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

Association between severity of nonalcoholic fatty liver disease and major adverse cardiovascular events in patients assessed by coronary computed tomography angiography

BACKGROUND

The effect of nonalcoholic fatty liver disease (NAFLD) on major adverse cardiovascular events (MACEs) can be influenced by the degree of coronary artery stenosis. However, the association between the severity of NAFLD and MACEs in patients who underwent coronary computed tomography angiography (CCTA) is unclear.

METHODS

A total of 341 NAFLD patients who underwent CCTA were enrolled. The severity of NAFLD was divided into mild NAFLD and moderate-severe NAFLD by abdominal CT results. The degree of coronary artery stenosis was evaluated by using Coronary Artery Disease Reporting and Data System (CAD-RADS) category. Cox regression analysis and Kaplan-Meier analysis were used to assess poor prognosis.

RESULTS

During the follow-up period, 45 of 341 NAFLD patients (13.20%) who underwent CCTA occurred MACEs. The severity of NAFLD (hazard ratio [HR] = 2.95[1.54-5.66]; p = 0.001) and CAD-RADS categories 3-5 (HR = 16.31[6.34-41.92]; p < 0.001) were independent risk factors for MACEs. The Kaplan-Meier analysis showed that moderate to severe NAFLD patients had a worsen prognosis than mild NAFLD patients (log-rank p < 0.001). Moreover, the combined receiver operating characteristic curve of the severity of NAFLD and CAD-RADS category showed a good predicting performance for the risk of MACEs, with an area under the curve of 0.849 (95% CI = 0.786-0.911).

CONCLUSION

The severity of NAFLD was independent risk factor for MACEs in patients with obstructive CAD, having CAD-RADS 3-5 categories on CCTA.

Assessment of left atrial function by two-dimensional speckle tracking echocardiography in patients with metabolic-associated fatty liver disease

BACKGROUND

Metabolic-associated fatty liver disease (MAFLD) and cardiovascular diseases have mutual risk factors that contribute to pathogenic processes, increasing mortality and morbidity. This study aimed to evaluate variations in left ventricular (LV) structure and diastolic function among different subtypes and severity degrees of MAFLD patients, allowing early identification, intervention, and prevention of severe cardiac outcomes in high-risk populations.

RESULTS

The cross-sectional study included 142 MAFLD patients and 142 non-MAFLD participants as a control group. All participants underwent abdominal ultrasound, transient elastography, transthoracic echocardiography, tissue Doppler, and strain imaging. The results showed a significant impairment in the diastolic left ventricular function, as assessed with tissue Doppler, and the left atrial (LA) function, as evaluated with strain imaging, in the MAFLD group. Additionally, the left atrial stiffness was significantly higher in the MAFLD group.

CONCLUSION

The use of strain imaging facilitated the detection of subtle impairments of the left atrial reservoir, contraction, conduit function, and left ventricular diastolic function in MAFLD patients.

Epicardial fat in patients with metabolic syndrome: A systematic review and meta-analysis

PURPOSE

Abnormally increased epicardial fat appears to be associated with an additional risk of major adverse cardiovascular events (MACEs) in the context of metabolic syndrome (MetS). However, evidence on the relationship between epicardial fat volumes (EFVs), epicardial fat thickness (EFT) and MetS remains inconsistent.

METHODS

Specific searches of electronic databases from 1 January 2000 to 31 October 2022 were independently performed by two researchers. In this study, two quantification measures of epicardial fat were included: comparison of total computed tomography-based EFVs and EFT between two groups (individuals with and without MetS), estimating standardized mean difference (SMD) with corresponding 95 % confidence intervals (CIs) through a random-effects model analysis. The heterogeneity in the included studies was explored by meta-regression and subgroup analyses.

RESULTS

The EFVs were significantly increased in MetS subjects compared with non-MetS subjects (SMD: 1.07, 95 % CI: 0.69-1.45, p < 0.001), and the EFT was also significantly larger in MetS patients than in the Non-MetS (SMD: 1.12, 95 % CI: 0.84-1.41, p < 0.001). We compared the Caucasian and American subgroups with the Asian and African subgroups, and the EFT was greater in the former subgroups (SMD: 1.32, 95 % CI: 0.44-2.20, p < 0.001). When comparing the EFT among the age subgroups, there was a significant SMD between adolescents and adults or elderly individuals (SMD: 1.21, 95 % CI: 0.84-1.52, p < 0.001).

