A systematic review: burden and severity of subclinical cardiovascular disease among those with nonalcoholic fatty liver; should we care?

Role of Noninvasive Tests in Clinical Gastroenterology Practices to Identify Patients With Nonalcoholic Steatohepatitis at High Risk of Adverse Outcomes: Expert Panel Recommendations

Nonalcoholic fatty liver disease (NAFLD) is generally considered a silent and potentially reversible condition. The subtype of NAFLD that can be classified as nonalcoholic steatohepatitis (NASH) can progress to advanced fibrosis and cirrhosis. Because of the metabolic nature of the pathogenic mechanism underlying NAFLD and NASH, it is often accompanied by common comorbidities such as obesity, insulin resistance, and type 2 diabetes mellitus. The increase in the prevalence of these comorbidities has resulted in a parallel increase in the prevalence of NAFLD and NASH, globally, nationally, and even in children. In recent years, it has been identified that the stage of fibrosis is the most important predictor of liver outcomes; therefore, identifying patients with NAFLD and NASH with more advanced stages of fibrosis can be essential for optimal management. Several noninvasive tools for diagnosing and staging NAFLD and NASH are available, but simple and straightforward recommendations on the use of these tools are not. Recognizing these unmet needs, hepatologists who are members of the American College of Gastroenterology and the Chronic Liver Disease Foundation created a practical decision tree/algorithm to risk stratify NAFLD/NASH as a resource in gastroenterology/hepatology clinical practices. This review will provide insight into how this algorithm was developed, describe it in detail, and provide recommendations for its use in clinical practice.

Extrahepatic Manifestations of Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease and encompasses a spectrum of pathology from simple steatosis to inflammation and significant fibrosis that leads to cirrhosis. NAFLD and its comorbid conditions extend well beyond the liver. It is a multisystemic clinical disease entity with extrahepatic manifestations such as cardiovascular disease, type 2 diabetes, chronic kidney disease, hypothyroidism, polycystic ovarian syndrome, and psoriasis. Indeed, the most common causes of mortality in subjects with NAFLD are cardiovascular disease, followed by malignancies and then liver-related complications as a distant third. This review focuses on several of the key extrahepatic manifestations of NAFLD and areas for future investigation. Clinicians should learn to screen and initiate treatment for these extrahepatic manifestations in a prompt and timely fashion before they progress to end-organ damage.

Semi-Quantitative Ultrasonographic Evaluation of NAFLD

Nonalcoholic fatty liver disease (NAFLD) embraces histopathological entities ranging from the relatively benign simple steatosis to the progressive form nonalcoholic steatohepatitis (NASH), which is associated with fibrosis and an increased risk of progression to cirrhosis and hepatocellular carcinoma. NAFLD is the most common liver disease and is associated with extrahepatic comorbidities including a major cardiovascular disease burden. The non-invasive diagnosis of NAFLD and the identification of subjects at risk of progressive liver disease and cardio-metabolic complications are key in implementing personalized treatment schedules and follow-up strategies. In this review, we highlight the potential role of ultrasound semiquantitative scores for detecting and assessing steatosis severity, progression of NAFLD, and cardio-metabolic risk. Ultrasonographic scores of fatty liver severity act as sensors of cardio-metabolic health and may assist in selecting patients to submit to second-line non-invasive imaging techniques and/or liver biopsy.

Association of hepatic steatosis with epicardial fat volume and coronary artery disease in symptomatic patients

AIMS

This study aims to investigate whether HS-when associated with an excessive amount of epicardial adipose tissue-correlates with CAD in subjects with symptoms suggestive of CVD.

METHODS AND RESULTS

CCTA images, demographic and clinical variables of 1.182 individuals were retrieved: semi-automated measurements for EFV, CAC, and MLD were obtained. Individuals were grouped into three categories according to the presence of CAD, resulting in absent (CAD₀), non-obstructive (CAD₁) or obstructive (CAD₂) disease-groups, and into two categories based on the presence of HS (with no HS, named HS^-, and with HS, named HS⁺). EFV was significantly higher in HS⁺ than in HS^- group (p < 0.001), whereas MLD was lower in CAD⁺ than in CAD^- subjects (p < 0.001). Two predictive models for CAD were tested: the former included clinical risk factors for CAD along with age, gender, EFV and MLD, whereas the latter did not include clinical variables. The logistic regression analysis of the second proposed model reliably discriminated CAD₀ from CAD₁ and CAD₂ (AUC of 0.712, range 0.682-0.742).

CONCLUSION

Lower MLD was associated with increased EFV, and MLD-as a marker of HS-discriminate symptomatic patients with CAD from whom without.

A Non-Invasive Prediction Model for Non-Alcoholic Fatty Liver Disease in Adults with Type 2 Diabetes Based on the Population of Northern Urumqi, China

BACKGROUND

High prevalence of non-alcoholic fatty liver disease (NAFLD) occurs in type 2 diabetes mellitus (T2DM), and about 13% of diabetic patients eventually die of liver cirrhosis or liver cancer. The purpose of our research was to develop a non-invasive predictive model of NAFLD in adults with T2DM.

PATIENTS AND METHODS

Adult patients diagnosed with T2DM during physical examination in 2018 in Urumqi were recruited, in total 40,921 cases. We chose questionnaire and physical measurement variables to build a simple, low-cost model. Variables were selected by the least absolute shrinkage and selection operator regression (LASSO). The features chosen by LASSO were used to build the nomogram prediction model of NAFLD. The receiver operating curve (ROC) and calibration were used for model validation.

