Influence of leptin on arterial distensibility: a novel link between obesity and cardiovascular disease?

Circulating leptin is associated with adverse vascular changes in young adult survivors of childhood cancer

INTRODUCTION

Proteomics may help discover novel biomarkers and underlying mechanisms for cardiovascular disease. This could be useful for childhood cancer survivors as they show an increased risk of cardiovascular disease. The aim of this study was to investigate circulating cardiovascular proteins in young adult survivors of childhood cancer and their relationship to previously reported subclinical cardiovascular disease.

METHODS

Ninety-two cardiovascular proteins were measured in 57 childhood cancer survivors and in 52 controls. For proteins that were significantly different between childhood cancer survivors and controls, we performed correlations between protein levels and measures of peripheral arterial stiffness (carotid distensibility and stiffness index, and augmentation index) and endothelial dysfunction (reactive hyperemia index).

RESULTS

Leptin was significantly higher in childhood cancer survivors compared to controls (normalized protein expression units: childhood cancer survivors 6.4 (1.5) versus 5.1 (1.7), p < 0.0000001) after taking multiple tests into account. Kidney injury molecule-1, MER proto-oncogene tyrosine kinase, selectin P ligand, decorin, alpha-1-microglobulin/bikunin precursor protein, and pentraxin 3 showed a trend towards group differences (p < 0.05). Among childhood cancer survivors, leptin was associated with anthracycline treatment after adjustment for age, sex, and body mass index (p < 0.0001). Higher leptin correlated with lower carotid distensibility after adjustment for age, sex, body mass index, and treatments with radiotherapy and anthracyclines (p = 0.005).

CONCLUSION

This proteomics approach identified that leptin is higher in young asymptomatic adult survivors of childhood cancer than in healthy controls and is associated with adverse vascular changes. This could indicate a role for leptin in driving the cardiovascular disease burden in this population.

Increased plasma lipopolysaccharide-binding protein and altered inflammatory mediators in overweight women suggest a state of subclinical endotoxemia

Chronic low-grade inflammation has been recognized as an underlying event linking obesity to cardiovascular disease (CVD). However, inflammatory alterations in individuals who are overweight remain understudied. To provide insight, we determined the levels of key circulating biomarkers of endotoxemia and inflammation, including lipopolysaccharide-binding protein (LBP), CRP, IL-6, leptin, and adiponectin in adult female subjects (n=40) who were lean or overweight and had high cholesterol and/or high blood pressure - two important conventional risk factors for CVD. Plasma levels of LBP were significantly higher in the overweight group compared with the lean group (P=0.005). The levels of CRP were also significantly higher in overweight subjects (P=0.01), as were IL-6 (P=0.02) and leptin (P=0.002), pro-inflammatory mediators associated with cardiovascular risk. Levels of adiponectin, an adipokine with anti-inflammatory and anti-atherogenic functions, were significantly lower in the overweight group (P=0.002). The leptin/adiponectin ratio, a preferential atherogenic marker was significantly increased in women who are overweight (P=0.02). LBP, CRP, leptin, and adiponectin levels significantly correlated with BMI, but not with age and there was a significant correlation between LBP and IL-6 levels. These results reveal the presence of subclinical endotoxemia and a pro-inflammatory state in overweight women and are of interest for further studies with the goal for improved understanding of cardiovascular health risks in women.

Increased plasma lipopolysaccharide-binding protein and altered inflammatory mediators in overweight women suggest a state of subclinical endotoxemia

Chronic low-grade inflammation has been recognized as an underlying event linking obesity to cardiovascular disease (CVD). However, inflammatory alterations in individuals who are overweight remain understudied. To provide insight, we determined the levels of key circulating biomarkers of endotoxemia and inflammation, including lipopolysaccharide-binding protein (LBP), CRP, IL-6, leptin, and adiponectin in adult female subjects (n = 20) who were lean or overweight and had high cholesterol and/or high blood pressure - two important conventional risk factors for CVD. Plasma levels of LBP (a recognized marker of metabolic endotoxemia in obesity) were significantly higher in the overweight group compared with the lean group (P = 0.005). The levels of CRP, a general marker of inflammation, were also significantly higher in overweight subjects (P = 0.01), as were IL-6 (P = 0.02) and leptin (P = 0.002), pro-inflammatory mediators associated with cardiovascular risk. Levels of adiponectin, an adipokine with anti-inflammatory and anti-atherogenic functions, were significantly lower in the overweight group (P = 0.002). The leptin/adiponectin ratio, a preferential atherogenic marker was significantly increased in women who are overweight (P = 0.02). LBP, CRP, leptin, and adiponectin levels significantly correlated with BMI, but not with age. These results reveal the presence of subclinical endotoxemia and a pro-inflammatory state in overweight women and are of interest for further studies with the goal for improved understanding of women's cardiovascular health.

Higher Body Mass Index is associated with increased arterial stiffness prior to target organ damage: a cross-sectional cohort study

BACKGROUND

Obesity is associated with several neurohumoral changes that play an essential role in organ damage. Increased arterial stiffness causes functional vessel wall changes and can therefore lead to accelerated target organ damage as well. Whether obesity causes an independent increase in central arterial stiffness is, however, not yet fully known.

METHODS

One hundred thirty-three patients (63.2% male) were included. Body Mass Index (BMI) was defined as body weight in kilograms, divided by the square of body height in meters. Chronic Kidney Disease Epidemiology Collaboration creatinine 2009 equation was used to estimate the glomerular filtration rate (eGFR). Non-invasive applanation tonometry was used for arterial stiffness measurements (Sphygmocor Atcor Medical, Sydney, Australia). All patients underwent coronarography.

RESULTS

The mean age of our patients was 65.0 ± 9.2 years. Their mean BMI was 28.5 ± 4.4 kg/m2, eGFR 75.5 ± 17.2 ml/min/1.73 m2 and ankle-brachial index (ABI) 1.0 ± 0.1. Their arterial stiffness measurements showed mean carotid-femoral pulse wave velocity (cfPWV) 10.3 ± 2.7 m/s, subendocardial viability ratio (SEVR) 164.4 ± 35.0%, and pulse pressure (PP) 47.8 ± 14.5 mmHg. Spearman's correlation test revealed a statistically significant correlation between BMI and SEVR (r = -0.193; p = 0.026), BMI and cfPWV (r = 0.417; p < 0.001) and between BMI and PP (r = 0.227; p = 0.009). Multiple regression analysis confirmed an independent connection between BMI and cfPWV (B = 0.303; p < 0.001) and between BMI and SEVR (B = -0.186; p = 0.040). There was no association between BMI and kidney function, ABI, or coronary artery disease.

CONCLUSION

Increased BMI is independently associated with augmented central arterial stiffness and reduced subendocardial perfusion but not with coronary artery disease, kidney function, or ABI.

Relationship between the novel and traditional anthropometric indices and subclinical atherosclerosis evaluated by carotid intima-media thickness (c-IMT)

Introduction

Over the last few years, novel anthropometric indices have been developed as an alternative to body mass index (BMI) and other traditional anthropometric measurements to enhance the estimate of fat proportion and its relationship to a future cardiovascular event. The purpose of this study was to investigate the association of carotid intima-media thickness (c-IMT) estimated by Doppler ultrasound with current anthropometric indices (traditional and novel).

Methods

A cross-sectional study was conducted on a total of 789 Spanish patients. Traditional (BMI, WHR, and WHtR) and new (WWI, AVI, ABSI, BRI, BAI, CUN-BAE, and CI) anthropometric indices were determined, and carotid Doppler ultrasound was performed to evaluate c-IMT (≥0.90 mm).

