Stroke risk in systolic and combined systolic and diastolic hypertension determined using ambulatory blood pressure. The Ohasama study.
BACKGROUND
To investigate the risk of stroke in subjects with isolated systolic hypertension (ISH), isolated diastolic hypertension (IDH), and combined systolic and diastolic hypertension (SDH) in a Japanese general population, we used 24-h ambulatory blood pressure (ABP) and casual-screening blood-pressure (CBP) readings.


METHODS
Subtypes of hypertension were defined based on systolic blood pressure (SBP) >135 mm Hg or diastolic blood pressure (DBP) >80 mm Hg for 24-h ABP, and SBP >140 mm Hg or DBP >90 mm Hg for CBP. We obtained 24-h ABP and CBP data for 1271 (40% male) subjects aged > or =40 years (mean age, 61 years) without a history of symptomatic stroke; their stroke-free survival was then determined. The prognostic significance of each subtype of hypertension was determined by Cox proportional hazard analysis.


RESULTS
There were 113 symptomatic strokes during follow-up (mean time, 11 years). Compared with normotension, among the hypertension subtypes determined by 24-h ABP, the adjusted relative hazards (RHs) of stroke were 2.24 for ISH (P = .002) and 2.39 for SDH (P = .0004). The association was less marked among subtypes determined by CBP (RH = 1.40 and P = .13 for ISH; RH = 2.07 and P = .017 for SDH). The IDH group was excluded from the Cox analysis because both the prevalence and the number of events were low in this group.


CONCLUSIONS
Isolated systolic hypertension, as determined by 24-h ABP measurements, was associated with a high risk of stroke, similar to that found in SDH subjects; this suggests that the prognosis of hypertensive patients would be improved by focusing treatment on 24-h systolic ABP.
Inoue
Ryusuke
R
21st Century COE Program Comprehensive Research and Education Center for Planning of Drug Development and Clinical Evaluation, Tohoku University, Sendai, Japan.
Ohkubo
Takayoshi
T
Kikuya
Masahiro
M
Metoki
Hirohito
H
Asayama
Kei
K
Obara
Taku
T
Hirose
Takuo
T
Hara
Azusa
A
Hoshi
Haruhisa
H
Hashimoto
Junichiro
J
Totsune
Kazuhito
K
Satoh
Hiroshi
H
Kondo
Yoshiaki
Y
Imai
Yutaka
Y
D000368:Aged; D001794:Blood Pressure / Q000502:physiology*; D018660:Blood Pressure Monitoring, Ambulatory / Q000379:methods*; D015331:Cohort Studies; D003971:Diastole / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006973:Hypertension / Q000150:complications* / Q000175:diagnosis* / Q000503:physiopathology; D007564:Japan; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D012307:Risk Factors; D020521:Stroke / Q000453:epidemiology* / Q000209:etiology; D013599:Systole / Q000502:physiology*