title: Serum 25-hydroxyvitamin D and the risk of stroke in Hong Kong Chinese.
abstract: Low vitamin D levels have been associated with various cardiovascular diseases; however, whether it is associated with stroke remains inconclusive. We aimed to evaluate the association between serum 25-hydroxyvitamin D and risk of stroke. We conducted a cohort study consisting of 3,458 participants from the Hong Kong Osteoporosis Study aged ≥45 at baseline, examined between 1995 and 2010 and followed up using electronic medical records. Ischaemic and haemorrhagic stroke were defined using the ICD-9 code. In multivariable Cox-proportional hazard regression, quintiles 1 and 4 were significantly associated with increased risk of stroke when compared to the highest quintile (Quintile 1: HR, 1.78; 95 % CI, 1.16-2.74 and quintile 4: HR, 1.61; 95 % CI, 1.07-2.43). A similar association was observed in both men and women. In subgroup analysis, the association was specifically observed for ischaemic stroke, but not haemorrhagic stroke. Using a penalized regression spline, the association between vitamin D and risk of stroke was in a reverse J-shape, with the lowest risk of stroke being observed at 25(OH)D levels between 70 and 80 nmol/l. In conclusion, a low vitamin D level is associated with increased risk of ischaemic stroke; however, whether high vitamin D level is also associated with increased risk of stroke requires further study.
authors: Raymond Y H
authors: RY
authors: Leung
authors: Yi
authors: Y
authors: Han
authors: Chor-Wing
authors: CW
authors: Sing
authors: Bernard M Y
authors: BM
authors: Cheung
authors: Ian C K
authors: IC
authors: Wong
authors: Kathryn C B
authors: KC
authors: Tan
authors: Annie W C
authors: AW
authors: Kung
authors: Ching-Lung Cheung, PhD, Department of Pharmacology and Pharmacy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, Tel.: +852 2831 5085, Fax: +852 2816 2095, Email: lung1212@hku.hk.
authors: Ching-Lung
authors: CL
authors: Cheung
mesh_terms: D000368:Aged; D044466:Asian People; D015415:Biomarkers / Q000097:blood; D002545:Brain Ischemia / Q000097:blood* / Q000175:diagnosis / Q000208:ethnology*; D016009:Chi-Square Distribution; D057286:Electronic Health Records; D005260:Female; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011379:Prognosis; D016016:Proportional Hazards Models; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D020521:Stroke / Q000097:blood* / Q000175:diagnosis / Q000208:ethnology*; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood* / Q000175:diagnosis / Q000208:ethnology*
chemical_list: D015415:Biomarkers; D014807:Vitamin D; C104450:25-hydroxyvitamin D
keywords: Stroke; epidemiological studies; vitamin D