title: Lifetime risk of stroke and impact of hypertension: estimates from the adult health study in Hiroshima and Nagasaki.
abstract: Very few reports have been published on lifetime risk (LTR) of stroke by blood pressure (BP) group. This study included participants in the Radiation Effects Research Foundation Adult Health Study who have been followed up by biennial health examinations since 1958. We calculated the LTR of stroke for various BP-based groups among 7847 subjects who had not been diagnosed with stroke before the index age of 55 years using cumulative incidence analysis adjusting for competing risks. By 2003, 868 subjects had suffered stroke (512 (58.9%) were women and 542 (62.4%) experienced ischemic stroke). BP was a significant factor in determining risk of stroke for men and women, with distributions of cumulative risk for stroke significantly different across BP groups. The LTR of all-stroke for normotension (systolic BP/diastolic BP < 120/80 mm Hg), prehypertension (120-139/80-89 mm Hg), stage 1 hypertension (140-159/90-99 mm Hg) and stage 2 hypertension (> 160/100 mm Hg) were 13.8-16.9-25.8-25.8% in men and 16.0-19.9-24.0-30.5% in women, respectively (P < 0.001 among BP groups in both sexes). The estimates did not differ significantly (P = 0.16) between normotensive and prehypertensive subjects. One in five Japanese atomic bomb survivor subjects experienced stroke over their lifetime from the age of 55 years. Long-term stroke risks were elevated in those with hypertension (> 140/90 mm Hg) at any of the index ages of 45, 55, 65 and 75 years.
authors.affiliation: Department of Clinical Studies, Radiation Effects Research Foundation, Hiroshima, Japan. iktakaha@rerf.or.jp
authors.forename: Ikuno
authors.initials: I
authors.lastname: Takahashi
authors.forename: Susan M
authors.initials: SM
authors.lastname: Geyer
authors.forename: Nobuo
authors.initials: N
authors.lastname: Nishi
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Ohshita
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Takahashi
authors.forename: Masazumi
authors.initials: M
authors.lastname: Akahoshi
authors.forename: Saeko
authors.initials: S
authors.lastname: Fujiwara
authors.forename: Kazunori
authors.initials: K
authors.lastname: Kodama
authors.forename: Masayasu
authors.initials: M
authors.lastname: Matsumoto
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D044466:Asian People / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D006973:Hypertension / Q000453:epidemiology* / Q000209:etiology; D007564:Japan / Q000453:epidemiology; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D054043:Nuclear Weapons / Q000706:statistics & numerical data; D012307:Risk Factors; D020521:Stroke / Q000453:epidemiology* / Q000209:etiology