Results

Most of the anthropometric indices analyzed were significantly higher among patients with pathological c-IMT, except for BMI, BAI, and CUN-BAE. In multiple linear regression analysis, c-IMT was positively related to ABSI, AVI, BRI, CI, and WWI but not to CUN-BAE, BAI, or traditional anthropometric indices. Similarly, in univariate analysis, all indices were associated with a c-IMT of ≥0.90 mm (p < 0.05), except BMI, BAI, and CUN-BAE; however, only ABSI (adjusted OR: 1.61; 95% CI: 1.08-2.40; p = 0.017), CI (adjusted OR: 1.73; 95% CI: 1.15-2.60; p = 0.008), and WWI (adjusted OR: 1.74; 95% CI: 1.14-2.64; p = 0.009) were significantly associated in multivariate analysis. Finally, CI, ABSI, and WWI provided the largest AUC, and BMI and CUN-BAE showed the lowest AUC.

Conclusion

ABSI, CI, and WWI were positively associated with pathological c-IMT (≥0.90 mm), independent of other confounders.

Obesity and diabetes

Obesity, which has currently reached pandemic dimensions, is usually accompanied by diabetes mellitus type 2 (T2DM). These two conditions share common pathophysiological mechanisms. Adipose tissue secretes cytokines which are involved in inflammation and various endocrine functions. As for T2DM, it is characterized also by inflammation, mitochondrial dysfunction, and hyperinsulinemia. These conditions occur also in other diseases related to obesity and T2DM, like cardiovascular disease (CVD) and nonalcoholic fatty liver disease (NAFLD). Thus, management of obesity-related complications with lifestyle modification, anti-obesity drugs, and bariatric surgery, all contribute to improvement in any of these conditions. This review provides an overview of the literature addressing the association between obesity and T2DM, briefly discussing the pathophysiological mechanisms linking these conditions and outlining the management approach at the overlap of obesity and T2DM.

Molecular Biomarkers for Cardiometabolic Disease: Risk Assessment in Young Individuals

Cardiometabolic diseases, including cardiovascular disease and diabetes, are major causes of morbidity and mortality worldwide. Despite progress in prevention and treatment, recent trends show a stalling in the reduction of cardiovascular disease morbidity and mortality, paralleled by increasing rates of cardiometabolic disease risk factors in young adults, underscoring the importance of risk assessments in this population. This review highlights the evidence for molecular biomarkers for early risk assessment in young individuals. We examine the utility of traditional biomarkers in young individuals and discuss novel, nontraditional biomarkers specific to pathways contributing to early cardiometabolic disease risk. Additionally, we explore emerging omic technologies and analytical approaches that could enhance risk assessment for cardiometabolic disease.

Effects of Angiotensin Receptor-Neprilysin Inhibitors (ARNIs) on the Glucose and Fat Metabolism Biomarkers Leptin and Fructosamine

(1) Background: Heart failure with reduced ejection fraction (HFrEF) remains a major health burden. Angiotensin-Receptor-Neprilysin-Inhibitors (ARNIs) are an established HFrEF therapy which increases natriuretic peptide levels by inhibiting neprilysin. Leptin is a lipid metabolism parameter, which is also involved in glucose metabolism and is suggested to correlate with HF burden. While the hormone also seems to interact with neprilysin, potential associations with ARNI therapy have not been investigated yet. (2) Methods: To study this issue, we measured levels of leptin and fructosamine in consecutive 72 HFrEF patients before initiation of ARNI therapy and 3-6 months after initiation of therapy in two European centers. Biomarker levels were correlated with clinical parameters including ejection fraction, LVEF, and NYHA class. (3) Results: During a follow-up of up to 6 months, clinical parameters improved significantly (LVEF: 30.2 ± 7.8% to 37.6 ± 10.0%, (p < 0.001) and a significant improvement of the mean NYHA class with initial 32 patients in NYHA III or IV and 8 patients in NYHA class III/IV during the follow up (p < 0.001). The initial NT-proBNP levels of 2251.5 ± 2566.8 pg/mL significantly improved to 1416.7 ± 2145 pg/mL, p = 0.008) during follow up. ARNI therapy was also associated with an increase in leptin levels (17.5 ± 23.4 µg/L to 22.9 ± 29.3, p < 0.001) and furthermore, affected glucose metabolism indicated by elevation of fructosamine values (333.9 ± 156.8 µmol/L to 454.8 ± 197.8 µmol/L, p = 0.013). (4) Conclusion: while in the early phase of therapy, ARNI promotes clinical improvement of HFrEF, and it also seems to affect fat and glucose parameters, indicating significant metabolic implications of this therapy regime.

Effects of fitness and fatness on age-related arterial stiffening in people with type 2 diabetes

People with type 2 diabetes (T2D) are at a greater risk of cardiovascular disease than the general population. Both non-modifiable (age) and modifiable (low aerobic fitness, high body fatness) factors are separately predictive of cardiovascular risk, although they often occur concomitantly. This study aimed to examine the (1) association between age and arterial stiffness, a subclinical marker of cardiovascular risk; and (2) effects of body fatness and aerobic fitness on age-related increases in arterial stiffness in people with T2D. Data from 64 individuals with T2D (age 59.8 ± 8.7 years, 40% female, HbA1c 8.4 ± 1.6%) were included in this cross-sectional analysis. Carotid-femoral pulse wave velocity (cfPWV) was used to quantify arterial stiffness. Aerobic fitness (relative V̇O2peak ) was determined via indirect calorimetry during maximal exercise testing. Central body fatness was determined using waist circumference. Data were analysed using hierarchical multiple regressions. After adjustment for sex and duration of T2D, each one standard deviation (SD) increase in age (8.68 years) was associated with a 0.63 m·s-1 increase in cfPWV (β = 0.416, p = 0.001). Following adjustment for aerobic fitness and body fatness, the standardized β was unchanged (0.417). A one SD increase in waist circumference (13.9 cm) and relative V̇O2peak (5.3 ml·kg-1 ·min-1 ) were associated with a similar magnitude of difference in cfPWV (0.47 m·s-1 and -0.44 m·s-1 , respectively). Therefore, age is a significant correlate of increased arterial stiffness in T2D, with higher aerobic fitness attenuating, and higher body fatness exacerbating, this increase. Interventions aimed at improving cardiovascular outcomes in people with T2D should target both increased aerobic fitness and reduced body fatness.

Infant weight growth patterns, childhood BMI, and arterial health at age 10 years

OBJECTIVE

Associations of obesity with cardiovascular disease may originate in childhood. This study examined critical periods for BMI in relation to arterial health at school age.

METHODS

Among 4,731 children from a prospective cohort study, associations of infant peak weight velocity, both age and BMI at adiposity peak, and BMI trajectories with carotid artery intima-media thickness and carotid artery distensibility at 10 years were examined.

RESULTS

A 1-standard deviation score (SDS) higher peak weight velocity and BMI at adiposity peak were associated with higher intima-media thickness (0.10 SDS; 95% CI: 0.06 to 0.13 and 0.08 SDS; 95% CI: 0.05 to 0.12) and lower distensibility (-0.07 SDS; 95% CI: -0.10 to -0.03 and -0.07 SDS; 95% CI: -0.11 to -0.03) at 10 years. For distensibility, current BMI explained these associations. Children within the highest BMI tertile at ages 2 and 10 years had the lowest distensibility (p < 0.05), but similar intima-media thickness, compared with children constantly within the middle tertile.

CONCLUSIONS

Infant weight growth patterns and childhood BMI are associated with subtle differences in carotid intima-media thickness and carotid distensibility at school age. For distensibility, current BMI seems critical. Follow-up is needed to determine whether these associations lead to adult cardiovascular disease.

