Natriuretic Peptide Deficiency Research Articles

Relative B-Type Natriuretic Peptide Deficiency May Exist in Diastolic Dysfunction in Subclinical Population.

Background: Heart failure patients are deficient in B-type natriuretic peptide (BNP) but the significance of subclinical BNP deficiency is unclear. Methods and Results: A total of 1,398 subjects without cardiovascular disease, with left ventricular ejection fraction (LVEF) ≥50% and BNP level <100 pg/mL, were selected from a 2005-2008 health checkup in Arita-cho, Japan, and divided into 2 groups: with and without LV diastolic dysfunction (DD+ or DD-). We performed propensity score matching on non-cardiac factors affecting BNP levels and analyzed 470 subjects in each group (372/940 men; median age, 66 years). The DD(+) group showed higher lateral E/e', an index of estimated left ventricular filling pressure, and greater prevalence of concentric hypertrophy (CH) despite similar BNP levels, suggesting a relative deficiency of BNP in DD(+) compared with DD(-). Multivariable logistic regression analysis revealed an increase in BNP correlated with decreased odds of CH (adjusted odds ratio [aOR] 0.663, 95% confidence interval (CI) 0.484-0.909, P=0.011), whereas an increase in lateral E/e' was associated with increased odds of CH (aOR, 2.881; 95% CI, 1.390-5.973; P=0.004). Furthermore, CH in combination with diastolic dysfunction independently predicted major adverse cardiovascular events (hazard ratio 3.272, 95% CI 1.215-8.809; P=0.019). Conclusions: Relative BNP deficiency was associated with CH, which had a poor prognosis in patients with diastolic dysfunction.

Differential Associations of A-/B-Type Natriuretic Peptides With Cardiac Structure, Function, and Prognosis in Heart Failure

BackgroundNatriuretic peptide (NP) elevations are prognostic in heart failure (HF), but relative atrial NP deficiency in acute HF has been suggested. ObjectivesThe authors compared plasma concentrations and relative strength of associations of A- and B-type NPs with cardiac structure/function and clinical outcomes in HF. MethodsMidregional pro–atrial natriuretic peptide (MR-proANP), B-type natriuretic peptide (BNP), and N-terminal pro–B-type natriuretic peptide (NT-proBNP) were measured in patients with compensated HF in a prospective, multicenter study. The primary outcome was a composite of HF-hospitalization or all-cause mortality. Secondary outcomes included individual primary outcome components and cardiovascular admission. ResultsAmong 1,278 patients (age 60.1 ± 12.1 years, 82% men, left ventricular ejection fraction [LVEF] 34% ± 14%), median concentrations of MR-proANP were 990 pg/mL (Q1-Q3: 557-1,563 pg/mL), NT-proBNP 1,648 pg/mL (Q1-Q3: 652-3,960 pg/mL), and BNP 291 pg/mL (Q1-Q3: 103-777 pg/mL). No subpopulation with inappropriately low MR-proANP (relative to BNP/NT-proBNP) was observed. Clinical event rates were similar for biomarker tertiles. Increments in MR-proANP exhibited steeper associations with concurrent shifts in left ventricular size, diastolic indexes and LVEF than BNP/NT-proBNP at baseline and serially (P < 0.05), and lower odds of beneficial left ventricular reverse remodeling: OR: 0.35 (95% CI: 0.18-0.70). In single-biomarker models, MR-proANP(log10) was associated with the highest hazard (4 to 6 times) for each outcome. In multimarker models, independent associations were observed for the primary outcome (MR-proANP and NT-proBNP), HF-hospitalization and cardiovascular admission (MR-proANP only), and all-cause mortality (NT-proBNP only) (P < 0.05). The discriminative value of MR-proANP was superior to BNP/NT-proBNP (HF-hospitalization) and BNP (primary outcome) (P < 0.05). ConclusionsMR-proANP was not inappropriately low relative to concurrent BNP/NT-proBNP values. Proportional increments in MR-proANP were more pronounced than for B-peptides for given decrements in cardiac structure/function. MR-proANP offered greater independent predictive power overall.

A State of Natriuretic Peptide Deficiency.

