Cardiac Remodeling in Obesity

Obesity and Serial NT-proBNP Levels in Guided Medical Therapy for Heart Failure With Reduced Ejection Fraction: Insights From the GUIDE-IT Trial

Background

Obese patients have lower NT‐proBNP (N‐terminal pro‐B‐type natriuretic peptide) levels. The prognostic implications of achieving NT‐proBNP levels ≤1000 pg/mL in obese patients with heart failure (HF) receiving biomarker‐guided therapy are not completely known. We evaluated the prognostic implications of obesity and having NT‐proBNP levels (≤1000 pg/mL) in the GUIDE‐IT (Guiding Evidence‐Based Therapy Using Biomarker‐Intensified Treatment in HF) trial participants.

Methods and Results

The risk of adverse cardiovascular events (HF hospitalization or cardiovascular mortality) was assessed using multivariable‐adjusted Cox proportional hazard models based on having NT‐proBNP ≤1000 pg/mL (taken as a time‐varying covariate), stratified by obesity status. The study outcome was also assessed on the basis of the body mass index at baseline. The predictive ability of NT‐proBNP for adverse cardiovascular events was assessed using the likelihood ratio test. Compared with nonobese patients, obese patients were mostly younger, Black race, and more likely to be women. NT‐proBNP levels were 59.0% (95% CI, 39.5%–83.5%) lower among obese individuals. The risk of adverse cardiovascular events was lower in obese (hazard ratio [HR], 0.48; 95% CI, 0.29–0.59) and nonobese (HR, 0.32; 95% CI, 0.19–0.57) patients with HF who had NT‐proBNP levels ≤1000 pg/mL, compared with those who did not. There was no interaction between obesity and having NT‐proBNP ≤1000 pg/mL on the study outcome (P>0.10). Obese patients had a greater risk of developing adverse cardiovascular events (HR, 1.39; 95% CI, 1.01–1.90) compared with nonobese patients. NT‐proBNP was the strongest predictor of adverse cardiovascular event risk in both obese and nonobese patients.

Conclusions

On‐treatment NT‐proBNP level ≤1000 pg/mL has favorable prognostic implications, irrespective of obesity status. NT‐proBNP levels were the strongest predictor of cardiovascular events in both obese and nonobese individuals in this trial.

Registration

URL: https://www.clinicaltrials.gov; Unique identifier: NCT01685840.

Diverse Adiposity and Atrio-Ventricular Dysfunction across Obesity Phenotypes: Implication of Epicardial Fat Analysis

Obesity has been conceptualized as a highly heterogeneous condition. We aim to investigate chamber-specific effects of obesity on the heart and relevant outcomes. A total of 2944 symptom-free individuals (age: 47.5 ± 10.0 years), free of known cardiovascular diseases were classified into four categories based on body mass index (BMI) (as normal-weight (NW) vs. overweight/obese (O)) and metabolic status (metabolically-healthy (MH) vs. unhealthy (MU)). Epicardial adipose thickness (EAT) using echocardiography method. Speckle-tracking based atrio-ventricular (LA/LV) deformations including global longitudinal strain (GLS) and peak atrial longitudinal strain (PALS) were also analyzed. MUNW had higher cardiometabolic risks and more impaired diastolic and GLS/PALS than MHNW phenotype. Both MHO and MUO phenotypes exhibited worst atrial functions. Greater EAT was independently associated with worse GLS and PALS after correcting for various anthropometrics, LV mass and LA volume, respectively, with unfavorable LA effects from EAT being more pronounced in the NW phenotypes (both p interactions < 0.05). During a median follow-up period of 5.3 years, BMI/EAT improved the reclassification for atrial fibrillation (AF) incidence (p for net reclassification improvement < 0.05) mainly in the NW phenotypes (p interaction < 0.001). Categorization of clinical obesity phenotypes based on excessive visceral adiposity likely provides increment prognostic impacts on atrial dysfunction, particularly in non-obese phenotypes.

Cardiovascular Imaging in Obesity

Obesity represents one of the most challenging public health problems of our century. It accounts for approximately 5% of deaths worldwide, mostly owing to cardiovascular disease and its associated complications. Cardiovascular noninvasive imaging may provide early accurate information about hypertrophy and ischemia/fibrosis in obese subjects. Echocardiography and nuclear cardiology have serious limitations in obese subjects owing to poor acoustic window and attenuation artifacts, respectively. Coronary computed tomography angiography can provide information about obstructive coronary disease; however, the use of radiation is a serious disadvantage. Finally, cardiac magnetic resonance (CMR) holds the promise of an "all in one" examination by combining evaluation of function, wall motion/thickness, stress rest/perfusion, replacement and diffuse fibrosis without radiation. Future studies are required to document the cost/benefit ratio of the CMR in the evaluation of cardiovascular risk in overweight/obese children and adolescents.

Sarcomere mutation negative hypertrophic cardiomyopathy is associated with ageing and obesity

Background

Despite advances in our understanding of the genetic causes of hypertrophic cardiomyopathy (HCM), a large portion of this patient population do not carry sarcomere gene mutations when screened. It remains largely unknown why patients without sarcomere mutations develop asymmetric myocardial hypertrophy.

Methods

We performed a retrospective analysis of probands with HCM who underwent genetic testing to determine if clinical phenotypes were different depending on sarcomere mutation status. A medical history, three generation family history and clinical phenotyping were performed on 127 probands with HCM. Genetic screening was performed using clinically available HCM genetic testing panels.

Results

We found that probands with HCM with pathogenic sarcomere mutations were over three times more likely to have a family history of HCM (66% vs 17%, p<0.0001) and were diagnosed with HCM at a much younger age (32 vs 51 years old, p<0.0001). In contrast, probands with HCM without sarcomere mutations were significantly more obese (body surface area p=0.003, body mass index p=0.04 adjusted for age) and were more likely to present with left ventricular outflow tract obstruction (p=0.0483).

Conclusion

Patients with sarcomere mutation negative HCM present at an older age and are more obese compared with patients with sarcomere mutation positive HCM. The role of ageing and obesity in asymmetric myocardial hypertrophy warrants further investigation.

Mechanisms and Perspectives of Sodium-Glucose Co-transporter 2 Inhibitors in Heart Failure

Heart failure (HF) is a common complication or late-stage manifestation of various heart diseases. Numerous risk factors and underlying causes may contribute to the occurrence and progression of HF. The pathophysiological mechanisms of HF are very complicated. Despite accumulating advances in treatment for HF during recent decades, it remains an intractable clinical syndrome with poor outcomes, significantly reducing the quality of life and expectancy of patients, and imposing a heavy economic burden on society and families. Although initially classified as antidiabetic agents, sodium-glucose co-transporter 2 (SGLT2) inhibitors have demonstrated reduced the prevalence of hospitalization for HF, cardiovascular death, and all-cause death in several large-scale randomized controlled clinical trials. These beneficial effects of SGLT-2 inhibitors can be attributed to multiple hemodynamic, inflammatory and metabolic mechanisms, not only reducing the serum glucose level. SGLT2 inhibitors have been used increasingly in treatment for patients with HF with reduced ejection fraction due to their surprising performance in improving the prognosis. In addition, their roles and mechanisms in patients with HF with preserved ejection fraction or acute HF have also attracted attention. In this review article, we discuss the possible mechanisms and applications of SGLT2 inhibitors in HF.

