Cardiac endocrine function is an essential component of the homeostatic regulation network: physiological and clinical implications

Neurohormonal activation in heart failure with reduced ejection fraction

Heart failure with reduced ejection fraction (HFrEF) develops when cardiac output falls as a result of cardiac injury. The most well-recognized of the compensatory homeostatic responses to a fall in cardiac output are activation of the sympathetic nervous system and the renin-angiotensin-aldosterone system (RAAS). In the short term, these 'neurohormonal' systems induce a number of changes in the heart, kidneys, and vasculature that are designed to maintain cardiovascular homeostasis. However, with chronic activation, these responses result in haemodynamic stress and exert deleterious effects on the heart and the circulation. Neurohormonal activation is now known to be one of the most important mechanisms underlying the progression of heart failure, and therapeutic antagonism of neurohormonal systems has become the cornerstone of contemporary pharmacotherapy for heart failure. In this Review, we discuss the effects of neurohormonal activation in HFrEF and highlight the mechanisms by which these systems contribute to disease progression.

Altered relation of the renin-aldosterone system and vasoactive peptides in type 2 diabetes: The KORA F4 study

BACKGROUND AND AIMS

The exact mechanism of premature atherosclerosis in diabetes is still unclear. Inappropriate activation of the renin-aldosterone-angiotensin system may be an important risk factor for cardiovascular disease. We investigated whether renin and aldosterone are associated with vasoactive peptides midregional-pro atrial natriuretic peptide (MR-proANP) and midregional-pro adrenomedullin (MR-proADM), or with intima media thickness (IMT) as a marker for early atherosclerotic alterations in the general community and in subjects with type 2 diabetes.

METHODS

In 1261 participants in the KORA F4 study, the associations of renin, aldosterone and aldosterone to renin ratio with MR-proANP, MR-proADM and IMT were assessed using linear regression models stratified for the presence of prediabetes and type 2 diabetes.

RESULTS

After adjustment for confounding factors, an inverse association of MR-proANP with renin (p = 0.002) and aldosterone (p = 0.021) and a direct association of MR-proADM with renin (p < 0.001) and aldosterone (p = 0.019) were seen in nondiabetic individuals. In diabetic subjects, there was no significant correlation of MR-proANP or MR-proADM with renin or aldosterone. Renin and aldosterone were not directly associated with IMT in non-diabetic subjects and the total cohort, whereas aldosterone was associated with IMT in diabetic participants (p = 0.005).

CONCLUSIONS

This study shows associations between renin, aldosterone and MR-proANP/MR-proADM plasma levels that are altered in type 2 diabetes. Plasma renin and aldosterone are not independent biomarkers for early atherosclerotic damages of the carotid arteries in the general community.

The Effects of Exercise on Natriuretic Peptides in Individuals without Heart Failure

Cardiac natriuretic peptides (NPs) play an important role in the regulation of energy expenditure in skeletal muscle and adipose tissue. A systematic review on the effects of exercise on NPs in patients with heart failure reported that aerobic and resistance training reduced NPs; however, the effects of exercise on NPs and the underlying mechanism of exercise-induced NP secretion in subjects without heart failure remain unknown. In athletes and young, healthy subjects, the NP concentration at rest is not elevated, but strenuous endurance exercise significantly increases NPs. The exercise-induced increase in NPs may be caused by transient myocardial wall stress, cardiomyocyte metabolic changes, or neuroendocrinological response, which may have cytoprotective and growth-regulating effects on the heart. On the other hand, in elderly, overweight/obese subjects, and patients with hypertension, NP concentrations also increase during exercise; however, NP secretion may be more susceptible to cardiac stress compared to young, healthy individuals. Recent studies have shown that NPs are associated with thermogenesis in fat tissue and oxidative capacity in skeletal muscles. NPs may also have a protective role for skeletal muscle in humans, although further studies are warranted to elucidate the physiological mechanism of exercise-induced NP secretion.

Inverse relationship of bone mineral density and serum level of N-terminal pro-B-type natriuretic peptide in peritoneal dialysis patients

Objective:

Chronic kidney disease is associated with decreased bone mineral density (BMD). In this study, the relationship between BMD and the fasting serum concentration of N-terminal pro-B-type natriuretic peptide (NT-pro-BNP) was evaluated in peritoneal dialysis (PD) patients.

Material and Methods:

Fasting blood samples were obtained from 52 PD patients. BMD was measured by dual energy X-ray absorptiometry of the lumbar vertebrae (L2–L4). The serum NT-pro-BNP level was measured by an electrochemiluminescence immunoassay.

Results:

Ten patients (19.2%) had osteoporosis, 23 patients (44.2%) had osteopenia, and 19 patients had normal BMD. Increased serum NT-pro-BNP (p < 0.001), advanced age (p = 0.012), decreased body mass index (p = 0.006), body height (p = 0.018), and body weight (p = 0.004) were associated with lower lumbar T-scores, but sex, menopausal status, PD modality, diabetes mellitus, and hypertension were not. Multivariate forward stepwise linear regression analysis with adjustment for age, body height, body weight, body mass index, and log-NT-pro-BNP indicated that a high serum level of log-NT-pro-BNP (R² change = 0.346; p < 0.001) and low body weight (R² change = 0.208; p < 0.001) were significantly and independently associated with poor lumbar BMD.

Conclusion:

A high serum level of NT-pro-BNP and low body weight were associated with poor BMD in PD patients.

Association between serum N-terminal pro-B-type natriuretic peptide levels and characteristics of coronary atherosclerotic plaque detected by coronary computed tomography angiography

The aim of the present study was to explore the association between the levels of serum N-terminal pro-B-type natriuretic peptide (NT-pro BNP) and the characteristics of coronary atherosclerotic plaque detected by coronary computed tomography angiography (CCTA), in patients with unstable angina (UA). A total of 202 patients (age range, 47-82 years) were divided into the following three groups: Non-cardiac disease group (57 patients); stable angina pectoris (SAP) group (62 patients); and UA group (83 patients). There were significant differences between the serum NT-pro BNP levels among the three groups (P=0.007). However, in multivariant diagnoses, NT-pro BNP level was not an independent risk factor for UA. The levels of serum NT-pro BNP were observed to be positively correlated with the number of vessels involved (r=0.462; P<0.001), SIS (r=0.475; P<0.001), segment-stenosis score (r=0.453; P<0.001), coronary calcification score (r=0.412; P=0.001), number of obstructive diseases (r=0.346; P<0.001), and the number of segments with non-calcified plaque (r=0.235; P=0.017), mixed plaque (r=0.234; P=0.017) and calcified plaque (r=0.431; P<0.001). The levels of serum NT-pro BNP were significantly higher in patients with UA and left main-left anterior descending (LM-LAD) disease, compared with UA patients without LM-LAD disease (P<0.001). In addition, serum NT-pro BNP was significantly higher in patients with obstructive disease and UA than in those without obstructive disease (P<0.001). The area under the curve of log(NT-pro BNP) was 0.656 (P=0.006; optimal cut-off value, 1.74; sensitivity, 77.6%; specificity, 51.9%). In conclusion, the levels of serum NT-pro BNP are associated with the burden and severity of coronary artery atherosclerotic disease in patients with UA, and may be helpful in risk stratification of patients with UA.

