Association between Admission Serum 25-Hydroxyvitamin D Levels and Functional Outcome of Thrombolyzed Stroke Patients

Background: 25-Hydroxyvitamin D (25(OH)D) deficiency is a frequent condition in patients who suffer a stroke, and several studies suggested that it may be associated with a poorer prognosis. The aim of this study was to investigate specifically the association between 25(OH)D levels and functional outcome at 3 months in ischemic stroke patients treated with intravenous thrombolysis. Methods: Consecutive ischemic stroke patients who received intravenous thrombolysis were enrolled between 2010 and 2013. Baseline characteristics were collected, and serum concentrations of 25(OH)D were measured within the first 24 hours after admission and were analyzed according to the quartiles of their distribution (<25 nmol/L versus >= 25 nmol/L). Multivariable ordinal logistic regression was used to evaluate the association between 25(OH)D and 3-month functional outcome assessed by the modified Rankin score. Results: Three hundred fifty-two patients were included (mean age 68.6 +/- 15.8, 50.7% women, mean 25(OH)D level 45 +/- 25 nmol/L). The characteristics of the patients only differed with regard to higher premorbid functional impairment in patients with low 25(OH)D. In univariate analysis, the risk of functional impairment in patients with low 25(OH)D levels was greater than that in patients with higher 25(OH) D levels (odds ratio [OR] 2.10, 95% confidence interval [CI]: 1.35-3.27, P = .001). This association was still observed after adjustment for confounding variables (OR 1.70, 95% CI: 1.06-2.71, P = .027). Conclusion: A low serum 25(OH)D level is associated with worse functional outcome in patients with acute ischemic stroke treated with intravenous thrombolysis. Further investigations are required to understand the underlying mechanisms of this association.