Effect of bariatric surgery on cardiac structure and function in obese patients: Role of the renin-angiotensin system

Echocardiographic alterations have been described in obesity, but their modifications after bariatric surgery (BS) and mechanisms are little known, mostly in normotensive patients. We aimed to analyze cardiac changes 1 year post‐BS and to explore possible mechanisms. A cohort of patients with severe obesity (58% normotensives) were prospectively recruited and examined before surgery and after 12 months. Clinical and echocardiographic data, 24 h BP, renin‐angiotensin‐aldosterone system (RAAS) components, cytokines, and inflammatory markers were analyzed at these two time points. Overall reduction in body weight was mean (IQR) = 30.0% (25.9–33.8). There were statistically significant decreases in left ventricle mass index^2.7(LVMI)^2.7, septum thickness (ST), posterior wall thickness (PWT), relative wall thickness (RWT), and E/e’, both in the whole cohort and in patients without RAAS blockers (p ≤ .04 for all). Plasma renin activity (PRA) decreased from (median, IQR) = 0.8 (0.3;1.35) to 0.4 (0.2;0.93) ng/ml/h, plasma aldosterone from 92 (58.6;126) to 68.1 (56.2;83.4) ng/dl, and angiotensin‐converting enzyme (ACE)‐2 activity from 7.7 (5.7;11.8) to 6.8 (5.3;11.2) RFU/µl/h, p < .05. The body weight loss correlated with a decrease in both 24 h SBP and 24 h DBP (Pearson's coefficient 0.353, p = .022 and 0.384, p = .012, respectively). Variation (Δ) of body weight correlated with ΔE/e’ (Pearson's coeff. 0.414, p = .008) and with Δ lateral e’ (Pearson's coeff. = −0.363, p = .018). Generalized linear models showed that ΔPRA was an independent variable for the final (12‐months post‐BS) LVMI^2.7 (p = .028). No other changes in cardiac parameters correlated with ΔBP. In addition to the respective baseline value, final values of PWT and RWT were dependent on 12‐month Δ of PRA, ACE, and ACE/ACE2 (p < .03 for all). We conclude that there are cardiac changes post‐BS in patients with severe obesity, normotensives included. Structural changes appear to be related to modifications in the renin‐angiotensin axis.

Joint influences of obesity, diabetes, and hypertension on indices of ventricular remodeling: Findings from the community-based Framingham Heart Study

Introduction

Obesity, hypertension, and diabetes are independently associated with cardiac remodeling and frequently co-cluster. The conjoint and separate influences of these conditions on cardiac remodeling have not been investigated.

Materials and methods

We evaluated 5,741 Framingham Study participants (mean age 50 years, 55% women) who underwent echocardiographic measurements of left ventricular (LV) mass (LVM), LV ejection fraction (LVEF), global longitudinal strain (GLS), mitral E/e’, left atrial end-systolic (peak) dimension (LASD) and emptying fraction (LAEF). We used multivariable generalized linear models to estimate the adjusted-least square means of these measures according to cross-classified categories of body mass index (BMI; normal, overweight and obese), hypertension (yes/no), and diabetes (yes/no).

Results

We observed statistically significant interactions of BMI category, hypertension, and diabetes with LVM, LVEF, GLS, and LAEF (p for all 3-way interactions <0.01). Overweight and obesity (compared to normal BMI), hypertension, and diabetes status were individually and conjointly associated with higher LVM and worse GLS (p<0.01 for all). We observed an increase of 34% for LVM and of 9% for GLS between individuals with a normal BMI and without hypertension or diabetes compared to obese individuals with hypertension and diabetes. Presence of hypertension was associated with higher LVEF, whereas people with diabetes had lower LVEF.

Conclusions

Obesity, hypertension, and diabetes interact synergistically to influence cardiac remodeling. These findings may explain the markedly heightened risk of heart failure and cardiovascular disease when these factors co-cluster.

NLRP3 inflammasome deficiency attenuates metabolic disturbances involving alterations in the gut microbial profile in mice exposed to high fat diet

Obesity-related diseases (e.g. type 2 diabetes mellitus and cardiovascular disorders) represent an increasing health problem worldwide. NLRP3 inflammasome activation may underlie obesity-induced inflammation and insulin resistance, and NLRP3 deficient mice exposed to high fat diet (HFD) appear to be protected from left ventricle (LV) concentric remodeling. Herein, we investigated if these beneficial effects were associated with alterations in plasma metabolites, using metabolomic and lipidomic analysis, and gut microbiota composition, using 16S rRNA sequencing of cecum content, comparing NLRP3 deficient and wild type (WT) mice on HFD and control diet. Obese NLRP3 deficient mice had lower systemic ceramide levels, potentially resulting attenuating inflammation, altered hepatic expression of fatty acids (FA) with lower mono-saturated FA and higher polyunsaturated FA levels, potentially counteracting development of liver steatosis, downregulated myocardial energy metabolism as assessed by proteomic analyses of LV heart tissue, and different levels of bile acids as compared with WT mice. These changes were accompanied by an altered composition of gut microbiota associated with decreased systemic levels of tri-methylamine-N-oxide and lipopolysaccharide, potentially inducing attenuating systemic inflammation and beneficial effects on lipid metabolism. Our findings support a role of NLRP3 inflammasome in the interface between metabolic and inflammatory stress, involving an altered gut microbiota composition.

Unraveling the Genotype-Phenotype Relationship in Hypertrophic Cardiomyopathy: Obesity-Related Cardiac Defects as a Major Disease Modifier

Hypertrophic cardiomyopathy (HCM) is the most common inherited cardiomyopathy and is characterized by asymmetric septal thickening and diastolic dysfunction. More than 1500 mutations in genes encoding sarcomere proteins are associated with HCM. However, the genotype‐phenotype relationship in HCM is incompletely understood and involves modification by additional disease hits. Recent cohort studies identify obesity as a major adverse modifier of disease penetrance, severity, and clinical course. In this review, we provide an overview of these clinical findings. Moreover, we explore putative mechanisms underlying obesity‐induced sensitization and aggravation of the HCM phenotype. We hypothesize obesity‐related stressors to impact on cardiomyocyte structure, metabolism, and homeostasis. These may impair cardiac function by directly acting on the primary mutation‐induced myofilament defects and by independently adding to the total cardiac disease burden. Last, we address important clinical and pharmacological implications of the involvement of obesity in HCM disease modification.

The Cardiotonic Steroid Marinobufagenin Is a Predictor of Increased Left Ventricular Mass in Obesity: The African-PREDICT Study

The endogenous Na+/K+-ATPase inhibitor, marinobufagenin (MBG), strongly associates with salt intake and a greater left ventricular mass index (LVMi) in humans and was shown to promote cardiac fibrosis and hypertrophy in animals. The adverse effects of MBG on cardiac remodeling may be exacerbated with obesity, due to an increased sensitivity of Na+/K+-ATPase to MBG. This study determined whether MBG is related to the change in LVMi over time in adults with a body mass index (BMI) ≥30 kg/m2 (obese) and <30 kg/m2 (non-obese). The study followed 275 healthy participants (aged 20-30 years) from the African-Prospective study on the Early Detection and Identification of Cardiovascular disease and Hypertension (African-PREDICT) study over 4.5 years. At baseline, we measured 24 h urine MBG excretion. MBG levels were positively associated with salt intake. LVMi was determined by two-dimensional echocardiography at baseline and after >4.5 years. With multivariate adjusted analyses in obese adults (N = 56), we found a positive association of follow-up LVMi (Adjusted (Adj.) R2 = 0.35; Std. β = 0.311; p = 0.007) and percentage change in LVMi (Adj. R2 = 0.40; Std. β = 0.336; p = 0.003) with baseline MBG excretion. No association of LVMi (Adj. R2 = 0.37; p = 0.85) or percentage change in LVMi (Adj. R2 = 0.19; p = 0.68) with MBG excretion was evident in normal weight adults (N = 123). These findings suggest that obese adults may be more sensitive to the adverse cardiac effects of MBG and provide new insight into the potential role of dietary salt, by way of MBG, in the pathogenesis of cardiac remodeling in obese individuals.