B-Type Cardiac Natriuretic Peptides in the Neonatal and Pediatric Intensive Care Units

During the last decade, interest in the brain natriuretic peptide (BNP) and N-terminal probrain natriuretic peptide (NT-proBNP) in the pediatric population has progressively increased. The aim of this article is to provide an up to date review of evidences regarding the use of BNP/NT-proBNP in pediatrics, with a particular focus on neonatal intensive care and congenital heart disease. The potentialities of the BNP have been demonstrated in multiple settings, particularly: the screening of congenital/acquired heart disease (CHD) versus pulmonary disease; the evaluation of CHD severity (grade of heart failure, degree of left-to-right shunts); the management of children undergoing cardiac surgery; and monitoring premature infants with patent arterial duct. BNP/NT-proBNP values may be considered an easy and relatively low cost additional diagnostic and prognostic tool. Interpretation of BNP values in children requires attention to important factors, including: laboratory methods, the type of cardiac defect, its severity, and the presence of extracardiac conditions. Of these, the hemodynamic characteristic of CHD and physiologic variations of BNP values occurring during the first weeks of life play a major role. The current evidences in favor of BNP use are mainly derived from single-center, nonrandomized studies, and cost-effectiveness analysis are still lacking. As such, despite sufficient evidences supporting the diagnostic and prognostic potentialities of BNP, these findings should be reinforced by multicenter, randomized studies specifically designed to evaluate outcomes and cost-effectiveness. In addition, standard consensus documents/guidelines, that are currently lacking, are warranted for a more systematic use of BNP in the pediatric age.

Multiphysics and multiscale modelling, data-model fusion and integration of organ physiology in the clinic: ventricular cardiac mechanics

With heart and cardiovascular diseases continually challenging healthcare systems worldwide, translating basic research on cardiac (patho)physiology into clinical care is essential. Exacerbating this already extensive challenge is the complexity of the heart, relying on its hierarchical structure and function to maintain cardiovascular flow. Computational modelling has been proposed and actively pursued as a tool for accelerating research and translation. Allowing exploration of the relationships between physics, multiscale mechanisms and function, computational modelling provides a platform for improving our understanding of the heart. Further integration of experimental and clinical data through data assimilation and parameter estimation techniques is bringing computational models closer to use in routine clinical practice. This article reviews developments in computational cardiac modelling and how their integration with medical imaging data is providing new pathways for translational cardiac modelling.

Biomarkers of Heart Failure with Preserved and Reduced Ejection Fraction

Biomarkers are increaingly being used in the management of heart failure not only for the purpose of screening, diagnosis, and risk stratification, but also as a guide to evaluate the response to treatment in the individual patient and as an entry criterion and/or a surrogate marker of efficacy in clinical trials testing novel drugs. In this chapter, we review the role of established biomarkers for heart failure management, according to the main classification of HF phenotypes, based on the measurement of left ventricular ejection fraction, including heart failure with reduced (<40%), preserved (≥50%), and, as recently proposed, mid-range (40-49%) ejection fraction.

Effect of testosterone treatment on cardiac biomarkers in a randomized controlled trial of men with type 2 diabetes

OBJECTIVE

To assess the effect of testosterone treatment on cardiac biomarkers in men with type 2 diabetes (T2D).

DESIGN

Randomized double-blind, parallel, placebo-controlled trial.

PATIENTS

Men aged 35-70 years with T2D and a total testosterone level ≤12·0 nmol/l (346 ng/dl) at high risk of cardiovascular events, median 10-year United Kingdom Prospective Diabetes Study (UKPDS) coronary heart disease (CHD) risk 21% (IQR 16%, 27%). Eighty-eight participants were randomly assigned to 40 weeks of intramuscular testosterone undecanoate (n = 45) or matching placebo (n = 43).

MAIN OUTCOME MEASURES

N-terminal pro B-type natriuretic peptide (NT-proBNP) and high-sensitivity cardiac troponin T (hs-cTnT).

RESULT

Testosterone treatment reduced NT-proBNP (mean adjusted difference (MAD) in change over 40 weeks across the testosterone and placebo groups, -17·9 ng/l [95% CI -32·4, -3·5], P = 0·047), but did not change hs-cTnT (MAD, 0·41 ng/l (95% CI -0·56, 1·39), P = 0·62). Six men, three in each group experienced an adverse cardiac event, displaying already higher baseline NT-proBNP (P < 0·01) and hs-cTnT levels (P = 0·01). At baseline, 10-year UKPDS CHD risk was associated positively with NT-proBNP (τ = 0·21, P = 0·004) and hs-cTnT (τ = 0·23, P = 0·003) and inversely with testosterone (total testosterone τ = -0·18, P = 0·02, calculated free testosterone τ = -0·19, P = 0·01), but there was no significant association between testosterone and cardiac biomarkers (P > 0·05).

CONCLUSIONS

In this trial of men with T2D and high cardiovascular risk, testosterone treatment reduced NT-proBNP and did not change hs-cTnT. Further studies should determine whether men with increased cardiac biomarkers prior to testosterone therapy are at higher risk of testosterone treatment-associated adverse cardiac events.

Sonographic chest B-lines anticipate elevated B-type natriuretic peptide level, irrespective of ejection fraction

BACKGROUND

Echocardiography and the N-terminal pro-brain-type natriuretic peptide (NT-proBNP) level are important tests for assessing left ventricular function in patients presenting to the emergency department with acute dyspnea. Chest ultrasound is becoming an important tool in diagnosing acute pulmonary edema.

AIM

To assess the diagnostic accuracy of chest ultrasound examination using echocardiography and a curvilinear probe for detecting B-lines in patients presenting with acute pulmonary edema compared with assessment using NT-proBNP.

METHODS

This paper reports a prospective observational study of 61 consecutive patients presenting with symptoms and signs of pulmonary edema and B-profile detected by echocardiography with a 5 MHz curvilinear probe. The emergency department physicians ordered NT-proBNP levels, and critical care physicians trained in ultrasound examination performed echocardiography and chest ultrasounds. The findings of the chest ultrasound were reviewed by another senior physician.

