title: Proportions of stroke subtypes among men and women > or =40 years of age in an urban Japanese city in 1992, 1997, and 2002.
abstract: OBJECTIVE
  Higher proportions of hemorrhagic stroke and lacunar infarction were reported in rural Japan compared with those in Western countries. We examined the relative proportions of stroke subtypes in an urban Japanese city where westernized lifestyles are more common than in rural areas.
  
  
  METHODS
  Stroke registration was performed in 1992, 1997, and 2002 for residents > or =40 years of age who were admitted with acute strokes to all of the 10 hospitals with > or =90 beds in Yao City, Osaka, Japan. Strokes were classified as intraparenchymal hemorrhage, subarachnoid hemorrhage, or ischemic strokes (embolic infarction, large-artery occlusive infarction, lacunar infarction, and unclassified thrombotic infarction) by criteria using computed tomography or MRI.
  
  
  RESULTS
  A total of 650 first-ever strokes were registered. The age-adjusted proportion of each stroke subtype was not significantly different among the 3 study periods in both men and women. Throughout the 3 periods, intraparenchymal hemorrhage, subarachnoid hemorrhage, and ischemic stroke accounted for 26%, 7%, and 65% in men, respectively. In women, the respective proportions were 29%, 21%, and 44%. The proportion of each subtype for total ischemic strokes was as follows: 51% to 61% lacunar infarction, 25% to 26% large-artery occlusive infarction, and 11% to 17% embolic infarction.
  
  
  CONCLUSIONS
  Our study showed that hemorrhagic stroke represented a large proportion of all strokes, especially among women, and lacunar infarction was the most common subtype of ischemic stroke among both men and women in Yao City, which differed from findings in Western countries.
authors.affiliation: Osaka Medical Center for Health Science and Promotion, Osaka, Japan. xkita@kenkoukagaku.jp
authors.forename: Akihiko
authors.initials: A
authors.lastname: Kitamura
authors.forename: Yuko
authors.initials: Y
authors.lastname: Nakagawa
authors.forename: Minoru
authors.initials: M
authors.lastname: Sato
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Iso
authors.forename: Shinichi
authors.initials: S
authors.lastname: Sato
authors.forename: Hironori
authors.initials: H
authors.lastname: Imano
authors.forename: Masahiko
authors.initials: M
authors.lastname: Kiyama
authors.forename: Takeo
authors.initials: T
authors.lastname: Okada
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Okada
authors.forename: Minoru
authors.initials: M
authors.lastname: Iida
authors.forename: Takashi
authors.initials: T
authors.lastname: Shimamoto
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D002545:Brain Ischemia / Q000150:complications; D002543:Cerebral Hemorrhage / Q000150:complications; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D017678:Sex Distribution; D020521:Stroke / Q000145:classification / Q000453:epidemiology* / Q000209:etiology*; D013345:Subarachnoid Hemorrhage / Q000150:complications; D014505:Urban Population / Q000706:statistics & numerical data*