Female Gender Is Associated with Higher Susceptibility of Weight Induced Arterial Stiffening and Rise in Blood Pressure

Arterial stiffness is an important predictor of cardiovascular events, independent of traditional risk factors. Stiffening of arteries, though an adaptive process to hemodynamic load, results in substantial increase in the pulsatile hemodynamic forces that detrimentally affects the microcirculation perfusing the vital organs such as the brain, heart and kidneys. Studies have proposed that arterial stiffness precedes and may contribute to the development of hypertension in individuals with obesity. Our study sought to determine the gender-based effects on arterial stiffening in obesity which may predispose to the development of hypertension. We found female sex is associated with higher susceptibility of weight-related arterial stiffening and rise in blood pressure in obesity. Women had significantly higher carotid-femoral pulse wave velocity (CF-PWV) with higher body mass index (BMI) status (normal: 7.9 ± 2 m/s; overweight: 9.1 ± 2 m/s; obese: 9 ± 2 m/s, p < 0.001), whereas it was similar in males across all BMI categories. The linear association between arterial stiffness and BMI following adjustment for age and brachial systolic and diastolic blood pressure (BP), remained significant in females (β = 0.06; 95% CI 0.01 to 0.1; p < 0.05) but not in males (β = 0.04; 95% CI -0.01 to 0.1; p > 0.05). The mean CF-PWV values increased by 0.1 m/s for every 1 kg/m² increase in BMI in the female subjects in the age adjusted linear model, while such effect was not seen in the male subjects. In line with arterial stiffening, the overweight and obese females demonstrated significantly higher systolic brachial BP. (BP difference: ΔBP 9-11 mmHg, p < 0.01) and central systolic pressure (ΔBP 8-10 mmHg, p < 0.05) compared to their lean counterparts, unlike the male subjects. Our results suggest that female gender is associated with higher susceptibility of weight-related arterial stiffening and rise in blood pressure.

Adipokines and Arterial Stiffness in Obesity

Adipokines are active molecules with pleiotropic effects produced by adipose tissue and involved in obesity-related metabolic and cardiovascular diseases. Arterial stiffness, which is a consequence of arteriosclerosis, has been shown to be an independent predictor of cardiovascular morbidity and mortality. The pathogenesis of arterial stiffness is complex but incompletely understood. Adipokines dysregulation may induce, by various mechanisms, vascular inflammation, endothelial dysfunction, and vascular remodeling, leading to increased arterial stiffness. This article summarizes literature data regarding adipokine-related pathogenetic mechanisms involved in the development of arterial stiffness, particularly in obesity, as well as the results of clinical and epidemiological studies which investigated the relationship between adipokines and arterial stiffness.

Serum leptin concentration can predict cardiovascular outcomes and all-cause death in maintenance hemodialysis patients

BACKGROUND

We explored the associations between serum leptin concentration and cardiovascular prognosis in maintenance hemodialysis patients.

METHODS

In our prospective study with no intervention, demographics data at baseline were collected from electronic medical records. Serum leptin concentration was determined by ELISA. Patients underwent body composition assessment and echocardiographic measurements after hemodialysis. The primary endpoints were defined as cardiovascular events (CVEs), cardiovascular death (CVD) and all-cause death.

RESULTS

A total of 165 eligible patients aged 51(43-65) y were enrolled and the mean serum leptin concentration was 35.49 (29.98) ng/ml. During a median follow-up of 18 (12-22) months, CVEs occurred in 37 (22.42%) patients and the cardiovascular and all-cause mortality was 10.91% and 21.82%. Serum leptin concentration was associated with CVEs (HR = 0.982, p = 0.003), CVD (HR = 0.934, p = 0.002) and all-cause death (HR = 0.943, p < 0.001). Decreased serum leptin concentration was an independent risk factor for the development of left ventricular hypertrophy (LVH, OR = 0.98, p = 0.007) and peripheral vascular disease (PVD, OR = 0.974, p = 0.007).

CONCLUSION

Serum leptin concentration can independently predict cardiovascular outcomes and all-cause death in MHD patients. The effects that serum leptin concentration on development of LVH and PVD maybe the potential mechanism.

The evolving obesity challenge: targeting the vagus nerve and the inflammatory reflex in the response

Obesity and the metabolic syndrome (MetS), which have reached pandemic proportions significantly increase the risk for type 2 diabetes, cardiovascular disease, and other serious conditions. Recent data with COVID-19 patients indicate that obesity also is a significant risk factor for this novel viral disease and poor outcome of associated critical illness. These findings considerably change the view of obesity as a driver of serious, but slowly-progressing chronic diseases, and emphasize the urgency to explore new therapeutic approaches. Inflammation is a recognized driver of metabolic derangements in obesity and MetS, and a core feature of COVID-19 pathobiology. Recent advances in our understanding of inflammatory regulation have highlighted the role of the nervous system and the vagus nerve-based inflammatory reflex. Current bioelectronic and pharmacological therapeutic explorations centered on the inflammatory reflex offer new approaches for conditions characterized by immune and metabolic dysregulation and for ameliorating the escalating burden of obesity, MetS, and COVID-19.

Leptin in Atherosclerosis: Focus on Macrophages, Endothelial and Smooth Muscle Cells

Increasing adipose tissue mass in obesity directly correlates with elevated circulating leptin levels. Leptin is an adipokine known to play a role in numerous biological processes including regulation of energy homeostasis, inflammation, vascular function and angiogenesis. While physiological concentrations of leptin may exhibit multiple beneficial effects, chronically elevated pathophysiological levels or hyperleptinemia, characteristic of obesity and diabetes, is a major risk factor for development of atherosclerosis. Hyperleptinemia results in a state of selective leptin resistance such that while beneficial metabolic effects of leptin are dampened, deleterious vascular effects of leptin are conserved attributing to vascular dysfunction. Leptin exerts potent proatherogenic effects on multiple vascular cell types including macrophages, endothelial cells and smooth muscle cells; these effects are mediated via an interaction of leptin with the long form of leptin receptor, abundantly expressed in atherosclerotic plaques. This review provides a summary of recent in vivo and in vitro studies that highlight a role of leptin in the pathogenesis of atherosclerotic complications associated with obesity and diabetes.

Cerebral hemodynamics in obesity: relationship with sex, age, and adipokines in a cohort-based study

Overweight and obesity are well-known independent risk factors for stroke in the general population although uncertain in the case of the elderly, according to the obesity paradox. Little is known about underlying mechanisms. Our study aims to assess whether there is a relationship between excess body weight (measured as waist circumference) and poor cerebral hemodynamics (measured by transcranial Doppler parameters: basal, mean flow velocity (MFV), and dynamic, cerebrovascular reserve (CvR) in the right middle cerebral artery (RMCA)). A possible underlying molecular mechanism was analyzed via plasma leptin, adiponectin, TNF-α, IL-6, VCAM, and CRP levels. One hundred sixty-five subjects were included. Bivariate and multivariate regression showed a linear correlation between waist circumference and hemodynamics in RMCA, with clear gender effects: MFV (global NS, men β - 0.26 p < 0.01; women NS), CvR (global: β - 0.15 p < 0.01; men: β - 0.29 p < 0.01, women: β - 0.19 p < 0.09). For subjects above 65 years, there is no significant relationship between AbP and cerebral hemodynamics. In multivariate regression models, only leptin correlated independently with MFV in RMCA (β 7.24, p < 0.01) and CvR (β - 0.30, p < 0.01). In both cases, waist circumference remains significantly related to both parameters. There is an inverse linear correlation between excess body weight and cerebral hemodynamics, independent of other vascular risk factors and clearly influenced by gender. This relation disappears in the elderly population. Leptin might play a role in this relationship. Nevertheless, there must be another associated mechanism, not identified in this study.

Adiponectin, Leptin and Cardiovascular Disorders

The landmark discoveries of leptin and adiponectin firmly established adipose tissue as a sophisticated and highly active endocrine organ, opening a new era of investigating adipose-mediated tissue crosstalk. Both obesity-associated hyperleptinemia and hypoadiponectinemia are important biomarkers to predict cardiovascular outcomes, suggesting a crucial role for adiponectin and leptin in obesity-associated cardiovascular disorders. Normal physiological levels of adiponectin and leptin are indeed essential to maintain proper cardiovascular function. Insufficient adiponectin and leptin signaling results in cardiovascular dysfunction. However, a paradox of high levels of both leptin and adiponectin is emerging in the pathogenesis of cardiovascular disorders. Here, we (1) summarize the recent progress in the field of adiponectin and leptin and its association with cardiovascular disorders, (2) further discuss the underlying mechanisms for this new paradox of leptin and adiponectin action, and (3) explore the possible application of partial leptin reduction, in addition to increasing the adiponectin/leptin ratio as a means to prevent or reverse cardiovascular disorders.

