Serum 25-hydroxyvitamin D deficiency predicts poor outcome amongst acute ischaemic stroke patients with low high density lipoprotein cholesterol

Background and purpose: Current observational studies indicate that a lower vitamin D level is associated with a higher risk of poor ischaemic stroke prognosis. Whether this association is affected by lipid levels is unclear. Our aim was to examine the effect of serum vitamin D especially its deficiency on the global outcome of ischaemic stroke stratified by individual lipid component level.

Methods: A total of 3181 ischaemic patients from China Antihypertensive Trial in Acute Ischaemic Stroke were included in this study and their baseline serum 25-hydroxyvitamin D levels were tested. They were prospectively followed up for death, major disability and vascular events for 3 months after acute ischaemic stroke. A multivariable logistic model was used to evaluate the association between serum 25-hydroxyvitamin D levels and clinical outcomes of ischaemic stroke in the 3-month period of follow-up in all patients and in different lipid-level subgroups.

Results: Vitamin D deficiency was associated with poor clinical outcomes only in ischaemic stroke patients with high density lipoprotein cholesterol (HDLC) <1.04 mmol/l rather than all patients. The multivariable adjusted odds ratios (95% confidence intervals) of major disability and composite adverse events were 1.98 (1.08-3.63) and 2.24 (1.22-4.12), respectively. There was a significant interaction effect between vitamin D and HDLC levels on major disability and the composite outcome (P for interaction < 0.05 for both). A significant linear trend existed between 25-hydroxyvitamin D and risk of poor prognosis (P = 0.03).

Conclusions: Vitamin D deficiency may be merely an independent risk factor of poor prognosis in ischaemic stroke patients with low HDLC level.