Reference values for 24-hour ambulatory blood pressure monitoring based on a prognostic criterion: the Ohasama Study.
Although reference values for ambulatory blood pressure (ABP) monitoring have been investigated in several population studies, these values were derived from cross-sectional observations and were based merely on the statistical distribution of blood pressure values. Therefore, we conducted a prospective cohort study to identify reference values for 24-hour ABP in relation to prognosis. We obtained measurements of 24-hour ABP for 1542 subjects (565 men) aged 40 years and over in a general population of a rural Japanese community and then followed-up their survival status. There were 117 deaths during the follow-up period (mean, 6.2 years). The association between baseline 24-hour ABP values and mortality, examined by the Cox proportional hazards regression model adjusted for possible confounding factors, showed a better fit with a second-degree equation than with a first-degree equation. On the basis of the results of this analysis, we identified the following reference values as the optimal blood pressure ranges that predict the best prognosis: 120 to 133 mm Hg for systolic blood pressure and 65 to 78 mm Hg for diastolic blood pressure. 24-Hour ABP values >134/79 mm Hg and <119/64 mm Hg were related to increased risks for cardiovascular and noncardiovascular mortality, respectively. This is the first report to propose reference values for 24-hour ABP based on a prognostic criterion.
Ohkubo
T
T
Department of Public Health, Tohoku University School of Medicine, Sendai, Japan. tohkubo@mail.cc.tohoku.ac.jp
Imai
Y
Y
Tsuji
I
I
Nagai
K
K
Ito
S
S
Satoh
H
H
Hisamichi
S
S
D000328:Adult; D018660:Blood Pressure Monitoring, Ambulatory; D015331:Cohort Studies; D005260:Female; D006801:Humans; D006973:Hypertension / Q000401:mortality / Q000503:physiopathology*; D007564:Japan; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D012016:Reference Values