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]D(3)) 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)D(3) 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)D(3) were found (median, 6.9 ng/mL). By using the Spearman rank correlation test, a significant positive correlation was observed between serum 25(OH)D(3) and Barthel Index score assessed on admission (rho=.218, P <.001) and discharge (rho=.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)D(3) 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)D(3) evaluation, comorbidity, surgical procedure type, and previous hip fractures. CONCLUSIONS: In the study population, serum 25(OH)D(3) 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.

Biochemical markers of nutrition and bone mineral density in the elderly.

BACKGROUND: Protein depletion is detrimental in bone health, but the association between bone mineral density (BMD) and serum albumin is controversial. We recently showed a positive association between femur BMD and total lymphocyte count (TLC), a validated marker of protein nutrition status, in hip-fractured women. OBJECTIVE: To investigate the association between femur BMD and both serum albumin and TLC in hip-fractured men and women. METHODS: 286 of 315 hip-fractured patients (243 women and 43 men) consecutively admitted to a rehabilitation hospital were studied. BMD was measured by DXA in the unfractured femur. The correlation between BMD and both TLC and serum albumin was studied by Pearson's coefficient and Bonferroni adjustment. RESULTS: In women a positive correlation was observed between, TLC but not albumin, and BMD measured in the total femur (r = 0.26; p < 0.01), femur neck (r = 0.21, p < 0.01), trochanter (r = 0.22, p < 0.01), intertrochanteric area (r = 0.25, p < 0.01) and Ward's triangle (r = 0.17, p < 0.05). Conversely in men a positive correlation was found between albumin, but not TLC, and BMD measured in the total femur (r = 0.50, p < 0.01), femur neck (r = 0.52, p < 0.01), intertrochanteric area (r = 0.52, p < 0.01) and Ward's triangle (r = 0.49, p < 0.01). Linear multiple regression showed that the associations were independent of age, weight, height, body mass index, erythrocyte sedimentation rate, time between surgery and blood sample collection and type of hip fracture. CONCLUSION: Our results support the role of protein nutrition in bone health, at least in elderly frail patients. TLC and serum albumin were suitable markers, however sex-related differences in their usefulness were observed.