The Influence of Epicardial Fat and Nonalcoholic Fatty Liver Disease on Heart Rate Recovery in Metabolic Syndrome

Pericardial Fat, Socioeconomic Status, and Biological Responses to Acute Mental Stress

OBJECTIVE

Central adiposity is associated with impaired biological responses to mental stress, and socioeconomic status (SES) might moderate this relationship. However, evidence for associations between pericardial fat, a fat depot implicated in the pathogenesis of cardiovascular disease (CVD), with cardiovascular and inflammatory responses to mental stress is lacking, and moderation by SES is unknown.

METHODS

The sample was 473 healthy men and women (mean age = 62.8 years) from the Whitehall II study. Cardiovascular and inflammatory responses to laboratory-induced mental stress, consisting of a 5-minute Stroop task and 5-minute mirror tracing task, were assessed. Pericardial fat volume was measured using electron bean computed tomography and adjusted for body surface area. SES was defined by grade of employment within the British civil service (higher/intermediate/lower).

RESULTS

Pericardial fat was associated with lower heart rate variability, raised heart rate, plasma interleukin-6, fibrinogen, and C-reactive protein at baseline. Furthermore, greater pericardial fat was associated with lower systolic blood pressure reactivity to mental stress, independent of sociodemographics, smoking status, waist-to-hip ratio, and baseline systolic blood pressure. There were no interactions between pericardial fat and SES for any outcome.

CONCLUSIONS

Greater pericardial fat was associated with numerous cardiovascular and inflammatory factors implicated in CVD. It was also related to reduced systolic blood pressure reactivity to acute mental stress, independent of central adiposity and baseline systolic blood pressure. This association did not vary by SES. Reduced systolic blood pressure reactivity to mental stress might contribute to the association between greater pericardial fat and CVD.

Cardiovascular disease risk in paediatric and young adult non-alcoholic fatty liver disease

OBJECTIVE

Longitudinal evidence is lacking regarding the long-term risk of major adverse cardiovascular events (MACE) in children and young adults with non-alcoholic fatty liver disease (NAFLD).

DESIGN

This nationwide cohort study included all Swedish children and young adults ≤25 years old with histologically confirmed NAFLD and without underlying cardiovascular disease (CVD) at baseline (1966-2016; n=699). NAFLD was defined from prospectively recorded histopathology, and further categorised as simple steatosis or non-alcoholic steatohepatitis (NASH). NAFLD patients were matched to ≤5 population controls without NAFLD or CVD (n=3353). Using Cox proportional hazards modelling, we calculated multivariable-adjusted HRs (aHRs) and 95% CIs for incident MACE (ie, ischaemic heart disease, stroke, congestive heart failure or cardiovascular mortality). In secondary analyses, we also explored rates of incident cardiac arrhythmias.

RESULTS

Over a median follow-up of 16.6 years, incident MACE was confirmed in 33 NAFLD patients and 52 controls. NAFLD patients had significantly higher rates of MACE than controls (3.1 vs 0.9/1000 person-years (PY); difference=2.1/1000 PY; aHR=2.33, 95% CI=1.43 to 3.78), including higher rates of ischaemic heart disease (difference=1.4/1000 PY; aHR=3.07, 95% CI 1.62 to 5.83) and congestive heart failure (difference=0.5/1000 PY; aHR=3.89, 95% CI=1.20 to 12.64). Rates of incident MACE outcomes appeared to be further augmented with NASH (aHR=5.27, 95% CI=1.96 to 14.19). In secondary analyses, NAFLD patients also had significantly higher rates of cardiac arrythmias (aHR=3.16, 95% CI=1.49 to 6.68).

CONCLUSION

Compared with matched population controls, children and young adults with biopsy-proven NAFLD had significantly higher rates of incident MACE, including ischaemic heart disease and congestive heart failure. Research to better characterise cardiovascular risk in children and young adults with NAFLD should be prioritised.

