Gastric Bypass Surgery Elevates NT-ProBNP Levels

Effects of Tirzepatide on the Clinical Trajectory of Patients With Heart Failure, Preserved Ejection Fraction, and Obesity

BACKGROUND

Patients with heart failure with preserved ejection fraction and obesity have significant disability and frequent exacerbations of heart failure. We hypothesized that tirzepatide, a long-acting agonist of glucose-dependent insulinotropic polypeptide and glucagon-like peptide-1 receptors, would improve a comprehensive suite of clinical end points, including measures of health status, functional capacity, quality of life, exercise tolerance, patient well-being, and medication burden, in these patients.

METHODS

We randomized (double-blind) 731 patients with class II to IV heart failure, ejection fraction ≥50%, and body mass index ≥30 kg/m2 to tirzepatide (titrated up to 15 mg SC weekly; n=364) or placebo (n=367) added to background therapy for a median of 104 weeks (quartile 1, 66; quartile 3, 126 weeks). The primary end points were whether tirzepatide reduced the combined risk of cardiovascular death or worsening heart failure and improved Kansas City Cardiomyopathy Questionnaire Clinical Summary Score. The current expanded analysis included sensitivity analyses of the primary end points, 6-minute walk distance, EQ-5D-5L health state index, Patient Global Impression of Severity Overall Health score, New York Heart Association class, use of heart failure medications, and a hierarchical composite based on all-cause death, worsening heart failure, and 52-week changes in Kansas City Cardiomyopathy Questionnaire Clinical Summary Score and 6-minute walk distance.

RESULTS

Patients were 65.2±10.7 years of age; 53.8% (n=393) were female; body mass index was 38.2±6.7 kg/m2; Kansas City Cardiomyopathy Questionnaire Clinical Summary Score was 53.5±18.5; 6-minute walk distance was 302.8±81.7 m; and 53% (n=388) had a worsening heart failure event in the previous 12 months. Compared with placebo, tirzepatide produced a consistent beneficial effect across all composites of death and worsening heart failure events, analyzed as time to first event (hazard ratios, 0.41-0.67). At 52 weeks, tirzepatide increased the Kansas City Cardiomyopathy Questionnaire Clinical Summary Score by 6.9 points (95% CI, 3.3-10.6; P<0.001), 6-minute walk distance 18.3 meters (95% CI, 9.9-26.7; P<0.001), and EQ-5D-5L 0.06 (95% CI, 0.03-0.09; P<0.001). The tirzepatide group shifted to a more favorable Patient Global Impression of Severity Overall Health score (proportional odds ratio, 1.99 [95% CI, 1.44-2.76]) and New York Heart Association class (proportional odds ratio, 2.26 [95% CI, 1.54-3.31]; both P<0.001) and required fewer heart failure medications (P=0.015). The broad spectrum of effects was reflected in benefits on the hierarchical composite (win ratio, 1.63 [95% CI, 1.17-2.28]; P=0.004).

CONCLUSIONS

Tirzepatide produced a comprehensive, meaningful improvement in heart failure across multiple complementary domains; enhanced health status, quality of life, functional capacity, exercise tolerance, and well-being; and reduced symptoms and medication burden in patients with heart failure with preserved ejection fraction and obesity.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT04847557.

Short-term and long-term changes in natriuretic peptide levels after bariatric surgery: a systematic review and meta-analysis

Bariatric surgery (BS) has demonstrated cardiovascular benefits in patients and was previously proven to be associated with an increased natriuretic peptide level without cardiac dysfunction. However, new studies have emerged, which require us to re-examine the relationship and extent of the correlation between BS, weight loss, and cardiac natriuretic peptide levels. A systematic search was conducted. Twenty-two studies with 1219 patients (33.2% male, 45.5% gastric bypass surgery) were included. The mean differences from baseline of short- and long-term N-terminal pro-B-type natriuretic peptide levels were 52.88 pg/mL (95% confidence interval [CI], 21.30-84.46) and 39.63 pg/mL (95% CI, -92.86 to 13.60). In contrast, a significant increase was observed in B-type natriuretic peptide levels in both the short and long term. BS is associated with increased natriuretic peptide levels without deteriorating cardiac function and improving ejection fraction (mean difference, .06; 95% CI, -1.95 to 2.07), but further studies should investigate its correlation with clinical symptoms and cardiac structural changes.