Measurement of natriuretic peptides (NPs) has proven its clinical value as biomarker, especially in the context of heart failure (HF). In contrast, a state of partial NP deficiency appears integral to several conditions in which lower NP concentrations in plasma presage overt cardiometabolic disease. Here, obesity and type 2 diabetes have attracted considerable attention. Other factors-including age, sex, race, genetics, and diurnal regulation-affect the NP "armory" and may leave some individuals more prone to development of cardiovascular disease. The molecular maturation of NPs has also proven complex, with highly variable O-glycosylation within the biosynthetic precursors. The relevance of this regulatory step in post-translational propeptide maturation has recently become recognized in biomarker measurement/interpretation and cardiovascular pathophysiology. An important proportion of people appear to have reduced effective net NP bioactivity in terms of receptor activation and physiological effects. The state of NP deficiency both entails a potential for further biomarker development and could also offer novel pharmacological possibilities. Alleviating the state of NP deficiency before development of overt cardiometabolic disease in selected patients could be a future path for improving precision medicine.

Potential of valsartan+sacubitril therapy in hypertensive heart disease

The course of hypertension is often complicated by left ventricular hypertrophy (or hypertensive heart disease, HHD). The main “corridor” of natural HHD is development of heart failure with preserved ejection fraction (HFpEF). With HFpEF, the bioavailability of natriuretic peptides (NP) is significantly reduced, as a result of which the activity of cGMP-PKG signaling pathway, which plays a key role in maintaining normal diastolic function, weakens. It is possible to increase the activity of this pathway using the neprilysin inhibitor sacubitril. In case of HFpEF, the greatest efficacy from valsartan+sacubitril therapy should be expected in patients with severe concentric LVH, who have the most pronounced natriuretic peptide deficiency. Valsartan+sacubitril therapy has a clear hypotensive effect, causes a reversal of left ventricular hypertrophy and fibrosis. Since no effective treatment has yet been found for HFpEF, the main way for HHD treatment should be to prevent the diastolic dysfunction progression, which justifies valsartan+sacubitril therapy starting from the early/ asymptomatic stages.

Cardiac natriuretic peptide deficiency sensitizes the heart to stress-induced ventricular arrhythmias via impaired CREB signalling

The cardiac natriuretic peptides [atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP)] are important regulators of cardiovascular physiology, with reduced natriuretic peptide (NP) activity linked to multiple human cardiovascular diseases. We hypothesized that deficiency of either ANP or BNP would lead to similar changes in left ventricular structure and function given their shared receptor affinities. We directly compared murine models deficient of ANP or BNP in the same genetic backgrounds (C57BL6/J) and environments. We evaluated control, ANP-deficient (Nppa-/-) or BNP-deficient (Nppb-/-) mice under unstressed conditions and multiple forms of pathological myocardial stress. Survival, myocardial structure, function and electrophysiology, tissue histology, and biochemical analyses were evaluated in the groups. In vitro validation of our findings was performed using human-derived induced pluripotent stem cell cardiomyocytes (iPS-CMs). In the unstressed state, both ANP- and BNP-deficient mice displayed mild ventricular hypertrophy which did not increase up to 1 year of life. NP-deficient mice exposed to acute myocardial stress secondary to thoracic aortic constriction (TAC) had similar pathological myocardial remodelling but a significant increase in sudden death. We discovered that the NP-deficient mice are more susceptible to stress-induced ventricular arrhythmias using both in vivo and ex vivo models. Mechanistically, deficiency of either ANP or BNP led to reduced myocardial cGMP levels and reduced phosphorylation of the cAMP response element-binding protein (CREBS133) transcriptional regulator. Selective CREB inhibition sensitized wild-type hearts to stress-induced ventricular arrhythmias. ANP and BNP regulate cardiomyocyte CREBS133 phosphorylation through a cGMP-dependent protein kinase 1 (PKG1) and p38 mitogen-activated protein kinase (p38 MAPK) signalling cascade. Our data show that ANP and BNP act in a non-redundant fashion to maintain myocardial cGMP levels to regulate cardiomyocyte p38 MAPK and CREB activity. Cardiac natriuretic peptide deficiency leads to a reduction in CREB signalling which sensitizes the heart to stress-induced ventricular arrhythmias.