RESULTS

Determinants in the nomogram included age, ethnicity, sex, exercise, smoking, dietary ratio, heart rate, systolic blood pressure (SBP), BMI, waist circumference, and atherosclerotic vascular disease (ASCVD). The area under ROC of developing group and validation group was 0.756 (95% confidence interval 0.750-0.761) and 0.755 (95% confidence interval 0.746-0.763), respectively, and the P values of the two calibration curves were 0.694 and 0.950, suggesting that the nomogram had good disease recognition ability and calibration.

CONCLUSION

A nomogram constructed with accuracy can calculate the possibility of NAFLD in adults with T2DM. If validated externally, this tool could be utilized as a non-invasive method to diagnose non-alcoholic fatty liver in adults with T2DM.

The association of the steatosis severity in fatty liver disease with coronary plaque pattern in general population

BACKGROUND AND AIMS

Nonalcoholic fatty liver disease (NAFLD) is commonly observed in patients with cardiovascular disease (CVD). However, whether the steatosis severity of NAFLD is independently associated with coronary artery atherosclerosis is still controversial.

METHODS

Consecutive Taiwanese individuals (1502) who received coronary computed tomography angiography (CCTA) and abdominal sonography as part of a general routine health evaluation were enrolled. The association between steatosis severity, coronary atherosclerosis involvement and various plaque patterns were analysed.

RESULTS

Compared with non-steatosis, NAFLD subjects had more cardiovascular risk factors that correlated with the severity of steatosis (P for the trend <.05). The presence of atherosclerotic plaques correlated with the severity of steatosis (none: 53%, mild: 64.1%, and moderate to severe: 66.9%; P for the trend <.001). Parameters of coronary atherosclerosis, including atheroma burden obstructive score (ABOS), segment involvement score (SIS) and segment stenosis score (SSS), were higher in the moderate to severe steatosis group. After adjusting for major confounding factors, the severity of steatosis still correlated with the mixed plaque pattern (P = .043). Subgroup analysis of the risk of the presence of overall coronary and mixed plaques showed a significant association with increasing severity of steatosis, especially among these who were <65 years old, male, without metabolic syndrome, and with lower low-density lipoprotein choleseterol values.

CONCLUSION

In this general population, steatosis severity of NAFLD is associated with coronary artery atherosclerosis burden. Furthermore, steatosis severity correlated with the risk of the presence of coronary plaques, especially high-risk plaques, and was independent of traditional risk factors.

Liver fibrosis marker is an independent predictor of cardiovascular morbidity and mortality in the general population

BACKGROUND

A growing body of evidence suggests that Non-alcoholic fatty liver disease (NAFLD) and liver fibrosis are associated with cardiovascular disease (CVD). However, the independent role of liver fibrosis markers in the prediction of CVD in the general population is seldom tested.

AIMS

To assess whether a marker of liver fibrosis predicts the first occurrence of a CVD event in a large sample of community-based general population.

METHODS

Historical cohort using data from a large health provider that operates a centralized computerized medical record. The level of liver fibrosis was measured by the fibrosis-4 (FIB-4) score, and the association with CVD was adjusted for the European Systematic Coronary Risk Evaluation calculator (SCORE).

RESULTS

The study included 8,511 individuals, 3,292 with inconclusive fibrosis and 195 with advanced fibrosis (FIB-4 ≥ 2.67). People with advanced fibrosis had higher risk for CVD, after adjustment for sociodemographic characteristics, the SCORE, use of statins and aspirin (HR [95%CI], 1.63 [1.29-2.06]). The association persisted in both women and men. Using age-specific cut-offs, there was a dose-response association between inconclusive and advanced fibrosis and CVD (HR [95%CI], 1.15 [1.01-1.31]) and HR [95%CI], 1.60 [1.27-2.01], respectively, P for trend<0.001).

CONCLUSIONS

A simple fibrosis score is independently associated with CVD, suggesting that fibrosis markers should be considered in primary-care risk assessment.

NAFLD in type 1 diabetes: overrated or underappreciated?

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in western countries, affecting 25-30% of the general population and up to 65% in those with obesity and/or type 2 diabetes. Accumulation of visceral adipose tissue and insulin resistance (IR) contributes to NAFLD. NAFLD is not an innocent entity as it not only may cause nonalcoholic steatohepatitis and cirrhosis but also contribute to cardiovascular morbidity and mortality. More and more people with type 1 diabetes (T1D) are becoming overweight and present with features of IR, but the prevalence and impact of NAFLD in this population are still unclear. The utility of noninvasive screening tools for NAFLD in T1D is being explored. Recent data indicate that based upon ultrasonographic criteria NAFLD is present in 27% (ranging between 19% and 31%) of adults with T1D. Magnetic resonance imaging data indicate a prevalence rate of 8.6% (ranging between 2.1% and 18.6%). There are, however, multiple factors affecting these data, ranging from study design and referral bias to discrepancies in between diagnostic modalities. Individuals with T1D have a 7-fold higher risk of cardiovascular disease (CVD) and cardiovascular mortality is the most prominent cause of death in T1D. Patients with T1D and NALFD are also more prone to develop CVD, but the independent contribution of NAFLD to cardiovascular events has to be determined in this population. Furthermore, limited data in T1D also point towards a 2 to 3 times higher risk for microvascular complications in those with NAFLD. In this article, we will discuss epidemiological and diagnostic challenges of NAFLD in T1D, explore the link between IR and NAFLD and chronic complications, and examine the independent contribution of NAFLD to the presence of macro-, and microvascular complications.