Effects of tirzepatide on circulatory overload and end-organ damage in heart failure with preserved ejection fraction and obesity: a secondary analysis of the SUMMIT trial

Patients with obesity-related heart failure with preserved ejection fraction (HFpEF) display circulatory volume expansion and pressure overload contributing to cardiovascular-kidney end-organ damage. In the SUMMIT trial, patients with HFpEF and obesity were randomized to the long-acting glucose-dependent insulinotropic polypeptide receptor and glucagon-like peptide-1 receptor agonist tirzepatide (n = 364, 200 women) or placebo (n = 367, 193 women). As reported separately, tirzepatide decreased cardiovascular death or worsening heart failure. Here, in this mechanistic secondary analysis of the SUMMIT trial, tirzepatide treatment at 52 weeks, as compared with placebo, reduced systolic blood pressure (estimated treatment difference (ETD) -5 mmHg, 95% confidence interval (CI) -7 to -3; P < 0.001), decreased estimated blood volume (ETD -0.58 l, 95% CI -0.63 to -0.52; P < 0.001) and reduced C-reactive protein levels (ETD -37.2%, 95% CI -45.7 to -27.3; P < 0.001). These changes were coupled with an increase in estimated glomerular filtration rate (ETD 2.90 ml min-1 1.73 m-2 yr-1, 95% CI 0.94 to 4.86; P = 0.004), a decrease in urine albumin-creatinine ratio (ETD 24 weeks, -25.0%, 95% CI -36 to -13%; P < 0.001; 52 weeks, -15%, 95% CI -28 to 0.1; P = 0.051), a reduction in N-terminal prohormone B-type natriuretic peptide levels (ETD 52 weeks -10.5%, 95% CI -20.7 to 1.0%; P = 0.07) and a reduction in troponin T levels (ETD 52 weeks -10.4%, 95% CI -16.7 to -3.6; P = 0.003). In post hoc exploratory analyses, decreased estimated blood volume with tirzepatide treatment was significantly correlated with decreased blood pressure, reduced microalbuminuria, improved Kansas City Cardiomyopathy Questionnaire Clinical Summary Score and increased 6-min walk distance. Moreover, decreased C-reactive protein levels were correlated with reduced troponin T levels and improved 6-min walk distance. In conclusion, tirzepatide reduced circulatory volume-pressure overload and systemic inflammation and mitigated cardiovascular-kidney end-organ injury in patients with HFpEF and obesity, providing new insights into the mechanisms of benefit from tirzepatide. ClinicalTrials.gov registration: NCT04847557 .

Semaglutide and NT-proBNP in Obesity-Related HFpEF: Insights From the STEP-HFpEF Program

BACKGROUND

The glucagon-like peptide-1 receptor agonist, semaglutide, improved health status and reduced body weight in patients with obesity-related heart failure (HF) with preserved ejection fraction (HFpEF) in the STEP-HFpEF (Semaglutide Treatment Effect in People with Obesity and HFpEF) program. Whether benefits were due to mechanical unloading or effects on HF pathobiology is uncertain.

OBJECTIVES

This study sought to determine if semaglutide 2.4 mg reduced N-terminal pro-B-type natriuretic peptide (NT-proBNP) in patients with obesity-related HFpEF and compare treatment responses by baseline NT-proBNP.

METHODS

This was a prespecified secondary analysis of pooled data from 2 double-blind, placebo-controlled, randomized trials (STEP-HFpEF [Research Study to Investigate How Well Semaglutide Works in People Living With Heart Failure and Obesity] and STEP-HFpEF DM [Research Study to Look at How Well Semaglutide Works in People Living With Heart Failure, Obesity and Type 2 Diabetes]) testing effects of semaglutide in patients with obesity-related HFpEF. The main outcomes were change in NT-proBNP at 52 weeks and change in the dual primary endpoints of Kansas City Cardiomyopathy Questionnaire Clinical Summary Score and body weight by baseline NT-proBNP.