Systematic Review and Meta-Analysis of the Usefulness of Epicardial Fat Thickness as a Non-Invasive Marker of the Presence and Severity of Nonalcoholic Fatty Liver Disease

We performed a systematic review and meta-analysis to assess the association between epicardial fat thickness (EFT) and nonalcoholic fatty liver disease (NAFLD). This systematic review was conducted in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) and was based on a registered protocol (CRD 4201809 5493). We searched Medline and Embase until December 2021 for studies reporting on the association between EFT and NAFLD. Qualitative reviews, meta-analyses and meta-regressions were performed to explore this association. Effect sizes are reported as standardized mean differences. We included 12 studies, comprising 3610 individuals. EFT was evaluated with trans-thoracic echocardiography in nine studies, two studies using cardiac computed tomography and one study using magnetic resonance imaging (MRI). The presence of NAFLD was evaluated using transabdominal liver ultrasound in nine studies. Other studies used histology, magnetic resonance spectroscopy and MRI-derived proton density fat fraction. Liver biopsy was performed to assess the severity of NAFLD in four studies. The random-effects meta-analysis indicated that, as compared to control patients with lean livers, patients with NAFLD displayed significantly higher EFT (standardized mean difference 0.61, 95% confidence interval: 0.47−0.75, p < 0.0001, I2 = 72%). EFT was further significantly higher in patients with severe liver steatosis versus patients with mild−moderate liver steatosis (standardized mean difference 1.21 95% confidence interval: 0.26−2.16, p < 0.001, I2 S = 96%). Through the meta-regression analysis, we found that patients with increasingly higher blood levels of aspartate aminotransferase displayed an increasingly higher depth of association. The current meta-analysis suggests that EFT may represent a useful surrogate for assessing the presence and severity of NAFLD in a non-invasive manner.

Non-alcoholic fatty liver disease association with structural heart, systolic and diastolic dysfunction: a meta-analysis

OBJECTIVE

Several studies have documented a relationship between non-alcoholic fatty liver disease (NAFLD) and structural heart disease, particularly diastolic function. This meta-analysis will be the first to examine the echocardiographic-derived cardiac function and structural characteristics in NAFLD patients, and its association with liver disease severity and metabolic profile.

METHODS

Medline and Embase were searched and pairwise meta-analysis was conducted in DerSimonian and Laird to obtain the odds ratio (OR) and mean difference (MD) for dichotomous and continuous variables, respectively, to compare the effects of NAFLD on the echocardiography parameters.

RESULTS

Forty-one articles involving 33,891 patients underwent echocardiography. NAFLD patients had worse systolic indices with lower ejection fraction (EF, MD: - 0.693; 95% CI: - 1.112 to - 0.274; p = 0.001), and worse diastolic indices with higher E/e' (MD: 1.575; 95% CI: 0.924 to 2.227; p < 0.001) compared to non-NAFLD patients. NAFLD patients displayed increased left ventricular mass (LVM, MD: 34.484; 95% CI: 26.236 to 42.732; p < 0.001) and epicardial adipose thickness (EAT, MD: 0.1343; 95% CI: 0.055 to 0.214; p = 0.001). An increased severity of NAFLD was associated with worse diastolic indices (decreased E/A ratio, p = 0.007), but not with systolic indices.

CONCLUSIONS

NAFLD is associated with impaired systolic and diastolic function with changes in cardiac structure. Concomitant metabolic risk factors and liver disease severity are independently associated with worsening systolic and diastolic function.

