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

From Beats to Metabolism: the Heart at the Core of Interorgan Metabolic Cross Talk

The heart, once considered a mere blood pump, is now recognized as a multifunctional metabolic and endocrine organ. Its function is tightly regulated by various metabolic processes, at the same time it serves as an endocrine organ, secreting bioactive molecules that impact systemic metabolism. In recent years, research has shed light on the intricate interplay between the heart and other metabolic organs, such as adipose tissue, liver, and skeletal muscle. The metabolic flexibility of the heart and its ability to switch between different energy substrates play a crucial role in maintaining cardiac function and overall metabolic homeostasis. Gaining a comprehensive understanding of how metabolic disorders disrupt cardiac metabolism is crucial, as it plays a pivotal role in the development and progression of cardiac diseases. The emerging understanding of the heart as a metabolic and endocrine organ highlights its essential contribution to whole body metabolic regulation and offers new insights into the pathogenesis of metabolic diseases, such as obesity, diabetes, and cardiovascular disorders. In this review, we provide an in-depth exploration of the heart's metabolic and endocrine functions, emphasizing its role in systemic metabolism and the interplay between the heart and other metabolic organs. Furthermore, emerging evidence suggests a correlation between heart disease and other conditions such as aging and cancer, indicating that the metabolic dysfunction observed in these conditions may share common underlying mechanisms. By unraveling the complex mechanisms underlying cardiac metabolism, we aim to contribute to the development of novel therapeutic strategies for metabolic diseases and improve overall cardiovascular health.

Adverse physiologic effects of Western diet on right ventricular structure and function: role of lipid accumulation and metabolic therapy

Little is known about the impact of metabolic syndrome (MS) on right ventricular (RV) structure and function. We hypothesized that mice fed a Western diet (WD) would develop RV lipid accumulation and impaired RV function, which would be ameliorated with metformin. Male C57/Bl6 mice were fed a WD or standard rodent diet (SD) for eight weeks. A subset of mice underwent pulmonary artery banding (PAB). Treated mice were given 2.5 g/kg metformin mixed in food. Invasive hemodynamics, histology, Western, and quantitative polymerase chain reaction (qPCR) were performed using standard techniques. Lipid content was detected by Oil Red O staining. Mice fed a WD developed insulin resistance, RV hypertrophy, and higher RV systolic pressure compared with SD controls. Myocardial lipid accumulation was greater in the WD group and disproportionately affected the RV. These structural changes were associated with impaired RV diastolic function in WD mice. PAB-WD mice had greater RV hypertrophy, increased lipid deposition, and lower RV ejection fraction compared with PAB SD controls. Compared to untreated mice, metformin lowered HOMA-IR and prevented weight gain in mice fed a WD. Metformin reduced RV systolic pressure, prevented RV hypertrophy, and reduced RV lipid accumulation in both unstressed stressed conditions. RV diastolic function improved in WD mice treated with metformin. WD in mice leads to an elevation in pulmonary pressure, RV diastolic dysfunction, and disproportionate RV steatosis, which are exacerbated by PAB. Metformin prevents the deleterious effects of WD on RV function and myocardial steatosis in this model of the metabolic syndrome.

Serum leptin level positively correlates with metabolic syndrome among elderly Taiwanese

OBJECTIVE

Leptin is an adipocyte-derived hormone and has shown positive correlation with obesity and metabolic syndrome (MetS) in many studies. However, there are few studies investigating this relation in elderly people. Therefore, we aimed to investigate the correlation between the fasting serum leptin level and MetS among older Taiwanese.

MATERIALS AND METHODS

The fasting serum leptin level was obtained from 62 Taiwanese participants over 65 years old and was measured using a commercially available enzyme immunoassay kit. MetS and its components were defined using diagnostic criteria from the International Diabetes Federation.