RESULTS

In total, 1,145 patients were randomized. Semaglutide compared with placebo reduced NT-proBNP at 52 weeks (estimated treatment ratio: 0.82; 95% CI: 0.74-0.91; P = 0.0002). Improvements in health status were more pronounced in those with higher vs lower baseline NT-proBNP (estimated difference: tertile 1: 4.5 points, 95% CI: 0.8-8.2; tertile 2: 6.2 points, 95% CI: 2.4-10.0; tertile 3: 11.9 points, 95% CI: 8.1-15.7; P interaction = 0.02; baseline NT-proBNP as a continuous variable: P interaction = 0.004). Reductions in body weight were consistent across baseline NT-proBNP levels (P interaction = 0.21).

CONCLUSIONS

In patients with obesity-related HFpEF, semaglutide reduced NT-proBNP. Participants with higher baseline NT-proBNP had a similar degree of weight loss but experienced larger reductions in HF-related symptoms and physical limitations with semaglutide than those with lower NT-proBNP.

Natriuretic peptide testing strategies in heart failure: A 2023 update

Natriuretic peptides (NPs), including B-type natriuretic peptide (BNP) and N-terminal pro-BNP (NT-proBNP), have been recommended as standard biomarkers for diagnosing heart failure (HF), and one of the strongest risk predictors for mortality and HF hospitalization regardless of ejection fraction (EF) and etiology of HF. BNP is an active neurohormone opposing renin-angiotensin-aldosterone and sympathetic nervous system overactivated in HF, whereas NT-proBNP is an inactive prohormone released from cardiomyocytes in response to wall stress. Despite substantial advances in the development of guideline-directed medical therapy (GDMT) for HF with reduced EF, studies demonstrating direct benefits of NP-guided chronic HF therapy on mortality, HF hospitalization, and GDMT optimization have yielded conflicting results. However, accumulating evidence shows that achieving prespecified BNP or NT-proBNP target over time is significantly associated with favorable outcomes, suggesting that benefits of serially measured NPs may be limited to particular groups of HF patients, such as those with extreme levels of baseline BNP or NT-proBNP, which could represent severe phenotypes of HF associated with natriuretic peptide resistance or cardiorenal syndrome. Over the past decade, clinical utilization of BNP and NT-proBNP has been expanded, especially using serial NP measurements for guiding HF therapy, optimizing GDMT and identifying at-risk patients with HF phenotypes who may be minimally symptomatic or asymptomatic.

Effect of various weight loss interventions on serum NT-proBNP concentration in severe obese subjects without clinical manifest heart failure

Obesity is associated with a “natriuretic handicap” indicated by reduced N-terminal fragment of proBNP (NT-proBNP) concentration. While gastric bypass surgery improves the natriuretic handicap, it is presently unclear if sleeve gastrectomy exhibits similar effects. We examined NT-proBNP serum concentration in n = 72 obese participants without heart failure before and 6 months after sleeve gastrectomy (n = 28), gastric bypass surgery (n = 19), and 3-month 800 kcal/day very-low calorie diet (n = 25). A significant weight loss was observed in all intervention groups. Within 6 months, NT-proBNP concentration tended to increase by a median of 44.3 pg/mL in the sleeve gastrectomy group (p = 0.07), while it remained unchanged in the other groups (all p ≥ 0.50). To gain insights into potential effectors, we additionally analyzed NT-proBNP serum concentration in n = 387 individuals with different metabolic phenotypes. Here, higher NT-proBNP levels were associated with lower nutritional fat and protein but not with carbohydrate intake. Of interest, NT-proBNP serum concentrations were inversely correlated with fasting glucose concentration in euglycemic individuals but not in individuals with prediabetes or type 2 diabetes. In conclusion, sleeve gastrectomy tended to increase NT-proBNP levels in obese individuals and might improve the obesity-associated “natriuretic handicap”. Thereby, nutritional fat and protein intake and the individual glucose homeostasis might be metabolic determinants of NT-proBNP serum concentration.

Does bariatric surgery improve cardiac autonomic modulation assessed by heart rate variability? A systematic review

