title: Serum total homocysteine concentrations and risk of stroke and its subtypes in Japanese.
abstract: BACKGROUND
  To date, no prospective studies have examined the association between serum homocysteine levels and the risk of stroke and stroke subtypes in Asian populations.
  
  
  RESULTS
  A prospective, nested, case-control study of Japanese subjects 40 to 85 years of age was conducted by using frozen serum samples from 11 846 participants in cardiovascular risk surveys collected from 1984 to 1995 for one community and 1989 to 1995 for the other two communities. By the end of 2000, we identified 150 incident strokes, the subtypes of which were confirmed by imaging studies. Three control subjects per case were selected by matching for sex, age, community, year of serum storage, and fasting status. Serum total homocysteine levels were measured by high-performance liquid chromatography. Compared with control subjects, total (n=150), hemorrhagic (n=52), and ischemic (n=98) strokes had higher geometric mean values of total homocysteine and higher proportions of homocysteine > or =11.0 micromol/L. The multivariate odds ratios (95% CI) for highest (> or =11.0 micromol/L) versus lowest quartiles (<7.0 micromol/L) of homocysteine after adjustment for body mass index, smoking, alcohol intake, hypertension, serum total cholesterol, and other cardiovascular risk factors were 2.99 (1.51 to 5.93) for total stroke, 3.89 (1.60 to 9.46) for ischemic stroke, 3.36 (1.27 to 8.90) for lacunar infarction, and 1.63 (0.44 to 6.00) for hemorrhagic stroke. The respective multivariate odds ratios associated with a 5-micromol/L increase in homocysteine were 1.40 (1.09 to 1.80), 1.52 (1.07 to 2.14), 1.48 (1.01 to 2.18), and 1.10 (0.76 to 1.59). The excess risk of total and ischemic strokes did not vary significantly according to sex, age, smoking status, or hypertensive status.
  
  
  CONCLUSIONS
  High total homocysteine concentrations were associated with the increased risk of total stroke, more specifically ischemic stroke and lacunar infarction, among Japanese men and women.
authors.affiliation: Department of Public Health Medicine, Institute of Community Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba-shi, Ibaraki-ken 305-8575, Japan. h-iso@md.tsukuba.ac.jp
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Iso
authors.forename: Yuri
authors.initials: Y
authors.lastname: Moriyama
authors.forename: Shinichi
authors.initials: S
authors.lastname: Sato
authors.forename: Akihiko
authors.initials: A
authors.lastname: Kitamura
authors.forename: Takeshi
authors.initials: T
authors.lastname: Tanigawa
authors.forename: Kazumasa
authors.initials: K
authors.lastname: Yamagishi
authors.forename: Hironori
authors.initials: H
authors.lastname: Imano
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Ohira
authors.forename: Tomonori
authors.initials: T
authors.lastname: Okamura
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Naito
authors.forename: Takashi
authors.initials: T
authors.lastname: Shimamoto
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D020520:Brain Infarction / Q000097:blood; D002545:Brain Ischemia / Q000097:blood; D016022:Case-Control Studies; D005260:Female; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D015994:Incidence; D020300:Intracranial Hemorrhages / Q000097:blood; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D011446:Prospective Studies; D012307:Risk Factors; D020521:Stroke / Q000097:blood* / Q000453:epidemiology
chemical_list: D006710:Homocysteine