CONCLUSIONS

MetS patients tend to present greater EFT near the right ventricular free wall and greater total EFVs. Increased epicardial fat, an imaging biomarker, independently affects the onset of MetS.

Impacts of Non-alcoholic Fatty Liver Disease on Acute Coronary Syndrome: Evidence and Controversies

PURPOSE OF REVIEW

Acute coronary syndrome (ACS) and non-alcoholic fatty liver disease (NAFLD) are two clinically common disease entities that share numerous risk factors. This review aimed to discuss the impacts of NAFLD on ACS.

RECENT FINDINGS

In an era of improved control of traditional risk factors, the substantial burden of cardiometabolic abnormalities has caused widespread concern. NAFLD is considered the hepatic component of metabolic syndrome, which can exert an impact on human health beyond the liver. Accumulating studies have demonstrated that NAFLD is closely related to cardiovascular disease, especially coronary artery disease. Interestingly, although recent data have suggested an association between NAFLD and the incidence and outcomes of ACS, the results are not consistent. In this review, we comprehensively summarized evidence and controversies regarding whether NAFLD is a contributor to either the development of ACS or worse outcomes in patients with ACS. The potential pathophysiological and molecular mechanisms involved in the impacts of NAFLD on ACS were also elucidated.

Effects of treatment of non-alcoholic fatty liver disease on heart failure with preserved ejection fraction

In the past few decades, non-alcoholic fatty liver disease (NAFLD) and heart failure with preserved ejection fraction (HFpEF) have become the most common chronic liver disease and the main form of heart failure (HF), respectively. NAFLD is closely associated with HFpEF by sharing common risk factors and/or by boosting systemic inflammation, releasing other secretory factors, and having an expansion of epicardial adipose tissue (EAT). Therefore, the treatments of NAFLD may also affect the development and prognosis of HFpEF. However, no specific drugs for NAFLD have been approved by the Food and Drug Administration (FDA) and some non-specific treatments for NAFLD are applied in the clinic. Currently, the treatments of NAFLD can be divided into non-pharmacological and pharmacological treatments. Non-pharmacological treatments mainly include dietary intervention, weight loss by exercise, caloric restriction, and bariatric surgery. Pharmacological treatments mainly include administering statins, thiazolidinediones, glucagon-like peptide-1 receptor agonists, sodium-glucose cotransporter 2 inhibitors, and metformin. This review will mainly focus on analyzing how these treatments may affect the development and prognosis of HFpEF.

Shared Mechanisms between Cardiovascular Disease and NAFLD

The burden of nonalcoholic fatty liver disease (NAFLD) is rising globally. Cardiovascular disease is the leading cause of death in patients with NAFLD. Nearly half of individuals with NAFLD have coronary heart disease, and more than a third have carotid artery atherosclerosis. Individuals with NAFLD are at a substantially higher risk of fatal and nonfatal cardiovascular events. NAFLD and cardiovascular disease share multiple common disease mechanisms, such as systemic inflammation, insulin resistance, genetic risk variants, and gut microbial dysbiosis. In this review, we discuss the epidemiology of cardiovascular disease in NAFLD, and highlight common risk factors. In addition, we examine recent advances evaluating the shared disease mechanisms between NAFLD and cardiovascular disease. In conclusion, multidisciplinary collaborations are required to further our understanding of the complex relationship between NAFLD and cardiovascular disease and potentially identify therapeutic targets.

The Importance of the Assessment of Epicardial Adipose Tissue in Scientific Research

Epicardial adipose tissue (EAT) exhibits morphological similarities with pericardial adipose tissue, however, it has different embryological origin and vascularization. EAT is a metabolically active organ and a major source of anti-inflammatory and proinflammatory adipokines, which have a significant impact on cardiac function and morphology. Moreover, it can regulate vascular tone by releasing various molecules. The relationship between EAT and cardiovascular disease and diseases of other organ systems is now considered a common discussion subject. The present clinical review article summarizes the epidemiological findings based on imaging techniques in studies conducted so far. In conclusion, evaluation of the epicardial adipose tissue constitutes a helpful scientific parameter, which can be assessed by means of different diagnostic imaging examinations.