Chronobiology of Natriuretic Peptides and Blood Pressure in Lean and Obese Individuals

BackgroundDiurnal variation of natriuretic peptide (NP) levels and its relationship with 24-h blood pressure (BP) rhythm has not been established. Obese individuals have a relative NP deficiency and disturbed BP rhythmicity. ObjectivesThis clinical trial evaluated the diurnal rhythmicity of NPs (B-type natriuretic peptide [BNP], mid-regional pro-atrial natriuretic peptide [MR-proANP], N-terminal pro–B-type natriuretic peptide [NT-proBNP]) and the relationship of NP rhythm with 24-h BP rhythm in healthy lean and obese individuals. MethodsOn the background of a standardized diet, healthy, normotensive, lean (body mass index 18.5 to 25 kg/m2) and obese (body mass index 30 to 45 kg/m2) individuals, age 18 to 40 years, underwent 24-h inpatient protocol involving ambulatory BP monitoring starting 24 h prior to the visit, controlled light intensity, and repeated blood draws for assessment of analytes. Cosinor analysis of normalized NP levels (normalized to 24-h mean value) was conducted to assess the diurnal NP rhythm and its relationship with systolic BP. ResultsAmong 52 participants screened, 40 participants (18 lean, 22 obese; 50% women; 65% Black) completed the study. The median range spread (percentage difference between the minimum and maximum values) over 24 h for MR-proANP, BNP, and NT-proBNP levels was 72.0% (interquartile range [IQR]: 50.9% to 119.6%), 75.5% (IQR: 50.7% to 106.8%), and 135.0% (IQR: 66.3% to 270.4%), respectively. A cosine wave-shaped 24-h oscillation of normalized NP levels (BNP, MR-proANP, and NT-proBNP) was noted both in lean and obese individuals (prhythmicity <0.05 for all). A larger phase difference between MR-proANP BP rhythm (−4.9 h vs. −0.7 h) and BNP BP rhythm (−3.3 h vs. −0.9 h) was seen in obese compared with lean individuals. ConclusionsThis human physiological trial elucidates evidence of diurnal NP rhythmicity and the presence of an NP-BP rhythm axis. There exists a misalignment of the NP-BP diurnal rhythm in the obese, which may contribute to the disturbed diurnal BP pattern observed among obese individuals. (The Diurnal Rhythm in Natriuretic Peptide Levels; NCT03834168)

Unexpectedly Low Natriuretic Peptide Levels in Patients With Heart Failure

ObjectivesThe purpose of this study was to determine the frequency of unexpectedly low natriuretic peptide (NP) levels in a clinical population. BackgroundHigher NP concentrations are typically observed as a compensatory response to elevated cardiac wall stress. Under these conditions, low NP levels may be indicative of a “NP deficiency.” MethodsWe identified 3 clinical scenarios in which high B-type natriuretic peptide (BNP) levels would be expected: 1) hospitalization for heart failure (HF); 2) abnormal cardiac structure or function; or 3) abnormal hemodynamics. In Vanderbilt’s electronic health record, 47,970 adult patients had BNP measurements. A total of 13,613 patients had at least 1 of the 3 conditions (hospitalized HF, n = 9,153; abnormal cardiac structure/function, n = 7,041; abnormal hemodynamics, n = 363). We quantified the frequency of low BNP levels. We performed whole exome sequencing of the NPPB gene in a subset of 9 patients. ResultsVery low BNP levels (<50 pg/ml) were observed in 4.9%, 14.0%, and 16.3% of patients with hospitalized HF, abnormal cardiac structure/function, or abnormal hemodynamics, respectively. A small proportion (0.1% to 1.1%) in each group had BNP levels below detection limits. Higher body mass index was the strongest predictor of unexpectedly low BNP. Exome sequencing did not reveal coding variation predicted to alter detection of BNP by clinical assays. ConclusionsA subset of patients with confirmed HF or cardiac dysfunction have unexpectedly low BNP levels. Obesity is the strongest correlate of unexpectedly low BNP levels. Our findings support the possible existence of NP deficiency, which may render some individuals more susceptible to volume or pressure overload.