Our study aimed to explore the influence of bariatric surgery (BS) on heart rate (HR) variability (HRV) through a systematic review. Manuscripts were selected based on electronic searches of the MEDLINE, EMBASE, and CINAHL databases from the inception of each database up to year 2020, and followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol. Searching of these studies was systematized using the Population Intervention Comparison Outcome Study Design strategy. We selected randomized and nonrandomized controlled trials and cohorts from prospective studies that reported the influence of BS on HRV. We assessed the quality rating using the Black and Downs questionnaire. Following the screening and eligibility stages, 14 studies were included in the review. All studies agreed that BS promotes an increase in parasympathetic HR control and HRV and a decrease in HR. Yet the literature does not provide evidence that these outcomes are directly caused by the surgical procedure. There is limited evidence to support that patients with type 2 diabetes have greater improvement in HRV as an interim measure, to individuals without. The decrease in insulin resistance was correlated with the increase in HRV in some studies, but, other studies are unsupportive of this outcome. Improvements in 2 metabolic parameters (e.g., leptin, N-terminal pro B-type natriuretic peptide) were connected with superior increases in HRV. This review demonstrated that BS promotes an increase in HRV, indicating improved autonomic control of HR.

Effect of bariatric surgery on natriuretic peptide levels: a systematic review and meta-analysis

The effect of bariatric surgery on natriuretic peptide levels in patients with obesity is unclear. The purpose of this study was to conduct a systematic review and meta-analysis to determine the effect of bariatric surgery on BNP and NT-proBNP levels. MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials (CENTRAL) were searched to February 2020. Primary outcomes included change in NT-proBNP or BNP levels following bariatric surgery and change in weight and body mass index (BMI). Secondary outcomes included change in blood pressure, echocardiographic findings, and heart failure symptoms. MINORS tool was used to assess quality of evidence. Twelve studies with 622 patients were included. Most patients underwent Roux-en-Y gastric bypass (RYGB) (70.5%). Mean absolute reduction in BMI was 23%. NT-proBNP levels increased significantly from baseline at 6 months (mean difference (MD) 53.67 pg/mL; 95% CI, 28.72-78.61; P = <0.001, I2 = 99%; 8 studies) and 12 months (MD 51.16 pg/mL; 95% CI, 20.46-81.86; P = 0.001, I2 = 99%; 8 studies) post-bariatric surgery. BNP levels also increased significantly at 6 months (MD 17.57 pg/mL; 95% CI, 7.62-27.51; P <0.001, I2 = 95%; 4 studies). Systolic and diastolic blood pressure decreased significantly 12 months after surgery. Studies measuring echocardiographic findings saw improvement in LV mass and E/A ratio, but no significant change in ejection fraction. Bariatric surgery is associated with increased natriuretic peptide levels in the absence of deteriorating cardiac function, and may be associated with improved cardiac and metabolic function after the procedure.

Cardiac natriuretic peptides

Investigations into the mixed muscle-secretory phenotype of cardiomyocytes from the atrial appendages of the heart led to the discovery that these cells produce, in a regulated manner, two polypeptide hormones - the natriuretic peptides - referred to as atrial natriuretic factor or atrial natriuretic peptide (ANP) and brain or B-type natriuretic peptide (BNP), thereby demonstrating an endocrine function for the heart. Studies on the gene encoding ANP (NPPA) initiated the field of modern research into gene regulation in the cardiovascular system. Additionally, ANP and BNP were found to be the natural ligands for cell membrane-bound guanylyl cyclase receptors that mediate the effects of natriuretic peptides through the generation of intracellular cGMP, which interacts with specific enzymes and ion channels. Natriuretic peptides have many physiological actions and participate in numerous pathophysiological processes. Important clinical entities associated with natriuretic peptide research include heart failure, obesity and systemic hypertension. Plasma levels of natriuretic peptides have proven to be powerful diagnostic and prognostic biomarkers of heart disease. Development of pharmacological agents that are based on natriuretic peptides is an area of active research, with vast potential benefits for the treatment of cardiovascular disease.

N-terminal Pro-B-Type Natriuretic Peptide and Malnutrition in Patients on Hemodialysis

Natriuretic peptides, brain natriuretic peptide (BNP), and N-terminal probrain natriuretic peptide (NT-proBNP) are mainly known as diagnostic markers for heart failure with high diagnostic and prognostic values in the general population. In patients who are undergoing hemodialysis (HD), changes in NT-proBNP can be related to noncardiac problems such as fluid overload, inflammation, or malnutrition and can also be influenced by the dialysis characteristics. The current review aimed to summarize findings from studies on the association between NT-proBNP and malnutrition in HD patients. Articles published after 2009 and over a ten-year period were considered for inclusion. We first briefly discuss the traditional functions of NT-proBNP, and after, we describe the functions of this prohormone by focusing on its relation with protein energy wasting (PEW) in HD patients. Mechanisms that could explain these relationships were also discussed. Overall, 7 studies in which the investigation of the relations between NT-proBNP and nutritional status in HD patients were among the main objects were taken into account. NT-proBNP levels correlated with several factors described in the 4 categories of markers indicative of PEW (body mass and composition, muscle mass, biochemical criteria, and dietary intakes) and/or were associated with PEW. Interactions between several parameters could be involved in the association between NT-proBNP and malnutrition with a strong role of weight status. NT-proBNP is elevated in HD patients and is associated with malnutrition. Nevertheless, the prognostic value of NT-proBNP on nutritional status should be evaluated.

