ABO blood type and stroke risk: the REasons for Geographic And Racial Differences in Stroke Study. (April 2014)

• Record Type: Journal Article
• Authors: Zakai, N. A.; Judd, S. E.; Alexander, K.; McClure, L. A.; Kissela, B. M.; Howard, G.; Cushman, M.
• Is Part Of: Journal of thrombosis and haemostasis. Volume 12:Number 4(2014:Apr.)
• Page Start: 564
• Page End: 570
• Publication Date: 2014-04
• Subjects: Thrombosis -- Periodicals; Hemostasis -- Periodicals; Blood coagulation disorders -- Periodicals; 616.1
• DOI: 10.1111/jth.12507
• Languages: English
• ISSNs: 1538-7933

Abstract

<abstract abstract-type="main" id="jth12507-abs-0001"> <title>Summary</title> <sec id="jth12507-sec-0001" sec-type="section"> <title>Background</title> <p>ABO blood type is an inherited trait associated with coagulation factor levels and vascular outcomes.</p> </sec> <sec id="jth12507-sec-0002" sec-type="section"> <title>Objectives</title> <p>To assess the association of blood type with stroke and whether blood type contributes to racial disparities in stroke in the United States.</p> </sec> <sec id="jth12507-sec-0003" sec-type="section"> <title>Patients and Methods</title> <p>The REasons for Geographic And Racial Differences in Stroke (REGARDS) Study recruited 30 239 participants between 2003 and 2007. Using a case‐cohort design, blood type was genotyped in 646 participants with stroke and a 1104‐participant cohort random sample. Cox models that adjusted for Framingham stroke risk factors were used to assess the association of blood type with stroke.</p> </sec> <sec id="jth12507-sec-0004" sec-type="section"> <title>Results</title> <p>During 5.8 years of follow‐up, blood types A or B vs. type O were not associated with stroke. Blood type AB vs. O was associated with an increased risk of stroke (adjusted hazard ratio [HR] 1.83, 95% confidence interval [CI] 1.01–3.30). The association of blood type AB vs. O was greater in those without diabetes (adjusted HR 3.33, 95% CI 1.61–6.88) than those with diabetes (adjusted HR 0.49, 95% CI 0.17–1.44) (<italic>P</italic> interaction = 0.02). Factor VIII levels accounted for 60% (95% CI 11%–98%) of the association of AB blood type and stroke risk.</p> </sec> <sec id="jth12507-sec-0005" sec-type="section"> <title>Conclusion</title> <p>Blood type AB is associated with an increased risk of stroke that is not attenuated by conventional stroke risk factors, and factor VIII levels were associated with 60% of the association. While blood type AB is rare in the US population, it is a significant stroke risk factor and may play an important role in stroke risk in these individuals.</p> </sec> </abstract>