The Relationship of Epicardial Adipose Tissue and Cardiovascular Disease in Chronic Kidney Disease and Hemodialysis Patients

Cardiovascular diseases remain the most common cause of morbidity and mortality in chronic kidney disease patients undergoing hemodialysis. Epicardial adipose tissue (EAT), visceral fat depot of the heart, was found to be associated with coronary artery disease in cardiac and non-cardiac patients. Additionally, EAT has been proposed as a novel cardiovascular risk in the general population and in end-stage renal disease patients. It has also been shown that EAT, more than other subcutaneous adipose tissue deposits, acts as a highly active organ producing several bioactive adipokines, and proinflammatory and proatherogenic cytokines. Therefore, increased visceral adiposity is associated with proinflammatory activity, impaired insulin sensitivity, increased risk of atherosclerosis, and high morbidity and mortality in hemodialysis patients. In the present review, we aimed to demonstrate the role of EAT in the pathophysiological mechanisms of increased cardiovascular morbidity and mortality in hemodialysis patients.

Role of non-alcoholic fatty liver disease in development of cardiovascular disease

With the improvement of the economic level and changes in dietary structure and lifestyle, the incidence of non-alcoholic fatty liver disease (NAFLD) has been increasing. It has gradually become the main cause of chronic liver diseases in the world. Cardiovascular disease (CVD) is the main cause of death in NAFLD patients, and more and more studies have found that there is a correlation between the two conditions. NAFLD patients are at greater risk of developing CVD than normal patients. Associated mechanisms may be related to dysfunction of blood vessels and endothelial cells, bile acid metabolism, oxidative stress, systemic inflammation, and activation of the renin-angiotensin system. Among them, metabolic syndrome plays an important role. Therefore, early identification of cardiovascular disease-related risk factors in NAFLD patients and thereby reducing cardiovascular-related complications are essential to improve the prognosis of those patients.

Association between non-alcoholic fatty liver disease and impaired cardiac sympathetic/parasympathetic balance in subjects with and without type 2 diabetes-The Cooperative Health Research in South Tyrol (CHRIS)-NAFLD sub-study

BACKGROUND AND AIMS

Cardiovascular disease (CVD) is the leading cause of death in patients with non-alcoholic fatty liver disease (NAFLD), both with and without type 2 diabetes mellitus (T2DM). Cardiac autonomic dysfunction is a risk factor for CVD morbidity and mortality. The aim of this pilot study was to assess whether there is an association between NAFLD and impaired cardiac autonomic function.

METHODS AND RESULTS

Among the first 4979 participants from the Cooperative Health Research in South Tyrol (CHRIS) study, we randomly recruited 173 individuals with T2DM and 183 age- and sex-matched nondiabetic controls. Participants underwent ultrasonography and vibration-controlled transient elastography (Fibroscan®, Echosens) to assess hepatic steatosis and liver stiffness. The low-to-high-frequency (LF/HF) power ratio and other heart rate variability (HRV) measures were calculated from a 20-min resting electrocardiogram (ECG) to derive a measure of cardiac sympathetic/parasympathetic imbalance. Among the 356 individuals recruited for the study, 117 had NAFLD and T2DM, 56 had T2DM alone, 68 had NAFLD alone, and 115 subjects had neither condition. Individuals with T2DM and NAFLD (adjusted odds ratio [OR] 4.29, 95% confidence intervals [CI] 1.90-10.6) and individuals with NAFLD alone (adjusted OR 3.41, 95% CI 1.59-7.29), but not those with T2DM alone, had a substantially increased risk of having cardiac sympathetic/parasympathetic imbalance, compared with those without NAFLD and T2DM. Logistic regression models were adjusted for age, sex, body mass index (BMI), hypertension, dyslipidemia, insulin resistance, hemoglobin A1c (HbA1c), C-reactive protein (CRP), and Fibroscan®-measured liver stiffness.

CONCLUSIONS

NAFLD was associated with cardiac sympathetic/parasympathetic imbalance, regardless of the presence or absence of T2DM, liver stiffness, and other potential confounding factors.