cGMP manipulation in cardiometabolic disease: chances and challenges

PURPOSE OF REVIEW

Cardiovascular and metabolic diseases are closely linked and commonly occur in the same patients. This review focuses on the cyclic guanosine monophosphate (cGMP) system and its crosstalk between metabolism and the cardiovascular system.

RECENT FINDINGS

Recent studies suggest that cGMP, which serves as second messenger for nitric oxide and for natriuretic peptides, improves oxidative metabolism and insulin signaling. The clinical evidence is particularly strong for the natriuretic peptide branch of the cGMP system. Clinical trials suggested improvements in insulin sensitivity and reductions in the risk of progressing to type 2 diabetes mellitus. However, further studies are needed.

SUMMARY

Enhancing cGMP signaling through nonpharmacological or pharmacological means may improve glucose metabolism in addition to affecting the cardiovascular system. However, excessive cGMP production could have significant unwanted cardiovascular and metabolic effects.

Natriuretic peptides in the control of lipid metabolism and insulin sensitivity

Natriuretic peptides have long been known for their cardiovascular function. However, a growing body of evidence emphasizes the role of natriuretic peptides in human substrate and energy metabolism, thereby connecting the heart with several insulin-sensitive organs like adipose tissue, skeletal muscle and liver. Obesity may be associated with an impaired regulation of the natriuretic peptide system, also indicated as a natriuretic handicap. Evidence points towards a contribution of this natriuretic handicap to the development of obesity, type 2 diabetes mellitus and cardiometabolic complications, although the causal relationship is not fully understood. Nevertheless, targeting the natriuretic peptide pathway may improve metabolic health in obesity and type 2 diabetes mellitus. This review will focus on current literature regarding the metabolic roles of natriuretic peptides with emphasis on lipid metabolism and insulin sensitivity. Furthermore, it will be discussed how exercise and lifestyle intervention may modulate the natriuretic peptide-related metabolic effects.

Effect of bariatric surgery on heart failure

INTRODUCTION

Obesity increases the risk of heart failure (HF), which continues to be a significant proportion of all cardiovascular diseases and affects increasingly younger populations. The cross-talk between adipose and the heart involves insulin resistance, adipokine signaling and inflammation, with the capacity of adipose tissue to mediate hemodynamic signals, promoting progressive cardiomyopathy. Areas covered: From a therapeutic perspective, there is not yet a single obesity-related pathway that when addressed, can ameliorate cardiomyopathy in obese patients and this is a matter of ongoing research. There is poor evidence of the beneficial long-term effect of small nonsurgical intentional weight loss on HF outcomes, in contrast to the field of HF accompanying severe obesity where observational studies have shown that bariatric surgery is associated with improved cardiac structure/function in severely obese patients with HF and preserved ejection fraction (HFpEF) as well as with improved cardiac structure/function in those with HF and reduced ejection fraction (HFrEF). Few studies report positive outcomes in subjects with obesity and HF, both severe, who underwent bariatric surgery as a rescue treatment, including bridge to heart transplantation. Expert commentary: The fast growing prevalence of obesity will continue to require the development of appropriate interventions directed at controlling or slowing pathways of cardiac damage in these patients, but at present, bariatric surgery should be considered an option to try to decrease morbidity associated with HF in severely obese adults.