Abstract 17325: Obesity, Blood Pressure, and Diurnal Variation in Natriuretic Peptides: A Clinical Trial

Background: Obese individuals have disturbed blood pressure (BP) rhythmicity and relative natriuretic peptide (NP) deficiency. The relationship of diurnal variation in NP levels and 24h BP rhythm is not known. Furthermore, mechanisms behind difference in circulating NPs in healthy obese and lean individuals has not been explored. We conducted a prospective clinical trial to evaluate 1) the diurnal rhythmicity of NPs and its relationship with 24-hour BP rhythm between healthy lean and obese individuals, and 2) elucidate mechanism behind NP deficiency in obese. Methods: Healthy, normotensive, lean (BMI:18.5-25 kg/m 2 ) and obese (BMI:30-45 kg/m 2 ) individuals aged 18-40 years, underwent 24-hour standardized inpatient protocol involving ambulatory BP monitoring (ABPM), controlled light intensity, and 10 blood draws, following 5-days of standardized diet. NP gene expression was evaluated in a cohort of 37 healthy donor heart tissues obtained from the MAGNet repository. Results: Among 52 participants screened, a total of 40 participants (18 lean; 22 obese) were enrolled. Diurnal variation in MRproANP levels was seen in both lean and obese individuals (p for rhythmicity=0.001). The mesor of the NP rhythm was 15% (8.5-21.6%) lower in obese. The diurnal variation in MRproANP was in antiphase with diurnal variation of systolic BP (p&lt;0.001) ( Figure ). Obese participants had lower 24h renin levels (p=0.06) and higher nocturnal sodium excretion (p=0.08). Among obese, there was lower expression of NP production genes ( NPPA, NPPB) (p&lt;0.05) , and higher expression of clearance gene ( NPR3 ) (p&lt;0.001) in heart tissue. Conclusions: In a mechanistic human trial, we elucidate key neurohormonal differences in rhythm and evidence of poor salt handling in obese. Decreased production and increased clearance may contribute to the NP deficiency in obese. Targeting the diurnal NP-BP rhythm axis may reduce the cardiovascular risk burden, specifically in obese individuals.

Early Stages of Obesity-related Heart Failure Are Associated with Natriuretic Peptide Deficiency and an Overall Lack of Neurohormonal Activation: The Copenhagen Heart Failure Risk Study

Objective:This study evaluated the associations between the natriuretic peptide activity and the neurohormonal response in non-obese and obese outpatients with and without heart failure (HF).Background:Obesity-related HF may be a distinct subtype of HF. Obesity is associated with lower plasma concentrations of natriuretic peptides. The associations between obesity and neurohormonal activation estimated by mid-regional pro-adrenomedullin (MR-proADM) and copeptin in patients with HF is not elucidated.Methods:This prospective cohort-study included 392 outpatients ≥60years, plus ≥1 risk-factor(-s) for HF (hypertension, ischemic heart disease, atrial fibrillation, diabetes, chronic kidney disease), and without known HF. Patients were categorized ‘non-obese’ BMI = 18.5–29.9 kg/m2 (n = 273) and ‘obese’ BMI ≥ 30 kg/m2 (n = 119). The diagnosis of HF required signs, symptoms, and abnormal echocardiography. NT-proBNP, MR-proANP, MR-proADM, and copeptin were analyzed.Results:Obese patients were younger, had a higher prevalence of diabetes and chronic kidney disease, but a lower prevalence of atrial fibrillation. A total of 39 (14.3%) non-obese and 26 (21.8%) obese patients were diagnosed with HF. In obese patients, HF was not associated with higher plasma concentrations of NT-proBNP (Estimate: 0.063; 95%CI: –0.037–1.300; P = 0.064), MR-proANP (Estimate: 0.207; 95%CI: –0.101–0.515; P = 0.187), MR-proADM (Estimate: 0.112; 95%CI: –0.047–0.271; P = 0.168), or copeptin (Estimate: 0.093; 95%CI: –0.333–0.518; P = 0.669). Additionally, obese patients with HF had lower plasma concentrations of NT-proBNP (Estimate: –0.998; 95%CI: –1.778–0.218; P = 0.012), and MR-proANP (Estimate: –0.488; 95%CI: –0.845–0.132; P = 0.007) compared to non-obese patients with HF, whereas plasma concentrations of MR-proADM (Estimate: 0.066; 95%CI: –0.119–0.250; P = 0.484) and copeptin (Estimate: 0.140; 95%CI: –0.354–0.633; P = 0.578) were comparable.Conclusions:Patients with obesity-related HF have natriuretic peptide deficiency and lack of increased plasma concentrations of MR-proADM and copeptin suggesting that patients with obesity-related HF have a blunted overall neurohormonal activity.

