Low Serum Vitamin D Is Independently Associated with Larger Lesion Volumes after Ischemic Stroke.

BACKGROUND

Despite its high prevalence, known association with vascular disease and stroke incidence and fatality, little is known about the contribution of vitamin D status to a worse outcome after ischemic stroke. Therefore, we sought to assess whether low serum 25-hydroxyvitamin D (25[OH]D), a marker of vitamin D status, is predictive of the ischemic infarct volume and whether it relates to a worse outcome.

METHODS

We retrospectively analyzed prospective, consecutive acute ischemic stroke patients evaluated from January 2013 to January 2014 at a tertiary referral center. All patients (n = 96) had a magnetic resonance imaging-proven acute ischemic stroke. Multivariable linear and logistic regression analyses were used to test whether vitamin D represents an independent predictor of infarct volume and poor 90-day outcome (modified Rankin Scale score of >2).

RESULTS

In univariable analyses, lacunar infarct etiology, lower admission National Institutes of Health Stroke Scale, and higher serum 25(OH)D concentration were associated with smaller infarct volumes (P < .05). The association of 25(OH)D with ischemic infarct volume was independent of other known predictors of the infarct extent (P = .001). Multivariable analyses showed that the risk for a poor 90-day outcome doubled with each 10-ng/mL decrease in serum 25(OH)D.

CONCLUSIONS

Low serum 25(OH)D was independently associated with larger ischemic infarct volume, which may partially explain observed worse outcomes in ischemic stroke patients with poor vitamin D status. Although causality remains to be proven, our results provide the rationale to further explore vitamin D as a promising marker for cerebral ischemic vulnerability and to identify stroke patients at high risk for poor outcome.