Γ-glutamyltransferase, hepatic enzymes, and risk of incident heart failure in older men

Systemic impacts of metabolic dysfunction-associated steatotic liver disease (MASLD) and metabolic dysfunction-associated steatohepatitis (MASH) on heart, muscle, and kidney related diseases

Metabolic dysfunction-associated steatotic liver disease (MASLD), previously known as non-alcoholic fatty liver disease (NAFLD), is the most common liver disorder worldwide, with an estimated global prevalence of more than 31%. Metabolic dysfunction-associated steatohepatitis (MASH), formerly known as non-alcoholic steatohepatitis (NASH), is a progressive form of MASLD characterized by hepatic steatosis, inflammation, and fibrosis. This review aims to provide a comprehensive analysis of the extrahepatic manifestations of MASH, focusing on chronic diseases related to the cardiovascular, muscular, and renal systems. A systematic review of published studies and literature was conducted to summarize the findings related to the systemic impacts of MASLD and MASH. The review focused on the association of MASLD and MASH with metabolic comorbidities, cardiovascular mortality, sarcopenia, and chronic kidney disease. Mechanistic insights into the concept of lipotoxic inflammatory "spill over" from the MASH-affected liver were also explored. MASLD and MASH are highly associated (50%-80%) with other metabolic comorbidities such as impaired insulin response, type 2 diabetes, dyslipidemia, hypertriglyceridemia, and hypertension. Furthermore, more than 90% of obese patients with type 2 diabetes have MASH. Data suggest that in middle-aged individuals (especially those aged 45-54), MASLD is an independent risk factor for cardiovascular mortality, sarcopenia, and chronic kidney disease. The concept of lipotoxic inflammatory "spill over" from the MASH-affected liver plays a crucial role in mediating the systemic pathological effects observed. Understanding the multifaceted impact of MASH on the heart, muscle, and kidney is crucial for early detection and risk stratification. This knowledge is also timely for implementing comprehensive disease management strategies addressing multi-organ involvement in MASH pathogenesis.

Non-alcoholic fatty liver disease in obese subjects as related to increasing insulin resistance and deteriorating glucose control: Three years of follow-up from a longitudinal survey

Purpose

This observational trial was performed to evaluate liver parameters in overweight or obese subjects in the context of insulin resistance and glucose control over time.

Subjects/Methods

Insulin resistance, glucose control and several parameters for liver integrity were monitored in 177 overweight (BMI > 28 kg/m2) subjects over a mean of 30 months. Volunteers were categorized according to insulin resistance (HOMAIR score) and glucose control in subjects with normal glucose control (NGT), impaired glucose control (IGT), or diabetes mellitus type 2 (T2DM). Liver fat and fibrosis were evaluated by sonographic elastography (FibroScan®) and clinical scores, such as the AST/ALT ratio, fatty liver index (FLI), and NAFLD fibrosis score (NFS).

Results

Liver fat fraction as estimated by the controlled attenuation parameter (CAP), and the FLI were significantly higher in subjects with T2DM compared to IGT and NGT. While fasting insulin levels and the HOMAIR score continuously increased over time, no change in CAP or FLI occurred during follow up. CAP was correlated with FLI (r = 0.50; p < 0.0001) and the HOMAIR score (r = 0.32; p < 0.0001). An inverse correlation was observed between serum adiponectin levels and FLI (r = -0.37; p < 0.0001), the HOMAIR score (r = -0.19; p < 0.001, and CAP (r = -0.15; p < 0.01).

Conclusions

In subjects with a BMI ≥ 28 kg/m2, liver fat fraction is significantly elevated in those with T2DM compared to IGT or NGT. Liver fat fraction is associated with deteriorating insulin sensitivity and loss of glucose control. Despite a continuous increase in insulin resistance, no change in liver fat content or stiffness occurred over 30 months.

Type 2 diabetes mellitus and cardiometabolic outcomes in metabolic dysfunction-associated steatotic liver disease population

The metabolic syndrome, characterized by type 2 diabetes mellitus (T2DM), hypertension, hyperlipidemia, and obesity, collectively increases the risk of cardiovascular diseases. Nonalcoholic fatty liver disease (NAFLD) is a prominent manifestation, affecting over a third of the global population with a concerning annual increase in prevalence. Nearly 70 % of overweight individuals have NAFLD, and NAFLD-related deaths are predicted to rise, especially among young adults. The association of T2DM and NAFLD has led to the proposal of "metabolic dysfunction-associated steatotic liver disease" (MASLD) terminology, encompassing individuals with T2DM, overweight/obesity, hypertension, hypertriglyceridemia, or low HDL-cholesterol. Patients with MASLD will likely have double the risk of developing T2DM, and the combination of insulin resistance, overweight/obesity, and MASLD significantly elevates the risk of T2DM. Cardiovascular diseases remain the leading cause of mortality in the MASLD and T2DM population, with MASLD directly associated with coronary artery disease, compounded by coexisting insulin resistance and T2DM. Urgency lies in early detection of subclinical cardiovascular diseases among patients with T2DM and MASLD. Novel strategies targeting multiple pathways offer hope for effectively improving cardiometabolic health. Understanding and addressing the intertwined factors contributing to these disorders can pave the way towards better management and prevention of cardiometabolic complications.

Non-Alcoholic Fatty Liver Disease as an Emerging Risk Factor for Heart Failure

PURPOSE OF THE REVIEW

Non-alcoholic fatty liver disease (NAFLD) and heart failure (HF) are two chronic diseases that have become important global public health problems. This narrative review provides a comprehensive overview of the association between NAFLD and increased risk of new-onset HF, briefly discusses the putative biological mechanisms linking these two conditions, and summarizes targeted pharmacotherapies for NAFLD that might also beneficially affect cardiac complications leading to new-onset HF.

RECENT FINDINGS

Recent observational cohort studies supported a significant association between NAFLD and the long-term risk of new-onset HF. Notably, this risk remained statistically significant even after adjustment for age, sex, ethnicity, adiposity measures, pre-existing type 2 diabetes and other common cardiometabolic risk factors. In addition, the risk of incident HF was further increased with more advanced liver disease, especially with higher severity of liver fibrosis. There are multiple potential pathophysiological mechanisms by which NAFLD (especially in its more advanced forms) may increase the risk of new-onset HF. Because of the strong link existing between NAFLD and HF, more careful surveillance of these patients will be needed. However, further prospective and mechanistic studies are required to better decipher the existing but complex link between NAFLD and risk of new-onset HF.

Non-alcoholic fatty liver disease and risk of new-onset heart failure: an updated meta-analysis of about 11 million individuals

OBJECTIVE

Recent studies reported an association between non-alcoholic fatty liver disease (NAFLD) and increased risk of new-onset heart failure (HF). However, the magnitude of the risk and whether this risk changes with severity of liver disease remains uncertain. We performed a meta-analysis of observational studies to quantify the magnitude of the association between NAFLD and risk of new-onset HF.