20th Annual Feigenbaum Lecture: Echocardiography for Precision Medicine—Digital Biopsy to Deconstruct Biology

Heart failure with preserved ejection fraction (HFpEF) is a complex, heterogeneous syndrome in need of improved classification given its high morbidity and mortality and few effective treatment options. HFpEF represents an ideal setting to examine the utility and feasibility of a precision medicine approach. This article (based on the 20th annual Feigenbaum Lecture, presented at the 2019 American Society of Echocardiography Scientific Sessions) describes the utility of echocardiography as a "digital biopsy" and how deep quantitative echocardiographic phenotyping, coupled with machine learning, can be used to identify novel HFpEF phenotypes. The cellular and ultrastructural basis of abnormal speckle-tracking echocardiography- (STE-) based measurements of cardiac mechanics can provide a window into cardiomyocyte calcium homeostasis. STE-based measurements of longitudinal strain can thus inform the extent of myocardial involvement in patients with HFpEF, which may help to determine responsiveness to cardiac-specific HF medications. However, classifying the complex, systemic, multiorgan nature of HFpEF appropriately likely requires more advanced methods. Using unsupervised machine learning, HFpEF can be classified into three distinct phenogroups with differing clinical and echocardiographic characteristics and outcomes: (1) natriuretic peptide deficiency syndrome; (2) extreme cardiometabolic syndrome; and (3) right ventricle-cardio-abdomino-renal syndrome. Each can be probed to determine their biological basis. The goal of improved classification of HFpEF is to match the right patient with the right treatment, with the hope of improving the track record of HFpEF clinical trials. This article emphasizes the central role of echocardiography in advancing precision medicine and illustrates the integration of basic, translational, clinical, and population research in echocardiography with the goal of better understanding the pathobiology of a complex cardiovascular syndrome.

SAT-080 Dexamethasone Administration Stimulates Acute Increases in Natriuretic Peptides in Humans: A Potential Diagnostic Test for "Natriuretic Peptide Hormone Deficiency"?

Background: Animal models and human genetic investigations suggest that lower levels of natriuretic peptides (NP), which are cardiac-derived hormones, are associated with the development of obesity, insulin resistance, type 2 diabetes, and hypertension. However, whether lower resting NP levels in humans reflect a true hormone deficiency (analogous to other hormone deficiencies like adrenal insufficiency) is unknown, in part, because a diagnostic test for NP deficiency is currently lacking. One strategy for developing a diagnostic test for NP deficiency is to identify a stimulus that provokes an increase in NP concentrations. Dexamethasone is a potent stimulus for NP production in animals, but its effect on NP levels in humans is not well defined. Objective: We sought to define the effects of dexamethasone on circulating NPs over time in healthy humans. We hypothesized that dexamethasone would stimulate increases in NP levels, and that we could characterize the magnitude and timing of the changes as a primary step toward developing a diagnostic test for NP deficiency. Methods: 10 healthy, lean women (mean age 28 + 5 years, mean BMI 22.5 + 1.6 kg/m2) received a single 4 mg IV dose of dexamethasone after an overnight fast. Plasma levels of N-terminal pro-atrial natriuretic peptide (NT-proANP) and N-terminal pro- b-type natriuretic peptide (NT-proBNP) were serially measured during 2 time periods following dexamethasone: 1) “Acute Phase”: 0-8 hours, and 2) “Extended Phase”: at 24, 48, and 72 hours. Changes in NPs were analyzed using a piecewise random effects model for the 2 time periods. Results: During the Acute Phase after dexamethasone, a biphasic change in NT-proANP was observed (nonlinear, p<0.001). Median NT-proANP initially increased, with a peak increase of 24% occurring at 2.5 hours, and thereafter decreased until 8 hours (to 21% below baseline). During the “Extended Phase,” NT-proANP levels rebounded (p<0.001) and returned to near baseline by 72 hours. Next, median NT-proBNP increased during the Acute Phase (p= 0.016), with a peak increase of 27% occurring at 8 hours, and subsequently declined during the Extended Phase (p= 0.04) to a median value 24% lower than baseline at 72 hours. Discussion: Dexamethasone appears to acutely stimulate NP production in humans, as evidenced by an initial increase, followed by a subsequent decline, in circulating NP levels. The time course differs between NT-proANP and NT-proBNP, with NT-proANP peaking earlier than NT-proBNP. These pilot data may inform larger studies for establishing population norms for the NP response to glucocorticoids and evaluating whether a NP stimulation test with glucocorticoids may be a useful test for diagnosing NP deficiency.