The association of pericardial fat and peri-aortic fat with severity of nonalcoholic fatty liver disease

Visceral adipose tissue (VAT) is associated with central obesity, insulin resistance and metabolic syndrome. However, the association of body-site specific adiposity and non-alcoholic fatty liver disease (NAFLD) has not been well characterized. We studies 704 consecutive subjects who underwent annual health survey in Taiwan. All subjects have been divided into three groups including normal (341), mild (227) and moderate and severe (136) NAFLD according to ultrasound finding. Pericardial (PCF) and thoracic peri-aortic adipose tissue (TAT) burden was assessed using a non-contrast 16-slice multi-detector computed tomography (MDCT) dataset with off-line measurement (Aquarius 3DWorkstation, TeraRecon, SanMateo, CA, USA). We explored the relationship between PCF/TAT, NAFLD and cardiometabolic risk profiles. Patients with moderate and mild NAFLD have greater volume of PCF (100.7 ± 26.3vs. 77.1 ± 21.3 vs. 61.7 ± 21.6 ml, P < 0.001) and TAT (11.2 ± 4.1 vs. 7.6 ± 2.6 vs. 5.5 ± 2.6 ml, P < 0.001) when compared to the normal groups. Both PCF and TAT remained independently associated with NAFLD after counting for age, sex, triglyceride, cholesterol and other cardiometabolic risk factors. In addition, both PCF and TAT provided incremental prediction value for NAFLD diagnosis. (AUROC: 0.85 and 0.87, 95%, confidence interval: 0.82-0.89 and 0.84-0.90). Both visceral adipose tissues strongly correlated with the severity of NAFLD. Compared to PCF, TAT is more tightly associated with NAFLD diagnosis in a large Asian population.

Higher epicardial fat in older adults living with HIV with viral suppression and relationship with liver steatosis, coronary calcium and cardiometabolic risks

OBJECTIVES

HIV infection is associated with ectopic fat deposition, which leads to chronic inflammation and cardiometabolic dysregulation. We assessed the epicardial adipose tissue (EAT) volume and its associated factors among people with HIV (PWH).

DESIGN

A cross-sectional study.

METHODS

We conducted a cross-sectional study among PWH aged at least 50 years and age-matched and sex-matched HIV-negative older individuals in Bangkok, Thailand. Participants underwent a noncontrast, cardiac computed tomography (CT) scan to assess coronary artery calcium (CAC) score and EAT between March 2016 and June 2017. Multivariate linear regression analyses were used to investigate HIV-related factors, cardiac and metabolic markers associated with EAT volume.

RESULTS

Median age was 55 years [interquartile range (IQR) 52-60] and 63% were men. Median duration of antiretroviral therapy (ART) was 16 years with 97% had HIV-1 RNA less than 50 copies/ml and median CD4 + cell count of 617 cells/μl. Median EAT volume was significantly higher in PWH [99 (IQR 75-122) cm 3 ] than HIV-negative individuals [93 (IQR 69-117) cm 3 ], P  = 0.022. In adjusted model, factors associated with EAT volume included male sex ( P  = 0.045), older age ( P  < 0.001), abnormal waist circumference ( P  < 0.001) and HOMA-IR ( P  = 0.01). In addition, higher CAC score was independently associated with EAT volume. Higher mean EAT volume was seen in PWH with severe liver steatosis than those without steatosis ( P  = 0.018). In adjusted PWH-only model, duration of HIV was significantly associated with higher EAT volume ( P  = 0.028).

CONCLUSION

In an aging cohort, PWH had higher EAT volume than HIV-negative controls. EAT was also independently associated with central fat accumulation, insulin resistance, liver steatosis and CAC score.

Nonalcoholic fatty liver disease and health outcomes: An umbrella review of systematic reviews and meta-analyses

Purpose:

A large number of systemic reviews and meta-analyses have explored the relationship between nonalcoholic fatty liver disease (NAFLD) and multiple health outcomes. The aim of this study is to conduct an umbrella review to assess the strength and evidence for the association between NAFLD and health outcomes.

Methods:

We systematically identified the present meta-analyses of observational studies reporting an association between NAFLD and health outcomes. For each meta-analysis, we assessed the quality with AMSTAR2 and graded the epidemiologic evidence.

Results:

Fifty-four articles comprising 111 unique meta-analyses were included in this study. Eighty-five unique outcomes showed significant associations ( P ← 0.05), whereas 26 unique outcomes showed insignificant associations, and we cannot assess the epidemiologic evidence. For 85 significant health outcomes, four outcomes (carotid intima-media thickness (C-IMT), peak A velocity, left ventricle end-diastolic diameter, incident chronic kidney disease (CKD) in adult patients) was graded as high quality of evidence, 23 outcomes were graded as the moderate quality of evidence, and the remaining 58 outcomes were graded as weak quality of evidence. Fourty-seven (87.03%) studies showed critically low methodological quality.