Effect of a Weight Loss Program on Biochemical and Immunological Profile, Serum Leptin Levels, and Cardiovascular Parameters in Obese Dogs

This study aimed to investigate the effects of a weight loss program (WLP) on biochemical and immunological profile, and cardiovascular parameters in a cohort of dogs with naturally occurring obesity. Eleven obese dogs [body condition scoring (BCS), ≥7/9] were enrolled into the study and underwent clinical and cardiovascular examination, and blood testing before (T0) and after 6 months (T1) of WLP. Eleven normal weight (BCS, 4/5) healthy dogs were used as a control (CTR) group. Compared to the CTR group, at T0 obese dogs expressed higher serum leptin concentrations (p < 0.0005) that significantly decreased after weight loss (p < 0.005) but remained higher than the CTR group. Furthermore, obese dogs showed considerably lower levels (p < 0.0005) of regulatory T cell (Treg) compared to the CTR group, but they did not change after weight loss at T1. In obese dogs, tumor necrosis factor (TNF)-α and interleukin (IL)-6 concentrations were substantially reduced at T1 (p < 0.0001 and p < 0.005). Regarding the cardiovascular parameters, only one obese dog was hypertensive at T0, and systolic blood pressure values showed no significant differences at the end of the WLP. The ratio of interventricular septal thickness in diastole to left ventricle internal diameter in diastole (IVSd/LVIDd) was significantly greater in obese dogs at T0 than in the CTR group (p < 0.005). It decreased after weight loss (p < 0.05). In obese dogs, troponin I level significantly reduced with weight loss (p < 0.05), while endothelin-1 level did not differ statistically. The results suggest that the immune dysregulation in the presence of high leptin levels and reduced number of Treg could affect obese dogs as well as humans. Based on our findings, we may speculate that a more complete immune-regulation restore could be obtained by a greater reduction in fat mass and a longer-term WLP. Finally, left ventricular remodeling may occur in some obese dogs. However, in canine species, further studies are needed to investigate the impact of obesity and related WLP on cardiovascular system.

Longitudinal Changes in Cardiac Structure and Function in Severe Obesity: 11-Year Follow-Up in the Utah Obesity Study

Background

Progressive cardiac remodeling and worsening myocardial function over time have been proposed as potential mediators of heart failure in obesity.

Methods and Results

We serially assessed cardiac structure and function in 254 subjects participating in a longitudinal study of obesity. Demographic, clinical, laboratory, and echocardiographic features were determined at baseline and 2‐, 6‐, and 11‐year follow‐up. We measured body mass index (BMI) exposure as the area under the curve of the BMI at each of the 4 visits. At enrollment, mean age of the subjects was 47 years, 79% were women, mean BMI was 44 kg/m², 26% had diabetes mellitus, 48% had hypertension, and 53% had hyperlipidemia. Between baseline and 11 years, BMI increased by 1.1 and 0.3 kg/m² in men and women, respectively. There were modest increases in left ventricular (LV) end‐diastolic volume, LV mass, and left atrial volume, and significant decreases in early/late mitral diastolic flow velocity ratio and E wave deceleration time. However, there were no significant changes in LV ejection fraction or ratio of early mitral diastolic flow velocity/early mitral annular velocity, whereas right ventricular fractional area change increased. Significant predictors of the change in LV mass were male sex, baseline BMI, BMI area under the curve, and change in LV stroke volume, but not smoking, hypertension, or diabetes mellitus.

Conclusions

In long‐standing, persistent severe obesity, there was evidence of cardiac remodeling over a period of 11 years, but no clear worsening of systolic or diastolic function. Measures of remodeling were most strongly related to BMI. The observed changes might predispose to heart failure with preserved ejection fraction, but are not classic for an evolving dilated cardiomyopathy.

Cardiovascular magnetic resonance native T2 and T2* quantitative values for cardiomyopathies and heart transplantations: a systematic review and meta-analysis

BACKGROUND

The clinical application of cardiovascular magnetic resonance (CMR) T2 and T2* mapping is currently limited as ranges for healthy and cardiac diseases are poorly defined. In this meta-analysis we aimed to determine the weighted mean of T2 and T2* mapping values in patients with myocardial infarction (MI), heart transplantation, non-ischemic cardiomyopathies (NICM) and hypertension, and the standardized mean difference (SMD) of each population with healthy controls. Additionally, the variation of mapping outcomes between studies was investigated.

METHODS

The PRISMA guidelines were followed after literature searches on PubMed and Embase. Studies reporting CMR T2 or T2* values measured in patients were included. The SMD was calculated using a random effects model and a meta-regression analysis was performed for populations with sufficient published data.

RESULTS

One hundred fifty-four studies, including 13,804 patient and 4392 control measurements, were included. T2 values were higher in patients with MI, heart transplantation, sarcoidosis, systemic lupus erythematosus, amyloidosis, hypertrophic cardiomyopathy (HCM), dilated cardiomyopathy (DCM) and myocarditis (SMD of 2.17, 1.05, 0.87, 1.39, 1.62, 1.95, 1.90 and 1.33, respectively, P <  0.01) compared with controls. T2 values in iron overload patients (SMD = - 0.54, P = 0.30) and Anderson-Fabry disease patients (SMD = 0.52, P = 0.17) did both not differ from controls. T2* values were lower in patients with MI and iron overload (SMD of - 1.99 and - 2.39, respectively, P <  0.01) compared with controls. T2* values in HCM patients (SMD = - 0.61, P = 0.22), DCM patients (SMD = - 0.54, P = 0.06) and hypertension patients (SMD = - 1.46, P = 0.10) did not differ from controls. Multiple CMR acquisition and patient demographic factors were assessed as significant covariates, thereby influencing the mapping outcomes and causing variation between studies.

CONCLUSIONS

The clinical utility of T2 and T2* mapping to distinguish affected myocardium in patients with cardiomyopathies or heart transplantation from healthy myocardium seemed to be confirmed based on this meta-analysis. Nevertheless, variation of mapping values between studies complicates comparison with external values and therefore require local healthy reference values to clinically interpret quantitative values. Furthermore, disease differentiation seems limited, since changes in T2 and T2* values of most cardiomyopathies are similar.

Echocardiography in the Era of Obesity

Patients with obesity are at increased risk for coronary artery disease and heart failure and often present with symptoms of dyspnea, fatigue, edema, or chest pain. Echocardiography is frequently used to help distinguish whether these symptoms are due to cardiac disease. Unfortunately, obesity has a significant impact on image quality because of signal attenuation. Ultrasound-enhancing agents may improve the detection of structural remodeling and subclinical left ventricular dysfunction in patients with obesity. Assessment of chamber sizes and cardiac remodeling in severely obese subjects must be interpreted with caution, however, as the current recommendations for indexing cardiac chamber sizes to body size may lead to false conclusions about chamber volumes or mass, particularly in settings in which weight is changing. As a result of increases in stroke volume and cardiac output, obesity may exacerbate hemodynamic compromise in obstructive structural or valvular disease. With regard to assessment of ischemic heart disease, stress echocardiography can effectively risk-stratify patients with obesity and may have advantages over other noninvasive modalities. In general, transesophageal echocardiography is safe in patients with obesity, although some precautions should be observed. Stress echocardiography using the transesophageal approach is an alternative for preoperative or ischemia evaluation in patients with suboptimal transthoracic views.

Correction of QRS voltage for body mass index does not improve the prediction of fatal and nonfatal cardiovascular events. The Moli-sani study

BACKGROUND AND AIMS

The diagnosis of LVH by ECG may particularly difficult in obese individuals. The aim of this study was to prospectively investigate whether the correction for body mass index (BMI) might improve the prognostic significance for cerebro and cardiovascular events of two electrocardiographic (ECG) criteria for left ventricular hypertrophy (LVH) in a large cohort of Italian adults.

METHODS AND RESULTS

In 18,330 adults (54 ± 11 years, 55% women) from the Moli-sani cohort, obesity was defined using the ATPIII criteria. The Sokolow-Lyon (SL) and Cornell Voltage (CV) criteria were used for ECG-LVH. In overweight and obese subjects, as compared with normal weight, the prevalence of ECG-LVH by the SL index was lower. During follow-up (median 4.3 yrs), 503 cerebro and cardiovascular events occurred. One standard deviation (1-SD) increment in uncorrected and in BMI-corrected SL index and CV was associated with an increased risk of events (HR 1.12, 95% CI 1.02-1.22 and HR 1.16, 95% CI 1.06-1.26 and HR 1.12, 95% CI 1.03-1.23 and HR 1.17, 95% CI 1.07-1.27, respectively for SL and CV). In obese subjects, 1-SD increment in uncorrected CV and in BMI-corrected CV was not associated to a significant risk of events (HR 1.05, 95% CI 0.910-1.22 and HR 1.08, 95% CI 0.95-1.23 respectively). Uncorrected SL index showed a significant association with events, which was marginally stronger with BMI-corrected SL voltage (HR 1.18, 95% CI 1.02-1.37 and HR 1.17, 95% CI 1.04-1.33 respectively, Akaike information criterion change from 3220 to 3218).

