Reza Ehsanian1,2,3,4, Molly A Timmerman3,5, Jerry M Wright2, Stephen McKenna6,2,4, Ben Dirlikov2, James Crew1,2,3. 1. Physical Medicine and Rehabilitation Department at Santa Clara Valley Medical Center, San Jose, CA. 2. Rehabilitation Research Center at Santa Clara Valley Medical Center, San Jose, CA. 3. Physical Medicine and Rehabilitation Division, Department of Orthopaedic Surgery, Stanford University, Palo Alto, CA. 4. Department of Neurosurgery, Stanford University, Palo Alto, CA. 5. Physical Medicine and Rehabilitation Department at Veterans Health Administration, Palo Alto, CA. 6. K. Physical Medicine and Rehabilitation, Department at Santa Clara Valley Medical Center, San Jose, CA.
Abstract
BACKGROUND: The role of vitamin D in the pathogenesis of venous thromboembolism (VTE) and prevalence of low vitamin D (LVitD) in spinal cord injury (SCI) has motivated vitamin D testing and supplementation. This is an exploratory study of data collected at a time before the routine clinical practice of vitamin D supplementation, allowing for evaluation of the natural history of vitamin D levels in patients with SCI. OBJECTIVE: To determine if vitamin D supplementation in persons with SCI and LVitD levels is associated with decreased prevalence of VTE. DESIGN: Retrospective cohort study. SETTING: Rehabilitation Center at a Level I Trauma Center. PARTICIPANTS: Patients with SCI admitted to acute inpatient rehabilitation (N = 282). MAIN OUTCOME MEASURES: VTE prevalence in patients with LVitD levels, grouped by presence or absence of vitamin D supplementation. RESULTS: Of the acute inpatient SCI population, 80% (227/282) of patients demonstrated vitamin D levels <30 ng/mL (LVitD). Although the incidence of VTE was almost double in the LVitD group, 19% (43/227) of the patients in the LVitD group had VTE versus 9% (5/55) of patients with vitamin D levels ≥30 ng/mL (normal VitD [NVitD]); this difference was not statistically significant (P = .108, Cramer's V = .104). When the role of vitamin D supplementation was analyzed, individuals in the LVitD group who received no vitamin D supplementation (LVitDSuppNegative) had a higher incidence of VTE (statistically significant) compared to the LVitD group with vitamin D supplementation (LVitDSuppPositive) (24% [42/178] vs. 2% [1/49]) (P < .001, Cramer's V = .226). In post hoc exploratory analyses, the VTE rate of patients in the LVitDSuppNegative group was noted to be significantly higher than that in all other patient groups combined (P < .001, Cramer's V = .229). A binary logistic regression model incorporating clinical covariates also showed this grouping to be significant. CONCLUSION: A significant association appears to exist between lack of vitamin D supplementation and VTE occurrence in persons with acute SCI and LVitD levels. LEVEL OF EVIDENCE: III.
BACKGROUND: The role of vitamin D in the pathogenesis of venous thromboembolism (VTE) and prevalence of low vitamin D (LVitD) in spinal cord injury (SCI) has motivated vitamin D testing and supplementation. This is an exploratory study of data collected at a time before the routine clinical practice of vitamin D supplementation, allowing for evaluation of the natural history of vitamin D levels in patients with SCI. OBJECTIVE: To determine if vitamin D supplementation in persons with SCI and LVitD levels is associated with decreased prevalence of VTE. DESIGN: Retrospective cohort study. SETTING: Rehabilitation Center at a Level I Trauma Center. PARTICIPANTS: Patients with SCI admitted to acute inpatient rehabilitation (N = 282). MAIN OUTCOME MEASURES: VTE prevalence in patients with LVitD levels, grouped by presence or absence of vitamin D supplementation. RESULTS: Of the acute inpatient SCI population, 80% (227/282) of patients demonstrated vitamin D levels <30 ng/mL (LVitD). Although the incidence of VTE was almost double in the LVitD group, 19% (43/227) of the patients in the LVitD group had VTE versus 9% (5/55) of patients with vitamin D levels ≥30 ng/mL (normal VitD [NVitD]); this difference was not statistically significant (P = .108, Cramer's V = .104). When the role of vitamin D supplementation was analyzed, individuals in the LVitD group who received no vitamin D supplementation (LVitDSuppNegative) had a higher incidence of VTE (statistically significant) compared to the LVitD group with vitamin D supplementation (LVitDSuppPositive) (24% [42/178] vs. 2% [1/49]) (P < .001, Cramer's V = .226). In post hoc exploratory analyses, the VTE rate of patients in the LVitDSuppNegative group was noted to be significantly higher than that in all other patient groups combined (P < .001, Cramer's V = .229). A binary logistic regression model incorporating clinical covariates also showed this grouping to be significant. CONCLUSION: A significant association appears to exist between lack of vitamin D supplementation and VTE occurrence in persons with acute SCI and LVitD levels. LEVEL OF EVIDENCE: III.