title: Ethnic differences in ischemic stroke subtypes in young-onset stroke: the Stroke Prevention in Young Adults Study.
abstract: BACKGROUND
  Prior studies indicate that young African-Americans (AA) have a greater frequency of ischemic stroke than similarly aged European-Americans (EA). We hypothesized that differences in stroke subtype frequency mediated through sex and differing risk factor profiles may play a role in ethnicity-specific stroke. Utilizing our biracial young-onset stroke population, we explored these relationships.
  
  
  METHODS
  Fifty nine hospitals in the Baltimore-Washington area participated in a population-based study of young-onset stroke in men (218-AA, 291-EA) and women (219-AA, 222-EA) aged 16-49. Data on age, sex, ethnicity and stroke risk factors (hypertension (HTN) and smoking) were gathered through standardized interview. A pair of vascular neurologists adjudicated each case to determine TOAST subtype. Logistic regression analyses evaluating for differences in stroke risk factors by TOAST subtype were performed.
  
  
  RESULTS
  Analyses controlling for age and sex demonstrated that AA were more likely to have a lacunar stroke than EA (OR = 1.61; 95% CI = 1.12-2.32; p = 0.011) when utilizing the other TOAST subtypes as the reference group. This effect was mediated by HTN, which increases the risk of lacunar stroke (OR = 2.03; 95% CI = 1.38-2.98; p = 0.0003) and large artery stroke (OR = 1.70; 95% CI = 1.01-2.88; p = 0.048) when controlling for sex, ethnicity, and age. Cases below age 40 were more likely to have a cardioembolic stroke than those above age 40 (OR = 1.62; 95% CI = 1.15-2.27; p = 0.006), controlling for sex and ethnicity. Lastly, current smokers were more likely to have a large artery stroke than non-smokers (OR = 1.79; 95% CI = 1.08-2.98; p = 0.024).
  
  
  CONCLUSIONS
  Our population-based data demonstrate ethnic differences in ischemic stroke subtypes. These findings may help clarify mechanisms of stroke in young adults which may in part be driven by ethnic-specific differences in early-onset traditional risk factors, thereby indicating differing emphasis on workup and prevention.
authors.affiliation: Department of Neurology, University of Maryland School of Medicine, Baltimore, MD, USA. megh.trivedi@som.umaryland.edu.|Veterans Affairs Medical Center, Baltimore, MD, USA. megh.trivedi@som.umaryland.edu.
authors.forename: Megh M
authors.initials: MM
authors.lastname: Trivedi
authors.affiliation: Department of Neurology, University of Maryland School of Medicine, Baltimore, MD, USA. kryan@medicine.umaryland.edu.|Veterans Affairs Medical Center, Baltimore, MD, USA. kryan@medicine.umaryland.edu.
authors.forename: Kathleen A
authors.initials: KA
authors.lastname: Ryan
authors.affiliation: Department of Neurology, University of Maryland School of Medicine, Baltimore, MD, USA. jcole@som.umaryland.edu.|Veterans Affairs Medical Center, Baltimore, MD, USA. jcole@som.umaryland.edu.
authors.forename: John W
authors.initials: JW
authors.lastname: Cole
mesh_terms: D000293:Adolescent; D000328:Adult; D001741:Black or African American / Q000208:ethnology*; D017668:Age of Onset; D015142:Baltimore / Q000208:ethnology; D002545:Brain Ischemia / Q000208:ethnology*; D004219:District of Columbia / Q000208:ethnology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D020521:Stroke / Q000208:ethnology*; D055815:Young Adult