CONCLUSIONS

BMI correction of ECG LVH voltage criteria does not significantly improve the prediction of cerebro and cardiovascular events in obese patients in a large cohort at low cardiovascular risk.

Association between insulin resistance and risk of atrial fibrillation in non-diabetics

AIMS

Previous studies from Western countries have been unable to demonstrate a relationship between insulin resistance and new-onset atrial fibrillation. We aimed to evaluate this relationship in the nondiabetic Asian population.

METHODS

Between 2001-2003, 8175 adults (mean age 51.5 years, 53% women) without both existing atrial fibrillation and diabetes and with insulin resistance measures at baseline were enrolled and were followed by biennial electrocardiograms thereafter until 2014. We constructed multivariable-adjusted Cox proportional hazard models for risk of incident atrial fibrillation.

RESULTS

Over a median follow-up of 12.3 years, 136 participants (1.89/1000 person-years) developed atrial fibrillation. Higher homeostasis model assessment of insulin resistance (HOMA-IR) was independently associated with newly developed atrial fibrillation (hazard ratio 1.61, 95% confidence interval 1.14-2.28). Atrial fibrillation development increased at the HOMA-IR levels approximately between 1-2.5, and then plateaued afterwards (p = 0.031).

CONCLUSION

There is a significant relationship between insulin resistance and atrial fibrillation development independent of other known risk factors, including obesity in a nondiabetic Asian population.

Ghrelin protects against obesity-induced myocardial injury by regulating the lncRNA H19/miR-29a/IGF-1 signalling axis

BACKGROUND

Obesity is associated with the impairment of cardiac fitness and consequent ventricular dysfunction and heart failure. Ghrelin has been largely documented to be cardioprotective against ischaemia/reperfusion injury. However, the role of ghrelin in obesity-induced myocardial injury is largely unknown. This study sought to determine the cardiac effect of ghrelin against obesity-induced injury and the underlying mechanisms.

METHODS

The effect of ghrelin was evaluated in a mouse model of obesity and a palmitic acid (PA)-treated cardiomyocyte cell line with or without ghrelin transfection. Gene and protein expression levels were determined by real-time PCR and western blot, respectively. Cell apoptosis was measured by flow cytometry analysis.

RESULTS

In the present study, we found that both a high-fat diet (HFD) and PA treatment caused myocardial injury by increasing apoptosis and the expression of inflammatory cytokines. Overexpression of ghrelin reversed the effects induced by HFD or PA treatment. Knockdown of lncRNA H19 or overexpression of miR-29a abrogated the cardioprotective effects of ghrelin against apoptosis and inflammation. We also found that IGF-1 was a target gene of miR-29a and that H19 regulated IGF-1 expression via miR-29a. Overexpression of IGF-1 partially reversed the apoptosis and inflammation promoting effects of miR-29a.

CONCLUSIONS

Our findings suggested that ghrelin protected against obesity-induced myocardial injury by regulating the H19/miR-29a/IGF-1 signalling axis, providing further evidence for the clinical application of ghrelin.

Cardiac hypertrophy with obesity is augmented after pregnancy in C57BL/6 mice

BACKGROUND

Over a third of reproductive-age women in the USA are obese, and the prevalence of cardiovascular disease (CVD) is rising in premenopausal women. Cardiac hypertrophy is an independent predictor of CVD. In contrast to pregnancy, where transiently increased left ventricular (LV) mass is not associated with cardiac damage, obesity-mediated cardiac hypertrophy is pathological. There is a paucity of data describing the effect of obesity during pregnancy on maternal cardiovascular health. The purpose of this study was to determine the long-term effect of obesity during pregnancy on cardiac function and structure in mice.

METHODS

Female C57BL/6 J mice were fed a high-fat (HF) or a low-fat (LF) diet for 20 weeks. After 4 weeks, LF- and HF-fed female mice were either crossed with males to become pregnant or remained non-pregnant controls. Following delivery, pups were euthanized, and females maintained on respective diets. After 20 weeks of diet feeding, cardiac function was quantified by echocardiography, and plasma leptin and adiponectin concentrations quantified in LF- and HF-fed postpartum and nulliparous females. mRNA abundance of genes regulating cardiac hypertrophy and remodeling was quantified from left ventricles using the NanoString nCounter Analysis System. Cardiac fibrosis was assessed from picrosirius red staining of left ventricles.

RESULTS

HF-fed postpartum mice had markedly greater weight gain and fat mass expansion with obesity, associated with significantly increased LV mass, cardiac output, and stroke volume compared with HF-fed nulliparous mice. Plasma leptin, but not adiponectin, concentrations were correlated with LV mass in HF-fed females. HF feeding increased LV posterior wall thickness; however, LV chamber diameter was only increased in HF-fed postpartum females. Despite the marked increase in LV mass in HF-fed postpartum mice, mRNA abundance of genes regulating fibrosis and interstitial collagen content was similar between HF-fed nulliparous and postpartum mice. In contrast, only HF-fed postpartum mice exhibited altered expression of genes regulating the extracellular matrix.

CONCLUSIONS

These results suggest that the combined effects of pregnancy and obesity augment cardiac hypertrophy and promote remodeling. The rising prevalence of CVD in premenopausal women may be attributed to an increased prevalence of women entering pregnancy with an overweight or obese BMI.

High salt intake during puberty leads to cardiac remodelling and baroreflex impairment in lean and obese male Wistar rats

Modern lifestyle increases the prevalence of obesity and its co-morbidities in the young population. High-salt (HS) diets are associated with hypertension and cardiac remodelling. The present study evaluated the potential effects of cardiometabolic programming induced by HS intake during puberty in lean and obese rats. Additionally, we investigated whether HS could exacerbate the impairment of cardiovascular parameters in adult life due to postnatal early overnutrition (PO). At postnatal day 3 (PN3), twenty-four litters of Wistar rats were divided into two groups: normal litter (NL, nine pups/dam) and small litter (SL, three pups/dam) throughout the lactation period; weaning was at PN21. At PN30, the pups were subdivided into two more groups: NL plus HS (NLHS) and SL plus HS (SLHS). HS intake was from PN30 until PN60. Cardiovascular parameters were evaluated at PN120. SL rats became overweight at adulthood due to persistent hyperphagia; however, HS exposure during puberty reduced the weight gain and food intake of NLHS and SLHS. Both HS and obesity raised the blood pressure, impaired baro- and chemoreflex sensitivity and induced cardiac remodelling but no worsening was observed in the association of these factors, except a little reduction in the angiotensin type-2 receptor in the hearts from SLHS animals. Our results suggest that the response of newborn offspring to PO and juveniles to a HS diet leads to significant changes in cardiovascular parameters in adult rats. This damage may be accompanied by impairment of both angiotensin signalling and antioxidant defence in the heart.

In vitro and in vivo cardioprotective and metabolic efficacy of vitamin E TPGS/Apelin

AIMS

Apelin and vitamin E have been proposed as signaling molecules, but their synergistic role is unknown. The aim of this work was to develop vitamin E TPGS/Apelin system to test their cardioprotective and metabolic efficacy in vitro and in vivo.

METHODS

FDA-approved surfactant D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS-1000) and Apelin complex were characterized by physico-chemical methods (CMC determination, dynamic light scattering and circular dichroism). In vitro studies were carried out on H9C2 cardiomyoblasts and isolated murine cardiomyocytes. In vivo studies were performed in isoproterenol- and high-fat diet-induced cardiac remodeling models in mice.

RESULTS

We found that vitamin E TPGS/Apelin provide cardioprotective and metabolic efficacy in vitro and in vivo. In vitro studies revealed that vitamin E TPGS/Apelin reduces hypoxia-induced mitochondrial ROS production in cultured cardiomyocytes and H9C2 cardiomyoblasts. In addition, vitamin E TPGS/Apelin confers apoptotic response to hypoxic stress in cells. In a mouse model of isoproterenol-induced cardiac injury, TPGS is not able to affect cardiac remodeling, however combination of vitamin E TPGS and Apelin counteracts myocardial apoptosis, oxidative stress, hypertrophy and fibrosis. Furthermore, combination treatment attenuated obesity-induced cardiometabolic and fibrotic remodeling in mice.