Effect of Leptin on Chronic Inflammatory Disorders: Insights to Therapeutic Target to Prevent Further Cardiovascular Complication

In response to obesity-associated chronic inflammatory disorders, adipose tissue releases a biologically active peptide known as leptin. Leptin activates the secretion of chemical mediators, which contribute to the pathogenesis of chronic inflammatory disorders, such as rheumatoid arthritis (RA), systemic lupus erythematosus (SLE) and psoriasis. Conversely, adiposity and obesity are the major aggravating risk factors in the pathogenesis of metabolic syndrome (MetS), including type II diabetes mellitus and obesity-associated hypertension. Elevated level of leptin in obesity-associated hypertension causes an increase in the production of aldosterone, which also results in elevation of arterial blood pressure. Hyperleptinemia is associated with the progress of the atherosclerosis through secretion of pro-inflammatory cytokines, like interleukin 6 (IL-6), tumor necrosis factor α (TNF-α), IL-17, and other cytokines to promote inflammation. The release of those cytokines leads to chronic inflammatory disorders and obesity-associated MetS. Thus, the aberrant leptin level in both MetS and chronic inflammatory disorders also leads to the complication of cardiovascular diseases (CVD). Therapeutic target of leptin regarding its pro-inflammatory effect and dysregulated sympathetic nervous system activity may prevent further cardiovascular complication. This review mainly assesses the mechanism of leptin on the pathogenesis and further cardiovascular risk complication of chronic inflammatory disorders.

Adipokines and Arterial Stiffness in the Elderly

INTRODUCTION

The aim of this study was to evaluate the relationship between adipokines and arterial stiffness in a group of 85 elderly subjects and the role of leptin and adiponectin on subclinical vascular damage, defined by a PWV>10 m/s.

METHODS

In each subject, we evaluated anthropometry, body composition by DXA (fat mass, fat mass%, lean mass), metabolic variables, leptin, adiponectin, systolic, diastolic, mean arterial pressure and pulse pressure (SBP, DBP, MAP, PP), carotid-femoral pulse wave velocity (cfPWV) and carotid-radial pulse wave velocity (crPWV).

RESULTS

In the study population, significant associations were observed between cfPWV and crPWV, age, SBP, MAP, waist circumference, fat body mass and leptin. The study population was subdivided in 2 subgroups according to adipokine patterns: group 1 included patients with high adiponectin and low leptin, and group 2 patients had high leptin and low adiponectin. SBP, PP, cfPWV were significantly higher in subjects with high leptin and low adiponectin (group 2). Even after adjustment for gender, fat mass%, MAP, HDL cholesterol and triglycerides, cfPWV was higher in group 2 than group 1. In a logistic binary regression on the entire population, considering subclinical vascular damage as a dependent variable and age, gender, MAP, fat mass%, triglycerides, HDL cholesterol and category of subjects with high leptin and low adiponectin as independent variables, MAP and category of subjects with high leptin and low adiponectin were significant predictors (OR, respectively, 1.09 and 3.61).

CONCLUSION

In conclusion, in the elderly, the presence at the same time of high leptin levels and low adiponectin levels seems to have synergic effects on arterial stiffness.

Effects of Moderate Combined Resistance- and Aerobic-Exercise for 12 Weeks on Body Composition, Cardiometabolic Risk Factors, Blood Pressure, Arterial Stiffness, and Physical Functions, among Obese Older Men: A Pilot Study

We demonstrated the hypothesis that combined exercise improves body composition, cardiometabolic risk factors, blood pressure (BP), arterial stiffness, and physical functions, in obese older men. Older men (n = 20) were randomly assigned to combined exercise training (EXP; n = 10) or control groups (CON; n = 10). The combined exercise was comprised of elastic-band resistance training and walking/running on a treadmill and bicycle at 60–70% of maximal heart rate for 3 days/weeks. EXP showed significant decreases in body weight, body mass index, and %body fat (p < 0.05). The exercise program significantly reduced BP, mean arterial pressure, pulse pressure, and brachial-ankle pulse wave velocity. Furthermore, while the plasma levels of low-density lipoprotein cholesterol and epinephrine were significantly reduced in EXP, VO₂ peak and grip strength were significantly enhanced (p < 0.05). In conclusion, it is indicated that 12-week regular combined exercise improves body composition, cardiometabolic risk factors, hemodynamics, and physical performance in obese older men.

Comparative effects of enalapril versus perindopril on serum levels of leptin and adiponectin in hypertensive patients

Introduction: Abnormal adipokine levels affect blood pressure (BP) regulation. Hypo-adiponectinaemia and hyperleptinaemia were reported in hypertension, little is known about how antihypertensive therapy affects these alterations. This study aimed to evaluate the effects of perindopril versus enalapril on plasma adiponectin, tumour necrosis alpha (TNF-α) and leptin levels in hypertensive individuals.Methods: In the present study, we analysed the samples obtained from 93 treatment-naıve, adult hypertensive patients, randomised to treatement with enalapril (10 mg/d, n = 31), perindopril (5 mg/d, n = 31), or maintained on life style modification (n = 31). Plasma levels of leptin, adiponectin, TNF-α and lipid profile were determined at baseline, and after 3 months.Results: Compared to subjects maintained on lifestyle modification (n = 31), enalapril or perindopril treatment was associated with a significant decrease in BP. Administration of perindopril or enalapril resulted in an increase in plasma adiponectin and a reduction in plasma leptin. No significant changes in lipid profile were observed after treatment.Conclusions: Our results indicate that perindopril is superior to enalapril when it comes to its effect on the human adipose-tissue-derived hormones. This suggests that angiotensin-converting enzyme inhibitors improves the adipokine profile, possibly allowing beneficial effects to hypertensive individuals.

Valsartan Versus Amlodipine Effect on Left Ventricular Multidirectional Deformation and Adipocytokines Levels in Hypertensive Patients: Speckle Tracking Echocardiography

INTRODUCTION

Structural and functional properties of the left ventricle (LV) wall have been reported to be altered in hypertension, even at early stages of the disease. Abnormal adipokine levels affect blood pressure regulation. Hypo-adiponectinaemia and hyper-leptinaemia were reported in hypertension.

AIM

To evaluate the effects of valsartan versus amlodipine on LV deformation also, on plasma adiponectin and leptin levels in hypertensive individuals.

METHODS

LV strain was measured by two-dimensional speckle tracking echocardiography, plasma levels of adiponectin and leptin was determined in 30 healthy individuals served as control group and in 200 hypertensive patients before and after treatment for 6 months with either valsartan 160 mg or amlodipine 10 mg.

RESULTS

Compared to control group longitudinal strain was significantly affected in hypertensive patients, adiponectin was significantly lower while TNF-α, hs-CRP and leptin levels were significantly higher in hypertensive group. A significant improvement in LV functions, along with a decrease in leptin and increase in adiponectin levels in valsartan group compared to amlodipine group.

CONCLUSIONS

Our results indicate that valsartan is superior to amlodipine when it comes to affecting the hormonal function of human adipose tissue. Valsartan has a beneficial effect on LV deformation and function presented in GLS.

Effects of diet and exercise on adipocytokine levels in patients with moderate to severe chronic kidney disease

BACKGROUND AND AIMS

Obesity is a pro-inflammatory risk factor for progression of CKD and cardiovascular disease. We hypothesized that implementation of caloric restriction and endurance exercise would improve adipocytokine profiles in patients with moderate to severe CKD.