Roles of the gut in the metabolic syndrome: an overview

The metabolic syndrome is a cluster of risk factors (central obesity, hyperglycaemia, dyslipidaemia and arterial hypertension), indicating an increased risk of diabetes, cardiovascular disease and premature mortality. The gastrointestinal tract is seldom discussed as an organ system of principal importance for metabolic diseases. The present overview connects various metabolic research lines into an integrative physiological context in which the gastrointestinal tract is included. Strong evidence for the involvement of the gut in the metabolic syndrome derives from the powerful effects of weight-reducing (bariatric) gastrointestinal surgery. In fact, gastrointestinal surgery is now recommended as a standard treatment option for type 2 diabetes in obesity. Several gut-related mechanisms that potentially contribute to the metabolic syndrome will be presented. Obesity can be caused by hampered release of satiety-signalling gut hormones, reduced meal-associated energy expenditure and microbiota-assisted harvest of energy from nondigestible food ingredients. Adiposity per se is a well-established risk factor for hyperglycaemia. In addition, a leaky gut mucosa can trigger systemic inflammation mediating peripheral insulin resistance that together with a blunted incretin response aggravates the hyperglycaemic state. The intestinal microbiota is strongly associated with obesity and the related metabolic disease states, although the mechanisms involved remain unclear. Enterorenal signalling has been suggested to be involved in the pathophysiology of hypertension and postprandial triglyceride-rich chylomicrons; in addition, intestinal cholesterol metabolism probably contributes to atherosclerosis. It is likely that in the future, the metabolic syndrome will be treated according to novel pharmacological principles interfering with gastrointestinal functionality.

NT-proBNP and diastolic left ventricular function in patients with Marfan syndrome

AIMS

Subclinical diastolic dysfuntion in patients with preclinical heart failure with preserved ejection fraction (HFpEF) has been demonstrated in patients with Marfan syndrome (MFS). We investigated the relationship between diastolic dysfunction and NT-proBNP levels in patients with MFS.

METHODS AND RESULTS

NT-proBNP, C-reactive protein (CRP) and diastolic function were assessed in 217 patients with MFS (31 ± 16 y, 110 f. and in 339 patients referred for suspected MFS in whom the diagnosis was ruled out according to the Ghent nosology (30 ± 15 y, 154 f). Assessment of cardiovascular remodeling, diastolic function in echocardiography, and NT-proBNP was analyzed with univariate analysis and multi-parameter analysis of covariance (MANCOVA). NT-proBNP was 70.6 ± 74.8 pg/ml in patients with Marfan syndrome and 58.4 ± 100.3 pg/ml in controls (p = 0.002, Kolmogorov-Smirnov). There were significant intergroup differences regarding end-diastolic left ventricular volume (p < 0.001), and aortic diameter (p < 0.001). The ratio of early diastolic mitral flow velocity (E) to early relaxation velocity in tissue Doppler (e'), E/e' (p < 0.001) was significantly higher in patients with Marfan syndrome than in controls, whereas e' (p < 0.001) and the ratio of E to inflow velocity during atrial contraction (A), E/A (p = 0.012) was significantly lower. Besides age and gender, diagnosis of MFS, diastolic function (e' and E/e'), Z-Score of aortic diameter, and left ventricular size were identified as significant independent parameters with impact on NT-proBNP levels.

CONCLUSIONS

MFS patients presenting with normal ejection fraction show disturbed diastolic function and higher NT-proBNP levels, which is partly explained by aortic Z-score. Assessment of diastolic function and NT-proBNP levels may therefore detect early abnormalities and guide surveillance and prevention management of patients with MFS.

Cardiovascular Changes After Gastric Bypass Surgery: Involvement of Increased Secretions of Glucagon-Like Peptide-1 and Brain Natriuretic Peptide

BACKGROUND

Obesity induces cardiovascular alterations, including cardiac hypertrophy, impaired relaxation, and heart rate variability (HRV), which are associated with increased mortality. Gastric bypass surgery (GBP) reduces cardiovascular mortality, but the mechanisms involved are not clearly established. To date, the implication of postsurgical hormonal changes has not been tested. Our aim was to study the relationships between the evolution of cardiovascular functions after GBP and changes in metabolic and hormonal parameters, including glucagon-like peptide-1 (GLP-1) and brain natriuretic peptide (N-terminal pro-brain natriuretic peptide (NT-proBNP)).

METHODS

Echocardiographic parameters, 24-h rhythmic Holter recording, plasma concentrations of GLP-1 before and after a test meal, and fasting NT-proBNP were assessed in 34 patients (M/F 2/32, age 36 ± 11 years, BMI 46 ± 6 kg/m(2)), before and 1 year after GBP.