RESULTS

Sixty-one participants were enrolled over a period of 6 months (49.2 % male, with a mean age 66.8). Forty-seven of the 61 patients had a B-profile. The median NT-proBNP level in the patients with B-profile was 6200, compared with the mean level in the patients with an A-profile of 180 (CI 0.33-0.82). The distributions in the two groups differed significantly (p = 0.034). Based on a threshold level of NT-proBNP in relation to age, the sensitivity and specificity (including the 95 % confidence interval) were determined; the sensitivity of finding B-profile on ultrasound was 92.0 %, and the specificity was 91.0 %. The positive predictive value of the B-profile was 97.0 %, and the negative predictive value was 71.0 %. The systolic function in the subjects with a B-profile was below 50 in 84.3 % of the subjects and normal in 15.7 % of the subjects. An A-profile was present in all of the subjects with systolic function >55 %. In the subjects with a B-profile, 94 % had a Framingham score of CHF >4; the subjects with all A-profile had scores <4, p < 0.0001. There was an NHANES score of >3 in 96 % of the subjects with a B-profile, and all of the subjects with an A-profile had scores <3 (p < 0.0001).

CONCLUSIONS

Detecting the B-profile with an echocardiography probe (curvilinear 5 MHz) in lung ultrasound is highly sensitive and specific for elevated NT-proBNP helping in diagnosing pulmonary edema, although of resolution inferior to micro convex probes.

MAPK3/1 is conducive to luteinizing hormone-mediated C-type natriuretic peptide decrease in bovine granulosa cells

C-type natriuretic peptide (CNP) plays a role as an oocyte maturation inhibitor (OMI) in many species, including the bovine. However, the effects of luteinizing hormone (LH) on CNP expression and its potential mechanisms have not reported in the bovine. In the present study, we aimed to study the effects of LH on CNP expression and to illuminate the potential molecular mechanism in this process. Our results showed that LH induced epidermal growth factor receptor (EGFR) phosphorylation, mitogen-activated protein kinase3/1 (MAPK3/1) activation and CNP mRNA decrease in cultured bovine granulosa cells. Further study revealed that LH suppressed CNP expression via the MAPK3/1 signaling pathway, which was activated by the EGFR pathway. In conclusion, our research suggested that MAPK3/1 is involved in LH-mediated decrease of CNP and that this process is related to the EGFR and MAPK3/1 signal pathways.

Usefulness of High-Sensitive Troponin Elevation After Effort Stress to Unveil Vulnerable Myocardium in Patients With Heart Failure

Elevation of resting high-sensitivity troponin (hs-Tn) holds prognostic value in heart failure (HF), but its pathophysiological meaning is unclear. We aimed to investigate hs-Tn elevation after maximal exercise in patients with systolic HF and its neurohormonal and hemodynamic correlates: 30 patients diagnosed with systolic HF (left ventricular ejection fraction 32 ± 8%, mean ± SD), on guideline-directed medical therapy and not recognized inducible ischemia, underwent maximal cardiopulmonary stress test, with assay of plasma N-terminal proB-type natriuretic peptide (NT-proBNP), norepinephrine (NE), and hs-TnT (hs-TnT) at baseline, peak, and 1 and 4 hours after exercise. Cardiac output (CO) was measured during effort, with a rebreathing technique. The natural logarithm of the ratio between percentage (%) increase in CO and NT-proBNP (ln[CO%/NT-proBNP% increase]) was evaluated, as a noninvasive estimate of Frank-Starling adaptation to effort, with NT-proBNP variation considered as a surrogate of end-diastolic left ventricular pressure variation. Hs-TnT increased during exercise with a 4-hour peak (p = 0.001); 10 patients had hs-TnT increase >20%. Patients with Hs-TnT increase >20% were more symptomatic at rest (p = 0.039) and showed greater NE at peak exercise (p = 0.003) and less ln[CO%/NT-proBNP% increase] (p = 0.034). A lower ln[CO%/NT-proBNP% increase] correlated with greater NE at peak exercise (r = -0.430, p = 0.018). In conclusion, acute troponin elevation after maximal exercise was detected in 1/3 of this series. The association of troponin release with NE, CO, and NT-proBNP changes after effort suggests a pathophysiological link among transient hemodynamic overload, adrenergic activation, and myocardial cell damage, likely identifying a clinical subset at greater risk for HF progression.

Copeptin in acute coronary syndromes and heart failure management: State of the art and future directions

Over the past two decades, the use of multiple biomarkers has changed cardiovascular disease management. Recently, several trials have assessed the diagnostic and prognostic performances of copeptin, especially in patients with heart failure or acute coronary syndromes. Primary results are interesting, with copeptin looking promising for: the management of patients who present at emergency departments early after chest pain onset and the risk stratification of patients with heart failure. The purpose of this article is to review the data on the place of copeptin in the management of patients with chest pain or heart failure.

Biomarkers of hemodynamic stress and aortic stiffness after STEMI: a cross-sectional analysis

Aim. Increased aortic stiffness might adversely affect cardiac structure, function, and perfusion. Release of biomarkers of hemodynamic stress is thought to be enhanced by these alterations. We aimed to evaluate the association between biomarkers of hemodynamic stress and aortic stiffness assessed at a chronic stage after ST-segment elevation myocardial infarction (STEMI). Methods. Fifty-four patients four months after STEMI were enrolled in this cross-sectional, single-center study. N-terminal pro–B-type natriuretic peptide (NT-proBNP), mid-regional pro–A-type natriuretic peptide (MR-proANP), and mid-regional proadrenomedullin (MR-proADM) levels were measured by established assays. Aortic stiffness was assessed by the measurement of pulse wave velocity using phase-contrast cardiovascular magnetic resonance. Results. NT-proBNP, MR-proANP, and MR-proADM concentrations were all correlated with aortic stiffness in univariate analysis (r = 0.378, r = 0.425, and r = 0.532; all P < 0.005, resp.). In multiple linear regression analysis, NT-proBNP (β = 0.316, P = 0.005) and MR-proADM (β = 0.284, P < 0.020) levels were associated with increased aortic stiffness independently of age, blood pressure, and renal function. NT-proBNP was the strongest predictor for high aortic stiffness (area under the curve: 0.82, 95% CI 0.67–0.96). Conclusion. At a chronic stage after STEMI, concentrations of biomarkers for hemodynamic stress, especially NT-proBNP, are positively correlated with aortic stiffness. These biomarkers might also be useful as predictors of high aortic stiffness after STEMI.