METHODS AND RESULTS

We enrolled patients with moderate to severe CKD through a multi-center pilot randomized trial of diet and exercise in a 4-arm design (dietary restriction of 10%-15% reduction in caloric intake, exercise three times/week, combined diet and exercise, and control) (NCT01150851). Adipocytokines (adiponectin and leptin) were measured at the beginning and end of the study period as secondary outcomes. Treatment effect was analyzed in a multivariable model adjusted for baseline outcome values, age, gender, site and diabetes. A total of 122 participants were consented, 111 were randomized (42% female, 25% diabetic, and 91% hypertensive), 104 started intervention and 92 completed the study (Figure 1). Plasma adiponectin levels increased significantly in response to diet by 23% (95% CI: 0.2%, 49.8%, p = 0.048) among participants randomized to the caloric restriction and usual activity arm but not to exercise, whereas circulating leptin did not change by either treatment.

CONCLUSION

Our data suggest that dietary caloric restriction increases plasma adiponectin levels in stage 3-4 CKD patients, with limited effect on leptin levels. These findings suggest the potential for improving the metabolic milieu of CKD with moderate calorie restriction.

Targeting perivascular and epicardial adipose tissue inflammation: therapeutic opportunities for cardiovascular disease

Major shifts in human lifestyle and dietary habits toward sedentary behavior and refined food intake triggered steep increase in the incidence of metabolic disorders including obesity and Type 2 diabetes. Patients with metabolic disease are at a high risk of cardiovascular complications ranging from microvascular dysfunction to cardiometabolic syndromes including heart failure. Despite significant advances in the standards of care for obese and diabetic patients, current therapeutic approaches are not always successful in averting the accompanying cardiovascular deterioration. There is a strong relationship between adipose inflammation seen in metabolic disorders and detrimental changes in cardiovascular structure and function. The particular importance of epicardial and perivascular adipose pools emerged as main modulators of the physiology or pathology of heart and blood vessels. Here, we review the peculiarities of these two fat depots in terms of their origin, function, and pathological changes during metabolic deterioration. We highlight the rationale for pharmacological targeting of the perivascular and epicardial adipose tissue or associated signaling pathways as potential disease modifying approaches in cardiometabolic syndromes.

The Role of Adipokines in the Development of Arterial Stiffness and Hypertension

The study aimed to assess the role and the relationship of adipokines as well as parameters of arterial stiffness in newly diagnosed hypertension. Forty-nine newly diagnosed hypertensive cases (median age 47 ± 6 years) and 48 normotensive patients (median age 47 ± 6 years) were enrolled to this study. Patients underwent echocardiography, noninvasive assessment of hemodynamic parameters using SphygmoCor tonometer (Atcor Med). The levels of the adipokines-leptin, adiponectin, and resistin-were investigated. The augmentation pressure, augmentation index, and pulse wave velocity (PWV) were higher in patients with hypertension compared with controls (Ps < .05). Patients with hypertension had higher E/E' ratio, higher diameter of left atrium, and lower tricuspid annular plane systolic excursion compared with the control group (Ps < .05). Patients with hypertension had significant higher levels of leptin (ng/mL) and lower levels of adiponectin (μg/mL) compared with normotensive patients. The multivariate analysis showed that PWV (odds ratio [OR] 1.95, 95% CI, 1.2-2.9; P = .002) and leptin level (OR 1.01, 95% CI, 1.004-1.031; P = .01) were significantly associated with hypertension. Arterial stiffness as determined by PWV and leptin are associated with newly diagnosed hypertension. Elevated serum leptin level may influence the potential mechanism leading to sympathetic activation.

Ablation of TRPV1 Elevates Nocturnal Blood Pressure in Western Diet-fed Mice

Background: This study tested the hypothesis that genetically ablation of transient receptor potential vanilloid type 1 (TRPV1) exacerbates impairment of baroreflex in mice fed a western diet (WD) and leads to distinct diurnal and nocturnal blood pressure patterns.

Methods: TRPV1 gene knockout (TRPV1^-/-) and wild-type (WT) mice were given a WD or normal diet (CON) for 4 months.

Results: Capsaicin, a selective TRPV1 agonist, increased ipsilateral afferent renal nerve activity in WT but not TRPV1^-/- mice. The sensitivity of renal sympathetic nerve activity and heart rate responses to baroreflex were reduced in TRPV1^-/--CON and WT-WD and further decreased in TRPV1^-/--WD compared to the WT-CON group. Urinary norepinephrine and serum insulin and leptin at day and night were increased in WT-WD and TRPV1^-/--WD, with further elevation at night in TRPV1^-/--WD. WD intake increased leptin, IL-6, and TNF-α in adipose tissue, and TNF-α antagonist III, R-7050, decreased leptin in TRPV1^-/--WD. The urinary albumin level was higher in TRPV1^-/--WD than WT-WD. Blood pressure was not dif-ferent during daytime among all groups, but increased at night in the TRPV1^-/--WD group compared with other groups.

Conclusions: TRPV1 ablation leads to elevated nocturnal but not diurnal blood pressure, which is probably attributed to fur-ther enhancement of sympathetic drives at night.

Influence of Second-Hand Smoke and Prenatal Tobacco Smoke Exposure on Biomarkers, Genetics and Physiological Processes in Children-An Overview in Research Insights of the Last Few Years

Children are commonly exposed to second-hand smoke (SHS) in the domestic environment or inside vehicles of smokers. Unfortunately, prenatal tobacco smoke (PTS) exposure is still common, too. SHS is hazardous to the health of smokers and non-smokers, but especially to that of children. SHS and PTS increase the risk for children to develop cancers and can trigger or worsen asthma and allergies, modulate the immune status, and is harmful to lung, heart and blood vessels. Smoking during pregnancy can cause pregnancy complications and poor birth outcomes as well as changes in the development of the foetus. Lately, some of the molecular and genetic mechanisms that cause adverse health effects in children have been identified. In this review, some of the current insights are discussed. In this regard, it has been found in children that SHS and PTS exposure is associated with changes in levels of enzymes, hormones, and expression of genes, micro RNAs, and proteins. PTS and SHS exposure are major elicitors of mechanisms of oxidative stress. Genetic predisposition can compound the health effects of PTS and SHS exposure. Epigenetic effects might influence in utero gene expression and disease susceptibility. Hence, the limitation of domestic and public exposure to SHS as well as PTS exposure has to be in the focus of policymakers and the public in order to save the health of children at an early age. Global substantial smoke-free policies, health communication campaigns, and behavioural interventions are useful and should be mandatory.

Epicardial Adipose Tissue, Adiponectin and Leptin: A Potential Source of Cardiovascular Risk in Chronic Kidney Disease

The importance of cardiometabolic factors in the inception and progression of atherosclerotic cardiovascular disease is increasingly being recognized. Beyond diabetes mellitus and metabolic syndrome, other factors may be responsible in patients with chronic kidney disease (CKD) for the high prevalence of cardiovascular disease, which is estimated to be 5- to 20-fold higher than in the general population. Although undefined uremic toxins are often blamed for part of the increased risk, visceral adipose tissue, and in particular epicardial adipose tissue (EAT), have been the focus of intense research in the past two decades. In fact, several lines of evidence suggest their involvement in atherosclerosis development and its complications. EAT may promote atherosclerosis through paracrine and endocrine pathways exerted via the secretion of adipocytokines such as adiponectin and leptin. In this article we review the current knowledge of the impact of EAT on cardiovascular outcomes in the general population and in patients with CKD. Special reference will be made to adiponectin and leptin as possible mediators of the increased cardiovascular risk linked with EAT.

