Longitudinal changes in late systolic cardiac load and serum NT-proBNP levels in healthy middle-aged Japanese men

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.

Mediation of Arterial Stiffness for Hyperuricemia-Related Decline of Cardiac Systolic Function in Healthy Men

Background: This prospective observational study examined whether hyperuricemia may be associated with impaired left ventricular (LV) systolic function and increased cardiac load resulting from increased arterial stiffness.

Methods and Results: In 1,880 middle-aged (mean [±SD] age 45±9 years) healthy men, serum uric acid (UA) levels, pre-ejection period/ejection time (PEP/ET) ratio, serum N-terminal pro B-type natriuretic peptide (NT-proBNP) levels, and brachial-ankle pulse wave velocity (baPWV) were measured at the start and end of the 3-year study period. Linear regression analysis revealed that serum UA levels measured at baseline were significantly associated with the PEP/ET ratio, but not with serum NT-proBNP levels, measured at baseline (β=0.73×10⁻¹, P<0.01) and at the end of the study period (β=0.68×10⁻¹, P<0.01). The change in the PEP/ET ratio during the study period was significantly greater in the High-UA (UA >7 mg/dL in 2009 and 2012) than Low-UA (UA ≤7 mg/dL in 2009 and 2012) group. Mediation analysis demonstrated both direct and indirect (via increases in baPWV) associations between serum UA measured at baseline and the PEP/ET ratio measured at the end of the study period.

Conclusions: In healthy middle-aged Japanese men, hyperuricemia may be associated with an accelerated decline in ventricular systolic function, both directly and indirectly, via increases in arterial stiffness.

Liver stiffness and arterial stiffness/abnormal central hemodynamics in the early stage of heart failure

Background

It remains to be clarified whether liver stiffness is a direct risk factor for heart failure (HF) or whether its association with HF is mediated by vascular damage. We conducted cross-sectional and prospective longitudinal studies to examine whether fibrosis 4 score (FIB-4 score) is directly associated with the serum NT-pro-BNP levels or the association is mediated by arterial stiffness and/or abnormal central hemodynamics.

Methods and results

In 3040 health Japanese subjects with serum NT-pro-BNP levels < 125 pg/ml, the FIB-4 score was calculated, and the serum NT-pro-BNP levels, brachial-ankle pulse wave (baPWV) velocity and radial augmentation index (rAI) were measured. These parameters were measured again after a 3-year interval in 2135 subjects. Multivariate linear regression analysis demonstrated a significant cross-sectional association of the FIB-4 scores with the log-transformed the serum NT-pro-BNP levels (beta = 0.08, p < 0.01), but not with the baPWV or rAI. The change of serum NT-pro BNP levels during the study period was significantly higher in subjects with increase of the FIB-4 score during the study period (8.2 ± 22.5 pg/ml) than that in those with decrease/no change (5.4 ± 22.3 pg/ml) (p < 0.05).

Conclusion

Liver stiffness may have a significant direct association with the development of HF from the early stage, without the mediation of arterial stiffness and/or abnormal central hemodynamics. Therefore, the FIB-4 score appears to serve as a direct risk factor for HF from the early stage, and its association with HF may not be mediated by vascular damages.