DESIGN

We systematically searched Scopus, Web of Science and PubMed from database inception to March 2022 to identify eligible observational studies, in which NAFLD was diagnosed by serum biomarkers/scores, International Classification of Diseases (ICD) codes, imaging techniques or liver histology. The primary outcome was new-onset HF, as assessed mainly by ICD codes. Data from selected studies were extracted, and meta-analysis was performed using random-effects models to obtain summary hazard ratios (HRs) with 95% CIs.

RESULTS

We identified 11 longitudinal cohort studies with aggregate data on 11 242 231 middle-aged individuals from different countries and 97 716 cases of incident HF over a median of 10 years. NAFLD was associated with a moderately higher risk of new-onset HF (pooled random-effects hazard ratio 1.50, 95% CI 1.34 to 1.67, p<0.0001; I 2=94.8%). This risk was independent of age, sex, ethnicity, adiposity measures, diabetes, hypertension and other common cardiovascular risk factors. Sensitivity analyses did not change these results. The funnel plot did not show any significant publication bias.

CONCLUSION

NAFLD is associated with a 1.5-fold higher long-term risk of new-onset HF, regardless of the presence of diabetes, hypertension and other common cardiovascular risk factors. However, the observational design of the studies does not allow for proving causality.

Non-alcoholic fatty liver disease-related risk of cardiovascular disease and other cardiac complications

BACKGROUND/AIM

Non-alcoholic fatty liver disease (NAFLD) affects approximately 25% of the global adult population. The aim of this narrative review is to describe the associations between NAFLD and cardiovascular disease (CVD), arrhythmias, cardiac conduction defects, myocardial remodelling and heart failure. We also discuss the potential mechanisms that mediate or attenuate the strength of these associations, and briefly summarize the effect of treatments that both ameliorate NAFLD and decrease risk of CVD.

METHODS

Searches of PubMed were performed by the two authors using the terms listed in Appendix. We limited the timeframe to the last decade due to the vast amount of research in the field (up to April 2021) for meta-analyses, reviews and original papers. Only articles published in English were considered.

RESULTS

NAFLD is associated with an increased risk of fatal/non-fatal CVD events and other cardiac and arrhythmic complications (left ventricular hypertrophy, aortic-valve sclerosis and certain arrhythmias), independently of common CVD risk factors. There are probably several underlying mechanisms, including hepatic/systemic insulin resistance, atherogenic dyslipidaemia, hypertension and pro-atherogenic, pro-coagulant and pro-inflammatory mediators released from the steatotic/inflamed liver that may be involved. Some genetic polymorphisms, such as PNPLA3 (rs738409 C>G) and TM6SF2 (rs58542926 C>T), may worsen the liver disease, but also attenuate the strength of the association between NAFLD and CVD, possibly via their effects on lipoprotein metabolism. Of the currently tested drugs for treating NAFLD that also benefit the vasculature, pioglitazone and GLP-1 receptor agonists are the most promising.

CONCLUSIONS

The complex interplay between the liver and cardiometabolic risk factors contributes to CVD, arrhythmias and cardiac disease in NAFLD. There is an urgent need for a multidisciplinary approach to manage both liver disease and cardiometabolic risk, and to test the cardiovascular and cardiac effects of new drugs for NAFLD.

Risk of Heart Failure in Patients With Nonalcoholic Fatty Liver Disease: JACC Review Topic of the Week

Heart failure (HF) and nonalcoholic fatty liver disease (NAFLD) are 2 conditions that have become important global public health problems. Emerging evidence supports a strong and independent association between NAFLD and the risk of new-onset HF, and there are multiple potential pathophysiological mechanisms by which NAFLD may increase risk of new-onset HF. The magnitude of this risk parallels the underlying severity of NAFLD, especially the level of liver fibrosis. Patients with NAFLD develop accelerated coronary atherosclerosis, myocardial alterations (mainly cardiac remodeling and hypertrophy), and certain arrhythmias (mainly atrial fibrillation), which may precede and promote the development of new-onset HF. This brief narrative review aims to provide an overview of the association between NAFLD and increased risk of new-onset HF, discuss the underlying mechanisms that link these 2 diseases, and summarize targeted pharmacological treatments for NAFLD that might also reduce the risk of HF.

Metabolic causes and consequences of nonalcoholic fatty liver disease (NAFLD)

Nonalcoholic fatty liver disease (NAFLD) is a multifactorial metabolic disorder that was first described in 1980. It has been prevalent and on the rise for many years and is associated with other metabolic disorders such as obesity and type 2 diabetes mellitus (T2DM). NAFLD can be best described as a metabolic dysfunction that stems from insulin resistance-induced hepatic lipogenesis. This lipogenesis increases oxidative stress and hepatic inflammation and is often potentiated by genetic and gut microbiome dysfunction. As NAFLD progresses from simple steatosis to non-alcoholic steatohepatitis (NASH) and to cirrhosis and hepatocellular carcinoma (HCC), the odds of complications including cardiovascular disease (CVD), chronic kidney disease (CKD), and overall mortality increase. The aim of this review is to describe the metabolic causes and consequences of NAFLD while examining the risks that each stage of NAFLD poses. In this review, the etiology of "lean" NAFLD, the impact of obesity, T2DM, genetics, and microbiome dysbiosis on NAFLD progression are all explored. This review will also discuss the core issue behind the progression of NAFLD: insulin resistance (IR). Upon describing the causes and consequences of NAFLD, the effectiveness of diet modification, lifestyle changes, and glucagon-like peptide 1 receptor (GLP-1) agonists to retard NAFLD progression and stem the rate of complications is examined.

Cardiac Morphology, Function, and Hemodynamics in Patients With Morbid Obesity and Nonalcoholic Steatohepatitis

Background The patients with nonalcoholic fatty liver disease demonstrate an increased cardiovascular risk. The adverse influence of liver abnormalities on cardiac function are among many postulated mechanisms behind this association. The aim of the study was to evaluate cardiac morphology and function in patients with morbid obesity referred for bariatric surgery with liver biopsy. Methods and Results We evaluated with echocardiography 171 consecutive patients without known cardiac disease (median age 42 [interquartile range, 37-48] years, median body mass index 43.7 [interquartile range, 41.0-47.5], 67% female patients. Based on the liver biopsy results, there were 44 patients with nonalcoholic steatohepatitis (NASH), 69 patients with isolated steatosis, and 58 patients without steatosis. Patients with NASH demonstrated signs of left ventricular concentric remodeling and hyperdynamic circulation, including indexed left ventricular end-diastolic diameter [cm/m2]: NASH 1.87 [0.22]; isolated steatosis 2.03 [0.33]; without steatosis 2.01 [0.19], P=0.001; relative wall thickness: NASH 0.49±0.05, isolated steatosis 0.47±0.06, without steatosis 0.46±0.06, P=0.011; cardiac index [L/m2]: NASH 3.05±0.54, isolated steatosis 2.80±0.44, without steatosis 2.79±0.50, P=0.013. After adjustment for sex, age, blood pressure, and heart rate, most of the measures of the left ventricular systolic and diastolic function, left atrial size, right ventricular function, and right ventricular size did not differ between groups. Conclusions In a group of patients with extreme obesity, NASH was associated with left ventricular concentric remodeling and hyperdynamic circulation. Increased cardiac output in NASH may represent an additional risk factor for incident cardiovascular events in this population.

