High von Willebrand factor levels increase the risk of stroke: the Rotterdam study.
OBJECTIVE
Many studies have investigated the role of plasma von Willebrand factor level in coronary heart disease, but few have investigated its role in stroke. The aim of this study was to determine if von Willebrand factor levels are associated with the risk of stroke.


METHODS
The study was part of the Rotterdam Study, a large population-based cohort study among subjects aged ≥55 years. We included 6 250 participants who were free from stroke at baseline (1997 to 2001) and for whom blood samples were available. Follow-up for incident stroke was complete up to January 1, 2005. Data were analyzed with Cox proportional hazards models adjusted for age and sex and additionally with models adjusted for other potential confounders including ABO blood group. A subgroup analysis was performed in participants without atrial fibrillation. Effect modification by sex was tested on a multiplicative and on an additive scale.


RESULTS
During an average follow-up time of 5.0 years, 290 first-ever strokes occurred, of which 197 were classified as ischemic. The risk of stroke increased with increasing von Willebrand factor levels (age- and sex-adjusted hazard ratios per SD increase in von Willebrand factor level: 1.12 [95% CI, 1.01 to 1.25] for stroke, 1.13 [95% CI, 0.99 to 1.29] for ischemic stroke). Adjustments for additional confounders slightly attenuated the association. The association was also present in subjects without atrial fibrillation and did not differ between sexes.


CONCLUSIONS
High von Willebrand factor levels are associated with stroke risk in the general population.
Wieberdink
Renske G
RG
Department of Epidemiology, Erasmus University Medical Center, PO Box 2040, 3000 CA Rotterdam, The Netherlands.
van Schie
Marianne C
MC
Koudstaal
Peter J
PJ
Hofman
Albert
A
Witteman
Jacqueline C M
JC
de Maat
Moniek P M
MP
Leebeek
Frank W G
FW
Breteler
Monique M B
MM
D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D015994:Incidence; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D012306:Risk; D012307:Risk Factors; D012907:Smoking; D020521:Stroke / Q000097:blood* / Q000453:epidemiology*; D014841:von Willebrand Factor / Q000032:analysis*
D014841:von Willebrand Factor