Physical Exercise Potentially Targets Epicardial Adipose Tissue to Reduce Cardiovascular Disease Risk in Patients with Metabolic Diseases: Oxidative Stress and Inflammation Emerge as Major Therapeutic Targets

Excess epicardial adiposity, within a state of obesity and metabolic syndrome, is emerging as an important risk factor for the development of cardiovascular diseases (CVDs). Accordingly, increased epicardial fat thickness (EFT) implicates the exacerbation of pathological mechanisms involving oxidative stress and inflammation within the heart, which may accelerate the development of CVDs. This explains increased interest in targeting EFT reduction to attenuate the detrimental effects of oxidative stress and inflammation within the setting of metabolic syndrome. Here, we critically discuss clinical and preclinical evidence on the impact of physical exercise on EFT in correlation with reduced CVD risk within a setting of metabolic disease. This review also brings a unique perspective on the implications of oxidative stress and inflammation as major pathological consequences that link increased EFT to accelerated CVD risk in conditions of metabolic disease.

Relationship between Epicardial Fat Tissue Thickness and CRP and Neutrophil-Lymphocyte Ratio in Metabolic Syndrome Patients Over 65 Years

Objective:

There are no data evaluating the association of neutrophil-to-lymphocyte ratio (NLR) and C-reactive protein (CRP) with epicardial fat tissue thickness (EFTT) in elderly metabolic syndrome (MS) patients. In this study, we aimed to investigate the relationship of EFTT with CRP and NLR in patients with MS over 65 years.

Methods:

A cross-sectional study was performed. Fifty patients (patient group) with MS and 25 subjects (control group) without MS were allocated in the study. All parameters were compared in patient and control groups. The correlations between NLR, CRP, and EFTT were evaluated.

Results:

White blood cell and neutrophil levels were higher in MS group (p=0.020 and p=0.019, respectively). Both transverse and longitudinal EFTT were increased in MS patients (p<0.001). There was a significant correlation between the EFTT and NLR but not with CRP in the MS group (r=0.4, p=0.003).

Conclusion:

Our study showed that both longitudinal and transverse EFTT are associated with NLR in patients older than 65 years with MS. In geriatric MS patients, higher NLR level may be an indicator of increased visceral fat around the myocardium.

The association between epicardial adipose tissue and non-alcoholic fatty liver disease: A systematic review of existing human studies

The prevalence of non-alcoholic fatty liver disease (NAFLD) has significantly risen all around the world. Although visceral fat mass has been identified as an independent risk factor for NAFLD, the association of other ectopic fat depots, such as Epicardial adipose tissue (EAT), with the disease has not been fully elucidated. The aim of the current study was to systematically review all available human studies conducted on the associations between EAT and NAFLD. All human studies published in English, which examined the association between the thickness or the volume of EAT and the incidence of NAFLD were systematically searched on PubMed, Scopus, and Google Scholar search engines, from inception up to April 2021. Eighteen studies that met inclusion criteria were included in the final review. A total of 86 studies were found through searching the databases. After excluding duplicates, seventy six remained studies were scanned by title and abstract, out of which, 58 were excluded. Finally, eighteen articles (thirteen cross-sectional studies and five case-control studies) published between 2008 and 2021, were included in the review. According to the results of the reviewed articles, EAT was associated with the presence and progression of NAFLD. Furthermore, NAFLD patients with thicker EAT may need a more intensive hepatic follow-up. However, we suggest further investigation to find out the underlying mechanisms describing the observed association.

Nonalcoholic Fatty Liver Disease: An Emerging Driver of Cardiac Arrhythmia

Cardiac arrhythmias and the resulting sudden cardiac death are significant cardiovascular complications that continue to impose a heavy burden on patients and society. An emerging body of evidence indicates that nonalcoholic fatty liver disease (NAFLD) is closely associated with the risk of cardiac arrhythmias, independent of other conventional cardiometabolic comorbidities. Although most studies focus on the relationship between NAFLD and atrial fibrillation, associations with ventricular arrhythmias and cardiac conduction defects have also been reported. Mechanistic investigations suggest that a number of NAFLD-related pathophysiological alterations may potentially elicit structural, electrical, and autonomic remodeling in the heart, contributing to arrhythmogenic substrates in the heart. NAFLD is now the most common liver and metabolic disease in the world. However, the upsurge in the prevalence of NAFLD as an emerging risk factor for cardiac arrhythmias has received little attention. In this review, we summarize the clinical evidence and putative pathophysiological mechanisms for the emerging roles of NAFLD in cardiac arrhythmias, with the purpose of highlighting the notion that NAFLD may serve as an independent risk factor and a potential driving force in the development and progression of cardiac arrhythmias.