Non-Alcoholic Fatty Liver Disease and Cardiovascular Comorbidities: Pathophysiological Links, Diagnosis, and Therapeutic Management

Non-alcoholic fatty liver disease (NAFLD) has a growing prevalence in recent years. Its association with cardiovascular disease has been intensively studied, and certain correlations have been identified. The connection between these two entities has lately aroused interest regarding therapeutic management. In order to find the best therapeutic options, a detailed understanding of the pathophysiology that links (NAFLD) to cardiovascular comorbidities is needed. This review focuses on the pathogenic mechanisms that are behind these two diseases and on the therapeutic management available at this time.

Three-dimensional speckle tracking echocardiography for early detection of left ventricular dysfunction in children with non-alcoholic fatty liver diseases

OBJECTIVES

To detect early left ventricular dysfunction in children with non-alcoholic fatty liver disease using three-dimensional speckle tracking echocardiography.

METHODS

Forty obese children with non-alcoholic fatty liver disease were included as group I. Another 40 obese children without non-alcoholic fatty liver disease of matched age, sex, and weight were included as group II. Forty healthy controls of matched age and sex served as a control group. Anthropometric measurements, laboratory investigations, and echocardiographic examinations including three-dimensional speckle tracking echocardiography were measured for all included children.

RESULTS

Abnormal lipid profile was detected in children with non-alcoholic fatty liver disease. Troponin I levels were significantly higher in children with non-alcoholic fatty liver disease compared to obese children without non-alcoholic fatty liver disease and to healthy controls. Three-dimensional speckle tracking echocardiography examination revealed a significant reduction of left ventricular global longitudinal strain, circumferential strain, radial strain, and area strain in children with non-alcoholic fatty liver disease inspite of normal left ventricular fraction shortening measured by conventional echocardiography. All strains were negatively correlated with the grade of non-alcoholic fatty liver disease.

CONCLUSION

Non-alcoholic fatty liver disease is associated with subclinical left ventricular dysfunction. Three-dimensional speckle tracking echocardiography can be helpful in identifying early left ventricular dysfunction in children with non-alcoholic fatty liver disease even in the presence of normal left ventricular ejection fraction.

The association of non-alcoholic fatty liver disease and cardiac structure and function-Framingham Heart Study

BACKGROUND & AIMS

Non-alcoholic fatty liver disease confers increased risk for cardiovascular disease, including heart failure (HF), for reasons that remain unclear. Possible pathways could involve an association of liver fat with cardiac structural or functional abnormalities even after accounting for body size.

METHODS

We analysed N = 2356 Framingham Heart Study participants (age 52 ± 12 years, 52% women) who underwent echocardiography and standardized computed tomography measures of liver fat.

RESULTS

In cross-sectional multivariable regression models adjusted for age, gender, cohort and cardiovascular risk factors, liver fat was positively associated with left ventricular (LV) mass (β = 1.45; 95% confidence interval (CI): 0.01, 2.88), LV wall thickness (β = 0.01; 95% CI: 0.00, 0.02), mass volume ratio (β = 0.02; 95% CI 0.01, 0.03), mitral peak velocity (E) (β = 0.83; 95% CI 0.31, 1.36) and LV filling pressure (E/e' ratio) (β = 0.16; 95% CI 0.09, 0.23); and inversely associated with global systolic longitudinal strain (β = 0.20, 95% CI 0.07, 0.33), diastolic annular velocity (e') (β = -0.12; 95% CI - 0.22, -0.03), and E/A ratio (β = -0.01; 95% CI - 0.02, -0.00). After additional adjustment for body mass index (BMI), statistical significance was attenuated for all associations except for that of greater liver fat with increased LV filling pressure, a possible precursor to HF (β = 0.11; 95% CI 0.03, 0.18).

CONCLUSION

Increased liver fat was associated with multiple subclinical cardiac dysfunction measures, with most of associations mediated by obesity. Interestingly, the association of liver fat and LV filling pressure was only partially mediated by BMI, suggesting a possible direct effect of liver fat on LV filling pressure. Further confirmatory studies are needed.

Higher fatty liver index is associated with increased risk of new onset heart failure in healthy adults: a nationwide population-based study in Korea

Background

Heart failure (HF) is relatively common cardiovascular disease with high mortality and morbidity. Although it is associated with many cardiovascular risk factors, the association between nonalcoholic fatty liver disease (NAFLD), the most common chronic liver disease, and HF has not been evaluated in a large-scale cohort study. Thus, we evaluated the ability of the fatty liver Index (FLI), a surrogate marker of NAFLD, to predict the development of HF in healthy individuals.

Methods

We analyzed the association between the FLI and new-onset HF with multivariate Cox proportional-hazards models in 308,578 healthy persons without comorbidities who underwent the National Health check-ups in the republic of Korea from 2009 to 2014.

Results

A total of 2532 subjects (0.8%) were newly diagnosed with HF during the study period (a median of 5.4 years). We categorized our subjects into quartile groups according to FLI (Q1, 0–4.9; Q2, 5.0–12.5; Q3, 12.6–31.0; and Q4, > 31.0). The cumulative incidence of HF was significantly higher in the highest FLI group than in the lowest FLI group (Q1, 307 [0.4%] and Q4, 890 [1.2%]; P < 0.001). Adjusted hazard ratio (HRs) indicated that the highest FLI group was independently associated with an increased risk for HF (HR between Q4 and Q1, 2.709; 95% confidence interval = 2.380–3.085; P < 0.001). FLI was significantly associated with an increased risk of new-onset HF regardless of their baseline characteristics.

Conclusions

Higher FLI was independently associated with increased risk of HF in a healthy Korean population.

Gamma-glutamyl transferase variability and the risk of hospitalisation for heart failure

Objective

Gamma-glutamyl transferase (GGT) is associated with oxidative stress, inflammation, cardiovascular disease and mortality. Variability in metabolic parameters has recently emerged as an indicator of adverse health outcomes, including heart failure (HF).

Methods

We investigated whether GGT variability was associated with the incidence of hospitalisation for heart failure (HHF) in a Korean population without previous HF, ischaemic heart disease or liver disease. This longitudinal cohort study analysed 119 201 individuals from the Korean National Health Insurance Service-National Health Screening Cohort. GGT variability was calculated as the coefficient of variation (CV), SD and variability independent of the mean (VIM).

