratio and aLM/ht(2). CONCLUSIONS: The significant association between 25-hydroxyvitamin D levels (and 25-hydroxyvitamin D/PTH ratio) and the ability to function in women with hip fractures was not mediated by aLM assessed by DXA.
Authors: Marco Di Monaco; Carlotta Castiglioni; Fulvia Vallero; Roberto Di Monaco; Rosa Tappero Journal: J Bone Miner Metab Date: 2013-11-08 Impact factor: 2.626
Authors: Alexandra Papaioannou; Courtney C Kennedy; Lora Giangregorio; George Ioannidis; Janet Pritchard; David A Hanley; Leonardo Farrauto; Justin DeBeer; Jonathan D Adachi Journal: BMC Musculoskelet Disord Date: 2011-06-20 Impact factor: 2.362