Nonalcoholic fatty liver disease and cardiovascular disease phenotypes

Nonalcoholic fatty liver disease is increasingly recognized as a major global health problem. Intertwined with diabetes, metabolic syndrome, and obesity, nonalcoholic fatty liver disease embraces a spectrum of liver conditions spanning from steatosis to inflammation, fibrosis, and liver failure. Compared with the general population, the prevalence of cardiovascular disease is higher among nonalcoholic fatty liver disease patients, in whom comprehensive cardiovascular risk assessment is highly desirable. Preclinical effects of nonalcoholic fatty liver disease on the heart include both metabolic and structural changes eventually preceding overt myocardial dysfunction. Particularly, nonalcoholic fatty liver disease is associated with enhanced atherosclerosis, heart muscle disease, valvular heart disease, and arrhythmias, with endothelial dysfunction, inflammation, metabolic dysregulation, and oxidative stress playing in the background. In this topical review, we aimed to summarize current evidence on the epidemiology of nonalcoholic fatty liver disease, discuss the pathophysiological links between nonalcoholic fatty liver disease and cardiovascular disease, illustrate nonalcoholic fatty liver disease-related cardiovascular phenotypes, and finally provide a glimpse on the relationship between nonalcoholic fatty liver disease and cardiac steatosis, mitochondrial (dys)function, and cardiovascular autonomic dysfunction.

Nonalcoholic Fatty Liver Disease Pandemic Fuels the Upsurge in Cardiovascular Diseases

Cardiovascular diseases (CVDs) remain a leading cause of death worldwide. Among the major risk factors for CVD, obesity and diabetes mellitus have received considerable attention in terms of public policy and awareness. However, the emerging prevalence of nonalcoholic fatty liver disease (NAFLD), as the most common liver and metabolic disease and a cause of CVD, has been largely overlooked. Currently, the number of individuals with NAFLD is greater than the total number of individuals with diabetes mellitus and obesity. Epidemiological studies have established a strong correlation between NAFLD and an increased risk of CVD and CVD-associated events. Although debate continues over the causal relationship between NAFLD and CVD, many mechanistic and longitudinal studies have indicated that NAFLD is one of the major driving forces for CVD and should be recognized as an independent risk factor for CVD apart from other metabolic disorders. In this review, we summarize the clinical evidence that supports NAFLD as a risk factor for CVD epidemics and discuss major mechanistic insights regarding the acceleration of CVD in the setting of NAFLD. Finally, we address the potential treatments for NAFLD and their potential impact on CVD.

Association of epicardial adipose tissue with non-alcoholic fatty liver disease: a meta-analysis

BACKGROUND

Increased epicardial adipose tissue (EAT) has been proposed as a risk factor for non-alcoholic fatty liver disease (NAFLD). The aim of this study was to investigate the association of EAT with NAFLD.

METHODS

The PubMed, EMBASE, and Cochrane databases were systematically reviewed by two independent investigators to identify relevant studies assessing the association of EAT thickness (EAT-t) and volume (EAT-v) with NAFLD. Comparisons between NAFLD subjects and controls were performed with meta-analysis and trial sequential analysis (TSA).