Results

During the 8.4 years of follow-up, 1387 cases of HHF (1.16%) developed. In the multivariable-adjusted model, the HR of HHF was 1.22 (95% CI 1.05 to 1.42) in the highest quartile of GGT variability compared with the lowest quartile, as assessed by CV after adjusting for confounding factors, including alcohol consumption and mean GGT levels. Consistent results were obtained using other indices of GGT variability such as SD (HR 1.37, 95% CI 1.16 to 1.62) and VIM (HR 1.29, 95% CI 1.11 to 1.50). In a subgroup analysis stratified by risk factor variables, although a similar relationship was observed, it was more prominent in individuals with dyslipidaemia.

Conclusions

The results of the present study demonstrated that variability in GGT was independently associated with the incidence of HHF. These findings suggest that higher GGT variability may be useful as an indicator of future risk of HF.

NAFLD: comorbidity and associated diseases

Non-alcoholic fatty liver disease (NAFLD) went beyond the competence of a gastroenterologist and acquired the character of a multidisciplinary problem. NAFLD requires the attention of many professionals. A characteristic feature of NAFLD is the variety of concomitant diseases and pathological conditions with common pathophysiological mechanisms. This review summarizes and presents the data available in the modern literature on the association of NAFLD with cardiovascular diseases, type 2 diabetes mellitus, hypothyroidism, polycystic ovary syndrome, chronic kidney disease, colorectal cancer, obstructive sleep apnea, osteoporosis, psoriasis.

Association between iron metabolism and cognitive impairment in older non-alcoholic fatty liver disease individuals: A cross-sectional study in patients from a Chinese center

Sparse is the research on the relationship between iron metabolism and mild cognitive impairment (MCI) in adults aged over 60 years with non-alcoholic fatty liver disease (NAFLD). The soluble transferrin receptor (sTfR), serum iron (SI), serum ferritin (SF), transferrin (TRF) and hemoglobin (HB) are indicators of iron metabolism.This study examined whether iron metabolism is associated with cognitive impairment in older individuals.A cross-sectional study was held in patients from a Chinese center. Individuals with NAFLD aged over 60 years were included if they did not have excessive alcohol intake and were free of stroke or dementia. Their cognitive function was assessed by the same neurologist. 3.0T H proton magnetic resonance spectroscopy (H-MRS) was performed to evaluate the hippocampus of the participants without contraindication. t test and Chi-square test were used to analyze the data. Binary logistic regression was used for correlation analysis.Fifty four (54%) of participants were diagnosed with MCI by the psychiatrist. MCI was significantly associated with higher sTfR after adjustment of all the covariates (OR = 2.565, 95%CI: 1.334∼4.934; P = .005). No statistically significant associations were observed between MCI and age or blood glucose or choline (Cho) /creatine (Cr) of theright hippocampus head.Increased age and low levels of sTfR and HB were associated with MCI in NAFLD individuals aged over 60 years.

Evaluation of left atrial function in type 2 diabetes mellitus patients with nonalcoholic fatty liver disease by two-dimensional speckle tracking echocardiography

OBJECTIVE

To assess left atrial function in type 2 diabetes mellitus (T2DM) patients with nonalcoholic fatty liver disease (NAFLD) by two-dimensional speckle tracking echocardiography (2D-STE).

METHODS

We classified 97 patients with T2DM into three groups according to the results of liver ultrasonography: group A (without NAFLD), group B (mild fatty liver), and group C (moderate to severe fatty liver). Conventional echocardiography parameters included left atrial end-systolic diameter (LAD), left ventricular end-systolic and end-diastolic diameter (LVDs, LVDd), end-diastolic thickness of ventricular septumi and LV posterior wall (IVSTd, LVPWTd), peak E and A of mitralis (E, A), septal and lateral early (e') mitral annular diastolic tissue velocities, then calculated E/A and E/mean e'. We measured LV ejection fraction (LVEF) and left atrial (LA) volumes (max, min, and preatrial contraction volume) by Simpson's rule, then calculated LA passive and active ejection fraction (LAPEF, LAAEF), left atrial maximum volume index (LAVImax). The global peak longitudinal systolic strain (LASRs), early diastolic strain (LASRe), and late diastolic strain (LASRa) rates of the LA were obtained by 2D-STE.

RESULTS

No differences were found between groups A and B (all P > 0.05). In group C, LAAEF and LASRa were obviously higher, while LAPEF, LASRe, and LASRs were obviously decreased compared with those values in groups A and B (all P < 0.05). The association between the severity of NAFLD and the differences in LA strain values remained significant after adjustment for confounders.

CONCLUSION

Two-dimensional speckle tracking echocardiography can evaluate the left atrial function in T2DM patients with NAFLD.

The association between diabetes mellitus and reduction in myocardial glucose uptake: a population-based 18F-FDG PET/CT study

BACKGROUND

In diabetes, dysregulated substrate utilization and energy metabolism of myocardium can lead to heart failure. To examine the dynamic changes of myocardium, most of the previous studies conducted dynamic myocardial PET imaging following euglycemic-hyperinsulinemic clamp, which involves complicated procedures. In comparison, the whole-body 18F-FDG PET/CT scan is a simple and widely used method. Therefore, we hope to use this method to observe abnormal myocardial glucose metabolism in diabetes and determine the influencing factors.

METHODS

We retrospectively analyzed PET/CT images of 191 subjects from our medical examination center. The levels of FDG uptake in myocardium were visually divided into 4 grades (Grade 0-3, from low to high). The differences in clinical and metabolic parameters among diabetes mellitus (DM), impaired fasting glucose (IFG), and normal fasting glucose (NFG) groups were analyzed, as well as their associations with myocardial FDG uptake.

RESULTS

Compared with NFG and IFG groups, DM group had more cardiovascular-related risk factors. The degree of myocardial FDG uptake was significantly decreased in DM group; when myocardial FDG uptake ≤ Grade 1, the sensitivity of DM prediction was 84.0%, and the specificity was 58.4%. Univariate analysis showed that the myocardial FDG uptake was weakly and negatively correlated with multiple metabolic-related parameters (r = - 0.173~ - 0.365, P < 0.05). Multivariate logistic regression analysis showed that gender (male), HOMA-IR and nonalcoholic fatty liver disease (NAFLD) were independent risk factors for poor myocardial FDG uptake.

CONCLUSIONS

Diabetes is associated with decreased myocardial glucose metabolism, which is mediated by multiple metabolic abnormalities.

NAFLD and cardiovascular disease

Nonalcoholic fatty liver disease (NAFLD) is an important cause of chronic hepatic disease and liver transplant in Western societies. The increasing prevalence is related to dietary changes and sedentarism and follows the increasing frequency of obesity and type 2 diabetes mellitus.

Growing evidence of association of NAFLD with cardiovascular diseases (CVD), independent of cardiovascular risk factors, has prompted the clarification of whether the liver is mainly a key-effector or a target-organ of the metabolic disarrangements in the metabolic syndrome. The therapeutic strategies able to alter liver disease progression and, through this, reduce the cardiovascular risk have also been tested in the last 2 decades.

This review focus on the possible interactions between hepatic disease, metabolic syndrome, and CVD, and on their implications for clinical practice.

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.

