Evaluating home blood pressure in treated hypertensives in comparison with the referential value of casual screening of blood pressure: The Ohasama study

OBJECTIVE: The target home blood pressure (BP) levels for antihypertensive treatment have not been fully investigated. We estimated home BP values that corresponded to the referential values of casual screening of BP using reduced major axis (RMA) regression for data from untreated and treated individuals in a general population. METHODS: The study included 2651 participants (778 treated) aged 20 years or above. The relationships between casual BP and home BP were examined using RMA regression to consider measurement errors. We calculated estimated home BP values that corresponded to casual BP using the regression equations. RESULTS: Although casual BPs and home BPs were significantly correlated (all: P<0.0001), the coefficients of determination in multiple regression were higher in untreated individuals than those in treated ones. When RMA regression was applied between casual BP (x) and morning home BP (y), the equations were expressed as y=0.78x+26.55 (systolic BP) and y=0.84x+14.34 (diastolic BP) in treated individuals and y=0.79x+19.29 (systolic BP) and y=0.85x+9.94 (diastolic BP) in untreated ones. The estimated home BPs corresponded to 140/90 mmHg of casual BP: 135.8/89.8 mmHg (morning), 132.2/86.6 mmHg (evening), and 133.9/87.8 mmHg (average) in treated individuals and 129.2/86.7 mmHg (morning), 127.8/84.8 mmHg (evening), and 128.2/85.2 mmHg (average) in untreated individuals. CONCLUSION: We estimated the referential values of home BP in treated hypertensives using a regression model; however, further intervention studies on home BP are needed to clarify the target treatment goals of home BP.