Plasma xanthine oxidoreductase activity in Japanese patients with type 2 diabetes across hospitalized treatment

Aims/Introduction

Xanthine oxidoreductase (XOR) is an enzyme that catalyzes hypoxanthine and xanthine to xanthine and uric acid, respectively. Plasma XOR activity has recently been measured in humans. However, limited information is known about plasma XOR activity in patients with type 2 diabetes mellitus, and its changes after short‐term glycemic control treatment.

Materials and Methods

We enrolled 28 Japanese patients (10 men/18 women) with type 2 diabetes mellitus who were hospitalized to undergo medical treatment for diabetes. Plasma XOR activity, quantified using triple quadrupole mass spectrometry and liquid chromatography, and other clinical parameters were examined at admission and 2 weeks after treatment during hospitalization. Changes in plasma XOR activity after treatment during hospitalization and associated clinical parameters were assessed.

Results

At the time of admission, the median plasma XOR activity was 83.1 pmol/h/mL, with a wide range of 14.4–1150 pmol/h/mL. Multiple regression analysis identified serum aspartate transaminase and alanine transaminase levels as significant and independent factors correlating with the baseline plasma XOR. Two weeks of treatment during hospitalization was associated with a significant decrease in plasma XOR activity. Changes in serum aspartate transaminase were also the only significant and independent factor correlating with changes in plasma XOR activity.

Conclusions

A close relationship was observed between plasma XOR activity and liver transaminases in patients with type 2 diabetes mellitus, cross‐sectionally, and also across treatment during hospitalization.

Translational insight into prothrombotic state and hypercoagulation in nonalcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is an emerging and threatening pathological condition, ranging from fatty liver (FL) to chronic steatohepatitis (NASH), liver cirrhosis, and eventually to hepatocellular carcinoma (HCC). Recent findings suggest that patients with NAFLD have a higher risk of cardiovascular events and thromboembolism and that this risk is independent of metabolic diseases that are frequently associated with NAFLD, such as diabetes, hyperlipidaemia, and obesity. The vascular involvement of NAFLD might be considered its systemic burden, conditioning higher mortality in patients affected by the disease. These clinical findings suggested the existence of a prothrombotic state in NAFLD, which is partially unexplored and whose underlying mechanisms are to date not completely understood. Here, we review the mechanisms involved in the pathogenesis of the prothrombotic state in NAFLD across the progression from the healthy liver through the different stages of the disease. We focused on the possible role of several metabolic features of NAFLD possibly leading to hypercoagulation other than endothelial and platelet activation, such as insulin-resistance, nitric oxide production regulation, and gut microbiota homeostasis. Also, we analysed the involvement of plasminogen activator inhibitor-1 (PAI-1) and thromboinflammation taking place in NAFLD. Finally, we described factors striking a prothrombotic imbalance in NASH cirrhosis, with a particular focus on the pathogenesis of portal vein thrombosis.

Non-alcoholic fatty liver disease is associated with cardiovascular disease in subjects with different glucose tolerance

INTRODUCTION

Non-alcoholic fatty liver disease (NAFLD) is associated with cardiovascular disease (CVD) in patients with type 2 diabetes; nonetheless, it is unknown whether the relationship between NAFLD and CVD occurs also in subjects with prediabetes. Herein, we evaluated whether NAFLD is associated with prevalent CVD in subjects with different glucose tolerance states independently of cardiovascular risk factors.

MATERIALS AND METHODS

Presence of NALFD, defined by liver ultrasound, and its association with prevalent composite and individual CVD, including coronary artery disease (CAD) and cerebrovascular disease, was assessed in a cohort of 1254 Caucasian subjects classified as having normal glucose tolerance (NGT, n = 517), prediabetes (n = 397) or type 2 diabetes (n = 340).

RESULTS

Prevalence of NAFLD in the study population was 47.9%. Presence of NAFLD was linked to an augmented prevalence of composite CVD and individual CAD in all the three glucose tolerance groups. In a logistic regression model adjusted for several cardio-metabolic risk factors, subjects with NGT and NAFLD exhibited a 3.2- and 3.4-fold increased risk of having CVD or CAD, respectively, as compared with those without NAFLD. Similarly, subjects with prediabetes and NAFLD showed an increased risk of having CVD or CAD by 2.3- and 2.0-fold, respectively, in comparison to their counterpart without NAFLD. Within the group with type 2 diabetes, subjects having NAFLD displayed a 2.3- and 2.0-fold higher risk of having CVD or CAD, respectively, in comparison to those without NAFLD.

CONCLUSION

Ultrasonography-defined NAFLD is independently associated with an increased risk of having CVD in individuals with different glucose tolerance.

