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.
Asayama
Kei
K
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
Ohkubo
Takayoshi
T
Hara
Azusa
A
Hirose
Takuo
T
Yasui
Daisaku
D
Obara
Taku
T
Metoki
Hirohito
H
Inoue
Ryusuke
R
Kikuya
Masahiro
M
Totsune
Kazuhito
K
Hoshi
Haruhisa
H
Satoh
Hiroshi
H
Imai
Yutaka
Y
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