Effect of Testosterone on NatriureticPeptide Levels.

Circulating natriuretic peptide (NP) levels are markedly lower in healthy men than women. A relative NP deficiency in men could contribute to their higher risk of hypertension and cardiovascular disease. Epidemiological studies suggest testosterone may contribute to sex-specific NP differences. This study aimed to determine the effect of testosterone administration on NP levels using a randomized, placebo-controlled design. One hundred and fifty-one healthy men (20 to 50 years of age) received goserelin acetate to suppress endogenous production of gonadal steroids, and anastrazole to suppress conversion of testosterone to estradiol. Subjects were randomized to placebo gel or 4 different doses of testosterone (1%) gel for 12weeks. Serum N-terminal-pro-B-type natriuretic peptide (NT-proBNP) and total testosterone levels were measured at baseline and follow-up. Men who did not receive testosterone replacement (placebo gel group) after suppression of endogenous gonadal steroid production experienced a profound decrease in serum testosterone (median 540 to 36ng/dl; p<0.0001). This was accompanied by an increase in median NT-proBNP (+8 pg/ml; p=0.02). Each 1-g increase intestosterone dose was associated with a 4.3% lower NT-proBNP at follow-up (95% confidence interval:-7.9% to-0.45%; p=0.029). An individual whose serum testosterone decreased by 500ng/dl had a 26% higher predicted follow-up NT-proBNP than someone whose serum testosterone remained constant. Suppression of testosterone production in men led to increases in circulating NT-proBNP, whichwereattenuated by testosterone replacement. Inhibition of NP production by testosterone may partly explain thelower NPlevels in men. (Dose-Response of Gonadal Steroids and Bone Turnover in Men; NCT00114114).

The Confounding Effects of Non-cardiac Pathologies on the Interpretation of Cardiac Biomarkers

Cardiac biomarkers play important roles in routine evaluation of cardiac patients. But while these biomarkers can be extremely valuable, none of them should ever be used by themselves-without adding the clinical context. This paper explores the non-cardiac pathologies that can be seen with the cardiac biomarkers most commonly used. High-sensitivity troponin assay gained FDA approval for use in the USA, and studies demonstrated its diagnostic utility can be extended to patients with renal impairment. Gender-specific cut points may be utilized for high-sensitivity troponin assays. In the realm of the natriuretic peptides, studies demonstrated states of natriuretic peptide deficiency in obesity and in subjects of African-American race. Regardless, BNP and NT-proBNP both retained prognostic utilities across a variety of comorbid conditions. We are rapidly gaining clinical evidence with use of soluble ST2 and procalcitonin levels in management of cardiac disease states. In order to get the most utility from their measurement, one must be aware of non-cardiac pathologies that may affect the levels of biomarkers as although many of these are actually true values, they may not represent the disease we are trying to delineate. A few take-home points are as follows: 1. A biomarker value should never be used without clinical context 2. Serial sampling of biomarkers is often helpful 3. Panels of biomarkers may be valuable.

