Vitamin D status and the risk of recurrent stroke and mortality in ischemic stroke patients: Data from a 24-month follow-up study in China

PURPOSE: In this study, we determined serum 25-hydroxyvitamin D [25(OH) D] levels in serum, and investigated their associations with risk of recurrent stroke and mortality in a 24-month follow up study in Chinese patients with first-ever ischemic stroke. METHODS: In this preplanned post hoc analysis, serum levels of 25(OH) D and NIH stroke scale (NIHSS) were measured at the time of admission in a cohort of patients with ischemic stroke. We used logistic regression model to assess the relationship between 25(OH) D levels and risk recurrent stroke or mortality. RESULTS: The follow-up rate was 98.2% in 220 stroke patients. Of 216 patients, 18.5% (95%CI: 13.3%-23.7%) patients had a stroke recurrence, and 30.1% (95% CI: 24.0%-36.2%) died. After adjustment for traditional risk factors, serum 25(OH) D levels were negatively associated with the risk of stroke recurrence (odds ratio [OR], 0.77; 95% confidence interval [CI], 0.70-0.85; P < 0.001) and negatively associated with mortality during 24 months of follow-up (OR, 0.72; 95% CI, 0.64-0.80; P< 0.001). Compared with the first quartile of serum 25(OH) D levels, the ORs for stroke recurrence and mortality were as follows: second quartile, 0.80 (95% CI, 0.63-0.93) and 0.77 (95% CI, 0.65-0.89); third quartile, 0.42 (95% CI, 0.31-0.55) and 0.39 (95% CI, 0.30-0.52); fourth quartile, 0.12 (95% CI, 0.07-0.19) and 0.10 (95% CI, 0.06-0.15), respectively. CONCLUSIONS: Lower serum levels of 25(OH) D are independently associated with the stroke recurrence and mortality at 24 months in ischemic stroke patients.