Association of non-alcoholic steatohepatitis with subclinical myocardial dysfunction in non-cirrhotic patients

BACKGROUND & AIMS

Non-alcoholic fatty liver disease (NAFLD) is associated with increased cardiovascular risk. Among categories of NAFLD, hepatic fibrosis is most likely to affect mortality. Myocardial function and its energy metabolism are tightly linked, which might be altered by an insulin resistant condition such as NAFLD. We investigated whether hepatic steatosis and fibrosis were associated with myocardial dysfunction relative to myocardial glucose uptake.

METHODS

A total of 308 patients (190 without NAFLD, 118 with NAFLD) were studied in a tertiary care hospital. Myocardial glucose uptake was evaluated at fasted state using [¹⁸F]-fluorodeoxyglucose-positron emission tomography (¹⁸FDG-PET). Hepatic steatosis and fibrosis were assessed by transient liver elastography (Fibroscan®) with controlled attenuation parameter, which quantifies hepatic fat and by surrogate indices (fatty liver index and NAFLD fibrosis score). Cardiac structure and function were examined by echocardiogram.

RESULTS

Compared to those without NAFLD, patients with NAFLD had alterations in cardiac remodeling, manifested by increased left ventricular mass index, left ventricular end-diastolic diameter, and left atrial volume index (all p <0.05). Hepatic steatosis was significantly associated with left ventricular filling pressure (E/e' ratio), which reflects diastolic dysfunction (p for trend <0.05). Those without NAFLD were more likely to have higher myocardial glucose uptake compared to those with NAFLD. Significant hepatic fibrosis was also correlated with diastolic dysfunction and impaired myocardial glucose uptake. Using multivariable linear regression, E/e' ratio was independently associated with hepatic fibrosis (standardized β = 0.12 to 0.27; all p <0.05). Association between hepatic steatosis and E/e' ratio was also significant (standardized β = 0.10 to 0.15; all p <0.05 excluding the model adjusted for adiposity).

CONCLUSIONS

Hepatic steatosis and fibrosis are significantly associated with diastolic heart dysfunction. This association is linked with myocardial glucose uptake evaluated by ¹⁸FDG-PET.

LAY SUMMARY

Non-alcoholic fatty liver disease is associated with an increased risk of cardiovascular disease. More severe forms of non-alcoholic fatty liver disease, where hepatic fibrosis occurs, are linked to increased mortality. In this study, we have shown that hepatic steatosis and fibrosis are associated with subclinical myocardial dysfunction. This association is linked to altered myocardial glucose uptake.

Nonalcoholic fatty liver disease and increased risk of 1-year all-cause and cardiac hospital readmissions in elderly patients admitted for acute heart failure

Nonalcoholic fatty liver disease (NAFLD) is an emerging risk factor for heart failure (HF). Although some progress has been made in improving survival among patients admitted for HF, the rates of hospital readmissions and the related costs continue to rise dramatically. We sought to examine whether NAFLD and its severity (diagnosed at hospital admission) was independently associated with a higher risk of 1-year all-cause and cardiac re-hospitalization in patients admitted for acute HF. We studied 212 elderly patients who were consecutively admitted with acute HF to the Hospital of Negrar (Verona) over a 1-year period. Diagnosis of NAFLD was based on ultrasonography, whereas the severity of advanced NAFLD fibrosis was based on the fibrosis (FIB)-4 score and other non-invasive fibrosis scores. Patients with acute myocardial infarction, severe valvular heart diseases, end-stage renal disease, cancer, known liver diseases or decompensated cirrhosis were excluded. Cox regression was used to estimate hazard ratios (HR) for the associations between NAFLD and the outcome(s) of interest. The cumulative rate of 1-year all-cause re-hospitalizations was 46.7% (n = 99, mainly due to cardiac causes). Patients with NAFLD (n = 109; 51.4%) had remarkably higher 1-year all-cause and cardiac re-hospitalization rates compared with their counterparts without NAFLD. Both event rates were particularly increased in those with advanced NAFLD fibrosis. NAFLD was associated with a 5-fold increased risk of 1-year all-cause re-hospitalization (adjusted-hazard ratio 5.05, 95% confidence intervals 2.78-9.10, p<0.0001) after adjustment for established risk factors and potential confounders. Similar results were found for 1-year cardiac re-hospitalization (adjusted-hazard ratio 8.05, 95% confidence intervals 3.77-15.8, p<0.0001). In conclusion, NAFLD and its severity were strongly and independently associated with an increased risk of 1-year all-cause and cardiac re-hospitalization in elderly patients admitted with acute HF.

Gamma-glutamyltransferase-friend or foe within?

Gamma-glutamyltransferase (GGT) is a liver enzyme, which is located on the plasma membranes of most cells and organ tissues, but more commonly in hepatocytes, and is routinely used in clinical practice to help indicate liver injury and as a marker of excessive alcohol consumption. Among the liver enzymes, important advances have especially been made in understanding the physiological functions of GGT. The primary role of GGT is the extracellular catabolism of glutathione, the major thiol antioxidant in mammalian cells, which plays a relevant role in protecting cells against oxidants produced during normal metabolism; GGT, therefore, plays an important role in cellular defence. Beyond its physiological functions, circulating serum GGT has been linked to a remarkable array of chronic conditions and diseases, which include nonalcoholic fatty liver disease, vascular and nonvascular diseases and mortality outcomes. This review summarizes the available epidemiological and genetic evidence for the associations between GGT and these adverse outcomes, the postulated biologic mechanisms underlying these associations, outlines areas of outstanding uncertainty and the implications for clinical practice.

Nonalcoholic fatty liver disease - A multisystem disease?

Non-alcoholic fatty liver disease (NAFLD) is one of the most common comorbidities associated with overweight and metabolic syndrome (MetS). Importantly, NAFLD is one of its most dangerous complications because it can lead to severe liver pathologies, including fibrosis, cirrhosis and hepatic cellular carcinoma. Given the increasing worldwide prevalence of obesity, NAFLD has become the most common cause of chronic liver disease and therefore is a major global health problem. Currently, NAFLD is predominantly regarded as a hepatic manifestation of MetS. However, accumulating evidence indicates that the effects of NAFLD extend beyond the liver and are negatively associated with a range of chronic diseases, most notably cardiovascular disease (CVD), diabetes mellitus type 2 (T2DM) and chronic kidney disease (CKD). It is becoming increasingly clear that these diseases are the result of the same underlying pathophysiological processes associated with MetS, such as insulin resistance, chronic systemic inflammation and dyslipidemia. As a result, they have been shown to be independent reciprocal risk factors. In addition, recent data have shown that NAFLD actively contributes to aggravation of the pathophysiology of CVD, T2DM, and CKD, as well as several other pathologies. Thus, NAFLD is a direct cause of many chronic diseases associated with MetS, and better detection and treatment of fatty liver disease is therefore urgently needed. As non-invasive screening methods for liver disease become increasingly available, detection and treatment of NAFLD in patients with MetS should therefore be considered by both (sub-) specialists and primary care physicians.