Natriuretic Peptide Deficiency Causes Skeletal Muscle Insulin Resistance in Mice

Cardiac natriuretic peptides (NP) have been shown to control energy homeostasis. Epidemiological studies have shown that low level of plasma NP predict future development of type 2 diabetes (T2D). We have also observed a reduced expression of the biologically active NP receptor GCA of about 50% in metabolic tissues of obese humans and mice. The purpose of this study was to demonstrate that NP deficiency causes T2D in mice. GCA+/- and atrial NP-/- (ANP) mice and their wild type (WT) littermates were studied under normal chow and high fat diet for 12 weeks. GCA+/- and ANP-/- mice exhibit signs of systemic insulin resistance and glucose intolerance when compared to their WT littermates. This metabolic phenotype is accompanied by skeletal muscle insulin resistance and reduced lipid oxidative capacity, without noticeable changes in inflammatory profile of liver and adipose tissues. Interestingly, we observed elevated levels of lipotoxic lipids in skeletal muscle along with reduced mitochondrial mass and respiratory chain complexes. Collectively, these data indicate that ANP/GCA deficiency causes T2D and that ANP contributes to long-term maintenance of insulin sensitivity. Disclosure C. Moro: None.

Sex‐specific associations of obesity and N‐terminal pro‐B‐type natriuretic peptide levels in the general population

Obese subjects have lower natriuretic peptide levels, but males and females have different anthropometric characteristics and fat distribution. Whether obesity-associated lowering of natriuretic peptides differs among males and females is unknown. Therefore, we investigated sex-specific associations of obesity and N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels among adults in the general population. Using 8260 participants (50.1% females) from the Prevention of REnal and Vascular ENd-stage Disease (PREVEND) cohort, we evaluated the relationship of NT-proBNP levels with obesity-associated parameters, i.e. waist circumference (WC), body mass index (BMI) and body weight in the overall population, and in males and females separately. NT-proBNP levels were higher in females (median, interquartile range: 50.5, 28.2-87.0 ng/L) than in males (24.3, 10.1-54.6 ng/L; P < 0.001). In the overall population, NT-proBNP levels were significantly lower in heavier individuals and displayed a 'U-shaped' relationship with increasing WC, but were not associated with BMI. After sex stratification, there was no significant association between NT-proBNP concentrations and anthropometric measures in females. However, in males increasing WC and BMI were associated with higher NT-proBNP levels (P < 0.05) while increasing body weight was associated with slightly lower NT-proBNP levels (P < 0.05). Age strongly confounded the association of NT-proBNP levels with obesity, and age-associated increases in NT-proBNP were significantly higher in males than in females (P < 0.001). In multivariable adjusted analyses, the inverse association of obesity and NT-proBNP levels was also significantly modified by sex: NT-proBNP levels were lower with increasing WC, BMI and body weight among females compared with males (Pinteraction < 0.05). After also accounting for BMI, abdominal obesity was associated with lower NT-proBNP levels in females, but not in males (Pinteraction < 0.001). Natriuretic peptide deficiency in obesity mostly pertains to females with abdominal obesity, whereas the relationship between obesity and natriuretic peptides appears to be more complex in males.

SP 04-1 THE ROLE OF NATRIURETIC PEPTIDES IN THE PATHOGENESIS OF CARDIOVASCULAR DISEASES

SP 04-1 THE ROLE OF NATRIURETIC PEPTIDES IN THE PATHOGENESIS OF CARDIOVASCULAR DISEASES

Cardiometabolic crosstalk in obesity-associated arterial hypertension.

Abdominal obesity and elevated blood pressure commonly occur in the same patient and are key components of the metabolic syndrome. However, the association between obesity and increased blood pressure is variable. We review mechanisms linking cardiovascular and metabolic disease in such patients including altered systemic and regional hemodynamic control, neurohumoral activation, and relative natriuretic peptide deficiency. Moreover, we discuss recent results using omics techniques providing insight in molecular pathways linking adiposity, metabolic disease, and arterial hypertension. Recognition of the mechanisms orchestrating the crosstalk between cardiovascular and metabolic regulation in individual patients may lead to better and more precise treatments. It is reassuring that recently developed cardiovascular and metabolic medications may in fact ameliorate, both, cardiovascular and metabolic risks.

