Is High Central BP but Normal Office Brachial BP a risk?-The ABC-J II Study-

Background: Clinical significance of central blood pressure (BP) in treated hypertensives has not been established. We tested the hypothesis that subjects with high central systolic BP (CBP) but normal office brachial BP (OBP) have high cardiovascular risk profile. Methods: All of the subjects were participants enrolled in the Antihypertensives and Blood pressure of Central artery study in Japan (ABC-J) II study. Radial applanation tonometry (Omron 9000AI) was performed in 4077 subjects, and they were classified as; Group 1: high OBP (>140/90 mmHg) and high CBP (>130 mmHg); Group 2: high OBP and normal CBP; Group 3: normal OBP and high CBP; and Group 4 as both normal. Plasma brain natriuretic peptide (BNP) was used as a measure of cardiovascular load. Results: The mean age was 65.9 ± 11.2 yrs, 49.2% were females, and 25.7% had diabetes. In both genders, subjects with Group 3 were oldest, and beta-blocker was most frequently used, but body mass index (BMI), rate of diabetes, and heart rate were lowest among the four groups. In ANOVA, Group 3 tended to have higher BNP levels in both genders. In multivariate analysis after adjusting for significant covariates, BNP in Group 3 tended to be high level in females, but not in males. Conclusion: In treated hypertensives, higher central SBP was associated with higher BNP levels regardless of office brachial BP levels, especially in females. The results imply that high central SBP (>130 mmHg) can be used to detect high risk hypertensives with cardiovascular overload.