BNP in children with congenital cardiac disease: is there now sufficient evidence for its routine use?

Interest in brain natriuretic peptide (BNP) and N-terminal pro-brain natriuretic peptide (NT-proBNP) in the management of children with CHD has increased. There are, however, no current guidelines for their routine use. The aim of this review article is to provide an update on the data regarding the use of BNP/NT-proBNP in the evaluation and surgical treatment of children with CHD. BNP/NT-proBNP levels in children with CHD vary substantially according to age, laboratory assay methods, and the specific haemodynamics associated with the individual congenital heart lesion. The accuracy of BNP/NT-proBNP as supplemental markers in the integrated screening, diagnosis, management, and follow-up of CHD has been established. In particular, the use of BNP/NT-proBNP as a prognostic indicator in paediatric cardiac surgery has been widely demonstrated, as well as its role in the subsequent follow-up of surgical patients. Most of the data, however, are derived from single-centre retrospective studies using multivariable analysis; prospective, randomised clinical trials designed to evaluate the clinical utility and cost-effectiveness of routine BNP/NT-proBNP use in CHD are lacking. The results of well-designed, prospective clinical trials should assist in formulating guidelines and expert consensus recommendations for its use in patients with CHD. Finally, the use of new point-of-care testing methods that use less invasive sampling techniques - capillary blood specimens - may contribute to a more widespread use of the BNP assay, especially in neonates and infants, as well as contribute to the development of screening programmes for CHD using this biomarker.

Higher serum concentrations of N-terminal pro-B-type natriuretic peptide associate with prevalent hypertension whereas lower associate with incident hypertension

Background

The role of the natriuretic peptides (NPs) in hypertension is complex. Thus, a higher blood NP concentration is a robust marker of pressure-induced cardiac damage in patients with hypertension, whereas genetically elevated NP concentrations are associated with a reduced risk of hypertension and overweight individuals presumably at high risk of hypertension have lower NP concentrations.

Objective

To investigate the associations between serum N-terminal pro-B-type natriuretic peptide (NT-proBNP), used as a surrogate marker for active BNP, and prevalent as well as 5-year incident hypertension in a Danish general population sample.

Methods

Cross-sectional and prospective population-based study.

Results

At baseline, among 5,307 participants (51.3% women, mean age 46.0±7.9 years) with a complete set of data, we recorded 1,979 cases with prevalent hypertension (PHT). Among 2,389 normotensive participants at baseline with a complete set of data, we recorded 324 cases with incident hypertension (IHT) on follow-up 5 years later. In models adjusted for age, sex, lifestyle, social, dietary, anthropometric, pulmonic, lipid, metabolic and renal risk factors, as well as heart rate and baseline blood pressure (only incident model), one standard deviation increase in baseline log-transformed NT-proBNP concentrations was on one side associated with a 21% higher risk of PHT (odds ratio [OR]: 1.21 [95% confidence interval (CI): 1.13-1.30], P<0.001), and on the other side with a 14% lower risk of IHT (OR: 0.86 [95%CI:0.76-0.98], P = 0.020).

Conclusions

Higher serum concentrations of NT-proBNP associate with PHT whereas lower concentrations associate with IHT. This suggests that a lower amount of circulating BNP, resulting in diminished vasodilation and natriuresis, could be involved in the pathogenesis of hypertension in its early stages.

State of the art of immunoassay methods for B-type natriuretic peptides: An update

The aim of this review article is to give an update on the state of the art of the immunoassay methods for the measurement of B-type natriuretic peptide (BNP) and its related peptides. Using chromatographic procedures, several studies reported an increasing number of circulating peptides related to BNP in human plasma of patients with heart failure. These peptides may have reduced or even no biological activity. Furthermore, other studies have suggested that, using immunoassays that are considered specific for BNP, the precursor of the peptide hormone, proBNP, constitutes a major portion of the peptide measured in plasma of patients with heart failure. Because BNP immunoassay methods show large (up to 50%) systematic differences in values, the use of identical decision values for all immunoassay methods, as suggested by the most recent international guidelines, seems unreasonable. Since proBNP significantly cross-reacts with all commercial immunoassay methods considered specific for BNP, manufacturers should test and clearly declare the degree of cross-reactivity of glycosylated and non-glycosylated proBNP in their BNP immunoassay methods. Clinicians should take into account that there are large systematic differences between methods when they compare results from different laboratories that use different BNP immunoassays. On the other hand, clinical laboratories should take part in external quality assessment (EQA) programs to evaluate the bias of their method in comparison to other BNP methods. Finally, the authors believe that the development of more specific methods for the active peptide, BNP1-32, should reduce the systematic differences between methods and result in better harmonization of results.

Effects of the angiotensin-(1-7)/Mas/PI3K/Akt/nitric oxide axis and the possible role of atrial natriuretic peptide in an acute atrial tachycardia canine model

OBJECTIVE

To investigate the effects of the angiotensin-(1-7) signaling pathway and the possible role of atrial natriuretic peptide (ANP) on atrial electrical remodeling in canines with acute atrial tachycardia.

METHODS

Forty dogs were randomly assigned to eight groups (five dogs/group): sham, paced control, paced + angiotensin-(1-7), paced + angiotensin-(1-7) + Mas inhibitor, paced + angiotensin-(1-7) + Akt inhibitor, paced + angiotensin-(1-7) + PI3K inhibitor, paced + angiotensin-(1-7) + nitric oxide (NO) inhibitor, and paced + angiotensin-(1-7) + A-71915 (ANP receptor antagonist). Rapid atrial pacing was maintained at 600 bpm for 2 h for all groups, except the sham group, and angiotensin-(1-7) (6 μg kg(-1) h(-1)), Mas inhibitor (5.83 μg kg(-1) h(-1)), Akt inhibitor (2.14 μg kg(-1) h(-1)), PI3K inhibitor (2.86 μg kg(-1) h(-1)), NO synthase inhibitor (180 μg kg(-1)h(-1)), or A-71915 (0.30 μg kg(-1) h(-1)) were administered intravenously. Atrial effective refractory periods, inducibility, and duration of atrial fibrillation (pacing cycle lengths: 300, 250, and 200 ms), and left atrial ANP concentrations were measured.

RESULTS

After pacing, the atrial effective refractory periods at the six sites shortened with increased inducibility and duration of atrial fibrillation, which was attenuated by angiotensin-(1-7), and increased ANP concentrations, which was promoted by angiotensin-(1-7) (paced control vs. sham; P < 0.05). All inhibitors and A-71915 blocked the electrophysiological effects of angiotensin-(1-7). ANP secretion induced by angiotensin-(1-7) was also blocked by all inhibitors.