Conclusion:

In this umbrella review, only four statistically significant health outcomes showed high epidemiologic evidence. NAFLD seems to relate to an increased risk of C-IMT, peak A velocity, left ventricle end-diastolic diameter, and incident CKD in adult patients.

Transient elastography and serum markers of liver fibrosis associate with epicardial adipose tissue and coronary artery calcium in NAFLD

Non-alcoholic fatty liver disease (NAFLD) is associated with cardiovascular disease morbimortality. However, it is not clear if NAFLD staging may help identify early or subclinical markers of cardiovascular disease. We aimed to evaluate the association of liver stiffness and serum markers of liver fibrosis with epicardial adipose tissue (EAT) and coronary artery calcium (CAC) in an observational cross-sectional study of 49 NAFLD patients that were seen at Clínica Universidad de Navarra (Spain) between 2009 and 2019. Liver elastography and non-invasive fibrosis markers were used to non-invasively measure fibrosis. EAT and CAC, measured through visual assessment, were determined by computed tomography. Liver stiffness showed a direct association with EAT (r = 0.283, p-value = 0.049) and CAC (r = 0.337, p-value = 0.018). NAFLD fibrosis score was associated with EAT (r = 0.329, p-value = 0.021) and CAC (r = 0.387, p-value = 0.006). The association of liver stiffness with CAC remained significant after adjusting for metabolic syndrome features (including carbohydrate intolerance/diabetes, hypertension, dyslipidaemia, visceral adipose tissue, and obesity). The evaluation of NAFLD severity through liver elastography or non-invasive liver fibrosis biomarkers may contribute to guide risk factor modification to reduce cardiovascular risk in asymptomatic patients. Inversely, subclinical cardiovascular disease assessment, through Visual Scale for CAC scoring, may be a simple and effective measure for patients with potential liver fibrosis, independently of the existence of other cardiovascular risk factors.

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.

Non-alcoholic Fatty Liver Disease and the Risk of Incident Atrial Fibrillation in Young Adults: A Nationwide Population-Based Cohort Study

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is a multisystem disease including cardiovascular. However, the association between NAFLD and the risk of incident atrial fibrillation (AF), especially in young adults, remains unclear. We aimed to evaluate the association between NAFLD as assessed by the fatty liver index (FLI) and the risk of AF in young adults.

METHODS

We identified individuals aged 20-39 years who underwent health examinations conducted by the Korean National Health Insurance Corporation between January 2009 and December 2012. Individuals with significant liver disease, heavy alcohol consumption, or prevalent AF were excluded. We categorized based on FLI: <30, 30 to <60, and ≥60. Incident AF was evaluated as the primary outcome.

RESULTS

We included 5,333,907 subjects (mean age, 31 ± 5 years; men, 57%). During a mean follow-up of 7.4 ± 1.1 years, 12,096 patients had newly diagnosed AF (incidence rate 0.31 per 1,000 person-years). After adjustment, subjects with FLI 30 to <60 and FLI ≥60 showed a higher risk of AF compared to those with FLI <30 (hazard ratio [HR] 1.21, 95% confidence interval [CI, 1.15-1.27] and HR 1.47, 95% CI [1.39-1.55], p < 0.001, respectively). In women, the increased AF risk was accentuated in the higher FLI group than in the individuals with FLI <30, compared with men (p-for-interaction = 0.023). A higher incident AF risk in the higher FLI groups was consistently observed in various subgroups.

CONCLUSION

Among young adults, NAFLD assessed using FLI was positively correlated with the AF risk. These findings support the evidence of AF screening in young adults with high FLI scores.

Risk of cardiovascular events in patients with non-alcoholic fatty liver disease: a systematic review and meta-analysis

AIMS 

Non-alcoholic fatty liver disease (NAFLD) is a highly prevalent disease and has been repeatedly associated with an increased risk of cardiovascular disease. However, the extent of such association is unclear. We conducted a systematic review and meta-analysis of the literature to evaluate the risk of myocardial infarction (MI), ischaemic stroke (IS), atrial fibrillation (AF), and heart failure (HF) in NAFLD patients.