Genetic Variants Associated with Non-Alcoholic Fatty Liver Disease Do Not Associate with Measures of Sub-Clinical Atherosclerosis: Results from the IMPROVE Study

Non-alcoholic fatty liver disease (NAFLD) and atherosclerosis-related cardiovascular diseases (CVD) share common metabolic pathways. We explored the association between three NAFLD-associated single nucleotide polymorphisms (SNPs) rs738409, rs10401969, and rs1260326 with sub-clinical atherosclerosis estimated by the carotid intima-media thickness (c-IMT) and the inter-adventitia common carotid artery diameter (ICCAD) in patients free from clinically overt NAFLD and CVD. The study population is the IMPROVE, a multicenter European study (n = 3711). C-IMT measures and ICCAD were recorded using a standardized protocol. Linear regression with an additive genetic model was used to test for association of the three SNPs with c-IMT and ICCAD. In secondary analyses, the association of the three SNPs with c-IMT and ICCAD was tested after stratification by alanine aminotransferase levels (ALT). No associations were found between rs738409, rs1260326, rs10401969, and c-IMT or ICCAD. Rs738409-G and rs10401969-C were associated with ALT levels (p < 0.001). In patients with ALT levels above 28 U/L (highest quartile), we observed an association between rs10401969-C and c-IMT measures of c-IMT_max and c-IMT_mean-max (p = 0.018 and 0.021, respectively). In conclusion, NAFLD-associated SNPs do not associate with sub-clinical atherosclerosis measures. However, our results suggest a possible mediating function of impaired liver function on atherosclerosis development.

Liver fat content might be an appropriate measure for estimation of cardiovascular disease risk in non-alcoholic steatohepatitis patients

Background: Non-alcoholic steatohepatitis (NASH) is increasing worldwide due to the metabolic syndrome epidemy. According to the current evidence, a higher cardiovascular disease risk (CVDR) is observed in NASH individuals than the general population. Objective: The relationship between liver fat content (LFC) and CVDR in a cohort of NASH patients was evaluated in this research. Methods: Consecutively selected patients with increased aminotransferase levels and fatty change in liver ultrasonography were enrolled in the study. Those with known causes of viral hepatitis, any hepatotoxic medications or alcohol consumption, autoimmune hepatitis, cigarette smoking, and ischemic heart disease were excluded from the project. The remaining was presumed to have NASH. The Framingham risk score (FRS) and LFC were calculated by means of an online calculator and a valid formula, respectively. The correlation between LFC and independent variables was measured using the Pearson correlation test. The P-value of less than 0.05 was considered significant. The statistical analysis was performed using SPSS program version 18. Results: Finally, two hundred NASH patients were included in the study. Considering diabetes mellitus as a confounder, there was a fair relationship between LFC and FRS (R=0.26 and 0.23, respectively, p<0.05) in the second and third visits. Even after adjustment for known cardiovascular risk factors, LFC was associated with increased CVDR (OR=9.181; 95% CI: 2.00-42.14, p=0.01). The cut-off value of 9.1% for LFC had a sensitivity of 92% and a specificity of 87% for discrimination of the FRS >20% and <20%. Conclusion: LFC might independently be correlated with CVDR in NASH patients. If further research confirmed this relationship, the inclusion of LFC into the FRS formula would provide an appropriate CVDR estimation tool in NASH.

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.

The metabolic basis of nonalcoholic steatohepatitis

Nonalcoholic fatty liver disease (NAFLD) is a major cause of chronic liver disease and is associated with significant morbidity and mortality worldwide, with a high incidence in Western countries and non-Western countries that have adopted a Western diet. NAFLD is commonly associated with components of the metabolic syndrome, type 2 diabetes mellitus and cardiovascular disease, suggesting a common mechanistic basis. An inability to metabolically handle free fatty acid overload-metabolic inflexibility-constitutes a core node for NAFLD pathogenesis, with resulting lipotoxicity, mitochondrial dysfunction and cellular stress leading to inflammation, apoptosis and fibrogenesis. These responses can lead to the histological phenotype of nonalcoholic steatohepatitis (NASH) with varying degrees of fibrosis, which can progress to cirrhosis. This perspective review describes the key cellular and molecular mechanisms of NAFLD and NASH, namely an excessive burden of carbohydrates and fatty acids that contribute to lipotoxicity resulting in hepatocellular injury and fibrogenesis. Understanding the extrahepatic dysmetabolic contributors to NASH is crucial for the development of safe, effective and durable treatment approaches for this increasingly common disease.

The effect of moderate alcohol drinking in nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is defined by fat accumulation in liver that is not caused by excessive alcohol consumption. Safe limits of alcohol consumption in NAFLD are usually defined as alcohol consumption of less than 210 g per week for men and 140 g per week for women (30 g/day in men, 20 g/day in women) and alcohol consumption below safe limits is generally regarded as moderate alcohol consumption. Many studies have investigated the effects of moderate alcohol consumption on NAFLD patients. Some studies showed that moderate alcohol consumption prevented the progression of fibrosis in the liver, whereas other reports showed worsening of fibrosis in the liver based on serologic, radiologic and liver biopsy findings compared with effects on total abstainers. NAFLD is also thought to be a hepatic manifestation of metabolic syndrome, and when combined with excessive alcohol consumption results in the development of components of metabolic syndrome and systemic harmful effects. The effects of moderate alcohol consumption on NAFLD have yet to be established.