CONCLUSION

Angiotensin-(1-7) prevented acute electrical remodeling in canines with acute atrial tachycardia via the angiotensin-(1-7)/Mas/PI3K/Akt/NO signaling pathway. ANP was related to the anti-arrhythmic effects of angiotensin-(1-7).

Natriuretic peptides and cardio-renal disease

The natriuretic peptide (NP) system is an important endocrine, autocrine and paracrine system, consisting of a family of peptides which provide cardiac, renal and vascular effects that, through their beneficial physiological actions, play a key role in maintaining overall cardiovascular health. Traditionally, the pathophysiological origins of cardio-renal disease have been viewed as the domain of the renin-angiotensin-aldosterone system (RAAS) and the sympathetic nervous system (SNS), with inappropriate activation of both systems leading to deleterious changes in cardio-renal function and structure. Therapies designed to suppress the RAAS and the SNS have been routinely employed to address the consequences of cardio-renal disease. However, it is now becoming increasingly apparent that enhancing the beneficial physiological effects of the NP system may represent an attractive alternative therapeutic approach to counter the pathophysiological effects of disease. In particular, innovative therapeutic strategies aimed at enhancing the physiological benefits afforded by NPs while simultaneously suppressing the RAAS are generating increasing interest as potential treatment options for the management of cardio-renal disease.

Obesity and natriuretic peptides, BNP and NT-proBNP: mechanisms and diagnostic implications for heart failure

Many advances have been made in the diagnosis and management of heart failure (HF) in recent years. Cardiac biomarkers are an essential tool for clinicians: point of care B-type natriuretic peptide (BNP) and its N-terminal counterpart (NT-proBNP) levels help distinguish cardiac from non-cardiac causes of dyspnea and are also useful in the prognosis and monitoring of the efficacy of therapy. One of the major limitations of HF biomarkers is in obese patients where the relationship between BNP and NT-proBNP levels and myocardial stiffness is complex. Recent data suggest an inverse relationship between BNP and NT-proBNP levels and body mass index. Given the ever-increasing prevalence of obesity world-wide, it is important to understand the benefits and limitations of HF biomarkers in this population. This review will explore the biology, physiology, and pathophysiology of these peptides and the cardiac endocrine paradox in HF. We also examine the clinical evidence, mechanisms, and plausible biological explanations for the discord between BNP levels and HF in obese patients.

B-type natriuretic peptide trends after pediatric heart transplantation

BNP is increasingly utilized in the management of pediatric HT recipients. Performing a retrospective single-center chart review, we sought to describe BNP changes during the first year after HT and identify factors that affect its trend. After exclusion for rejection, 316 BNP levels from 50 patients were evaluated. BNP underwent an exponential decline 120 days after HT followed by a plateau. Log10 BNP decline strongly correlated with time (r = -0.70, p < 0.0001). Initial BNP was less in pretransplant VAD (p = 0.0016) and lower post-HT inotrope use (p = 0.0043). Infant recipients, IT >4 h, and those bridged medically were associated with higher plateau BNP. Multivariable logistic regression demonstrated IT >4 h independently predicted plateau BNP in the upper quartile (OR 7.1, p = 0.02). No significant change in BNP coincided with rejection (N = 6 patients) without severe hemodynamic compromise. BNP correlated modestly with right atrial pressure (r = 0.4652, p < 0.0001) and pulmonary capillary wedge pressure (r = 0.2660, p < 0.001), but poorly with echocardiogram (r = -0.18, p = 0.003). Trending BNP could help provide insight into how the graft recovers after HT and IT >4 h independently predicted higher plateau BNP and may reflect subtle changes in graft performance.

Are levels of NT-proBNP and SDMA useful to determine diastolic dysfunction in chronic kidney disease and renal transplant patients?

BACKGROUND

The aim of the study was to determine the clinical usefulness of N-terminal pro-B-type natriuretic peptide (NT-proBNP) and symmetric dimethylarginine (SDMA) for detection of renal and left ventricular (LV) diastolic dysfunction in chronic kidney disease (CKD) patients and renal transplant (RT) recipients.

METHODS

We included 98 CKD and 44 RT patients. We assessed LV function using pulsed-wave Doppler ultrasound. Diastolic dysfunction was defined when the E:A ratio was <1.

RESULTS

Independent predictors of NT-proBNP levels were age, creatinine, and albumin in CKD patients and age and urea in RT patients. Determinants of SDMA in CKD patients were glomerular filtration rate (GFR) and NT-proBNP and creatinine in RT patients. In RT patients with diastolic dysfunction, NT-proBNP and SDMA were significantly higher than in patients without diastolic dysfunction (F = 7.478, P < 0.011; F = 2.631, P < 0.017). After adjustment for GFR, the differences were not seen. In CKD patients adjusted NT-proBNP and SDMA values for GFR were not significantly higher in patients with diastolic dysfunction than in patients without diastolic dysfunction.

CONCLUSIONS

NT-proBNP is useful for detection of LV diastolic dysfunction in RT recipients. When evaluating both NT-proBNP and SDMA it is necessary to consider GFR as a confounding factor.

Plasma NT pro-BNP, hs-CRP and big-ET levels at admission as prognostic markers of survival in hospitalized patients with dilated cardiomyopathy: a single-center cohort study

Background

Circulating N-terminal pro-B-type natriuretic peptide (NT pro-BNP), high- sensitivity C-reactive protein (hs-CRP) and big endothelin (big-ET) have been shown to be increased in heart failure and to contribute to both hemodynamic deterioration and cardiovascular remodeling. Here, we examined the prognostic value of the three neurohormones at admission in a population of hospitalized patients with dilated cardiomyopathy (DCM).

Methods and results

This cohort study was undertaken in 622 hospitalized patients with DCM in Fuwai Hospital from January 2005 to September 2011 (female 26.5%, 51.4 ± 14.6 years old). Standard demographics, echocardiography and routine blood samples were obtained shortly after admission. NT pro-BNP, hs-CRP and big-ET were measured, and their concentrations in relation to all-cause mortality were assessed through a mean follow-up of 2.6 ± 1.6 years. Kaplan-Meier curves showed that the all-cause mortality rates were higher in patients with NT pro-BNP > 2247 pmol/L compared to patients with NT pro-BNP < 2247 pmol/L (11.9% vs 34.8%, log-rank χ² = 35.588, P < 0.001), in patients with hs-CRP > 3.90 mg/L compared to patients with hs-CRP < 3.90 mg/L (12.8% vs 33.6%, log-rank χ² = 39.662, P < 0.001) and in patients with big-ET > 0.95 pmol/L compared to patients with big-ET <0.95 pmol/L (12.5% vs 31.0%, log-rank χ² = 17.890, P < 0.001). High circulating concentrations of NT pro-BNP (HR 2.217, 95% CI 1.015-4.846, P = 0.046) and hs-CRP (HR 1.922, 95% CI 1.236-2.988, P = 0.004), but not big-ET, in addition to left atrial diameter and fasting blood glucose, were independent predictors of the outcome defined as all-cause mortality.