Role of Leptin in Cardiovascular Diseases

The adipocyte-derived adipokine leptin exerts pleiotropic effects, which are essential for the regulation of energy balance and cell metabolism, for controlling inflammatory and immune responses, and for the maintenance of homeostasis of the cardiovascular system. Leptin resistance in obese or type 2 diabetes mellitus (T2DM) patients is defined as a decrease in tissue response to leptin. In the cardiovascular system, leptin resistance exhibits the adverse effect on the heart's response to stress conditions and promoting cardiac remodeling due to impaired cardiac metabolism, increased fibrosis, vascular dysfunction, and enhanced inflammation. Leptin resistance or leptin signaling deficiency results in the risk increase of cardiac dysfunction and heart failure, which is a leading cause of obesity- and T2DM-related morbidity and mortality. Animal studies using leptin- and leptin receptor- (Lepr) deficient rodents have provided many useful insights into the underlying molecular and pathophysiological mechanisms of obese- and T2DM-associated metabolic and cardiovascular diseases. However, none of the animal models used so far can fully recapitulate the phenotypes of patients with obese or T2DM. Therefore, the role of leptin in the human cardiovascular system, and whether leptin affects cardiac function directly or acts through a leptin-regulated neurohumoral pathway, remain elusive. As the prevalence of obesity and diabetes is continuously increasing, strategies are needed to develop and apply human cell-based models to better understand the precise role of leptin directly in different cardiac cell types and to overcome the existing translational barriers. The purpose of this review is to discuss the mechanisms associated with leptin signaling deficiency or leptin resistance in the development of metabolic and cardiovascular diseases. We analyzed and comprehensively addressed substantial findings in pathophysiological mechanisms in commonly used leptin- or Lepr-deficient rodent models and highlighted the differences between rodents and humans. This may open up new strategies to develop directly and reliably applicable models, which resemble the human pathophysiology in order to advance health care management of obesity- and T2DM-related cardiovascular complications.

Functional Relationship between Leptin and Nitric Oxide in Metabolism

Leptin, the product of the ob gene, was originally described as a satiety factor, playing a crucial role in the control of body weight. Nevertheless, the wide distribution of leptin receptors in peripheral tissues supports that leptin exerts pleiotropic biological effects, consisting of the modulation of numerous processes including thermogenesis, reproduction, angiogenesis, hematopoiesis, osteogenesis, neuroendocrine, and immune functions as well as arterial pressure control. Nitric oxide (NO) is a free radical synthesized from L-arginine by the action of the NO synthase (NOS) enzyme. Three NOS isoforms have been identified: the neuronal NOS (nNOS) and endothelial NOS (eNOS) constitutive isoforms, and the inducible NOS (iNOS). NO mediates multiple biological effects in a variety of physiological systems such as energy balance, blood pressure, reproduction, immune response, or reproduction. Leptin and NO on their own participate in multiple common physiological processes, with a functional relationship between both factors having been identified. The present review describes the functional relationship between leptin and NO in different physiological processes.

Relationship between BMI and aortic stiffness: influence of anthropometric indices in hypertensive men and women

BACKGROUND

Increased aortic stiffness could be one of the mechanisms by which obesity increases cardiovascular risk independently of traditional risk factors. Studies have suggested that anthropometric indices may be predictors of cardiovascular risk but few studies have investigated their relations with aortic stiffness in high cardiovascular risk population. We investigated the strength of correlation between different anthropometric indices with aortic stiffness in hypertensive and diabetic patients.

METHODS

A cross-sectional study was performed in 474 hypertensive patients. Anthropometric indices were calculated: BMI, waist circumference, waist-hip ratio, and waist-height ratio (WHtR). Aortic stiffness was assessed by measurement of carotid-femoral pulse wave velocity (PWV). Correlations between indices and PWV were investigated by linear regression analyses and hierarchical analyses after adjusting for cardiovascular risk factors.

RESULTS

Regional anthropometric indices were more strongly correlated with PWV than BMI in both sexes. In linear regression analyses, WHtR presented the highest correlation with PWV than other indices in our study population. In adjusted hierarchical regression used, WHtR had the highest additive value on top of BMI while there no additive value of BMI on top of WHtR. These differences remained after adjustment on cardiovascular events. In men WHtR was more closely correlated with PWV than others. In women, waist-hip ratio and WHtR were equally correlated with PWV compared with BMI.

CONCLUSION

Regional anthropometric indices are more closely correlated with PWV than BMI in hypertensive patients. WHtR presents the highest correlation with PWV beyond BMI.

REGISTRATION

The study was registered in the French National Agency for Medicines and Health Products Safety (No. 2013-A00227-38) and was approved by the Advisory Committee for Protection of Persons in Biomedical Research.

Weight Loss and Hypertension in Obese Subjects

Arterial hypertension is strongly related to overweight and obesity. In obese subjects, several mechanisms may lead to hypertension such as insulin and leptin resistance, perivascular adipose tissue dysfunction, renal impairment, renin-angiotensin-aldosterone-system activation and sympathetic nervous system activity. Weight loss (WL) seems to have positive effects on blood pressure (BP). The aim of this review was to explain the mechanisms linking obesity and hypertension and to evaluate the main studies assessing the effect of WL on BP. We analysed studies published in the last 10 years (13 studies either interventional or observational) showing the effect of WL on BP. Different WL strategies were taken into account-diet and lifestyle modification, pharmacological intervention and bariatric surgery. Although a positive effect of WL could be identified in each study, the main difference seems to be the magnitude and the durability of BP reduction over time. Nevertheless, further follow-up data are needed: there is still a lack of evidence about long term effects of WL on hypertension. Hence, given the significant results obtained in several recent studies, weight management should always be pursued in obese patients with hypertension.

Associations of Cardiorespiratory Fitness and Adiposity With Arterial Stiffness and Arterial Dilatation Capacity in Response to a Bout of Exercise in Children

Purpose: To investigate the associations of directly measured peak oxygen uptake ( V˙O2peak ) and body fat percentage (BF%) with arterial stiffness and arterial dilatation capacity in children. Methods: Findings are based on 329 children (177 boys and 152 girls) aged 8-11 years. V˙O2peak was assessed by a maximal cardiopulmonary exercise test on a cycle ergometer and scaled by lean body mass (LM). BF% and LM were measured by bioelectrical impedance. Stiffness index (measure of arterial stiffness) and change in reflection index (ΔRI, measure of arterial dilatation capacity) were assessed by pulse contour analysis. Data were analyzed by linear regression models. Results:V˙O2peak/LM was positively associated with ΔRI in boys adjusted for age and BF% (β = 0.169, P = .03). Further adjustments for systolic blood pressure, heart rate, and the study group had no effect on this association, but additional adjustment for clinical puberty attenuated it (β = 0.171, P = .07). BF% was inversely related to ΔRI in boys adjusted for age and V˙O2peak/LM (β = -0.171, P = .03). V˙O2peak or BF% was not associated with ΔRI in girls or with stiffness index in either boys or girls. Conclusion: Increasing cardiorespiratory fitness and decreasing adiposity may improve arterial health in childhood, especially among boys.

Leptinemia is Associated With Peripheral Artery Disease

BACKGROUND

Leptin, adiponectin, and resistin are in a class of hormones called adipokines that are produced by adipocytes and have been implicated in the causal pathway of atherosclerosis. We examined the association between adipokine levels and peripheral artery disease (PAD), hypothesizing that after adjusting for fat mass, leptin and resistin would be higher, whereas adiponectin would be lower, in patients with PAD.

METHODS

A cross-sectional sample of 179 predominately male (97%) vascular surgery outpatients was recruited from the San Francisco Veterans Affairs Medical Center (SFVAMC). PAD was defined as either an ankle-brachial index < 0.9 plus symptoms of claudication or prior revascularization for symptomatic PAD (n = 141). Controls had an ankle-brachial index ≥0.9 and no history of atherosclerotic disease (n = 38). Adipokines were assayed using commercially available ELISA kits and values were log-transformed. Fat mass was measured using bioelectrical impedance.

RESULTS

In an analysis adjusting for body mass index (BMI) and atherosclerotic risk factors, higher serum leptin was associated with PAD (OR 2.54, 95% CI 1.07-6.01, P = 0.03), whereas high molecular weight adiponectin was inversely associated, though not significantly (OR 0.60, 95% CI 0.33-1.08, P = 0.09). Resistin was not associated with PAD. Sensitivity analyses using fat mass/height² rather than BMI yielded similar results.

