Abstract WMP53: Vitamin D Levels Are Lower In Acute Ischemic Stroke Patients Compared To Matched Controls

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Introduction: Vitamin D deficiency is increasingly recognized as a global pandemic. In longitudinal healthy population studies, vitamin D deficiency is associated with increased incidence of ischemic stroke. We compared serum 25-OH vitamin D levels between Asian ischemic stroke patients within 1 week of stroke onset with age and gender matched healthy individuals. Methods: We prospectively recruited 133 consecutive Asian acute ischemic stroke patients admitted to the Singapore General Hospital. Blood samples were collected within seven days of stroke onset. Stroke patients were matched for age and gender to individuals with no history of stroke from a database of healthy Asian controls. Serum 25-OH vitamin D was measured using Roche competitive electrochemiluminescence immunoassay for both stroke patients and healthy controls in the same laboratory. Vitamin D deficiency was defined as serum 25-OH vitamin D <20 μg/L and insufficiency as 20-40 μg/L. Matched statistical analyses were performed using Wilcoxon and McNemar tests. Results: Among the 133 matched pairs of ischemic stroke patients and healthy controls, median age was 60 years and 75% are males. Median serum 25-OH vitamin D level was lower among stroke patients (23.2 IQR 16.65-29.60 μg/L) compared to healthy controls (28.9 IQR 21.75-35.50 μg/L) (p<0.0001). Stroke patients had a higher prevalence of vitamin D deficiency (39%) compared to healthy controls (20%) (p<0.0001). A high proportion of stroke patients had insufficient vitamin D compared to healthy controls (95% vs 84%, p=0.007). Corrected serum calcium was lower in stroke patients (median 2.26 mmol/L IQR 2.21-2.35) than controls (median 2.34 mmol/L IQR 2.28- 2.41) (p<0.0001). There was no difference in serum phosphate (p=0.266) and parathyroid hormone levels (p=0.807). Conclusion: This cross-sectional study of 25-OH vitamin D levels in Asian patients within 1 week of ischemic stroke onset contributes to the growing evidence that vitamin D insufficiency/ deficiency is a stroke risk factor. Vitamin D measurement within 1 week of stroke onset likely reflects pre-stroke levels and is not influenced by post-stroke effects. Our findings provide impetus for future studies to investigate if vitamin D supplementation reduces stroke incidence.