Conclusions

In a large population of patients with DCM, the circulating concentrations of NT pro-BNP and hs-CRP, but not big-ET, were independent markers of all-cause mortality.

Metabolic actions of natriuretic peptides and therapeutic potential in the metabolic syndrome

Natriuretic peptides (NPs) are a group of peptide-hormones mainly secreted from the heart, signaling via c-GMP coupled receptors. NP are well known for their renal and cardiovascular actions, reducing arterial blood pressure as well as sodium reabsorption. Novel physiological functions have been discovered in recent years, including activation of lipolysis, lipid oxidation, and mitochondrial respiration. Together, these responses promote white adipose tissue browning, increase muscular oxidative capacity, particularly during physical exercise, and protect against diet-induced obesity and insulin resistance. Exaggerated NP release is a common finding in congestive heart failure. In contrast, NP deficiency is observed in obesity and in type-2 diabetes, pointing to an involvement of NP in the pathophysiology of metabolic disease. Based upon these findings, the NP system holds the potential to be amenable to therapeutical intervention against pandemic diseases such as obesity, insulin resistance, and arterial hypertension. Various therapeutic approaches are currently under development. This paper reviews the current knowledge on the metabolic effects of the NP system and discusses potential therapeutic applications.

Comparative effects of recombinant human brain natriuretic peptide and dobutamine on acute decompensated heart failure patients with different blood BNP levels

Background

Recombinant human B-type natriuretic peptide (rhBNP) has been indicated for the treatment of acute decompensated heart failure (ADHF). However, the therapeutic efficacy of intravenous rhBNP is not always satisfactory in patients with extremely high blood BNP levels. In this study, we evaluated the effects of rhBNP on patients with different BNP levels.

Methods

One hundred and five patients with ADHF whose left ventricular ejection fraction (LVEF) was <40%, were assigned to a high BNP group (BNP ≤ 3000 pg/mL) or an extra-high BNP group (BNP > 3000 pg/mL) , depending on their admission plasma BNP levels. Each group was then subdivided into rhBNP or dobutamine subgroups according to intravenous administration with either rhBNP or dobutamine for 24-72h. In the high BNP group, 58 patients were randomized to subgroup rhBNP (n = 28) and subgroup dobutamine (n = 30). In the extra-high BNP group, 47 patients were randomized to subgroup rhBNP (n = 24) and subgroup dobutamine (n = 23). The effects of rhBNP and dobutamine on patients in the high and extra-high BNP groups were compared.

Results

In the high BNP group, rhBNP was more efficient than dobutamine at improving NYHA classification (P < 0.05), decreasing plasma BNP levels (P < 0.05), increasing LVEF (P < 0.05), and reducing hospital length of stay (P < 0.05). However, rhBNP displayed no superior therapeutic efficacy to dobutamine in the extra-high BNP group. Adverse cardiovascular events in patients treated with rhBNP were similar to adverse events in patients treated with dobutamine in both the high and extra-high BNP groups.

Conclusions

rhBNP was more efficient than dobutamine at improving heart function in patients with ADHF when plasma BNP was ≤3000 pg/mL. However, rhBNP treatment showed no advantages over dobutamine when plasma BNP reached extremely high levels (>3000 pg/mL).

Trial registration

ClinicalTrials.gov Identifier: NCT01837849.

The Value of N-Terminal Pro–B-Type Natriuretic Peptide in Determining Antihypertensive Benefit

We investigated 3 hypotheses: (1) N-terminal pro–B-type natriuretic peptide (NT-proBNP) predicts cardiovascular disease events in patients with hypertension, (2) NT-proBNP is associated with blood pressure variability, and (3) NT-proBNP predicts benefit from antihypertensive regimens. The Anglo-Scandinavian Cardiac Outcomes Trial (ASCOT) randomized a subset of 6549 patients at risk with no history of coronary heart disease to either atenolol-based or amlodipine-based blood pressure–lowering treatment. During 5.5 years of follow-up, 485 cardiovascular disease cases accrued and were matched with 1367 controls. Baseline and 6-month in-trial NT-proBNP were measured. The results show that NT-proBNP improves cardiovascular disease risk prediction beyond established predictors, continuous net reclassification improvement of 22.3% ( P <0.0001). Furthermore, a 1-mm Hg increase in the SD of systolic blood pressure was associated with 2% higher baseline NT-proBNP in a multivariable regression analysis ( P <0.0001). However, NT-proBNP predicted cardiovascular disease risk independently of blood pressure variation (odds ratio per SD increase in log NT-proBNP 1.24; 95% confidence interval, 1.06–1.45; P =0.007). Atenolol-based treatment led to a 69.6% increase in NT-proBNP at 6 months ( P <0.0001). In contrast, amlodipine-based treatment reduced NT-proBNP by 36.5% ( P <0.0001). Amlodipine recipients who achieved a 6-month NT-proBNP below the median (61 pg/mL) were at lower risk of cardiovascular disease when compared with those who did not (odds ratio, 0.58; 95% confidence interval, 0.37–0.91) after adjustment for confounders inclusive of baseline NT-proBNP and achieved blood pressure. If confirmed, these novel results suggest that NT-proBNP, as well as aiding cardiovascular disease risk assessment, may also help assess the efficacy of specific antihypertensive regimens. Further relevant studies seem warranted.

N-terminal pro-B-type natriuretic peptide level inversely associates with metabolic syndrome in elderly persons

AIMS

Serum N-terminal pro-B-type natriuretic peptide (NT-proBNP) was lower in the general population with metabolic syndrome (MetS). The aim of this study was to evaluate the relationship between MetS and fasting serum NT-proBNP concentration in elderly persons.

METHODS

Fasting blood samples were obtained from 84 elderly volunteers aged 65 years or older. MetS and its components were defined using diagnostic criteria from the International Diabetes Federation.

