Increased blood pressure (BP) variability, an index of hemodynamic stress, leads to cardiac overload and worse cardiovascular prognosis. The association between day-by-day home BP variability and NT-proBNP (N-terminal pro-B-type natriuretic peptide) as an index of cardiac overload may be amplified by increased arterial stiffness as assessed by brachial-ankle pulse wave velocity (baPWV). J-HOP (Japan Morning Surge-Home Blood Pressure) Study participants who were selected from a practitioner-based population with at least one cardiovascular risk factor underwent home BP monitoring, and their BP levels and SD, coefficient of variation, and average real variability as indexes of systolic BP variability were assessed. We analyzed 2115 individuals without prevalent heart failure and divided them into lower (<1800 cm/s, n=1464) and higher (≥1800 cm/s, n=651) baPWV groups. The higher baPWV group had significantly higher SDSBP, CVSBP, ARVSBP values, and NT-proBNP levels than the lower baPWV group (all P<0.001). In the higher baPWV group, a multiple linear regression analysis revealed that the SDSBP was associated with the NT-proBNP level after adjustment for traditional cardiovascular risk factors including the average home systolic BP (coefficient per 1 SD increase, 0.049 [95% CI, 0.018-0.081]; P=0.002). Similar trends were found for CVSBP (P=0.003) and ARVSBP (P=0.004). However, these associations were not found in the lower baPWV group. There was an interaction between all indexes of systolic BP variability and the NT-proBNP level according to lower or higher baPWV group (all P<0.05). Arterial stiffness amplified the association between home BP variability and cardiac overload.
Keywords: Japan; blood pressure; heart failure; hypertension; regression analysis; vascular stiffness.