NAFLD and cardiovascular diseases: a clinical review

Non-alcoholic fatty liver DISEASE (NAFLD) is the most common chronic liver disease in Western countries and affects approximately 25% of the adult population. Since NAFLD is frequently associated with further metabolic comorbidities such as obesity, type 2 diabetes mellitus, or dyslipidemia, it is generally considered as the hepatic manifestation of the metabolic syndrome. In addition to its potential to cause liver-related morbidity and mortality, NAFLD is also associated with subclinical and clinical cardiovascular disease (CVD). Growing evidence indicates that patients with NAFLD are at substantial risk for the development of hypertension, coronary heart disease, cardiomyopathy, and cardiac arrhythmias, which clinically result in increased cardiovascular morbidity and mortality. The natural history of NAFLD is variable and the vast majority of patients will not progress from simple steatosis to fibrosis and end stage liver disease. However, patients with progressive forms of NAFLD, including non-alcoholic steatohepatitis (NASH) and/or advanced fibrosis, as well as NAFLD patients with concomitant types 2 diabetes are at highest risk for CVD. This review describes the underlying pathophysiological mechanisms linking NAFLD and CVD, discusses the role of NAFLD as a metabolic dysfunction associated cardiovascular risk factor, and focuses on common cardiovascular manifestations in NAFLD patients.

Coronary heart disease is associated with nonalcoholic fatty liver disease in patients without hypertension and diabetes

This study was performed to explore the relationship between coronary heart disease (CHD) and nonalcoholic fatty liver disease (NAFLD) in patients without hypertension and diabetes with a focus on predicting CHD.In total, 78 consecutive patients without hypertension and diabetes who were suspected of CHD underwent coronary angiography (CAG) or computed tomography CAG. They were segregated into the CHD and non-CHD group according to the CAG or computed tomography angiography results. The Gensini score was calculated based on CAG results in the CHD group. All patients underwent ultrasonographic measurement of the liver, subcutaneous fat, and visceral fat thickness.The CHD and the Gensini score were significantly correlated with V1, V2, and NAFLD. As the grade of NAFLD increases, the Gensini score was increased. After correcting for confounding factors, NAFLD (B = 2.474, P < .001, 95% confidence interval: 3.32-42.406) and cholesterol (B = 1.176, P = 0.025, 95% confidence interval: 1.155-9.101) were predictor for CHD.The CHD is associated with NAFLD in the patients without hypertension and diabetes. The high-grade NAFLD may be predicted the risk of CHD in patients without hypertension and diabetes.

Dysregulated Neurovascular Control Underlies Declining Microvascular Functionality in People With Non-alcoholic Fatty Liver Disease (NAFLD) at Risk of Liver Fibrosis

Background/Aims

Increasing evidence shows that non-alcoholic fatty liver disease (NAFLD) is associated with dysregulation of microvascular perfusion independently of established cardio-metabolic risk factors. We investigated whether hepatic manifestations of NAFLD such as liver fibrosis and liver fat are associated with microvascular hemodynamics through dysregulation of neurovascular control.

Methods

Microvascular dilator (post-occlusive reactive hyperemia) and sympathetically mediated constrictor (deep inspiratory breath-hold) responses were measured at the forearm and finger, respectively, using laser Doppler fluximetry. Non-linear complexity-based analysis was used to assess the information content and variability of the resting blood flux (BF) signals, attributable to oscillatory flow-motion activity, and over multiple sampling frequencies.

Results

Measurements were made in 189 adults (113 men) with NAFLD, with (n = 65) and without (n = 124) type 2 diabetes mellitus (T2DM), age = 50.9 ± 11.7 years (mean ± SD). Microvascular dilator and constrictor capacity were both negatively associated with age (r = −0.178, p = 0.014, and r = −0.201, p = 0.007, respectively) and enhanced liver fibrosis (ELF) score (r = −0.155, p = 0.038 and r = −0.418, p < 0.0001, respectively). There was no association with measures of liver fat, obesity or T2DM. Lempel-Ziv complexity (LZC) and sample entropy (SE) of the BF signal measured at the two skin sites were associated negatively with age (p < 0.01 and p < 0.001) and positively with ELF score (p < 0.05 and p < 0.0001). In individuals with an ELF score ≥7.8 the influence of both neurogenic and respiratory flow-motion activity on LZC was up-rated (p < 0.0001).

Conclusion

Altered microvascular network functionality occurs in adults with NAFLD suggesting a mechanistic role for dysregulated neurovascular control in individuals at risk of severe liver fibrosis.

Fibroblast Growth Factor 21 is Related to Atherosclerosis Independent of Nonalcoholic Fatty Liver Disease and Predicts Atherosclerotic Cardiovascular Events

Background FGF21 (fibroblast growth factor 21), a novel hepatokine regulating lipid metabolism, has been linked to atherosclerotic disease. However, whether this relationship exists in patients without nonalcoholic fatty liver disease is unclear. We assessed the association between serum FGF21 levels and atherosclerosis in patients without nonalcoholic fatty liver disease, and investigated whether baseline FGF21 could predict incident atherosclerotic cardiovascular disease in a 7-year prospective cohort. Methods and Results Baseline serum FGF21 was measured in a cross-sectional cohort of 371 patients with type 2 diabetes mellitus without nonalcoholic fatty liver disease (determined by hepatic magnetic resonance spectroscopy), and in a population-based prospective cohort of 705 patients from the Shanghai Diabetes Study. In the cross-sectional study, FGF21 was significantly higher in patients with than in those without subclinical carotid atherosclerosis (P<0.01). The association remained significant after adjusting for demographic and traditional cardiovascular risk factors. In the prospective cohort, 80 patients developed atherosclerotic cardiovascular disease during follow-up. Baseline FGF21 was significantly higher in those who developed ischemic heart disease or cerebral infarction than in those who did not. Using a cutoff serum concentration of 232.0 pg/mL, elevated baseline FGF21 independently predicted incident total atherosclerotic cardiovascular disease events, ischemic heart disease, and cerebral infarction in a nondiabetic population (all P<0.05), and significantly improved the discriminatory and reclassifying abilities of our prediction model after adjustment for established cardiovascular risk factors. Conclusions This study provides the first evidence that FGF21 levels are elevated in patients without nonalcoholic fatty liver disease with subclinical atherosclerosis. Baseline FGF21 is an independent predictor of atherosclerotic cardiovascular disease and represents a novel biomarker for primary prevention in the general population.