MANP: a novel particulate guanylyl cyclase A receptor/cGMP activator for resistant hypertension: preliminary first in human clinical trial results

MANP is a novel natriuretic peptide developed at the Mayo Clinic following its discovery from a familial frameshift mutation of the atrial natriuretic peptide (ANP) gene (NPPA) [1,2]. MANP possesses the 28 amino acid (AA) core structure of ANP with a novel 12 AA extended C-terminus resulting in a 40 AA peptide. MANP activates the particulate guanylyl cyclase A (pGC-A) receptor with equal potency to ANP and is highly resistant to degradation by neprilysin. In vivo, MANP has greater and longer lasting blood pressure (BP) lowering, natriuretic and aldosterone suppressing actions than ANP [3]. In animal models of hypertension, MANP potently reduces BP and enhances renal function while in experimental hypertensive heart failure, MANP has more potent renal and aldosterone suppressing actions than the cyclic guanylyl monophosphate (cGMP)-activating therapeutic agent nitroglycerin [4]. In vivo administered subcutaneously, MANP activates plasma cGMP 10-fold greater than ANP with a 4-fold greater half-life [3,4]. Based upon its potent cGMP mediated cardiorenal actions and studies which suggest that human hypertension may represent a relative natriuretic peptide deficiency state, MANP is being developed for treatment of severe resistant hypertension.

Differential response of the natriuretic peptide system to weight loss and exercise in overweight or obese patients.

Relative atrial natriuretic peptide (ANP) deficiency has been implicated in the pathogenesis of obesity-associated cardiovascular and metabolic disease. We tested the hypothesis that more than 5% body weight reduction through 6 months hypocaloric dieting alters ANP release at rest and more so during exercise in overweight or obese patients. Venous mid-regional pro-ANP concentration was assessed at rest and after incremental exhaustive exercise testing before and after weight reduction. We also measured natriuretic peptide receptor A and C mRNA expression in subcutaneous adipose tissue to gauge both ANP responsiveness and clearance mechanisms. The average weight reduction of 9.1 ± 3.8 kg was associated with reductions in visceral and subcutaneous abdominal fat mass, liver fat content, insulin resistance, and ambulatory blood pressure. However, mid-regional pro-ANP plasma concentrations were unchanged with weight loss (51 ± 24 vs. 53 ± 24 pmol/l). Exercise elicited similar acute mid-regional pro-ANP increases before and after weight loss. Adipose tissue natriuretic peptide receptor type A mRNA expression remained unchanged, whereas natriuretic peptide receptor type C mRNA decreased with weight loss. We conclude that physical exercise acutely increases ANP release in obese patients, whereas modest diet-induced weight loss primarily affects ANP clearance mechanisms. Interventions combining weight loss and regular physical exercise may be particularly efficacious in reversing obesity-associated relative natriuretic peptide deficiency.

Natriuretic peptides in cardiometabolic regulation and disease.

In the 30 years since the identification of the natriuretic peptides, their involvement in regulating fluid and blood pressure has become firmly established. Data indicating a role for these hormones in lifestyle-related metabolic and cardiovascular disorders have also accumulated over the past decade. Dysregulation of the natriuretic peptide system has been associated with obesity, glucose intolerance, type 2 diabetes mellitus, and essential hypertension. Moreover, the natriuretic peptides have been implicated in the protection against atherosclerosis, thrombosis, and myocardial ischaemia. All these conditions can coexist and potentially lead to heart failure, a syndrome associated with a functional natriuretic peptide deficiency despite high circulating concentrations of immunoreactive peptides. Therefore, dysregulation of the natriuretic peptide system, a 'natriuretic handicap', might be an important factor in the initiation and progression of metabolic dysfunction and its accompanying cardiovascular complications. This Review provides a summary of the natriuretic peptide system and its involvement in these cardiometabolic conditions. We propose that these peptides might have an integrating role in lifestyle-related metabolic and cardiovascular disorders.