METHODS AND RESULTS 

According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we systematically searched PubMed and EMBASE, from inception to 6 March 2021, and included all studies reporting the incidence of MI, IS, AF, and HF in patients with and without NAFLD. Random-effect fmodels were used to estimate pooled odds ratio (OR), 95% confidence intervals (CI), and 95% prediction intervals (PI); subgroup analyses, meta-regressions, and sensitivity analyses were additionally performed. Among 3254 records retrieved from literature, 20 studies were included. Non-alcoholic fatty liver disease was associated with an increased risk of MI (OR: 1.66, 95% CI: 1.39-1.99, 95% PI: 0.84-3.30), IS (OR: 1.41, 95% CI: 1.29-1.55, 95% PI 1.03-1.93), AF (OR: 1.27, 95% CI: 1.18-1.37, 95% PI: 1.07-1.52), and HF (OR: 1.62, 95% CI: 1.43-1.84, 95% CI: 1.04-2.51). We identified significant subgroup differences according to geographical location, study design, NAFLD definition, and risk of bias; meta-regressions identified mean age, male sex, and study-level characteristics as potential moderators of the risk of MI and IS.

CONCLUSIONS 

Non-alcoholic fatty liver disease was associated with increased risk of MI, IS, AF, and HF. Age, sex, and study characteristics may moderate the strength of this association. Further studies are required to evaluate specific cardiovascular prevention strategies in patients with NAFLD.

Pathophysiological Molecular Mechanisms of Obesity: A Link between MAFLD and NASH with Cardiovascular Diseases

Obesity is now a worldwide epidemic ensuing an increase in comorbidities’ prevalence, such as insulin resistance, type 2 diabetes (T2D), metabolic dysfunction-associated fatty liver disease (MAFLD), nonalcoholic steatohepatitis (NASH), hypertension, cardiovascular disease (CVD), autoimmune diseases, and some cancers, CVD being one of the main causes of death in the world. Several studies provide evidence for an association between MAFLD and atherosclerosis and cardio-metabolic disorders, including CVDs such as coronary heart disease and stroke. Therefore, the combination of MAFLD/NASH is associated with vascular risk and CVD progression, but the underlying mechanisms linking MAFLD/NASH and CVD are still under investigation. Several underlying mechanisms may probably be involved, including hepatic/systemic insulin resistance, atherogenic dyslipidemia, hypertension, as well as pro-atherogenic, pro-coagulant, and pro-inflammatory mediators released from the steatotic/inflamed liver. MAFLD is strongly associated with insulin resistance, which is involved in its pathogenesis and progression to NASH. Insulin resistance is a major cardiovascular risk factor in subjects without diabetes. However, T2D has been considered the most common link between MAFLD/NASH and CVD. This review summarizes the evidence linking obesity with MAFLD, NASH, and CVD, considering the pathophysiological molecular mechanisms involved in these diseases. We also discuss the association of MAFLD and NASH with the development and progression of CVD, including structural and functional cardiac alterations, and pharmacological strategies to treat MAFLD/NASH and cardiovascular prevention.

Review article: non-alcoholic fatty liver disease and cardiovascular diseases: associations and treatment considerations

BACKGROUND

There are increasing data on the association between non-alcoholic fatty liver disease (NAFLD) and cardiovascular diseases (CVD).

AIM

To summarise evidence on the association between NAFLD and CVD in the clinical setting and provide potential therapeutic implications.

METHODS

We searched PubMed. Evidence was primarily derived from meta-analyses. and then, if data were insufficient, from clinical trials, and then from observational studies.

RESULTS

NAFLD has been linked to arterial hypertension, arterial stiffness, atherosclerosis, coronary artery disease, atrial fibrillation and aortic valvular sclerosis. Advanced liver fibrosis is a crucial prognostic factor for end-stage liver disease and for cardiovascular and overall mortality. Weight loss through lifestyle modifications (diet and exercise) remains the cornerstone of the management of both NAFLD and CVD, but is difficult to achieve and possibly more difficult to sustain long term. Therefore, pharmacological management of NAFLD seems to be important, although no licenced medication currently exists. Pioglitazone, proposed for non-alcoholic steatohepatitis (NASH) by most guidelines, increases weight and should be avoided in congestive heart failure. Statins should not be avoided in NAFLD patients at risk for CVD. Glucagon-like peptide 1 receptor agonists and sodium-glucose cotransporter-2 inhibitors, two classes of anti-diabetic drugs, have shown promising results in NAFLD and CVD, but more studies with hard end points are needed. Obeticholic acid, a promising medication for NASH under investigation, should be carefully considered, owing to its adverse effect on lipid profile.