Early Predictors of Cardiovascular Disease Risk in Nonalcoholic Fatty Liver Disease: Non-obese Versus Obese Patients

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is regarded as a risk factor of cardiovascular disease (CVD). However, the association between non-obese NAFLD and CVD has not been well established.

AIM

We aimed to compare the CVD risk between non-obese and obese NAFLD patients, and explored the factors associated with subclinical atherosclerosis.

METHOD

Consecutive NAFLD patients estimated by magnetic resonance imaging-based proton density fat fraction (MRI-PDFF) were recruited. Liver fat content (LFC) and liver stiffness were measured with MRI-PDFF and shear wave elastography, respectively. CVD risk was estimated by atherosclerosis index (AI), carotid intima-media thickness, carotid plaque, and Framingham risk score (FRS).

RESULTS

This study included 543 NAFLD patients. The presence of carotid intima-media thickening and carotid plaque, FRS, and AI were comparable between non-obese and obese patients. Age increased per 10 years (OR 9.68; P < 0.001) and liver fibrosis (liver stiffness > 6.1 kPa, OR 4.42; P = 0.004) were significant factors associated with carotid intima-media thickening in non-obese patients, while age increased per 10 years (OR 2.02; P < 0.001), liver fibrosis (OR 2.18; P = 0.039), and LFC > 10% (OR 2.29; P = 0.021) were independent predictors in obese patients. Only elevated triglyceride was significantly associated with carotid plaque in non-obese patients (OR 2.42; P = 0.033), while age increased per 10 years (OR 1.77; P = 0.002) and LFC > 10% (OR 2.83; P = 0.019) were significant predictors in obese patients.

CONCLUSIONS

Liver stiffness and age were strongly predictive of subclinical atherosclerosis in all NAFLD, while LFC was an additional predictor in obese NAFLD patients. Our findings highlight that early CVD screening strategy should be established for NAFLD patients according to different BMIs.

Non-alcoholic fatty liver disease and Atherosclerosis at a crossroad: The overlap of a theory of change and bioinformatics

Atherosclerosis (ATH) and non-alcoholic fatty liver disease (NAFLD) are medical conditions that straddle a communal epidemiology, underlying mechanism and a clinical syndrome that has protean manifestations, touching every organ in the body. These twin partners, ATH and NAFLD, are seemingly straightforward and relatively simple topics when considered alone, but their interdependence calls for more thought. The study of the mutual relationship of NAFLD and ATH should involve big data analytics approaches, given that they encompass a constellation of diseases and are related to several recognized risk factors and health determinants and calls to an explicit theory of change, to justify intervention. Research studies on the “association between aortic stiffness and liver steatosis in morbidly obese patients”, published recently, sparsely hypothesize new mechanisms of disease, claiming the “long shadow of NAFLD” as a risk factor, if not as a causative factor of arterial stiffness and ATH. This statement is probably overreaching the argument and harmful for the scientific credence of this area of medicine. Despite the verification that NAFLD and cardiovascular disease are strongly interrelated, current evidence is that NAFLD may be a useful indicator for flagging early arteriosclerosis, and not a likely causative factor. Greater sustainable contribution by precision medicine tools, by validated bioinformatics approaches, is needed for substantiating conjectures, assumptions and inferences related to the management of big data and addressed to intervention for behavioral changes within an explicit theory of change.

Relationship between non-alcoholic fatty liver disease and cardiovascular disease

With the in-depth study of non-alcoholic fatty liver disease (NAFLD), it has been found in recent years that NAFLD is closely related to cardiovascular disease (CVD). It has been proved that NAFLD is not only an important risk factor for CVD, but it is also an important mechanism of atherosclerosis, coronary heart disease, and hypertension in young people. This article reviews the recent progress in the understanding of the relationship between NAFLD and CVD, with an aim to improve the knowledge of CVD physicians on liver disease and provide reference for prevention and treatment of these conditions.

Association of Fetuin-B with Subclinical Atherosclerosis in Obese Chinese Adults

Aim: We aimed to explore the independent associations of serum Fetuin-B and common genetic variants in FETUB locus with subclinical atherosclerosis.

Methods: A cross-sectional study of 1,140 obese adults, who underwent serum Fetuin-B testing, hepatic ultrasonography scanning, genotyping on four tagging single nucleotide polymorphisms (SNPs) in FETUB locus and atherosclerosis detection, was conducted in Xiamen, China.

Results: Increasing tertiles of brachial ankle pulse wave velocity (ba-PWV) were significantly associated with higher prevalence of nonalcoholic fatty liver disease (NAFLD) (48.8%, 61.5%, and 70.5% for tertiles of 1–3, respectively, p < 0.001) and serum Fetuin-B (3.85 ± 1.39, 4.09 ± 1.40, and 4.27 ± 1.46 µg/ml, p = 0.047). Multivariable linear regression analyses with adjustment for potential confounding factors, even NAFLD per se, showed that serum Fetuin-B were significantly and positively associated with ba-PWV, with standardized regression coefficients (β) ranging from 0.055 to 0.075 (all p-values < 0.05) in different models. However, the significant relationship between serum Fetuin-B and ba-PWV disappeared with further adjustment for insulin resistance. Serum Fetuin-B was not significantly associated with ankle-brachial index (ABI). All genotypes of the four tested FETUB tagging SNPs were not significantly associated with either ba-PWV or ABI with adjustment for potential confounding factors

Conclusion: Serum Fetuin-B was positively associated with ba-PWV and may link liver fat accumulation to subclinical atherosclerosis via insulin resistance.