CONCLUSION

Together, our data demonstrated the therapeutic benefits of vitamin E TPGS/Apelin complex to combat cardiovascular and metabolic disorders.

Landscape of heart proteome changes in a diet-induced obesity model

Obesity is a pandemic associated with a high incidence of cardiovascular disease; however, the mechanisms are not fully elucidated. Proteomics may provide a more in-depth understanding of the pathophysiological mechanisms and contribute to the identification of potential therapeutic targets. Thus, our study evaluated myocardial protein expression in healthy and obese rats, employing two proteomic approaches. Male Wistar rats were established in two groups (n = 13/group): control diet and Western diet fed for 41 weeks. Obesity was determined by the adipose index, and cardiac function was evaluated in vivo by echocardiogram and in vitro by isolated papillary muscle analysis. Proteomics was based on two-dimensional gel electrophoresis (2-DE) along with mass spectrometry identification, and shotgun proteomics with label-free quantification. The Western diet was efficient in triggering obesity and impaired contractile function in vitro; however, no cardiac dysfunction was observed in vivo. The combination of two proteomic approaches was able to increase the cardiac proteomic map and to identify 82 differentially expressed proteins involved in different biological processes, mainly metabolism. Furthermore, the data also indicated a cardiac alteration in fatty acids transport, antioxidant defence, cytoskeleton, and proteasome complex, which have not previously been associated with obesity. Thus, we define a robust alteration in the myocardial proteome of diet-induced obese rats, even before functional impairment could be detected in vivo by echocardiogram.

Loss of MD1 increases vulnerability to ventricular arrhythmia in diet-induced obesity mice via enhanced activation of the TLR4/MyD88/CaMKII signaling pathway

BACKGROUND AND AIM

Obesity is an important risk factor for ventricular arrhythmia (VA), and myeloid differentiation protein 1 (MD1) has been reported to decrease in obese hearts. Nevertheless, underlying mechanisms linking MD1 and VA have not been fully studied. This study aims to investigate the regulatory role of MD1 in VA caused by diet-induced obesity.

METHODS AND RESULTS

MD1 knock-out (KO) and wild type (WT) mice from experimental groups were fed with a high-fat diet (HFD) since the age of six weeks for 20 weeks. The body weight gain, fast glucose and serum lipid levels were measured and recorded. In addition, pathological analysis, echocardiography, electrocardiography, langendorff-perfused heart and molecular analysis were performed to detect HFD-induced vulnerability to VA and its underlying mechanisms. After a 20-week HFD feeding, the mice showed an increase in body weight, glycemic, lipid levels, QTc interval, LVEDd, LVEDs and LVFS. HFD feeding also increased vulnerability to VA, as shown by the prolonged action potential duration (APD), enhanced APD alternans threshold and greater incidence of VA. Moreover, HFD feeding caused LV hypertrophy and fibrosis, and decreased the protein expressions of Kv4.2, Kv4.3, Kv1.5, Kv2.1 and Cav1.2 channels. At last, the above-mentioned HFD-induced adverse effects were further exacerbated in KO mice compared with WT mice. Mechanistically, MD1 deletion markedly enhanced the activation of TLR4/MyD88/CaMKII signaling pathway in HFD-fed mice.

CONCLUSION

MD1 deficiency increased HFD-induced vulnerability to VA. This is mainly caused by the aggravated maladaptive LV hypertrophy, fibrosis and decreased protein expressions of ion channels, which are induced by the enhanced activation of the TLR4/MyD88/CaMKII signaling pathway.

Evaluation of subclinical left ventricular dysfunction in overweight people with 3D speckle-tracking echocardiography

OBJECTIVE

Obesity is associated with cardiovascular risk factors and is a major predictor of cardiovascular disease and mortality. This global burden affects myocardial function by inducing structural and functional alterations. Although subclinical left ventricular (LV) dysfunction is known in obese subjects, there is not sufficient information about overweight people. The aim of the present study was to evaluate subclinical LV dysfunction in overweight people with three-dimensional speckle-tracking echocardiography (3D-STE).

METHODS

One hundred eighteen consecutive patients between 18 and 80 years old were enrolled into the study. Patients were divided into three groups according to body mass index (BMI): normal (BMI: 18.5-24.9 kg/m2) (n=35), overweight (BMI: 25-29.9 kg/m2) (n=43), and obese (BMI ≥30 kg/m2) (n=40). 3D-STE was performed, and global longitudinal strain (GLS), global circumferential strain (GCS), global radial strain (GRS), and global area strain (GAS) were measured. 3D-STE results were compared between the groups.

RESULTS

The mean age of the patients was 60.97+-8.94 years, and 55.1% of the patient population were male. Mean GCS was -13.5, GLS was -11.9, GRS was 32.3, and GAS was -22. As BMI increased, GCS and all other strain parameters were significantly worse [p<0.001 (normal-overweight), p<0.001 (normal-obese), and p<0.001 (overweight-obese) for GCS, GLS, GRS, and GAS]. A positive linear correlation was observed between BMI and all measured strain parameters (r=0.673, p<0.001 for BMI and GCS).

CONCLUSION

3D-STE is a non-invasive parameter to detect subclinical LV dysfunction, and global strain values are significantly correlated with BMI. Subclinical LV dysfunction was detected in overweight people in addition to obese subjects.

NLRP3 Inflammasome Promotes Myocardial Remodeling During Diet-Induced Obesity

Background: Obesity is an increasingly prevalent metabolic disorder in the modern world and is associated with structural and functional changes in the heart. The NLRP3 inflammasome is an innate immune sensor that can be activated in response to endogenous danger signals and triggers activation of interleukin (IL)-1β and IL-18. Increasing evidence points to the involvement of the NLRP3 inflammasome in obesity-induced inflammation and insulin resistance, and we hypothesized that it also could play a role in the development of obesity induced cardiac alterations.

Methods and Results: WT, Nlrp3^−/−, and ASC^−/− (Pycard^−/−) male mice were exposed to high fat diet (HFD; 60 cal% fat) or control diet for 52 weeks. Cardiac structure and function were evaluated by echocardiography and magnetic resonance imaging, respectively. Whereas, NLRP3 and ASC deficiency did not affect the cardiac hypertrophic response to obesity, it was preventive against left ventricle concentric remodeling and impairment of diastolic function. Furthermore, whereas NLRP3 and ASC deficiency attenuated systemic inflammation in HFD fed mice; long-term HFD did not induce significant cardiac fibrosis or inflammation, suggesting that the beneficial effects of NLRP3 inflammasome deficiency on myocardial remodeling at least partly reflect systemic mechanisms. Nlrp3 and ASC (Pycard) deficient mice were also protected against obesity-induced systemic metabolic dysregulation, as well as lipid accumulation and impaired insulin signaling in hepatic and cardiac tissues.

Conclusions: Our data indicate that the NLRP3 inflammasome modulates cardiac concentric remodeling in obesity through effects on systemic inflammation and metabolic disturbances, with effect on insulin signaling as a potential mediator within the myocardium.

Effects of Exercise to Improve Cardiovascular Health

Obesity is a complex disease that affects whole body metabolism and is associated with an increased risk of cardiovascular disease (CVD) and Type 2 diabetes (T2D). Physical exercise results in numerous health benefits and is an important tool to combat obesity and its co-morbidities, including cardiovascular disease. Exercise prevents both the onset and development of cardiovascular disease and is an important therapeutic tool to improve outcomes for patients with cardiovascular disease. Some benefits of exercise include enhanced mitochondrial function, restoration and improvement of vasculature, and the release of myokines from skeletal muscle that preserve or augment cardiovascular function. In this review we will discuss the mechanisms through which exercise promotes cardiovascular health.

The nonepigenetic role for small molecule histone deacetylase inhibitors in the regulation of cardiac function

Eight million US adults are projected to suffer from heart failure (HF) by 2030. Of concern, 5-year mortality rates following HF diagnosis approximate 40%. Small molecule histone deacetylase (HDAC) inhibitors have demonstrated efficacy for the treatment and reversal of HF. Historically, HDACs were studied as regulators of nucleosomal histones, in which lysine deacetylation on histone tails changed DNA-histone protein electrostatic interactions, leading to chromatin condensation and changes in gene expression. However, recent proteomics studies have demonstrated that approximately 4500 proteins can be acetylated in various tissues; the function of most of these remains unknown. This Review will focus on the nonepigenetic role for lysine acetylation in the heart, with a focus on nonepigenetic actions for HDAC inhibitors on cardiac function.