RESULTS

Thirty elderly participants (48.4%) had MetS. The serum leptin level was positively correlated with MetS (P < 0.001). Multivariate logistic regression analysis of the factors significantly associated with MetS showed that logarithmically transformed leptin (log-leptin, each increase 0.1 ng/mL log-leptin, odds ratio: 1.276, 95% confidence interval: 1.015-1.603, P = 0.037) was still an independent predictor of MetS in elderly persons. Univariable linear analysis showed that body weight (r = 0280, P = 0.028), body mass index (r = 0.417, P = 0.001), waist circumference (r = 0.419, P = 0.001), blood urea nitrogen (r = 0255, P = 0.046), log-insulin (r = 0436, P < 0.001), and logarithmically transformed homeostasis model assessment of insulin resistance (r = 0359, P = 0.004) positively correlated with fasting serum log-leptin levels. Multivariate forward stepwise linear regression analysis of the factors significantly associated with fasting serum log-leptin levels revealed that waist circumference (adjusted R2 = 0.083, P = 0.002), statin use (adjusted R2 = 0.058, P = 0.016), and female gender (adjusted R2 = 0.041, P = 0.034) were independent predictors of fasting serum log-leptin levels among elderly participants.

CONCLUSION

In elderly Taiwanese, the serum leptin level was positively correlated with MetS. Waist circumference, statin use, and female gender were independent predictors of the fasting serum leptin level in elderly participants.

Low serum adiponectin level is associated with metabolic syndrome and is an independent marker of peripheral arterial stiffness in hypertensive patients

BACKGROUND

Adiponectin has been implicated in metabolic syndrome (MetS) and arterial stiffness (AS). We aim to determine the relationship between serum adiponectin concentration as well as peripheral AS in hypertensive patients.

METHODS

Fasting blood samples were obtained from 101 hypertensive patients. Brachial-ankle pulse wave velocity (baPWV) was measured with an automatic pulse wave analyzer. Serum adiponectin concentrations were determined by using an enzyme immunoassay kit. A baPWV >14.0 m/s was defined as high AS.

RESULTS

MetS and high AS were present in 62.4 and 71.3% of the study population. Adiponectin was inversely associated with MetS and high AS (both P < 0.001). Serum higher high-density lipoprotein cholesterol (HDL-C) (P = 0.012), triglycerides (P = 0.001), C-reactive protein (P < 0.001), insulin (P = 0.027), body weight (P = 0.002), waist circumference (WC, P < 0.001), body mass index (P = 0.001) bilateral-baPWV (P < 0.001), systolic blood pressure (SBP, P < 0.001), diastolic blood pressure (DBP, P = 0.012), pulse pressure (P = 0.019), homeostasis model assessment of insulin resistance (HOMA1-IR (P = 0.026) and HOMA2-IR (P = 0.020)) and lower glomerular filtration rate (GFR, P = 0.029) were significantly associated with high AS. Multivariate logistic regression analysis of the factors significantly associated with AS revealed that adiponectin [odds ratio: 0.932, 95% confidence interval (CI) 0.881-0.985, P = 0.012], and SBP (odds ratio: 1.059, 95% CI 1.008-1.113, P = 0.022) were the independent predictors of arterial stiffness in hypertensive patients. Subgroup analysis revealed that SBP (odds ratio: 1.126, 95% CI 1.024-1.237, P = 0.014) and GFR (odds ratio: 0.858, 95% CI 0.739-0.996, P = 0.043) were the independent predictors of arterial stiffness in hypertensive patients without MetS; adiponectin (odds ratio: 0.909, 95% CI 0.931-0.996, P = 0.040) was the independent predictor of arterial stiffness in hypertensive patients with MetS.

CONCLUSIONS

Hypoadiponectinemia has positive association with MetS and peripheral AS in hypertensive patients.

Biomarkers of Metabolic Syndrome: Biochemical Background and Clinical Significance

Biomarkers of the metabolic syndrome are divided into four subgroups. Although dividing them in groups has some limitations, it can be used to draw some conclusions. In a first part, the dyslipidemias and markers of oxidative stress are discussed, while inflammatory markers and cardiometabolic biomarkers are reviewed in a second part. For most of them, the biochemical background and clinical significance are discussed, although here also a well-cut separation cannot always be made. Altered levels cannot always be claimed as the cause, risk, or consequence of the syndrome. Several factors are interrelated to each other and act in a concerted, antagonistic, synergistic, or modulating way. Most important conclusions are summarized at the end of every reviewed subgroup. Genetic biomarkers or influences of various food components on concentration levels are not included in this review article.