CONCLUSIONS

NAFLD is associated with CVD, which may have certain clinical and therapeutic implications.

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.

Non-alcoholic fatty liver disease, insulin resistance, metabolic syndrome and their association with vascular risk

The prevalence of non-alcoholic fatty liver disease (NAFLD), one of the most common liver diseases, is rising. About 25% of adults worldwide are probably affected by NAFLD. Insulin resistance (IR) and fat accumulation in the liver are strongly related. The association between NAFLD, metabolic syndrome (MetS) and IR is established, but an independent impact of NAFLD on vascular risk and progression of cardiovascular (CV) disease (CVD) still needs to be confirmed. This narrative review considers the evidence regarding the link between NAFLD, IR and CVD risk. There is strong evidence for a "concomitantly rising incidence" of NAFLD, IR, MetS and CVD but there is no definitive evidence regarding whether NAFLD is, or is not, an independent and significant risk factor the development of CVD. There are also considerations that type 2 diabetes mellitus (T2DM) may be a common link between NAFLD/non-alcoholic steatohepatitis (NASH) and CVD. NAFLD may be associated with widespread abnormal peri-organ or intra-organ fat (APIFat) deposition (e.g. epicardial adipose tissue) which may further contribute to CV risk. It is clear that NAFLD patients have a greater CV risk (independent or not) which needs to be addressed in clinical practice.

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.

Diabetic Kidney Disease, Cardiovascular Disease and Non-Alcoholic Fatty Liver Disease: A New Triumvirate?

Non-alcoholic fatty liver disease is a highly prevalent disease worldwide with a renowned relation to cardiovascular disease and chronic kidney disease. These diseases share a common pathophysiology including insulin resistance, oxidative stress, chronic inflammation, dysbiosis and genetic susceptibilities. Non-alcoholic fatty liver disease is especially prevalent and more severe in type 2 diabetes. Patients with non-alcoholic fatty liver disease should have liver fibrosis assessment in order to identify those at the highest risk of adverse outcomes so that appropriate management strategies can be implemented. Early diagnosis and treatment of non-alcoholic fatty liver disease could ameliorate the burden of cardiovascular disease and chronic kidney disease.

Inhibition of Notch Signaling Promotes the Differentiation of Epicardial Progenitor Cells into Adipocytes

Background

The role of Notch signaling pathway in the differentiation of epicardial progenitor cells (EPCs) into adipocytes is unclear. The objective is to investigate the effects of Notch signaling on the differentiation of EPCs into adipocytes.

Methods

Frozen sections of C57BL/6J mouse hearts were used to observe epicardial adipose tissue (EAT), and genetic lineage methods were used to trace EPCs. EPCs were cultured in adipogenic induction medium with Notch ligand jagged-1 or γ-secretase inhibitor DAPT. The adipocyte markers, Notch signaling, and adipogenesis transcription factors were determined.

Results

There was EAT located at the atrial-ventricular groove in mouse. By using genetic lineage tracing methods, we found that EPCs were a source of epicardial adipocytes. EPCs had lipid droplet accumulation, and the expression of adipocyte markers FABP-4 and perilipin-1 was upregulated under adipogenic induction. Activating the Notch signaling with jagged-1 attenuated the adipogenic differentiation of EPCs and downregulated the key adipogenesis transcription factor peroxisome proliferator activated receptor-γ (PPAR-γ), while inhibiting the signaling promoted adipogenic differentiation and upregulated PPAR-γ. When blocking PPAR-γ, the role of Notch signaling in promoting adipogenic differentiation was inhibited.

Conclusions

EPCs are a source of epicardial adipocytes. Downregulation of the Notch signaling pathway promotes the differentiation of EPCs into adipocytes via PPAR-γ.

The correlation between hepatic fat fraction evaluated by dual-energy computed tomography and high-risk coronary plaques in patients with non-alcoholic fatty liver disease

PURPOSE

To determine the relationship between non-alcoholic fatty liver disease (NAFLD) evaluated by a hepatic fat fraction (HFF) using dual-energy computed tomography (DECT) and high-risk coronary plaques (HRP) in NAFLD patients.