Non-alcoholic fatty liver disease and risk of cardiovascular disease

Non-alcoholic fatty liver disease (NAFLD) has become the leading cause of chronic liver diseases worldwide, causing considerable liver-related mortality and morbidity. During the past decade, it has also become increasingly evident that NAFLD is a multisystem disease that affects many extra-hepatic organ systems, including the heart and the vascular system. In this updated clinical review, we discuss the rapidly expanding body of clinical and epidemiological evidence that supports a strong association of NAFLD with cardiovascular diseases (CVDs) and other functional and structural myocardial abnormalities. We also discuss some recently published data that correlate NAFLD due to specific genetic polymorphisms with the risk of CVDs. Finally, we briefly examine the assessment tools for estimating the global CVD risk in patients with NAFLD as well as the conventional and the more innovative pharmacological approaches for the treatment of CVD risk in this group of patients.

Cardiovascular Disease and Myocardial Abnormalities in Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in many developed countries, affecting an estimated 30 % of the adult population. In this updated clinical review, we summarize the current knowledge regarding the strong association between NAFLD and the risk of coronary heart disease (CHD) and other functional, structural, and arrhythmic cardiac complications (e.g., left ventricular dysfunction, heart valve diseases and atrial fibrillation). We also briefly discuss the putative biological mechanisms linking NAFLD with these important extra-hepatic complications. To date, a large body of evidence has suggested that NAFLD is not simply a marker of CHD and other functional, structural, and arrhythmic cardiac complications, but also may play a part in the development and progression of these cardiac complications. The clinical implication of these findings is that patients with NAFLD may benefit from more intensive surveillance and early treatment interventions aimed at decreasing the risk of CHD and other cardiac and arrhythmic complications.

Increased serum gamma-glutamyltransferase levels are associated with ventricular instability in type 2 diabetes

The purpose of our study is to examine the association between serum GGT levels and ventricular instability in Chinese patients with T2DM. We conducted a cross-sectional, community-based study in Nanjing, China from June to November 2011. Among 10,050 patients aged 40-79 years, we enrolled 2444 with pre-diabetes, 2496 with T2DM, and 4521 without diabetes (non-diabetes). Electrocardiograms were performed to measure the QT interval corrected for heart rate (QTc) and QT interval dispersion (QTd). Serum GGT levels, metabolic parameters, body mass index, and blood pressure were also measured. We found that there were no significant associations of increased QTc/QTd with serum GGT levels in participants with pre-existing T2DM and non-diabetes, after adjusting for age, duration of diabetes, and metabolic parameters. Even after adjustment, higher risks of QTc ≥ 440 ms/√s and QTd ≥ 58 ms were found in participants with serum GGT levels ≥49 U/L compared with those with <15 U/L in the pre-diabetes (QTc: OR 1.96, 95 % CI 1.23-2.47; QTd: OR 1.34, 95 % CI 1.07-1.94) and newly diagnosed T2DM (QTc: OR 2.01, 95 % CI 1.39-2.51; QTd: OR 1.53, 95 % CI 1.03-1.99) groups. We conclude that Increased serum GGT levels are associated with some markers of ventricular repolarization abnormalities in the early stage of T2DM.

Extrahepatic Manifestations of Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease worldwide with an increased prevalence of metabolic, macro- and microvascular complications. The primary causes of mortality in NAFLD are cardiovascular disease (CVD), malignancy and liver disease. NAFLD is a multisystem disease that affects a variety of extra-hepatic organ systems. The main focus of this review is to summarize the reported extra-hepatic associations, which include CVD, chronic kidney disease, obstructive sleep apnea, osteoporosis, psoriasis, colorectal cancer, iron overload and various endocrinopathies (e.g. type 2 diabetes mellitus, thyroid dysfunction, and polycystic ovarian syndrome). Due to the systemic manifestations of NAFLD patients require a multidisciplinary assessment and may benefit from more rigorous surveillance and early treatment interventions to decrease mortality related to malignancy or cardiometabolic diseases.

γ-Glutamyltransferase and Risk of Sudden Cardiac Death in Middle-Aged Finnish Men: A New Prospective Cohort Study

Background

γ‐Glutamyltransferase (GGT) has been linked to an increased risk of several cardiovascular outcomes; however, the relationship of GGT with sudden cardiac death (SCD) has not been investigated previously. We aimed to assess the association of GGT with risk of SCD.

Methods and Results

Serum GGT activity was assessed at baseline in the Kuopio Ischemic Heart Disease prospective cohort of 1780 men, and 136 SCDs were recorded during 22 years of follow‐up. Correction for within‐person variability was made using data from repeated measurements taken several years apart. The regression dilution ratio of log_eGGT adjusted for age was 0.68 (95% CI 0.61–0.74). Serum GGT was log‐linearly associated with risk of SCD. The hazard ratio for SCD per 1 SD higher baseline log_eGGT values (2‐fold higher) was 1.30 (95% CI 1.10–1.54; P=0.002) after adjustment for several established risk factors and remained consistent with further adjustment for alcohol consumption, resting heart rate, lipids, and C‐reactive protein (hazard ratio 1.26, 95% CI 1.05–1.50; P=0.014). The corresponding hazard ratios were 1.48 (95% CI 1.15–1.89; P=0.002) and 1.40 (95% CI 1.07–1.82; P=0.014) after correction for within‐person variability. Hazard ratios remained unchanged after accounting for incident coronary events and did not vary importantly by levels or categories of prespecified conventional risk factors.

Conclusions

GGT is positively, log‐linearly, and independently associated with future risk of SCD in the general male population. Further research is needed to replicate these findings.

Nonalcoholic Fatty Liver Disease Is Associated With Higher 1-year All-Cause Rehospitalization Rates in Patients Admitted for Acute Heart Failure

Repeat hospitalization due to acute heart failure (HF) is a global public health problem that markedly impacts on health resource use. Identifying novel predictors of rehospitalization would help physicians to determine the optimal postdischarge plan for preventing HF rehospitalization. Nonalcoholic fatty liver disease (NAFLD) is an emerging risk factor for many heart diseases, including HF. We assessed whether NAFLD at hospital admission predicts 1-year all-cause rehospitalization in patients with acute HF. We enrolled all patients consecutively admitted for acute HF to our General Medicine Division, from January 2013 to April 2014, after excluding patients with acute myocardial infarction, severe heart valve diseases, malignancy, known liver diseases, and those with volume overload related to extracardiac causes. NAFLD was diagnosed by ultrasonography and exclusion of competing etiologies. The primary outcome of the study was the 1-year all-cause rehospitalization rate. Among the 107 patients enrolled in the study, the cumulative rehospitalization rate was 12.1% at 1 month, 25.2% at 3 months, 29.9% at 6 months, and 38.3% at 1 year. Patients with NAFLD had markedly higher 1-year rehospitalization rates than those without NAFLD (58% vs 21% at 1 y; P < 0.001 by the log-rank test). Cox regression analysis revealed that NAFLD was associated with a 5.5-fold increased risk of rehospitalization (adjusted hazard ratio 5.56, 95% confidence interval 2.46-12.1, P < 0.001) after adjustment for multiple HF risk factors and potential confounders. In conclusion, NAFLD was independently associated with higher 1-year rehospitalization in patients hospitalized for acute HF.

