Repeated evening home blood pressure measurement improves prognostic significance for stroke: a 12-year follow-up of the Ohasama study.
OBJECTIVE
To compare the predictive power of home blood pressure (HBP) measured in the evening (E-HBP) and that of casual screening BP (CBP) for stroke risk in relation to the number of E-HBP measurements.


METHODS
We obtained E-HBP (measured once in the evening just before going to bed for 4 weeks) and CBP (measured twice during the health checkup) from 2234 Japanese participants aged >or=35 years who had no history of a previous stroke. The participants were followed-up for a median duration of 11.9 years. The multivariate adjusted relative hazard (RH) and 95% confidence intervals (CI) for each 10 mmHg (systolic) or 5 mmHg (diastolic) increase in BP was determined by Cox regression model.


RESULTS
There were 226 incidences of stroke. Even the initial E-HBP values significantly predicted future stroke events (systolic RH=1.19, 95% CI=1.11-1.28; diastolic RH=1.12, 95% CI=1.06-1.19), and the predictive power of E-HBP increased progressively with the increased number of measurements. When initial systolic E-HBP and systolic CBP values were simultaneously included into the Cox model, only initial E-HBP was significantly related with stroke risk (E-HBP RH=1.17, 95% CI=1.08-1.26; CBP RH=1.07, 95% CI=0.99-1.15).


CONCLUSIONS
E-HBP has a stronger predictive power than CBP regardless of the number of measurements. Our findings emphasize the important clinical significance of E-HBP over CBP, even though the measurement conditions of E-HBP are generally less strict than that of morning HBP measurements.
Comprehensive Research and Education Center for Planning of Drug Development and Clinical Evaluation, Tohoku University 21st Century COE Program, Aoba-ku, Sendai, Japan. kei@asayama.org
Kei
K
Asayama
Takayoshi
T
Ohkubo
Azusa
A
Hara
Takuo
T
Hirose
Daisaku
D
Yasui
Taku
T
Obara
Hirohito
H
Metoki
Ryusuke
R
Inoue
Masahiro
M
Kikuya
Kazuhito
K
Totsune
Haruhisa
H
Hoshi
Hiroshi
H
Satoh
Yutaka
Y
Imai
D000328:Adult; D000368:Aged; D001795:Blood Pressure Determination / Q000379:methods*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D012306:Risk; D012648:Self Care / Q000379:methods*; D020521:Stroke / Q000453:epidemiology* / Q000209:etiology