METHODS

We conducted a matched case-control study involving 172 NAFLD individuals recruited from August 2019 to September 2020. They underwent dual-energy coronary computed tomographic angiography and were classified as no-plaque, HRP negative and HRP positive groups. HFF values were measured using multimaterial decomposition algorithm of DECT, and the differences among three groups were compared. Multiple logistic regression analysis was performed to determine the independent correlation between HFF and HRP. Spearman rank correlation was used to assess the correlations between HFF and multiple variables.

RESULTS

HRP positive group (15.3%) had higher HFF values than no-plaque (6.9%) and HRP negative groups (8.9%) (P < 0.001). After adjusting for confounding variables, the results indicated that HFF was an independent risk factor for HRP (OR 1.93, P < 0.001). Additionally, HFF significantly correlated with coronary artery calcium score, hepatic CT attenuation, epicardial and pericoronary adipose tissue volume, and CT attenuation (all P < 0.001).

CONCLUSIONS

As a new imaging marker for the quantification of liver fat, HFF was independently associated with HRP.

Metabolic Syndrome and Abnormal Peri-Organ or Intra-Organ Fat (APIFat) Deposition in Chronic Obstructive Pulmonary Disease: An Overview

Chronic obstructive pulmonary disease (COPD) is a common disorder with an increasing prevalence, characterised by persistent respiratory symptoms and airflow limitation. Systemic inflammation is involved in the pathogenesis of COPD and can also predispose to metabolic disorders (e.g., metabolic syndrome (MetS) and non-alcoholic fatty liver disease (NAFLD)). Such comorbidities can negatively affect COPD outcomes, cardiovascular risk, and quality of life. Apart from NAFLD, abnormal peri-organ or intra-organ fat (APIFat) could be considered as markers for cardiometabolic diseases and even for COPD. The present narrative review considers the associations of COPD with MetS, NAFLD, and other APIFat, including epicardial, perirenal, peripancreatic, and intramuscular adipose tissue. Further research is needed to define these relationships and identify any potential clinical implications.

Association of epicardial adipose tissues with obstructive sleep apnea and its severity: A meta-analysis study

BACKGROUND AND AIMS

Obstructive sleep apnea (OSA) is a global disease that is a manifestation of metabolic syndrome. Epicardial adipose tissue (EAT), a special type of visceral adipose tissue, has been proposed to be an independent predictor of visceral adiposity. Both OSA and EAT have a close association with diabetes and coronary artery disease. Whether EAT thickness is associated with OSA is controversial.

METHODS AND RESULTS

Several databases were searched from their inception to October 13, 2019. We estimated the summarized weighted mean difference (WMD) with 95% confidence intervals (CIs) for EAT thickness in the OSA and non-OSA groups. Then, we conducted a meta-analysis to evaluate the association between EAT thickness and OSA. The relationship between EAT thickness and OSA severity was also assessed. Nine studies with a total of 1178 participants were included. Globally, patients with OSA had a higher EAT thickness than patients without OSA (WMD = 0.95, 95% CI: 0.73-1.16, P < 0.001). Compared to the non-OSA patients, those with mild, moderate, and severe OSA had a progressively higher EAT thickness (WMD = 0.62, 95% CI: 0.41-0.83; WMD = 0.83, 95% CI: 0.50-1.15; and WMD = 1.06, 95% CI: 0.70-1.43, respectively; all P < 0.001).

CONCLUSION

EAT thickness was shown to be higher in patients with OSA than in patients with non-OSA measured by echocardiography. The increase in the EAT thickness was associated with OSA severity.

Epicardial Adipose Tissue: Clinical Biomarker of Cardio-Metabolic Risk

Epicardial adipose tissue (EAT) is part of the visceral adipose tissue (VAT) that surrounds the heart and it is a quantifiable, modifiable, and multifaceted tissue that has both local and systemic effects. When EAT is enlarged, EAT contributes to atherosclerotic cardiovascular disease (ASCVD) risk and plays a role in the development of metabolic syndrome (MetS). In this review, we will discuss the role of EAT in various facets of MetS, including type 2 diabetes mellitus (T2DM) and insulin resistance. We examine the association between EAT and liver steatosis. We also address the correlations of EAT with HIV therapy and with psoriasis. We discuss racial differences in baseline EAT thickness. We conclude that EAT measurement serves as a powerful potential diagnostic tool in assessing cardiovascular and metabolic risk. Measurement of EAT is made less costly, more convenient, and yet accurate and reliable by transthoracic echocardiography. Furthermore, modification of EAT thickness has therapeutic implications for ASCVD, T2DM, and MetS.