Serum levels of 25-Hydroxyvitamin D and functional recovery after hip fracture

Abstract 

Di Monaco M, Vallero F, Di Monaco R, Mautino F, Cavanna A. Serum levels of 25-hydroxyvitamin D and functional recovery after hip fracture.

Objective

To evaluate the association between serum levels of 25-hydroxyvitamin D (25[OH]D₃) and functional recovery after hip fracture.

Design

Cross-sectional study.

Setting

Rehabilitation hospital in Italy.

Participants

A total of 350 white hip-fracture patients consecutively admitted to a rehabilitation hospital. Thirty-five patients were excluded because their hip fracture was caused by major trauma or cancer affecting the bone or they could not complete rehabilitation.

Interventions

Not applicable.

Main outcome measures

Patients underwent 25(OH)D₃ assessment at a mean ± standard deviation of 21.3±8.1 days after the hip fracture. Functional recovery was evaluated by using Barthel Index scores.

Results

Low levels of 25(OH)D₃ were found (median, 6.9ng/mL). By using the Spearman rank correlation test, a significant positive correlation was observed between serum 25(OH)D₃ and Barthel Index score assessed on admission (ρ=.218, P<.001) and discharge (ρ=.198, P<.001), but not with the change in Barthel Index score attributable to rehabilitation. Linear multiple regression showed that the association between 25(OH)D₃ and Barthel Index score was independent of 11 confounding variables: age, sex, hip-fracture type, pressure ulcers, cognitive impairment, neurologic impairment, infections, time between fracture occurrence and 25(OH)D₃ evaluation, comorbidity, surgical procedure type, and previous hip fractures.

Conclusions

In the study population, serum 25(OH)D₃ was an independent predictor of functional recovery assessed by Barthel Index score after hip fracture but not of the change in the functional score resulting from rehabilitation.

Key words:  Hip fracture , Osteoporosis , Rehabilitation , Vitamin D