Association of nonalcoholic fatty liver disease with subclinical myocardial remodeling and dysfunction: A population-based study

Nonalcoholic fatty liver disease (NAFLD) and heart failure (HF) are obesity-related conditions with high cardiovascular mortality. Whether NAFLD is independently associated with subclinical myocardial remodeling or dysfunction among the general population is unknown. We performed a cross-sectional analysis of 2,713 participants from the multicenter, community-based Coronary Artery Risk Development in Young Adults (CARDIA) study who underwent concurrent computed tomography (CT) quantification of liver fat and comprehensive echocardiography with myocardial strain measured by speckle tracking during the Year-25 examination (age, 43-55 years; 58.8% female and 48.0% black). NAFLD was defined as liver attenuation ≤40 Hounsfield units after excluding other causes of liver fat. Subclinical left ventricular (LV) systolic dysfunction was defined using values of absolute peak global longitudinal strain (GLS). Diastolic dysfunction was defined using Doppler and tissue Doppler imaging markers. Prevalence of NAFLD was 10.0%. Participants with NAFLD had lower early diastolic relaxation (e') velocity (10.8 ± 2.6 vs. 11.9 ± 2.8 cm/s), higher LV filling pressure (E/e' ratio: 7.7 ± 2.6 vs. 7.0 ± 2.3), and worse absolute GLS (14.2 ± 2.4% vs. 15.2 ± 2.4%) than non-NAFLD (P < 0.0001 for all). When adjusted for HF risk factors or body mass index, NAFLD remained associated with subclinical myocardial remodeling and dysfunction (P < 0.01). The association of NAFLD with e' velocity (β = -0.36 [standard error = 0.15] cm/s; P = 0.02), E/e' ratio (β = 0.35 [0.16]; P = 0.03), and GLS (β = -0.42 [0.18]%; P = 0.02) was attenuated after controlling for visceral adipose tissue. Effect modification by race and sex was not observed.

CONCLUSIONS

NAFLD is independently associated with subclinical myocardial remodeling and dysfunction and provides further insight into a possible link between NAFLD and HF.

NAFLD: a multisystem disease

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in Western countries that is predicted to become also the most frequent indication for liver transplantation by 2030. Over the last decade, it has been shown that the clinical burden of NAFLD is not only confined to liver-related morbidity and mortality, but there is now growing evidence that NAFLD is a multisystem disease, affecting extra-hepatic organs and regulatory pathways. For example, NAFLD increases risk of type 2 diabetes mellitus (T2DM), cardiovascular (CVD) and cardiac diseases, and chronic kidney disease (CKD). Although the primary liver pathology in NAFLD affects hepatic structure and function to cause morbidity and mortality from cirrhosis, liver failure and hepatocellular carcinoma, the majority of deaths among NAFLD patients are attributable to CVD. This narrative review focuses on the rapidly expanding body of clinical evidence that supports the concept of NAFLD as a multisystem disease. The review discusses the factors involved in the progression of liver disease in NAFLD and the factors linking NAFLD with other extra-hepatic chronic diseases, such as T2DM, CVD, cardiac diseases and CKD. The review will not discuss NAFLD treatments as these are discussed elsewhere in this issue of the Journal. For this review, PubMed was searched for articles using the keywords "non-alcoholic fatty liver disease" or "fatty liver" combined with "diabetes", "cardiovascular (or cardiac) disease", "cardiovascular mortality" or "chronic kidney disease" between 1990 and 2014. Articles published in languages other than English were excluded.

Association of gamma-glutamyltransferase with non-alcoholic fatty liver disease and other related diseases

Gamma-glutamyltransferase (GGT) activity is a sensitive marker of liver dysfunction. It is commonly used to evaluate liver diseases such as viral hepatitis or alcoholic hepatitis. Several studies have shown the association between GGT levels and risk of non-alcoholic fatty liver disease, insulin resistance, metabolic syndrome and cardiovascular disease. This paper will review recent advances in understanding the association of GGT with these diseases.

Prevalence of heart failure signs and symptoms in a large primary care population identified through the use of text and data mining of the electronic health record

BACKGROUND

The electronic health record (EHR) contains a tremendous amount of data that if appropriately detected can lead to earlier identification of disease states such as heart failure (HF). Using a novel text and data analytic tool we explored the longitudinal EHR of over 50,000 primary care patients to identify the documentation of the signs and symptoms of HF in the years preceding its diagnosis.

METHODS AND RESULTS

Retrospective analysis consisted of 4,644 incident HF cases and 45,981 group-matched control subjects. Documentation of Framingham HF signs and symptoms within encounter notes were carried out with the use of a previously validated natural language processing procedure. A total of 892,805 affirmed criteria were documented over an average observation period of 3.4 years. Among eventual HF cases, 85% had ≥1 criterion within 1 year before their HF diagnosis, as did 55% of control subjects. Substantial variability in the prevalence of individual signs and symptoms were found in both case and control subjects.

CONCLUSIONS

HF signs and symptoms are frequently documented in a primary care population as identified through automated text and data mining of EHRs. Their frequent identification demonstrates the rich data available within EHRs that will allow for future work on automated criterion identification to help develop predictive models for HF.

Associations between total serum GGT activity and metabolic risk: MESA

AIM

To evaluate associations between total serum GGT activity, metabolic risk factors and prevalent metabolic disease in MESA.

PATIENTS & METHODS

Continuous associations between GGT and fasting blood glucose (FBG), fasting insulin, HbA1c and Homeostasis Model Assessment Index of Insulin Resistance (HOMA-IR) were evaluated in the entire MESA cohort and in metabolic disease subgroups using linear regression models incrementally adjusted for age, gender, site, race, lifestyle, traditional risk factors and medications. Cross-sectional odds of prevalent impaired FBG, metabolic syndrome and Type 2 diabetes were calculated for GGT quintiles in the entire cohort and in subgroups defined by age (< or ≥65 years) and ethnicity.

RESULTS

In multivariable models, significant associations were present between GGT activity and FBG, fasting insulin, HbA1c and HOMA-IR, with the interaction between GGT and BMI affecting the association between GGT and HOMA-IR as well as the association between BMI and HOMA-IR (p < 0.0001). Adjusted odds ratios (95% CIs) of prevalent impaired FBG, metabolic syndrome and Type 2 diabetes for quintile 5 versus 1 in the entire cohort were 2.4 (1.7-3.5), 3.3 (2.5-4.5) and 2.8 (1.8-4.4), respectively (p < 0.0001). GGT associations weakened with age. The significance of linear trends for increased prevalent metabolic disease by increasing GGT quintile varied by ethnicity.

CONCLUSION

GGT is strongly associated with both cardiovascular and metabolic risk factors, including prevalent metabolic disease, in the MESA cohort.