CONCLUSIONS

These results indicate that after adjusting for BMI or fat mass, serum leptin levels are positively and independently associated with PAD, whereas high molecular weight adiponectin might be inversely associated. Using a more representative, nonveteran sample, further investigations should focus on the potential role of adipokines in the pathophysiology of PAD as well as determine whether leptin levels have clinical utility in predicting PAD outcomes.

The effect of periodic energy restriction on growth performance, serum biochemical indices, and meat quality in sheep

Energy is a key factor regulated by the neuroendocrine system. The objective of this study was to compare growth performance, serum biochemical indices, carcass traits, meat quality, and nutrient composition of lambs fed restricted metabolizable energy (ME) intakes to mimic the seasonal changes of the natural grasslands of northwest China. Nineteen male Dorper × Small Tailed Han lambs were assigned to treatments, control (CON) fed at 1.0 MJ/W0.75 × d-1 throughout the 180 d study, and restricted ME (RES) fed by sequentially restricting ME every 30 d (0.56, 0.84, 1.0, 0.84, 0.56, and 0.28 MJ/W0.75 × d-1). Lambs were harvested at the end of the study. Lambs fed the CON diet demonstrated higher (P < 0.05) average daily gain (ADG) compared with RES-fed lambs (158.79 and 57.01 g/d, for CON and RES, respectively), although ADG were lower in each period with the last period being a negative ADG for RES-fed lambs resulting in a loss of body weight. Both treatments demonstrated lower ADG in the last 3 study periods compared with the first 2 periods, which may be explained by cold stress (<-3 °C) increasing the lamb's energy requirement. Feeding lambs a restricted ME diet resulted in lower (P < 0.05) blood serum glucose, triglycerides, total protein, calcium, phosphorus, immunoglobulin G, immunoglobulin M, and immunoglobulin A concentrations compared with CON-fed lambs, but both treatments were similar (P > 0.05) for cholesterol and high-density lipoprotein-cholesterol. Feeding lambs a restricted ME diet increased (P < 0.05) meat pH, while reducing the cooked meat rate compared with CON-fed lambs. Thus, the carcass yield, rib eye muscle area, and shear force were lower (P < 0.05) for RES-fed lambs compared with CON-fed lambs. The meat water concentration was higher (P < 0.05), whereas the concentrations of dry matter, crude fat, crude protein, and carbohydrate were lower (P < 0.05) for lambs fed a RES ME diet compared to CON-fed lambs. These results demonstrate that sequentially restricting ME intake, as natural grasslands might experience during seasonal forage quality and quantity changes, resulted in a reduction of body weight because lambs were mobilizing body reserves as a source of ME. The reduction in concentrations of key serum nutrients, as well as carcass traits and meat composition, demonstrate the body is responding to the meet the lambs ME requirements, which has implications for both meat quality and the animal's physiological functions.

Comparison of BMI, waist circumference, and waist-to-height ratio for identification of subclinical cardiovascular risk in pediatric kidney transplant recipients

BACKGROUND

Kidney transplant recipients are at high risk for CV morbidity. However, the measure of obesity that best predicts CV risk has not been established.

OBJECTIVE

A prospective, controlled study was conducted to compare the ability of BMI, WC, and WHr to identify CV risk in pediatric kidney transplant recipients.

METHODS

Transplant recipients, aged 3-20 years, had echocardiogram, CIMT, BMI, WC, WHr, blood pressure, lipids, and leptin measured. Receiver operating characteristic analysis was used to compare the ability of BMI, WC, and WHr to detect a composite adverse CV outcome. Presence of the composite outcome was defined by ≥3 of the following five criteria: (a) LVH, (b) high CIMT, (c) impaired myocardial strain, (d) dyslipidemia, and/or (e) hypertension. Multivariate analysis was conducted by generalized estimating equation regression.

RESULTS

We analyzed 108 visits of 42 transplant recipients. Prevalence of obesity by WHr (43.5%) was higher than BMI (24.1%) and WC (12.0%). Proportion of WHr-obese who met criteria for the adverse CV outcome was higher (62.2%) than BMI (34.6%) and WC-obese (33.3%). Leptin levels were higher in children with obesity. Area under the ROC curve for WHr-obese (0.77) was higher compared to BMI (0.47) and WC (0.48) to detect the CV outcome, P = 0.0006. WHr-obesity was associated with 5.72 increased odds of having the adverse CV outcome, P = 0.0001, while BMI and WC were not significant.

CONCLUSION

WHr is more sensitive than BMI or WC to detect subclinical CV risk and should be included in screening of pediatric kidney transplant recipients.

Hyperleptinemia is associated with the aortic augmentation index in kidney transplant recipients

Objective

Increased circulating leptin, a marker of leptin resistance, is common in patients with obesity and is also an independent factor in prediction of cardiovascular disease. The aim of this study was to evaluate the relationship between fasting serum leptin levels and the aortic augmentation index (AIx) in kidney transplant recipients.

Materials and Methods

Fasting blood samples were obtained from 70 kidney transplant recipients. The aortic AIx was measured using a validated tonometry system (SphygmoCor). Plasma leptin levels were measured using a commercial enzyme-linked immunosorbent assay kit.

Results

Simple linear analysis of the aortic AIx in kidney transplant recipients showed that body fat mass (P = 0.002), diastolic blood pressure (DBP) (P = 0.020), logarithmically transformed triglycerides (P = 0.035), and leptin (P < 0.001) were positively correlated, while height (P = 0.004) and the glomerular filtration rate (P = 0.022) were negatively correlated with the aortic AIx in kidney transplant recipients. Forward stepwise linear regression analysis of the factors significantly associated with the aortic AIx showed that leptin (P < 0.001), DBP (P = 0.014), and body height (P = 0.036) were independent predictors of the aortic AIx in kidney transplant recipients.

Conclusion

These results suggest that the serum fasting leptin level is associated with the aortic AIx in kidney transplant recipients.

The interplay between adipose tissue and the cardiovascular system: is fat always bad?

Obesity is a risk factor for cardiovascular disease (CVD). However, clinical research has revealed a paradoxically protective role for obesity in patients with chronic diseases including CVD, suggesting that the biological 'quality' of adipose tissue (AT) may be more important than overall AT mass or body weight. Importantly, AT is recognised as a dynamic organ secreting a wide range of biologically active adipokines, microRNAs, gaseous messengers, and other metabolites that affect the cardiovascular system in both endocrine and paracrine ways. Despite being able to mediate normal cardiovascular function under physiological conditions, AT undergoes a phenotypic shift characterised by acquisition of pro-oxidant and pro-inflammatory properties in cases of CVD. Crucially, recent evidence suggests that AT depots such as perivascular AT and epicardial AT are able to modify their phenotype in response to local signals of vascular and myocardial origin, respectively. Utilisation of this unique property of certain AT depots to dynamically track cardiovascular biology may reveal novel diagnostic and prognostic tools against CVD. Better understanding of the mechanisms controlling the 'quality' of AT secretome, as well as the communication links between AT and the cardiovascular system, is required for the efficient management of CVD.

Serum leptin is a predictor for central arterial stiffness in hypertensive patients

AIM

Serum adipokines have a role in the development of arterial stiffness. We aimed to investigate the risk factors of developing arterial stiffness and the association of leptin and arterial stiffness in hypertensive (HTN) patients.

METHODS

There were 101 HTN patients enrolled. Fasting blood samples and baseline characteristics were obtained and carotid-femoral pulse wave velocity (cfPWV) was measured with the SphygmoCor system. A cfPWV > 10 m/s was defined as high arterial stiffness, and ≤ 10 m/s as low arterial stiffness.