Cardiac remodeling in morbidly obese women and its association with adverse perinatal outcomes

OBJECTIVES

To determine the association of cardiac remodeling in early pregnancy and adverse perinatal outcomes among women with BMI ≥ 40 kg/m².

STUDY DESIGN

We performed a retrospective cohort study including women with BMI ≥ 40 kg/m² without known cardiac disease. Women who underwent screening transthoracic echocardiography prior to gestational age 24 weeks were included. Women were analyzed by group with normal or abnormal geometry, including concentric remodeling, eccentric hypertrophy, and concentric hypertrophy. Multivariable logistic regression was used to assess the association of abnormal geometry with perinatal outcomes. We had 80% power with alpha 0.05 to detect a 3.0-fold increase in the primary outcome among women with abnormal geometry.

MAIN OUTCOME MEASURES

Our primary outcome was a composite of adverse perinatal outcomes including any 1 of the following: preterm birth (<37 weeks), low birth weight (<2500 g), or hypertensive disorders of pregnancy, including gestational hypertension, preeclampsia, and chronic hypertension with superimposed preeclampsia.

RESULTS

Of 140 women, 53 (37.9%) had abnormal geometry. The average BMI was similar between those with normal and abnormal geometry (44.7 vs. 44.2 kg/m², p = 0.53). The primary outcome occurred in 20.7% with normal geometry and 30.2% with abnormal geometry (p = 0.20). After adjustment for parity, chronic hypertension, and tobacco use, abnormal cardiac geometry was not associated with the composite primary outcome (adjusted OR 2.01 [95% CI 0.84-4.78]) but was associated with hypertensive disorders of pregnancy (adjusted OR 2.82 [95% CI 1.03-7.78]).

CONCLUSIONS

Cardiac remodeling early in pregnancy is associated with hypertensive disorders of pregnancy.

A Novel Mathematical Model for Correcting the Physiologic Variance of Two-Dimensional Echocardiographic Measurements in Healthy Chinese Adults

BACKGROUND

To facilitate differentiation between normal and abnormal values, it is necessary to correct echocardiographic measurements for physiologic variance induced by age, gender, and body size variables.

METHODS

A total of 34 two-dimensional echocardiographic parameters were measured in 1,224 healthy Chinese adults with body mass index < 25.0 kg/m². An optimized multivariate allometric model and scaling equations were first developed in 858 subjects (group A), and their reliability was then verified in the remaining 366 subjects (group B). The traditional single-variable isometric model in which parameters are linearly corrected by a single body size variable (height, weight, body mass index, or body surface area) was used for comparison. The success of correction was defined as the absence of significant correlations (r > 0.20, P < .05) between the corrected values and age or any body size variables, while maintaining high correlations (r > 0.80) between the corrected and uncorrected values.

RESULTS

Before correction, all 34 parameters correlated significantly with one or more of the physiologic variables of age and body size and differed significantly between men and women on 29 parameters (85.3%) in both groups. The success rate of correction with the single-variable isometric model was only 11.0% (15 of 136 corrections due to four variable corrections used for each parameter), while use of the optimized multivariate allometric model successfully corrected all 34 parameters (100%) for physiologic variance induced by age and body size variables and eliminated the gender differences in 32 parameters (94.1%). A new set of reference values for corrected echocardiographic measurements independent of age, gender, and body size variables were established.

CONCLUSIONS

The novel optimized multivariate allometric model developed in this study is superior to traditional the single-variable isometric model in the correction of echocardiographic parameters for physiologic effects of age, gender, and body size variables and thus should be encouraged in both scientific research and clinical practice.

Independent Effects of Hypertension and Obesity on Left Ventricular Mass and Geometry: Evidence from the Cardiovision 2030 Study

Obesity and hypertension independently promote pathological left ventricular remodelling (LVR) and left ventricular hypertrophy (LVH), but to what extent they do so when they do not coexist is unclear. We used data from the Cardiovision Brno 2030 study to assess-for the first time in a region where no investigations have been previously carried out-the independent association of obesity and hypertension with LV geometry, and to evaluate the effects of hypertension in normal weight patients and the effects of obesity in normotensive patients. Overall, 433 individuals, aged 25⁻65 years, with no history of cardiovascular disease and/or antihypertensive treatment, were stratified into four groups according to BMI and hypertension: normal weight non-hypertensive (NWNH), normal weight hypertensive (NWH), overweight/obese non-hypertensive (ONH) and overweight/obese hypertensive (OH). LVR was classified as normal, concentric LVR (cLVR), concentric LVH (cLVH) or eccentric LVH (eLVH). Linear regression analysis demonstrated that body mass index (BMI) and systolic blood pressure (SBP) are the main predictors of LV mass and that they interact: SBP had a stronger effect in overweight/obese (β = 0.195; p = 0.033) compared to normal weight patients (β = 0.134; p = 0.048). Hypertension increased the odds of cLVR (OR = 1.78; 95%CI = 1.04⁻3.06; p = 0.037) and cLVH (OR = 8.20; 95% CI = 2.35⁻28.66; p = 0.001), independent of age, sex and BMI. Stratified analyses showed that NWH had a greater odd of cLVH (OR = 7.96; 95%CI = 1.70⁻37.08; p = 0.008) and cLVR (OR = 1.62; 95%CI = 1.02⁻3.34; p = 0.047) than NWNH. In the absence of hypertension, obesity was not associated with LVM and abnormal LV geometry, suggesting that it is not per se a determinant of LVR. Thus, antihypertensive therapy still remains the first-line approach against LVH in hypertensive patients, though weight loss interventions might be helpful in those who are obese.

Association of obesity phenotypes with electrocardiographic left ventricular hypertrophy in the general population

OBJECTIVE

Increasing evidence doubts the benign nature of metabolically healthy obesity (MHO). An investigation of the association of MHO and other obesity phenotypes with electrocardiographic left ventricular hypertrophy (ECG-LVH), a risk factor for cardiovascular disease (CVD), can give insight into the pathophysiological basis for increased risk of CVD linked to these phenotypes.

METHODS

This analysis included 3997 participants (58.7 ± 13.6 years; 51.8% women) without CVD from the NHANES-III. Metabolic syndrome was defined according to the Adult Treatment Panel III. Obesity was defined as body mass index ≥30 kg/m2. Multivariable logistic regression was used to examine the cross-sectional association between 4 obesity phenotypes (metabolically healthy non-obese (MHNO) (reference), metabolically unhealthy non-obese (MUNO), MHO and metabolically unhealthy obese (MUO) with Cornell voltage ECG-LVH.

RESULTS

There was an incremental increase in the prevalence of ECG-LVH across obesity phenotypes with the highest prevalence in the MUO followed by MHO, MUNO and then MHNO (ECG-LVH = 6.45%, 5%, 4.71%, and 1.69%, respectively, trend p-value < 0.001). Also, there was incremental increase in the strength of associations with ECG-LVH across obesity phenotypes with higher odds of ECG-LVH in the MUO (OR (95% CI): 4.12 (2.30-7.39) followed by MUNO (OR (95% CI): 2.62 (1.45-4.73) then MHO (OR (95% CI): 2.45 (1.11-5.43) compared to MHNO. The MHO association with ECG-LVH was stronger in men than women (OR (95% CI): 5.55 (1.49-20.70) vs. 1.94 (0.71-5.24) respectively; interaction p-value = 0.04).

CONCLUSIONS

Obesity phenotypes including MHO are associated with ECG-LVH, thus further questioning the concept of benign obesity.