Diagnosis of Non-Alcoholic Fatty Liver Disease (NAFLD) Is Independently Associated with Cardiovascular Risk in a Large Austrian Screening Cohort

BACKGROUND

Many patients with non-alcoholic fatty liver disease (NAFLD) simultaneously suffer from cardiovascular (CV) disease and often carry multiple CV risk factors. Several CV risk factors are known to drive the progression of fibrosis in patients with NAFLD.

OBJECTIVES

To investigate whether an established CV risk score, the Framingham risk score (FRS), is associated with the diagnosis of NAFLD and the degree of fibrosis in an Austrian screening cohort for colorectal cancer.

MATERIAL AND METHODS

In total, 1965 asymptomatic subjects (59 ± 10 years, 52% females, BMI 27.2 ± 4.9 kg/m²) were included in this study. The diagnosis of NAFLD was present if (1) significantly increased echogenicity in relation to the renal parenchyma was present in ultrasound and (2) viral, autoimmune or hereditary liver disease and excess alcohol consumption were excluded. The FRS (ten-year risk of coronary heart disease) and NAFLD Fibrosis Score (NFS) were calculated for all patients. High CV risk was defined as the highest FRS quartile (>10%). Both univariable and multivariable logistic regression models were used to calculate associations of FRS with NAFLD and NFS.

RESULTS

Compared to patients without NAFLD (n = 990), patients with NAFLD (n = 975) were older (60 ± 9 vs. 58 ± 10 years; p < 0.001), had higher BMI (29.6 ± 4.9 vs. 24.9 ± 3.6 kg/m²; p < 0.001) and suffered from metabolic syndrome more frequently (33% vs. 7%; p < 0.001). Cardiovascular risk as assessed by FRS was higher in the NAFLD-group (8.7 ± 6.4 vs. 5.4 ± 5.2%; p < 0.001). A one-percentage-point increase of FRS was independently associated with NAFLD (OR 1.04, 95%CI 1.02-1.07; p < 0.001) after correction for relevant confounders in multivariable logistic regression. In patients with NAFLD, NFS correlated with FRS (r = 0.29; p < 0.001), and FRS was highest in patients with significant fibrosis (F3-4; 11.7 ± 5.4) compared to patients with intermediate results (10.9 ± 6.3) and those in which advanced fibrosis could be ruled-out (F0-2, 7.8 ± 5.9, p < 0.001). A one-point-increase of NFS was an independent predictor of high-risk FRS after correction for sex, age, and concomitant diagnosis of metabolic syndrome (OR 1.30, 95%CI 1.09-1.54; p = 0.003).

CONCLUSION

The presence of NAFLD might independently improve prediction of long-term risk for CV disease and the diagnosis of NAFLD might be a clinically relevant piece in the puzzle of predicting long-term CV outcomes. Due to the significant overlap of advanced NAFLD and high CV risk, aggressive treatment of established CV risk factors could improve prognosis in these patients.

Bile acids aggravate nonalcoholic steatohepatitis and cardiovascular disease in SHRSP5/Dmcr rat model

BACKGROUND AND AIMS

Nonalcoholic steatohepatitis (NASH) is linked to an increased risk of cardiovascular disease, regardless of the risk factors in metabolic syndrome. However, the intermediary factors between NASH and cardiovascular disease are still unknown. A previous study revealed that serum and hepatic bile acid (BA) levels are increased in some NASH patients. We aimed to examine whether NASH and cardiovascular disease were aggravated by BA using an animal model.

METHOD AND RESULTS

From 10 to 18 weeks of age, SHRSP5/Dmcr rats divided into 3 groups were fed 3 types of high-fat and high-cholesterol (HFC) diets which were changed in the cholic acid (CA) concentration (0%, 2%, or 4%). The nitro oxide synthase inhibition (L-NAME) was administered intraperitoneally from 16 to 18 weeks of age. The 4% CA groups showed the worst LV dysfunction and myocardial fibrosis, and demonstrated severe hepatic fibrosis and lipid depositions. In addition, a large amount of lipid accumulation was observed in the aortas of the 4% CA group, and NFκB and VCAM-1 gene expression levels were increased. These findings were not seen in the 0% CA group.

CONCLUSION

In the SHRSP5/Dmcr rat model, NASH and cardiovascular disease were aggravated with increasing BAs concentrations in an HFC diet.

Associations of subclinical atherosclerosis with nonalcoholic fatty liver disease and fibrosis assessed by non-invasive score

BACKGROUND & AIMS

Nonalcoholic fatty liver disease (NAFLD) has been considered as a risk factor of adverse cardiovascular prognosis, but the relationship between subclinical atherosclerosis and NAFLD remains controversial. We aimed to investigate the impact of subclinical atherosclerosis on incident NAFLD and liver fibrosis.