RESULTS

Thirty-eight elderly persons (45.2%) had MetS. Fasting NT-proBNP level was negatively correlated with MetS among elderly patients (p = 0.001). Univariate linear regression analysis showed that age (r = 0.338; p = 0.002) was positively correlated with fasting serum log-NT-proBNP levels, while height (r = -0.253; p = 0.020), body weight (r = -0.238; p = 0.029), waist circumference (r = -0.270; p = 0.013), body fat mass (r = -0.356; p = 0.002) and triglyceride (r = -0.291; p = 0.007) were negatively correlated with fasting serum log-NT-proBNP levels among the elderly persons. Multivariate forward stepwise linear regression analysis of the significant variables showed that age (R2 change = 0.114, p = 0.011), triglyceride (R2 change = 0.118, p < 0.001), body fat mass (R2 change = 0.084, p < 0.001), and height (R2 change = 0.101, p < 0.001) were the independent predictor of fasting serum log-NT-proBNP levels in elderly persons.

CONCLUSIONS

NT-proBNP level is significantly reduced in elderly persons affected by MetS, and is significantly positively related to age, while negatively related to triglyceride, body fat mass, height in these subjects.

Serum soluble triggering receptor expressed on myeloid cells-1 and procalcitonin can reflect sepsis severity and predict prognosis: a prospective cohort study

Objective. To investigate the prognostic significance of serum soluble triggering receptor expressed on myeloid cells-1 (sTREM-1), procalcitonin (PCT), N-terminal probrain natriuretic peptide (NT-pro-BNP), C-reactive protein (CRP), cytokines, and clinical severity scores in patients with sepsis. Methods. A total of 102 patients with sepsis were divided into survival group (n = 60) and nonsurvival group (n = 42) based on 28-day mortality. Serum levels of biomarkers and cytokines were measured on days 1, 3, and 5 after admission to an ICU, meanwhile the acute physiology and chronic health evaluation II (APACHE II) and sequential organ failure assessment (SOFA) scores were calculated. Results. Serum sTREM-1, PCT, and IL-6 levels of patients in the nonsurvival group were significantly higher than those in the survival group on day 1 (P < 0.01). The area under a ROC curve for the prediction of 28 day mortality was 0.792 for PCT, 0.856 for sTREM-1, 0.953 for SOFA score, and 0.923 for APACHE II score. Multivariate logistic analysis showed that serum baseline sTREM-1 PCT levels and SOFA score were the independent predictors of 28-day mortality. Serum PCT, sTREM-1, and IL-6 levels showed a decrease trend over time in the survival group (P < 0.05). Serum NT-pro-BNP levels showed the predictive utility from days 3 and 5 (P < 0.05). Conclusion. In summary, elevated serum sTREM-1 and PCT levels provide superior prognostic accuracy to other biomarkers. Combination of serum sTREM-1 and PCT levels and SOFA score can offer the best powerful prognostic utility for sepsis mortality.

Biomarkers in congenital heart disease: do natriuretic peptides hold the key?

Congenital heart disease is the most common congenital abnormality. The long-term prognosis of these patients has changed significantly over the last half century, thanks to improvements in cardiovascular diagnosis, surgery and postoperative care. However, residual lesions are not uncommon and many of the interventions performed remain palliative rather than reparative, leading to the development of ventricular dysfunction and heart failure. Natriuretic peptides are well-established markers of disease severity and prognosis in patients with heart failure due to noncongenital (acquired) heart disease. However, the role of biomarkers in congenital heart disease is unclear. This review highlights the impact of neurohormonal activation in patients with congenital heart disease, as well as the usefulness of assessing natriuretic peptide levels in specific clinical situations.

Prognostic value of NT-proBNP and an adapted monin score in patients with asymptomatic aortic stenosis

INTRODUCTION AND OBJECTIVES

Our objective was to assess the prognostic value of NT-proBNP in patients with asymptomatic moderate/severe aortic stenosis and to validate an adapted Monin score using natriuretic peptide levels in our setting.

METHODS

Prospective study of 237 patients with degenerative asymptomatic moderate/severe aortic stenosis. NT-proBNP was determined in all patients, who were then followed up clinically. The adapted Monin score was defined as follows: (peak velocity [m/s]×2)+(logn NT-proBNP×1.5)(+1.5 if woman). A clinical event was defined as surgery, hospital admission due to angina, heart failure or syncope, or death.

RESULTS

A total of 51% were women, and the mean age was 74 years. Mean (SD) echocardiographic values were as follows: peak velocity 4.14 (0.87) m/s; mean gradient, 43.2 (16.0) mmHg; aortic valve area, 0.87 (0.72) cm(2), and aortic valve area index, 0.49 (0.14) cm(2)/m(2). The median NT-pro-BNP value was 490.0 [198.0-1312.0] pg/mL. There were 153 events during follow-up (median 18 months). The optimum NT-proBNP cut-point was 515 pg/mL, giving event-free survival rates at 1 and 2 years of 93% and 57%, respectively, in patients with NT-proBNP <515 pg/mL compared with 50% and 31% in those with NT-proBNP >515 pg/mL. Patients were divided into quartiles based on the Monin score. Event-free survival at 1 and 2 years was 87% and 79% in the first quartile, compared with 45% and 28% in the fourth quartile, respectively.

CONCLUSIONS

NT-proBNP determination provides prognostic information in patients with asymptomatic moderate/severe aortic stenosis. The adapted Monin score is useful in our setting and allows a more precise prognosis than does the use of NT-proBNP alone.

Depletion of proBNP1-108 in patients with heart failure prevents cross-reactivity with natriuretic peptides

BACKGROUND

After synthesis by cardiomyocytes, precursor proBNP1-108 is cleaved into NT-proBNP and BNP. Recently, cross-reactivity between these assays was discussed. The aim of this study was to characterize the cross-reactivities, through a new biochemical innovative approach consisting in the total depletion of the circulating proBNP1-108 in patients with heart failure (HF).

METHODS

This prospective study included 180 patients with chronic HF. BNP and NT-proBNP were dosed with commercial kits. ProBNP1-108 was determined using an ELISA research assay specific to the precursor. ProBNP1-108 depletion was performed by immunocapture with a specific antibody targeting exclusively the ProBNP1-108 hinge region. ProBNP1-108, BNP and NT-proBNP levels were determined before and after depletion using this process in HF patients.

RESULTS

Mean age was 74.34 +/-12.5 y, and 69% of patients were males. NYHA classes II and III were the most frequent (32% and 45% respectively). Before depletion, ProBNP1-108, NT-proBNP and BNP levels were 316.8+/-265.9 pg/ml; 6,054.0+/-11,539 pg/ml and 684.3+/-82.1 pg/ml respectively, and were closely correlated with NHYA classes. After immuno-depletion, proBNP1-108 was decreased in mean by 96% (p<0.0001), BNP by 53% (p<0.0001) and NT-proBNP by 5%. The relationship between BNP or NT-proBNP and NHYA classes remained unchanged.