Healthy Weight and Obesity Prevention: JACC Health Promotion Series

Overweight and obesity have reached epidemic levels in the United States and worldwide, and this has contributed to substantial cardiovascular and other health risks. However, controversy exists concerning the causes of obesity and effective modalities for its prevention and treatment. There is also controversy related to the concept of metabolically healthy obesity phenotype, the "obesity paradox," and on the importance of fitness to protect individuals who are overweight or obese from cardiovascular diseases. In this state-of-the-art review, the authors focus on "healthy weight" with the emphasis on the pathophysiologic effects of weight gain on the cardiovascular system; mechanistic/triggering factors; and the role of preventive actions through personal, education/environment, and societal/authoritative factors, as well as factors to provide guidance for caregivers of health promotion. Additionally, the authors briefly review metabolically healthy obesity, the obesity paradox, and issues beyond lifestyle consideration for weight loss with medications and bariatric surgery.

Obesity-mediated regulation of cardiac protein acetylation: parallel analysis of total and acetylated proteins via TMT-tagged mass spectrometry

Lysine residues undergo diverse and reversible post-translational modifications (PTMs). Lysine acetylation has traditionally been studied in the epigenetic regulation of nucleosomal histones that provides an important mechanism for regulating gene expression. Histone acetylation plays a key role in cardiac remodeling and function. However, recent studies have shown that thousands of proteins can be acetylated at multiple acetylation sites, suggesting the acetylome rivals the kinome as a PTM. Based on this, we examined the impact of obesity on protein lysine acetylation in the left ventricle (LV) of male c57BL/6J mice. We reported that obesity significantly increased heart enlargement and fibrosis. Moreover, immunoblot analysis demonstrated that lysine acetylation was markedly altered with obesity and that this phenomenon was cardiac tissue specific. Mass spectral analysis identified 2515 proteins, of which 65 were significantly impacted by obesity. Ingenuity Pathway Analysis® (IPA) further demonstrated that these proteins were involved in metabolic dysfunction and cardiac remodeling. In addition to total protein, 189 proteins were acetylated, 14 of which were significantly impacted by obesity. IPA identified the Cardiovascular Disease Pathway as significantly regulated by obesity. This network included aconitate hydratase 2 (ACO2), and dihydrolipoyl dehydrogenase (DLD), in which acetylation was significantly increased by obesity. These proteins are known to regulate cardiac function yet, the impact for ACO2 and DLD acetylation remains unclear. Combined, these findings suggest a critical role for cardiac acetylation in obesity-mediated remodeling; this has the potential to elucidate novel targets that regulate cardiac pathology.

Free fatty acid can induce cardiac dysfunction and alter insulin signaling pathways in the heart

Background

Insulin resistance has been independently related to heart failure. However, the specific mechanisms of high FFA levels in the pathophysiology of heart failure in insulin-resistant states are remain largely unclear. This study investigated whether elevated circulating free fatty acids (FFA) levels result in impaired cardiac structure and function in vivo via insulin-related signaling pathways in myocardium.

Methods

Male Wistar rats were randomly divided into the intralipid group (20% intralipid plus heparin infusion) and the control group (glycerol infusion). Blood samples were collected before and after 6-, 12-, and 24-h infusions. Cardiac structure and function were measured using echocardiography. Maximum velocity of myocardial contraction (+dP/dt _max) and diastole (−dP/dt _max) were measured using a physiological polygraph in vivo. Heart tissues were collected for western blotting.

Results

Compared with the control group, plasma FFA, plasma glucose, and serum insulin levels increased significantly in the intralipid group. With increasing infusion time, cardiac function in the intralipid group decreased gradually compared with the control group. After a 24-h infusion, early (E’, cm/s) diastolic peak velocities and (−dP/dt _max) decreased significantly. Protein expression of phosphatidylinositol 3-kinase (PI3K), the serine/threonine kinase Akt, and phosphorylated Akt in myocardium increased after a 6-h infusion and decreased significantly after a 24-h infusion in the intralipid group. Protein expression of glucose transporter type 4 (GLUT4), Adenosine 5′-monophosphate -activated protein kinase (AMPK), phosphorylated AMPK(p-AMPK), and endothelial nitric oxide synthase (eNOS) in myocardium gradually decreased in the intralipid group.

Conclusions

Elevated FFA levels may impair cardiac function and cardiac dysfunction might result from myocardial insulin resistance with significant changes to PI3K-Akt-GLUT4 and AMPK-eNOS signaling pathways with increasing FFA levels.

Biochemical and Ultrastructural Cardiac Changes Induced by High-Fat Diet in Female and Male Prepubertal Rabbits

Early weight gain induced by high-fat diet has been identified as a predictor for cardiac disease, one of the most serious public health problems. Our goal is to study the influence of a HFD on biochemical, oxidant stress parameters, and the cardiac ultrastructure in both male and female prepubertal models. Experiments were carried on 24 prepubertal New Zealand white rabbits, randomly assigned to male and female control (MC and FC, resp.) or HFD (MHFD and FHFD, resp.) groups (n = 6) for 3 months. Body and heart weights and some biochemical and oxidative stress parameters such as lipids, calcium, CKMB, MDA, uric acid, ascorbic acid, and AOA are evaluated in plasma and the left ventricle. Under HFD effect, plasma parameters, such as lipids (TL, PL, and LDL-C), MDA, and CK-MB, increase more significantly in male than in female groups, when AA decreases. Some cardiac parameters such as TG and UA increase, when AA and AOA decrease; these variations are more significant in FHFD. In both male and female rabbits, HFD caused changes in heart ultrastructure, junctional complexes, mitochondria size and form, and so on. Early HFD feeding induced overweight, oxidative stress, and metabolic alterations in plasma and the heart of prepubertal rabbits, whereas lipotoxicity has especially a negative impact on male plasma but affects more the female heart ultrastructure.

Gender-specific contribution of cardiometabolic index and lipid accumulation product to left ventricular geometry change in general population of rural China

Background

Despite current interest in the unfavorable impact of cardiometabolic index (CMI) and lipid accumulation product (LAP) on diabetes and cardiovascular risk, information regarding the relation of CMI and LAP to left ventricular (LV) geometry has not been specifically addressed. We aimed to examine the hypothesis: (1) CMI and LAP represent an independent determinant of LV remodeling in general population of rural China; (2) there are gender differences in obesity-related alterations in terms of LV morphology.

Methods

The sample for this cross-sectional analysis included 11,258 participants (mean age 53.9 years; 54.0% females) who underwent assessment of basic metabolic and anthropometric parameters in rural areas of northeast China. Comprehensive echocardiography-defined LV geometric pattern was determined according to left ventricular mass index and relative wall thickness.

Results

The prevalence rate of eccentric and concentric LV hypertrophy (LVH) presented a proportional increase with elevated quartiles of CMI and LAP in a dose-response manner (all P < 0.005). When CMI and LAP were entered as a continuous variable in multivariable adjusted model, we observed the independent effect of 1 SD increment in CMI and LAP with the probability of eccentric and concentric LVH, while this relationship was more pronounced in females than in males. Likewise, the odds ratio comparing the top versus bottom quartiles of CMI were 2.105 (95%CI:1.600–2.768) for eccentric LVH and 2.236 (95%CI:1.419–3.522) for concentric LVH in females. Males in the highest CMI quartile exhibited a nearly doubled (OR:1.724, 95%CI:1.287–2.311) and 1.523-fold (95%CI:1.003–2.313) greater risk of eccentric and concentric LVH, respectively. Increasing LAP entailed a higher possibility of eccentric LVH by a factor of 3.552 and 1.768 in females and males, respectively. In contrast to females, where LAP fourth quartile and concentric LVH were positively associated (OR:2.544, 95%CI:1.537–4.209), higher LAP did not correlate with concentric LVH in males (OR:1.234, 95%CI:0.824–1.849).

Conclusions

CMI and LAP give rise to a new paradigm of accounting for gender difference in obesity-related abnormal LV geometry, an effect that was substantially greater in females. These two indices, acting in concert, may also be advantageous prognostically for refining cardiovascular risk stratification in individuals with LV remodeling.

Electronic supplementary material

The online version of this article (10.1186/s12872-018-0798-0) contains supplementary material, which is available to authorized users.