RESULTS

A total of thirteen case-control studies (n = 2260 patients) were included in the final analysis. The EAT was significantly increased in NAFLD patients compared with the controls (EAT, SMD: 0.73, 95% CI 0.51-0.94, p < 0.001; TSA-adjusted 95% CI 0.07-0.18; p < 0.001). When comparing the subgroups of NAFLD, the EAT-t in the severe-hepatic steatosis subgroup was thicker than that in the moderate subgroup (SMD: 1.43, 95% CI 0.15-2.71, p = 0.029). This study indicated that the EAT-t in the F3-4 fibrosis subgroup was thicker than that in the F0-2 fibrosis subgroup (SMD: 0.72, 95% CI 0.30-1.14, p = 0.001). The proportion of hypertension (OR = 1.64, 95% CI = 1.24-2.18, p = 0.001) and atherosclerotic cardiovascular disease (ASCVD) (OR = 1.66, 95% CI = 1.21-2.28, p = 0.002) was higher in the high-EAT-t group compared with the low-EAT-t group in NAFLD patients.

CONCLUSIONS

The EAT was increased in the NAFLD subjects compared to the controls. The increase in the EAT was associated with the severity of steatosis, fibrosis and cardiovascular disease in patients with NAFLD. These findings provide new information regarding the development and progression of NAFLD.

The association of non-alcoholic fatty liver disease and atrial fibrillation: a review

Non-alcoholic fatty liver disease (NAFLD) is highly prevalent and causes an enormous burden to human health and health-care systems all over the world. A great proportion of this burden results from increased risk of cardiovascular diseases. Atrial fibrillation (AF) is the most common chronic heart arrhythmia globally and it increases the risk of embolic stroke and heart failure. Recent studies have explored the association between NAFLD and AF with somewhat conflicting results. However, ultrasound-verified prospective studies concur that NAFLD is associated with the incidence of AF. According to epidemiological evidence, the greater the prevalence of NALFD in a population, the stronger the association with AF incidence and prevalence. Specifically, diabetic individuals with NAFLD are at the greatest risk of AF. Additionally, the risk of AF may concentrate most in individuals with advanced NAFLD, particularly those with liver fibrosis. The possible mechanistic factors between NAFLD and AF, particularly obesity and systemic inflammation, are diverse and form a complex interplaying network. However, further studies are needed to elucidate whether NAFLD has a causative role in the development of AF. The purpose of this article is to review and discuss the epidemiologic evidence and possible mechanistic links between these two conditions. KEY MESSAGES Although epidemiologic studies have provided conflicting results on the association of NAFLD and AF, prospective studies with ultrasound-verified NAFLD concur that NAFLD is associated with about 2-fold greater incidence of AF among general population and about 6-fold greater incidence among subjects with type 2 diabetes. The risk of AF among individuals with NAFLD is increased by other cardiovascular risk factors, especially type 2 diabetes and advanced age. The possible mechanistic links between NALFD and AF are diverse, with obesity and systemic inflammation having a significant role, but further studies are needed until NAFLD can be established as a causal factor in the incidence of AF.

Risk of cardiomyopathy and cardiac arrhythmias in patients with nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is a common, progressive liver disease that affects up to one-quarter of the adult population worldwide. The clinical and economic burden of NAFLD is mainly due to liver-related morbidity and mortality (nonalcoholic steatohepatitis, cirrhosis or hepatocellular carcinoma) and an increased risk of developing fatal and nonfatal cardiovascular disease, chronic kidney disease and certain types of extrahepatic cancers (for example, colorectal cancer and breast cancer). Additionally, there is now accumulating evidence that NAFLD adversely affects not only the coronary arteries (promoting accelerated coronary atherosclerosis) but also all other anatomical structures of the heart, conferring an increased risk of cardiomyopathy (mainly left ventricular diastolic dysfunction and hypertrophy, leading to the development of congestive heart failure), cardiac valvular calcification (mainly aortic-valve sclerosis), cardiac arrhythmias (mainly atrial fibrillation) and some cardiac conduction defects. This Review focuses on the association between NAFLD and non-ischaemia-related cardiac disease, discusses the putative pathophysiological mechanisms and briefly summarizes current treatment options for NAFLD that might also beneficially affect cardiac disease.