CONCLUSION

Current BNP and NT-proBNP assays measured as well proBNP molecule. This cross reactivity percentage has been controversial. Thanks to the removal of circulating proBNP1-108 with our immunodepletion process, we are now able to assess the remaining "true" BNP and NT-proBNP molecules and further evaluate their clinical relevance.

Serum atrial natriuretic peptide level inversely associates with metabolic syndrome in older adults

AIM

Atrial natriuretic peptide (ANP) is a potent lipolytic agent that acts in adipose tissue. Low levels of ANP might lead to reduced lipolysis and excessive weight gain, which could be one of the biological alterations that contribute to the development of obesity. The aim of the present study was to evaluate the relationship between metabolic syndrome and fasting serum ANP concentrations in older adults.

METHODS

Fasting blood samples were obtained from 90 older adults. Metabolic syndrome and its components were defined using diagnostic criteria from the International Diabetes Federation.

RESULTS

A total of 40 older adults (44.4%) had metabolic syndrome. Fasting ANP level was negatively correlated with metabolic syndrome (P = 0.015). Univariate linear regression analysis showed that high-density lipoprotein cholesterol (P < 0.001) was positively correlated with serum logANP levels, whereas waist circumference (P = 0.001) and body fat mass (P = 0.002) were negatively correlated with fasting serum logANP levels. Multivariate forward stepwise linear regression analysis of the significant variables showed that high-density lipoprotein cholesterol (β = 0.419, R(2) = 0.268, P < 0.001) and body fat mass (β = -0.396, R(2) = 0.154, P = 0.002) were independent predictors of fasting serum logANP levels in geriatric persons.

CONCLUSIONS

Serum ANP levels were reduced in geriatric persons affected by metabolic syndrome. Body fat mass and high-density lipoprotein cholesterol were independent predictors of fasting serum ANP levels in older adults.

Systems biology and biomechanical model of heart failure

Heart failure is seen as a complex disease caused by a combination of a mechanical disorder, cardiac remodeling and neurohormonal activation. To define heart failure the systems biology approach integrates genes and molecules, interprets the relationship of the molecular networks with modular functional units, and explains the interaction between mechanical dysfunction and cardiac remodeling. The biomechanical model of heart failure explains satisfactorily the progression of myocardial dysfunction and the development of clinical phenotypes. The earliest mechanical changes and stresses applied in myocardial cells and/or myocardial loss or dysfunction activate left ventricular cavity remodeling and other neurohormonal regulatory mechanisms such as early release of natriuretic peptides followed by SAS and RAAS mobilization. Eventually the neurohormonal activation and the left ventricular remodeling process are leading to clinical deterioration of heart failure towards a multi-organic damage. It is hypothesized that approaching heart failure with the methodology of systems biology we promote the elucidation of its complex pathophysiology and most probably we can invent new therapeutic strategies.

Inverse association of long-acting natriuretic peptide with metabolic syndrome in congestive heart failure patients

AIMS

Long-acting natriuretic peptide (LANP) is one of the peptide hormones in atrial natriuretic peptide (ANP) pro-hormone. Low levels of natriuretic peptide may lead to reduced lipolysis and excessive weight gain in obese patients. The aim of this study was to investigate the relationship between fasting serum LANP level and the metabolic syndrome (MetS) among congestive heart failure (CHF) patients.

METHODS

Fasting blood samples were obtained from 186 patients with normal renal function in cardiac clinic outpatients. CHF defined by the American College of Cardiology Foundation and the American Heart Association 2005 Guidelines. MetS and its components were defined using diagnostic criteria from the International Diabetes Federation.

RESULTS

Ninety-eight patients (52.7%) had CHF. There was a tendency of increased fasting LANP levels as the NYHA CHF functional classes increased (p = 0.002). Forty-six of the CHF patients (46.9%) had MetS. Fasting LANP level negatively correlated with MetS among CHF patients (p < 0.001). Univariate linear regression analysis showed that BUN (p = 0.026) positively correlated with fasting serum LANP levels, while body weight (p = 0.009), BMI (p = 0.004), homeostasis model assessment of insulin resistance (HOMA-IR; p = 0.024) and HOMA-β (p = 0.001) negatively correlated with fasting serum LANP levels among the CHF patients. Multivariate forward stepwise linear regression analysis of the significant variables showed that the HOMA-β (R2 change = 0.292, p < 0.001) and HOMA-IR (R2 change = 0.081, p = 0.019) were independent predictors of fasting serum LANP levels in CHF patients.

CONCLUSIONS

LANP level is significantly reduced in CHF patients affected by MetS. HOMA-β and HOMA-IR were independent predictors of serum LANP levels in CHF patients.

Low serum long-acting natriuretic peptide level correlates with metabolic syndrome in hypertensive patients: a cross-sectional study

BACKGROUND AND AIMS

Long-acting natriuretic peptide (LANP) is one of the peptide hormones in atrial natriuretic peptide (ANP) prohormone. Its biological properties are blood pressure regulation, maintenance of plasma volume and anticancer effects. The aim of this study was to evaluate the relationship between metabolic syndrome (MetS) and fasting serum LANP concentration in hypertensive patients.

METHODS

Fasting blood samples were obtained from 224 patients with or without hypertension. MetS and its components were defined using diagnostic criteria from the International Diabetes Federation.

RESULTS

Eighty-eight hypertensive patients (59.5 %) had MetS. Hypertensive patients with MetS had higher body weight (p = 0.003), waist circumference (p = 0.003), body mass index (p = 0.002), triglyceride concentrations (p = 0.029), insulin levels (p = 0.001), HOMA-IR (p <0.003) and HOMA-β (p = 0.049) and lower HDL-C concentrations (p = 0.001), LANP levels (p = 0.012) than those without MetS. The univariable linear regression analysis showed that age (p = 0.038) and the BUN concentration (p = 0.022) were positively correlated with the serum LANP levels, whereas the insulin level (p = 0.001), HOMA-IR (p = 0.004), and HOMA-β (p = 0.001) were negatively correlated with the fasting serum LANP levels among the hypertensive patients. Multivariable forward stepwise linear regression analysis of the significant variables showed that the HOMA-β (β = -0.387, R(2) = 0.141, p <0.001) was an independent predictor of fasting serum LANP levels in hypertensive patients.

CONCLUSIONS

LANP level is significantly reduced in hypertensive patients affected by MetS and is negatively related to pancreatic beta cell function in hypertensive patients.