RESULTS

After GBP, excess weight loss was 79 ± 20%. Blood pressure (BP), heart rate, and left ventricular mass decreased, while HRV and diastolic function (E/A ratio) improved. Plasma concentrations of NT-proBNP and postprandial (PP) GLP-1 increased. Changes in cardiovascular parameters were related to BMI and insulin sensitivity. Furthermore, the decrease in BP was independently associated with the increase of PP GLP-1 level and HRV was positively associated with NT-proBNP concentration after surgery.

CONCLUSIONS

The increase in endogenous GLP-1 observed after GBP was associated with decreased BP but not with improvement of other cardiovascular parameters, whereas the increase in NT-proBNP, within the physiological range, was associated with improved HRV.

INTERACTING DISCIPLINES: Cardiac natriuretic peptides and obesity: perspectives from an endocrinologist and a cardiologist

Since their discovery in 1981, the cardiac natriuretic peptides (cNP) atrial natriuretic peptide (also referred to as atrial natriuretic factor) and brain natriuretic peptide have been well characterised in terms of their renal and cardiovascular actions. In addition, it has been shown that cNP plasma levels are strong predictors of cardiovascular events and mortality in populations with no apparent heart disease as well as in patients with established cardiac pathology. cNP secretion from the heart is increased by humoral and mechanical stimuli. The clinical significance of cNP plasma levels has been shown to differ in obese and non-obese subjects. Recent lines of evidence suggest important metabolic effects of the cNP system, which has been shown to activate lipolysis, enhance lipid oxidation and mitochondrial respiration. Clinically, these properties lead to browning of white adipose tissue and to increased muscular oxidative capacity. In human association studies in patients without heart disease higher cNP concentrations were observed in lean, insulin-sensitive subjects. Highly elevated cNP levels are generally observed in patients with systolic heart failure or high blood pressure, while obese and type-2 diabetics display reduced cNP levels. Together, these observations suggest that the cNP system plays a role in the pathophysiology of metabolic vascular disease. Understanding this role should help define novel principles in the treatment of cardiometabolic disease.

Plasma N-terminal pro-B-type natriuretic peptide concentration in healthy retired racing Greyhounds

BACKGROUND

N-terminal pro-B-type natriuretic peptide (NT-proBNP) is a cardiac biomarker whose plasma concentration is high in some dogs with cardiopulmonary disease. NT-proBNP is a diagnostic tool that can be used to help determine if a patient has congestive heart failure. Greyhounds have functional heart murmurs, relative cardiomegaly, and high serum cTnI concentration.

OBJECTIVES

The purpose of the study was to evaluate the plasma concentration of NT-proBNP in healthy Greyhounds and compare it to non-Greyhound dogs.

METHODS

We prospectively evaluated healthy client-owned dogs including retired racing Greyhounds and non-Greyhounds. Plasma was obtained and transferred into tubes containing a protease inhibitor and submitted for a specific NT-proBNP ELISA assay.

RESULTS

The plasma NT-proBNP concentration in Greyhounds was significantly higher than in non-Greyhound control dogs (946 vs 632 pmol/L; P < .005); 46% of Greyhounds had NT-proBNP > 1000 pmol/L.

CONCLUSIONS

Plasma NT-proBNP concentration in Greyhounds is high and should be interpreted with caution.

Cardiac natriuretic peptides in plasma increase after dietary induced weight loss in obesity

Background

Cardiac natriuretic peptides are established biomarkers in heart disease, but are also affected by body mass index (BMI). The purpose of the present study was to examine the impact of weight loss and changes in body composition following dietary intervention on plasma concentrations of the prohormones to A- and B-type natriuretic peptides (proANP and proBNP) and adrenomedullin (proADM).

Results

A total of 52 healthy obese subjects, 47 women and 5 men (BMI 36.5 ± 5.6 kg/m²) were randomised to either an intensive weight reduction programme using a combination of very low calorie diet (810 kcal/day) and conventional hypo-energetic diet (1200 kcal/day) for 52 weeks, or to a control group that was offered diet-related counselling. N-terminal proBNP (NT-proBNP), mid-regional proANP (MR-proANP) and proADM (MR-proADM) and body composition using dual-energy x-ray absorptiometry (DEXA) scanning were determined at baseline and after 52 weeks. Comparisons between groups were analysed using t-tests. Changes from the baseline within the groups were analysed with paired tests. Changes in the variables, delta (∆), were calculated as 52 weeks minus the baseline.