High Serum Adipocyte Fatty Acid Binding Protein Is Associated with Metabolic Syndrome in Patients with Type 2 Diabetes

Adipocyte fatty acid binding protein (A-FABP) is a key mediator of obesity-related metabolic syndrome (MetS). The aim of this study was to evaluate the relationship between A-FABP concentration and MetS in type 2 diabetes mellitus (DM) patients. Fasting blood samples were obtained from 165 type 2 DM volunteers. MetS and its components were defined using diagnostic criteria from the International Diabetes Federation. Among 165 DM patients, 113 patients (68.5%) had MetS. Diabetic persons who had MetS had significantly higher A-FABP levels (P < 0.001) than those without MetS. Female DM persons had higher A-FABP level than man (P < 0.001). No statistically significant differences in A-FABP levels were found in use of statin, fibrate, or antidiabetic drugs. Multivariate forward stepwise linear regression analysis revealed that body fat mass (P < 0.001), logarithmically transformed creatinine (log-creatinine; P < 0.001), female DM patients (P < 0.001), and logarithmically transformed high sensitive C-reactive protein (log-hs-CRP; P = 0.013) were positively correlated, while albumin (P = 0.004) and glomerular filtration rate (GFR; P = 0.043) were negatively correlated with serum A-FABP levels in type 2 DM patients. In this study, higher serum A-FABP level was positively associated with MetS in type 2 DM patients.

Atrial natriuretic peptide in cardiovascular biology and disease (NPPA)

Atrial natriuretic peptide (ANP) is a cardiac hormone that regulates salt-water balance and blood pressure by promoting renal sodium and water excretion and stimulating vasodilation. ANP also has an anti-hypertrophic function in the heart, which is independent of its systemic blood pressure-lowering effect. In mice, ANP deficiency causes salt-sensitive hypertension and cardiac hypertrophy. Recent studies have shown that ANP plays an important role in regulating vascular remodeling and energy metabolism. Variants in the human NPPA gene, encoding the ANP precursor, are associated with hypertension, stroke, coronary artery disease, heart failure (HF) and obesity. ANP and related peptides are used as biomarkers for heart disease. Recombinant proteins and small molecules that enhance the ANP pathway have been developed to treat patients with HF. In this review, we discuss the role of ANP in cardiovascular biology and disease.

Atrial natriuretic peptide gene variants and circulating levels: implications in cardiovascular diseases

ANP (atrial natriuretic peptide), discovered 30 years ago in rat cardiac atria, has been extensively investigated with regard to physiology, pathophysiology, cardiovascular disease therapeutics and molecular genetic aspects. Besides its diuretic, natriuretic and vasorelaxant effects, novel properties of this hormone have been described. Thus anti-hypertrophic, anti-fibrotic, anti-proliferative and anti-inflammatory actions suggest that ANP contributes not only to haemodynamic homoeostasis and adjustments, but has also a role in cardiovascular remodelling. Circulating ANP levels represent a valuable biomarker in cardiovascular diseases. ANP structure is highly conserved among species, indicating a key role in cardiovascular health. Thus an abnormal ANP structure may contribute to an increased risk of disease due to altered functions at either the vascular or cardiac level. Among others, the 2238T>C exon 3 variant has been associated with endothelial cell damage and dysfunction and with an increased risk of acute cardiovascular events, a frameshift mutation within exon 3 has been related to increased risk of atrial fibrillation, and ANP gene variants have been linked to increased risk of hypertension in different ethnic groups. On the other hand, the rs5068 variant, falling within the 3' UTR and associated with higher circulating ANP levels, has been shown to have a beneficial cardioprotective and metabolic effect. Dissecting out the disease mechanisms dependent on specific ANP molecular variants may reveal information useful in the clinical setting for diagnostic, prognostic and therapeutic purposes. Furthermore, insights from molecular genetic analysis of ANP may well integrate advancing knowledge on the role of ANP as a significant biomarker in patients affected by cardiovascular diseases.

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.