Heart rate modulates the relationship of augmented systolic blood pressure with the blood natriuretic peptide levels

AIMS: Augmented central systolic blood pressure (cSBP), which is known to affect the cardiac afterload, is an independent risk factor for cardiovascular disease. While an inverse relationship is known to exist between the heart rate (HR) and the cSBP, it has not yet been clarified if the HR also modulates the association between the cSBP and the cardiac afterload. The present study was conducted to clarify whether the association of the cSBP with the serum levels of the N‐terminal fragment B‐type natriuretic peptide (NT‐proBNP) differs between subjects with high and low HRs, using data obtained from the same subjects on two occasions (2009 and 2012) so as to confirm their consistency. METHODS AND RESULTS: The radial augmentation index, systolic pressure at the second peak of the radial pressure waveform (SBP2), and serum NT‐proBNP levels were measured and analysed in a worksite cohort of 2000 middle‐aged men in 2009 and in 2012. The subjects were divided into three groups by the HR (i.e. ≤69, 70–79, and ≥80 b.p.m.). While the serum NT‐proBNP levels were similar among the three groups, the radial augmentation index increased (from 61 ± 12% to 72 ± 13%, P < 0.01 in 2009 and from 61 ± 13% to 73 ± 12%, P < 0.01 in 2012) and the SBP1‐2 decreased (from 18 ± 7 to 13 ± 7 mmHg, P < 0.01 in 2009 and from 19 ± 7 to 13 ± 6 mmHg, P < 0.01 in 2012) significantly with decreasing HR. After the adjustment, the SBP2 showed a significant association with the serum NT‐proBNP levels in the overall study population [non‐standardized coefficient (B) = 0.005, standard error (SE) = 0.001, P < 0.01 in 2009 (n = 2257) and B = 0.004, SE = 0.001, P < 0.01 in 2012 (n = 1986)]. In subgroup analyses, the SBP2 showed a significant association with the serum NT‐proBNP levels [B = 0.004, SE = 0.002, P = 0.02 in 2009 (n = 1291) and B = 0.005, SE = 0.001, P < 0.01 in 2012 (n = 1204)] only in the subject group with an HR of ≤69 b.p.m. CONCLUSIONS: In middle‐aged Japanese men, the relationship between the cSBP and the cardiac afterload appears to differ depending on the HR; the results of our analysis showed that the relationship between the cSBP and the cardiac overload may be more pronounced and strongly significant in patients with low HRs as compared with patients with high HRs.