In the intervention group, BMI decreased by almost 20% (31.6 ± 6.2 vs. 37.1 ± 6.1 kg/m²; P <0.001) with a loss of body fat of 23.5 ± 15.5% (P < 0.001). Plasma concentrations of NT-proBNP and MR-proANP increased (from 55 ± 31 to 97 ± 55 pg/ml; P < 0.001, and from 59 ± 21 to 74 ± 26 pmol/L; P < 0.001), whereas MR-proADM decreased (from 573 ± 153 to 534 ± 173 pmol/L; P <0.001). Changes (Δ) in MR-proANP correlated with Δfat mass (r = −0.359; P = 0.011) and Δglucose (r = −0.495; P <0.001), while increases in NT-proBNP were primarily associated with reduced plasma glucose (r = −0.462; P <0.001). A modest but significant weight loss of 6% (P < 0.001) was found in the control group with no changes in plasma concentrations of NT-proBNP or MR-proANP, and a minor change in MR-proADM.

Conclusions

Plasma NT-proBNP and MR-proANP concentrations increase and MR-proADM concentration decreases during weight loss, underlining the dynamic impact of BMI, body composition and glucose metabolism on these cardiovascular biomarkers.

The evaluation of brain natriuretic peptide changes and difficult airway predictors during perioperative period of pregnancy

AIM

Airway changes, difficult ventilation, and intubation are the leading causes of morbidity and mortality in pregnancy, but no prospective study has evaluated the relationship between airway changes and brain natriuretic peptide (BNP) before and after cesarean section operations. The purpose of this study was to evaluate the relationship between BNP and airway changes in women undergoing delivery and during the postoperative period.

MATERIALS AND METHODS

Included in this prospective study were a total of 35 pregnant females with ASA I physical status who were scheduled for cesarean section under general anesthesia. BNP levels, Mallampati classification, mouth opening, thyromental distance, sternomental distance, and the degree of neck extension were recorded before cesarean section and 24 h after the operation. Laryngeal views were also documented after intubation.

RESULTS

Significant differences in BNP levels, Mallampati classification, mouth opening, thyromental distance, sternomental distance, and the degree of neck extension measurements arose between initial measurements and those measurements made 24 h postoperatively. Pre-delivery Mallampati I, II, III, IV scores of 6, 18, 7, 4 had by 24 h after cesarean section changed to 13, 13, 6, 3, respectively (p < 0.05). Initial BNP levels were 7.59 ± 6.30; postoperative levels were 52.39 ± 48.17. In this study we found a correlation between perioperative BNP levels and difficult intubation parameters.

CONCLUSIONS

Within 24 h postpartum, Mallampati scores changed in 13 patients (30.95 %). Besides the correlation between BNP levels and difficult intubation parameters, we also found significant differences in initial and postoperative BNP values.

Endogenous Glucagon-Like Peptide-1 as a Potential Mediator of the Resolution of Diabetic Kidney Disease following Roux en Y Gastric Bypass: Evidence and Perspectives

Diabetic kidney disease in patients with type 2 diabetes strongly correlates with the incidence of major cardiovascular events and all-cause mortality. Pharmacological and lifestyle based management focusing on glycaemic, lipid, and blood pressure control is the mainstay of treatment but efficacy remains limited. Roux en Y gastric bypass is an efficacious intervention in diabetes. Emerging evidence also supports a role for bypass as an intervention for early diabetic kidney disease. This paper firstly presents level 1 evidence of the effects of bypass on hyperglycaemia and hypertension and then summarises emerging data on its effects on diabetic kidney disease. Glucagon-like peptide-1 is implicated as a central mediator of diabetes resolution following bypass through the incretin effect. It has been ascribed vasodilatory, pronatriuretic, and antioxidant properties and its exogenous administration or optimisation of its endogenous levels via dipeptidyl peptidase IV inhibition results in antioxidant and antiproteinuric effects in preclinical models of DKD. Some evidence is emerging of translation of coherent effects in the clinical setting. These findings raise the question of whether pharmacotherapy targeted at optimising circulating hormone levels may be capable of recapitulating some of the effects of bypass surgery on renal injury.

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.