Inhibition of PIKfyve prevents myocardial apoptosis and hypertrophy through activation of SIRT3 in obese mice

PIKfyve is an evolutionarily conserved lipid kinase that regulates pleiotropic cellular functions. Here, we identify PIKfyve as a key regulator of cardiometabolic status and mitochondrial integrity in chronic diet‐induced obesity. In vitro, we show that PIKfyve is critical for the control of mitochondrial fragmentation and hypertrophic and apoptotic responses to stress. We also provide evidence that inactivation of PIKfyve by the selective inhibitor STA suppresses excessive mitochondrial ROS production and apoptosis through a SIRT3‐dependent pathway in cardiomyoblasts. In addition, we report that chronic STA treatment improves cardiometabolic profile in a mouse model of cardiomyopathy linked to obesity. We provide evidence that PIKfyve inhibition reverses obesity‐induced cardiac mitochondrial damage and apoptosis by activating SIRT3. Furthermore, treatment of obese mice with STA improves left ventricular function and attenuates cardiac hypertrophy. In contrast, STA is not able to reduce isoproterenol‐induced cardiac hypertrophy in SIRT3.KO mice. Altogether, these results unravel a novel role for PIKfyve in obesity‐associated cardiomyopathy and provide a promising therapeutic strategy to combat cardiometabolic complications in obesity.

Fruit vinegars attenuate cardiac injury via anti-inflammatory and anti-adiposity actions in high-fat diet-induced obese rats

CONTEXT

Fruit vinegars (FVs) are used in Mediterranean folk medicine for their hypolipidemic and weight-reducing properties.

OBJECTIVE

To investigate the preventive effects of three types of FV, commonly available in Algeria, namely prickly pear [Opuntia ficus-indica (L.) Mill (Cectaceae)], pomegranate [Punica granatum L. (Punicaceae)], and apple [Malus domestica Borkh. (Rosaceae)], against obesity-induced cardiomyopathy and its underlying mechanisms.

MATERIALS AND METHODS

Seventy-two male Wistar rats were equally divided into 12 groups. The first group served as normal control (distilled water, 7 mL/kg bw), and the remaining groups were respectively treated with distilled water (7 mL/kg bw), acetic acid (0.5% w/v, 7 mL/kg bw) and vinegars of pomegranate, apple or prickly pear (at doses of 3.5, 7 and 14 mL/kg bw, acetic acid content as mentioned above) along with a high-fat diet (HFD). The effects of the oral administration of FV for 18 weeks on the body and visceral adipose tissue (VAT) weights, plasma inflammatory and cardiac enzymes biomarkers, and in heart tissue were evaluated.

RESULTS

Vinegars treatments significantly (p < .05) attenuated the HFD-induced increase in bw (0.2-0.5-fold) and VAT mass (0.7-1.8-fold), as well as increase in plasma levels of CRP (0.1-0.3-fold), fibrinogen (0.2-0.3-fold), leptin (1.7-3.7-fold), TNF-α (0.1-0.6-fold), AST (0.9-1.4-fold), CK-MB (0.3-1.4-fold) and LDH (2.7-6.7-fold). Moreover, vinegar treatments preserved myocardial architecture and attenuated cardiac fibrosis.

DISCUSSION AND CONCLUSION

These findings suggest that pomegranate, apple and prickly pear vinegars may prevent HFD-induced obesity and obesity-related cardiac complications, and that this prevention may result from the potent anti-inflammatory and anti-adiposity properties of these vinegars.

Saturated high-fat diet-induced obesity increases adenylate cyclase of myocardial β-adrenergic system and does not compromise cardiac function

Obesity is a worldwide pandemic associated with high incidence of cardiovascular disease. The mechanisms by which the obesity leads cardiac dysfunction are not fully elucidated and few studies have evaluated the relationship between obesity and proteins involved in myocardial β‐adrenergic (βA) system. The purpose of this study was to evaluate the cardiac function and βA pathway components in myocardium of obese rats. Male Wistar rats were distributed into two groups: control (n = 17; standard diet) and obese (n = 17; saturated high‐fat diet) fed for 33 weeks. Nutritional profile and comorbidities were assessed. Cardiac structure and function was evaluated by macroscopic postmortem, echocardiographic and isolated papillary muscle analyzes. Myocardial protein expression of β₁‐ and β₂‐adrenergic receptors, Gαs protein, adenylate cyclase (AC) and protein kinase A (PKA) was performed by Western blot. Cardiac cyclic adenosine monophosphate (cAMP) levels and PKA activity were assessed by ELISA. Obese rats showed increased adiposity index (P < 0.001) and several comorbidities as hypertension, glucose intolerance, insulin resistance, and dyslipidemia compared with control rats. Echocardiographic assessment revealed increased left atrium diameter (C: 4.98 ± 0.38 vs. Ob: 5.47 ± 0.53, P = 0.024) and posterior wall shortening velocity (C: 37.1 ± 3.6 vs. Ob: 41.8 ± 3.8, P = 0.007) in obese group. Papillary muscle evaluation indicated that baseline data and myocardial responsiveness to isoproterenol stimulation were similar between the groups. Protein expression of myocardial AC was higher in obese group than in the control (C: 1.00 ± 0.21 vs. Ob: 1.25 ± 0.10, P = 0.025), whereas the other components were unchanged. These results suggest that saturated high‐fat diet‐induced obesity was not effective in triggering cardiac dysfunction and impair the beta‐adrenergic signaling.

The association of sleep disordered breathing with left ventricular remodeling in CAD patients: a cross-sectional study

Background

There is still insufficient knowledge on the potential effect of mild to moderate sleep-disordered breathing (SDB) that is widely prevalent, often asymptomatic, and largely undiagnosed in patients with stable coronary artery disease (CAD). SDB affects 34% of men and 17% of women aged between 30 and 70. The objective of this study was to evaluate the association between SDB and left ventricular (LV) hypertrophy as well as structural remodeling in stable CAD patients.

Methods

The study was based on a cross-sectional design. Echocardiography and polysomnography was performed in 772 patients with CAD and with untreated sleep apnea. All study participants underwent testing by Epworth Sleepiness Scale questionnaire. Their mean age, NYHA and left ventricular ejection fraction were, respectively: 57 ± 9 years, 2.1 ± 0.5 and 51 ± 8%, and 76% were men. Sleep apnea (SA) was defined as an apnea-hypopnea-index (AHI) ≥5 events/h, and, non-SA, as an AHI <5.

Results

Sleep apnea was present in 39% of patients, and a large fraction of those patients had no complaints on excessive daytime sleepiness. The patients with SA were older, with higher body mass and higher prevalence of hypertension. LV hypertrophy (LVH), defined by allometrically corrected (LV mass/height^2.7) gender-independent criteria, was more common among the patients with SA than those without (86% vs. 74%, p < 0.001). The frequency of LVH by wall thickness criteria (interventricular septal thickness or posterior wall thickness ≥ 12 mm: 49% vs. 33%, p < 0.001) and concentric LVH (61% vs. 47%, p = 0.001) was higher in CAD patients with SA. The patients with SA had significantly higher values of both interventricular septal thickness and posterior wall thickness. Multiple logistic regression analysis showed that even mild sleep apnea was an independent predictor for LVH by wall thickness criteria and concentric LVH (OR = 1.5; 95% CI 1.04–2.2 and OR = 1.9; 1.3–2.9 respectively).

Conclusions

We concluded that unrecognized sleep apnea was highly prevalent among patients with stable CAD, and the majority of those patients did not report daytime sleepiness. Mild to moderate sleep apnea was associated with increased LV wall thickness, LV mass, and with higher prevalence of concentric LV hypertrophy independently of coexisting obesity, hypertension, diabetes mellitus or advancing age.

Obesity and Cardiometabolic Defects in Heart Failure Pathology

Obesity is a major global epidemic that sets the stage for diverse multiple pathologies, including cardiovascular disease. The obesity-related low-grade chronic inflamed milieu is more pronounced in aging and responsive to cardiac dysfunction in heart failure pathology. Metabolic dysregulation of obesity integrates with immune reservoir in spleen and kidney network. Therefore, an integrative systems biology approach is necessary to delay progressive cardiac alternations. The purpose of this comprehensive review is to largely discuss the impact of obesity on the cardiovascular pathobiology in the context of problems and challenges, with major emphasis on the diversified models, and to study cardiac remodeling in obesity. The information in this article is immensely helpful in teaching advanced undergraduate, graduate, and medical students about the advancement and impact of obesity on cardiovascular health. © 2017 American Physiological Society. Compr Physiol 7:1463-1477, 2017.