Computed tomographic bone mineral density is independently associated with adverse in-hospital outcomes in Dutch level-1 trauma patients

BACKGROUND: Aging, inactivity, and malnutrition are risk factors for adverse in-hospital outcomes and can manifest in bone loss. Use of bone mineral density (BMD) as an objective marker might improve early identification of patients at risk for complications.

AIM: To assess the association of computed tomography (CT) determined BMD values of the first lumbar vertebra with in-hospital complications and outcomes in trauma patients.

METHODS: All consecutive hospitalized trauma patients (≥ 16 years) that underwent CT-imaging within 7 days of admission in 2017 were included. Patients with an active infection or antibiotic treatment upon admission, severe neurologic trauma, or an unassessable vertebra were excluded. BMD at the first lumbar vertebra was determined with CT by placing a circular region of interest in homogeneous trabecular bone to obtain mean Hounsfield Units (HU). Regression analyses were performed to assess the association of BMD with in-hospital complications and outcomes.

RESULTS: In total, 410 patients were included (median age: 49 years [interquartile range 30-64], 68.3% men, mean BMD 159 ± 66 HU). A total of 94 complications, primarily infection-related, were registered in 74 patients. After adjustment for covariates, a decrease of BMD by one standard deviation was significantly associated with increased risk of complications (odds ratio [OR] 1.9, 95% confidence interval [CI] 1.1-3.1), pneumonia (OR 2.2, 95% CI 1.2-4.5), delirium (OR 4.5, 95% CI 1.7-13.5), and intensive care unit (ICU) admission (OR 1.8, 95% CI 1.1-2.9).

CONCLUSION: Bone mineral density of the first lumbar vertebra is independently associated with in-hospital complications, pneumonia, delirium, and ICU admission. These findings could help identify patients at risk early.