Risk of cardiovascular, cardiac and arrhythmic complications in patients with non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) has emerged as a public health problem of epidemic proportions worldwide. Accumulating clinical and epidemiological evidence indicates that NAFLD is not only associated with liver-related morbidity and mortality but also with an increased risk of coronary heart disease (CHD), abnormalities of cardiac function and structure (e.g., left ventricular dysfunction and hypertrophy, and heart failure), valvular heart disease (e.g., aortic valve sclerosis) and arrhythmias (e.g., atrial fibrillation). Experimental evidence suggests that NAFLD itself, especially in its more severe forms, exacerbates systemic/hepatic insulin resistance, causes atherogenic dyslipidemia, and releases a variety of pro-inflammatory, pro-coagulant and pro-fibrogenic mediators that may play important roles in the pathophysiology of cardiac and arrhythmic complications. Collectively, these findings suggest that patients with NAFLD may benefit from more intensive surveillance and early treatment interventions to decrease the risk for CHD and other cardiac/arrhythmic complications. The purpose of this clinical review is to summarize the rapidly expanding body of evidence that supports a strong association between NAFLD and cardiovascular, cardiac and arrhythmic complications, to briefly examine the putative biological mechanisms underlying this association, and to discuss some of the current treatment options that may influence both NAFLD and its related cardiac and arrhythmic complications.

The Role of Non-alcoholic Fatty Liver Disease in Cardiovascular Disease

Non-alcoholic fatty liver disease (NAFLD) has become the most prevalent chronic liver disease in western countries and is closely related to the metabolic syndrome. When NAFLD is associated with hepatocellular damage and inflammation (non-alcoholic steatohepatitis [NASH]) it can lead to severe liver disease. However, it has become clear that NAFLD is also associated with an increased risk of cardiovascular disease (CVD), independently of classical known risk factors for the latter. In the current review we briefly summarise the current clinical evidence on the role of NAFLD in CVD and discuss the potential mechanisms by which NAFLD can be linked to the pathophysiology of CVD.

Non-alcoholic fatty liver disease is associated with an increased prevalence of atrial fibrillation in hospitalized patients with type 2 diabetes

NAFLD (non-alcoholic fatty liver disease) and AF (atrial fibrillation) are two pathological conditions that are highly prevalent in developed countries and share multiple risk factors. The relationship between NAFLD and AF in Type 2 diabetes is currently unknown. We studied a hospital-based sample of 702 patients with Type 2 diabetes discharged from our Division of Endocrinology during 2007-2011. The diagnosis of AF was confirmed in affected participants on the basis of ECGs and medical history by experienced cardiologists. NAFLD was defined by ultrasonographic detection of hepatic steatosis in the absence of other liver diseases. Of the 702 hospitalized patients included in the study, 514 (73.2%) of them had NAFLD and 85 (12.1%) had persistent or permanent AF. NAFLD was associated with an increased risk of prevalent AF {OR (odds ratio), 3.04 [95% CI (confidence interval), 1.54-6.02]; P<0.001}. Adjustments for age, sex, systolic BP (blood pressure), HbA1c, (glycated haemoglobin), estimated GFR (glomerular filtration rate), total cholesterol, electrocardiographic LVH (left ventricular hypertrophy), COPD (chronic obstructive pulmonary disease), and prior history of HF (heart failure), VHD (valvular heart disease) or hyperthyroidism did not attenuate the association between NAFLD and AF [adjusted OR, 5.88 (95% CI, 2.72-12.7); P<0.001]. In conclusion, our results show that ultrasound-diagnosed NAFLD is strongly associated with an increased prevalence of persistent or permanent AF in patients with Type 2 diabetes, independently of several clinical risk factors for AF. The potential impact of NAFLD on AF deserves particular attention, especially with respect to the implications for screening and surveillance strategies in the growing number of patients with NAFLD.

Non-alcoholic fatty liver disease is associated with an increased incidence of atrial fibrillation in patients with type 2 diabetes

Background

The relationship between non-alcoholic fatty liver disease (NAFLD) and atrial fibrillation (AF) in type 2 diabetes is currently unknown. We examined the relationship between NAFLD and risk of incident AF in people with type 2 diabetes.

Methods and Results

We prospectively followed for 10 years a random sample of 400 patients with type 2 diabetes, who were free from AF at baseline. A standard 12-lead electrocardiogram was undertaken annually and a diagnosis of incident AF was confirmed in affected participants by a single cardiologist. At baseline, NAFLD was defined by ultrasonographic detection of hepatic steatosis in the absence of other liver diseases. During the 10 years of follow-up, there were 42 (10.5%) incident AF cases. NAFLD was associated with an increased risk of incident AF (odds ratio [OR] 4.49, 95% CI 1.6–12.9, p<0.005). Adjustments for age, sex, hypertension and electrocardiographic features (left ventricular hypertrophy and PR interval) did not attenuate the association between NAFLD and incident AF (adjusted-OR 6.38, 95% CI 1.7–24.2, p = 0.005). Further adjustment for variables that were included in the 10-year Framingham Heart Study-derived AF risk score did not appreciably weaken this association. Other independent predictors of AF were older age, longer PR interval and left ventricular hypertrophy.

Conclusions

Our results indicate that ultrasound-diagnosed NAFLD is strongly associated with an increased incidence of AF in patients with type 2 diabetes even after adjustment for important clinical risk factors for AF.

Soluble ST2 associates with diabetes but not established cardiovascular risk factors: a new inflammatory pathway of relevance to diabetes?

Preliminary data mostly from animal models suggest the sST2/IL-33 pathway may have causal relevance for vascular disease and diabetes and thus point to a potential novel inflammatory link to cardiometabolic disease. However, the characterisation of sST2 levels in terms of metabolic or vascular risk in man is completely lacking. We sought to address this gap via a comprehensive analysis of risk factor and vascular correlates of sST2 in a cross-sectional study (pSoBid). We measured sST2 in plasma in 639 subjects and comprehensively related it to cardiovascular and diabetes risk factors and imaged atherosclerosis measures. Circulating sST2 levels increased with age, were lower in women and in highest earners. After adjusting for age and gender, sST2 levels associated strongly with markers of diabetes, including triglycerides [effect estimate (EE) per 1 standard deviation increase in sST2:1.05 [95%CI 1.01,1.10]), liver function (alanine aminotransaminase [ALT] and γ-glutamyl transferase [GGT]: EE 1.05 [1.01,1.09] and 1.13 [1.07,1.19] respectively), glucose (1.02 [1.00,1.03]) and sICAM-1 (1.05 [1.02,1.07]). However, sST2 levels were not related to smoking, cholesterol, blood pressure, or atheroma (carotid intima media thickness, plaque presence). These results suggest that sST2 levels, in individuals largely without vascular disease, are related principally to markers associated with diabetes and ectopic fat and add support for a role of sST2 in diabetes. Further mechanistic studies determining how sST2 is linked to diabetes pathways may offer new insights into the inflammatory paradigm for type 2 diabetes.