title: Risk Factors for Stroke among Young-Old and Old-Old Community-Dwelling Adults in Japan: The Ohasama Study.
abstract: OBJECTIVE
  Few studies have addressed stroke risk factors in older populations, particularly among the old-old. We examined differences in traditional risk factors for stroke among the old-old compared with the young-old in community-dwelling Japanese adults.
  
  
  METHODS
  We followed 2,065 residents aged ≥ 60 years who had no history of stroke. Traditional risk factors for stroke were obtained from a self-administered questionnaire at baseline. We classified participants into two age categories, 60-74 years (n=1,502) and ≥ 75 years (n=563), and assessed whether traditional risk factors were differentially associated with stroke incidence according to age category. Hazard ratios were calculated by the Cox proportional hazards model, adjusting for confounding factors and competing risk of death.
  
  
  RESULTS
  During a median follow-up of 12.8 and 7.9 years, 163 and 111 participants aged 60-74 and ≥ 75 years, respectively, developed a first stroke. Hypertension was consistently associated with increased risk of stroke, regardless of age category. Diabetes mellitus was associated with increased risk of stroke in those aged 60-74 years (hazard ratio, 1.50; 95% confidence interval, 1.00-2.25), but not in those aged ≥ 75 years (hazard ratio, 0.65; 95% confidence interval, 0.33-1.29), with significant interaction by age (P=0.035). No traditional risk factor other than hypertension was associated with stroke among those aged ≥ 75 years.
  
  
  CONCLUSIONS
  Those with hypertension had significantly higher stroke risk among old people, while diabetes mellitus was differentially associated with stroke according to age category. Our findings indicate the importance of different prevention strategies for stroke incidence according to age category.
authors.affiliation: Department of Hygiene and Public Health, Teikyo University School of Medicine.
authors.forename: Keiko
authors.initials: K
authors.lastname: Murakami
authors.forename: Kei
authors.initials: K
authors.lastname: Asayama
authors.forename: Michihiro
authors.initials: M
authors.lastname: Satoh
authors.forename: Ryusuke
authors.initials: R
authors.lastname: Inoue
authors.forename: Megumi
authors.initials: M
authors.lastname: Tsubota-Utsugi
authors.forename: Miki
authors.initials: M
authors.lastname: Hosaka
authors.forename: Ayako
authors.initials: A
authors.lastname: Matsuda
authors.forename: Kyoko
authors.initials: K
authors.lastname: Nomura
authors.forename: Takahisa
authors.initials: T
authors.lastname: Murakami
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kikuya
authors.forename: Hirohito
authors.initials: H
authors.lastname: Metoki
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Imai
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Ohkubo
mesh_terms: D000328:Adult; D000368:Aged; D055812:Community-Based Participatory Research; D003920:Diabetes Mellitus / Q000503:physiopathology*; D005260:Female; D006801:Humans; D006973:Hypertension / Q000150:complications*; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D020521:Stroke / Q000453:epidemiology / Q000209:etiology*