RESULT

Forty-seven patients (46.5 %) had high arterial stiffness, and had a higher percentage of diabetes (P = 0.044), , older age (P < 0.001), higher pulse pressure (P = 0.049), and higher serum blood urea nitrogen (P = 0.029), creatinine (P = 0.027), intact parathyroid hormone (P = 0.004), serum leptin level (P = 0.002), C-reactive protein (P < 0.001), but lower estimated glomerular filtration rate (P = 0.006) compared to patients with low arterial stiffness. After adjusting for factors significantly associated with arterial stiffness by multivariate logistic regression analysis, it revealed that leptin (aOR = 1.037, 95% CI = 1.007-1.067, P = 0.014), having DM (aOR = 4.885, 95% CI = 1.590-15.006, P = 0.006), and elevated CRP (aOR = 1.503, 95% CI = 1.110-2.0371,P = 0.009) were significant independent predictors of arterial stiffness in HTN patients.

CONCLUSIONS

Serum leptin level could be a predictor for arterial stiffness in HTN patients.

Leptin Modifies the Rat Heart Performance Associated with Mitochondrial Dysfunction Independently of Its Prohypertrophic Effects

BACKGROUND

Functional receptors for leptin were described on the surface of cardiomyocytes, and there was a prohypertrophic effect with high concentrations of the cytokine. Therefore, leptin could be a link between obesity and the prevalence of cardiovascular diseases. On the other hand, a deleterious effect of leptin on mitochondrial performance was described, which was also associated with the evolution of cardiac hypertrophy to heart failure. The goal of our study was to analyze the effect of the exposure of rat hearts to a high concentration of leptin on cardiac and mitochondrial function.

METHODS

Rat hearts were perfused continuously with or without 3.1 nM leptin for 1, 2, 3, or 4 hours. Homogenates and mitochondria were prepared by centrifugation and analyzed for cardiac actin, STAT3, and pSTAT3 by Western blotting, as well as for mitochondrial oxidative phosphorylation, membrane potential, swelling, calcium transport, and content of oxidized lipids.

RESULTS

In our results, leptin induced an increased rate-pressure product as a result of increased heart rate and contraction force, as well oxidative stress. In addition, mitochondrial dysfunction expressed as a loss of membrane potential, decreased ability for calcium transport and retention, faster swelling, and less respiratory control was observed.

CONCLUSIONS

Our results support the role of leptin as a deleterious factor for cardiac function and indicates that mitochondrial dysfunction could be a trigger for cardiac hypertrophy and failure.

Correlation of Adiposity Indices with Electrocardiographic Ventricular Variables and Vascular Stiffness in Young Adults

INTRODUCTION

Excess adiposity constitute an important public health problem because of the associated increased risk of hypertension, coronary heart disease, type 2 diabetes and other disorders. Not only the contribution of general measures of adiposity but also central measures of adiposity have been observed.

AIM

To compare and correlate the central and general adiposity indices with ventricular electrocardiographic variables and vascular stiffness indices in normal, overweight and obese young adults.

MATERIALS AND METHODS

This was a cross-sectional study. Nearly ninety subjects were enrolled and were divided into 30 normal weight, 30 overweight and 30 obese group based on the BMI classification of WHO for Asian population with their age ranging from 18-25 years. Waist and hip circumferences were measured using stretchable tape. Two novel indices-conicity index and abdominal volume index were calculated using standard formula. ECG and pulse wave were recorded using the Physiopac - Medicaid systems. Statistical analysis was done using SPSS version 19.0 software. ANOVA test was done to compare the variables among three groups. Pearson's correlation coefficients were applied to establish the correlations between variables.

RESULTS

In our study Body Mass Index (BMI) and Conicity Index (CI) was significantly and strongly correlated with the ventricular electrocardiographic variables especially with QRS duration, QTc interval and with vascular stiffness indices. These indices can be used to assess the electrocardiographic abnormalities and vascular stiffness status.

CONCLUSION

Excess adipose tissue in young adults was closely linked to ventricular depolarization and repolarization abnormalities and also to increased vascular stiffness. Adiposity indices in particular (BMI, CI) provide a simple and non invasive approach to assess these abnormalities at the earliest in order to prevent future complications.

Leptin predicts short-term major adverse cardiac events in patients with coronary artery disease

INTRODUCTION

Leptin is an adipose tissue-derived hormone associated with cardiovascular risk factors. We examined whether leptin predicts major adverse cardiac events (MACE) in coronary artery disease (CAD) patients.

METHODS

Fasting plasma leptin levels were measured in 1327 male and 619 female CAD patients. The patients were followed up for two years. The primary endpoint (MACE) was the composite of a hospitalisation for congestive heart failure (CHF) or a cardiac death. The secondary endpoint was the composite of an acute coronary syndrome (ACS) or a stroke.

RESULTS

In regression analysis including established risk variables, high leptin levels were associated with a significantly increased risk of MACE (HR 3.37; 95%CI 1.64-6.90; p = 0.001) and ACS or stroke (HR 1.95; 95%CI 1.29-2.96; p = 0.002). Adding leptin to the risk model for MACE increased the C-index from 0.78 (95%CI 0.71-0.85) to 0.81 (0.74-0.88) and improved classification (NRI 0.36; 95%CI 0.13-0.60; p = 0.002) and discrimination of the patients (IDI 0.016; 95%CI 0.001-0.030; p = 0.031).

CONCLUSIONS

High plasma leptin levels predict short-term occurrence of CHF or cardiac death and ACS or stroke in patients with CAD independently of established risk factors. The possible harmful effects of leptin should be thoroughly investigated. Key messages Leptin is a peptide hormone secreted mainly by adipose tissue. It has been associated with several cardiovascular risk factors. High leptin levels predict the short-term occurrence of congestive heart failure or cardiac death and ACS or stroke in patients with CAD independently of established risk factors. The possible detrimental effects of leptin on the cardiovascular system should be thoroughly investigated.

Galantamine alleviates inflammation and insulin resistance in patients with metabolic syndrome in a randomized trial

BACKGROUND

Metabolic syndrome (MetS) is an obesity-driven condition of pandemic proportions that increases the risk of type 2 diabetes and cardiovascular disease. Pathophysiological mechanisms are poorly understood, though inflammation has been implicated in MetS pathogenesis. The aim of this study was to assess the effects of galantamine, a centrally acting acetylcholinesterase inhibitor with antiinflammatory properties, on markers of inflammation implicated in insulin resistance and cardiovascular risk, and other metabolic and cardiovascular indices in subjects with MetS.

METHODS

In this randomized, double-blind, placebo-controlled trial, subjects with MetS (30 per group) received oral galantamine 8 mg daily for 4 weeks, followed by 16 mg daily for 8 weeks or placebo. The primary outcome was inflammation assessed through plasma levels of cytokines and adipokines associated with MetS. Secondary endpoints included body weight, fat tissue depots, plasma glucose, insulin, homeostasis model assessment of insulin resistance (HOMA-IR), cholesterol (total, HDL, LDL), triglycerides, BP, heart rate, and heart rate variability (HRV).

RESULTS

Galantamine resulted in lower plasma levels of proinflammatory molecules TNF (-2.57 pg/ml [95% CI -4.96 to -0.19]; P = 0.035) and leptin (-12.02 ng/ml [95% CI -17.71 to -6.33]; P < 0.0001), and higher levels of the antiinflammatory molecules adiponectin (2.71 μg/ml [95% CI 1.93 to 3.49]; P < 0.0001) and IL-10 (1.32 pg/ml, [95% CI 0.29 to 2.38]; P = 0.002) as compared with placebo. Galantamine also significantly lowered plasma insulin and HOMA-IR values, and altered HRV.

CONCLUSION

Low-dose galantamine alleviates inflammation and insulin resistance in MetS subjects. These findings support further study of galantamine in MetS therapy.

TRIAL REGISTRATION

ClinicalTrials.gov, number NCT02283242.

FUNDING

Fundação de Amparo a Pesquisa do Estado de São Paulo (FAPESP) and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Brazil, and the NIH.