METHODS

We included 3433 subjects aged ≥40 years and free of NAFLD. Brachial-ankle pulse wave velocity (ba-PWV) and carotid intima-media thickness (CIMT) were measured at baseline to assess subclinical atherosclerosis status. At follow-up visit, NAFLD was diagnosed by hepatic ultrasound and fibrosis was assessed by NAFLD fibrosis score (NFS), fibrosis-4 score (FIB-4) and aspartate aminotransferase to platelet ratio index (APRI).

RESULTS

A total of 654 (19.1%) subjects developed NAFLD during the follow-up period of 4.3 years. In the multivariate logistic regression models, each standard deviation (SD) increment of ba-PWV was associated with 20% (95% confidence interval [CI] 1.07-1.33), 22% (95% CI 1.08-1.39), 17% (95% CI 1.04-1.32) and 37% (95% CI 1.07-1.75) higher risk of incident NAFLD, higher NFS, FIB-4 and APRI respectively. Compared with the lowest quartile of ba-PWV, the highest quartile ba-PWV had 63% (95% CI 1.20-2.22), 112% (95% CI 1.42-3.17), 86% (95% CI 1.28-2.69) and 201% (95% CI 1.29-7.04) higher risk of incident NAFLD, higher NFS, FIB-4 and APRI respectively. Besides, per SD increase of CIMT was associated with a 12% (95% CI 1.01-1.24) higher risk of incident NAFLD.

CONCLUSIONS

Increased ba-PWV was independently associated with incident NAFLD and higher probability of fibrosis, whereas CIMT was associated with incident NAFLD but not with fibrosis.

Non-alcoholic Fatty Liver Disease: Growing Burden, Adverse Outcomes and Associations

Nonalcoholic fatty liver disease (NAFLD) is a systemic disorder with a complex multifactorial pathogenesis and heterogenous clinical manifestations. NAFLD, once believed to be an innocuous condition, has now become the most common cause of chronic liver disease in many countries worldwide. NAFLD is already highly prevalent in the general population, and owing to a rising incidence of obesity and diabetes mellitus, the incidence of NAFLD and its impact on global healthcare are expected to increase in the future. A subset of patients with NAFLD develops progressive liver disease leading to cirrhosis, hepatocellular carcinoma, and liver failure. NAFLD has emerged as one of the leading causes of cirrhosis and hepatocellular carcinoma in recent years. Moreover, HCC can occur in NAFLD even in absence of cirrhosis. Compared with the general population, NAFLD increases the risk of liver-related, cardiovascular and all-cause mortality. NAFLD is bidirectionally associated with metabolic syndrome. NAFLD increases the risk and contributes to aggravation of the pathophysiology of atherosclerosis, cardiovascular diseases, diabetes mellitus, and chronic kidney disease. In addition, NAFLD is linked to colorectal polyps, polycystic ovarian syndrome, osteoporosis, obstructive sleep apnea, stroke, and various extrahepatic malignancies. Extended resection of steatotic liver is associated with increased risk of liver failure and mortality. There is an increasing trend of NAFLD-related cirrhosis requiring liver transplantation, and the recurrence of NAFLD in such patients is almost universal. This review discusses the growing burden of NAFLD, its outcomes, and adverse associations with various diseases.

Association between liver fibrosis scores and the risk of mortality among patients with coronary artery disease

BACKGROUND AND AIMS

Fatty liver diseases are highly prevalent in patients with coronary artery disease (CAD) and might progress to irreversible liver fibrosis. Whether baseline liver fibrosis (LF) scores are associated with long-term mortality among patients with CAD requires investigation.

METHODS

The analysis was conducted based on a prospective cohort study among 3263 patients with CAD in China. Cox models were used to assess the association of baseline levels of LF scores, including non-alcoholic fatty liver disease fibrosis score (NFS), fibrosis 4 score (FIB-4), aspartate aminotransferase to platelet ratio index (APRI), gamma-glutamyltransferase to platelet ratio (GPR), and Forns score, with the risk of all-cause and cardiovascular mortality among CAD patients.

RESULTS

During a median follow-up period of 7.56 (inter-quartile range: 6.86-8.31) years, 538 deaths were identified, 319 of those were due to cardiovascular diseases. Compared with patients with lowest score levels, multivariable-adjusted HRs (95% CI) for those with highest levels of NFS, FIB-4, APRI, GPR and Forns score were 2.89 (2.14-3.91), 2.84 (2.14-3.76), 1.77 (1.33-2.36), 1.47 (1.19-1.83) and 3.10 (1.88-5.11) for all-cause mortality, 3.02 (2.05-4.45), 3.34 (2.29-4.86), 1.99 (1.40-2.83), 1.80 (1.36-2.39) and 2.43 (1.28-4.61) for cardiovascular mortality, respectively. These associations were consistent when we excluded those who died within the first year of follow-up or stratified patients by different sex, age, BMI, diabetes status, metabolic syndrome status, CAD type and hsCRP level.

CONCLUSIONS

Higher LF scores are associated with increased risks of all-cause and cardiovascular mortality among CAD patients. LF scores might play a potential role in CAD prognosis prediction.

Modulation of P2Y11-related purinergic signaling in inflammation and cardio-metabolic diseases

Chronic inflammation is the hallmark of cardiovascular pathologies with a major role in both disease progression and occurrence of long-term complications. The massive release of ATP during the inflammatory process activates various purinergic receptors, including P2Y11. This receptor is less studied but ubiquitously expressed in all cells relevant for cardiovascular pathology: cardiomyocytes, fibroblasts, endothelial and immune cells. While several studies suggested a potential pro-inflammatory role for P2Y11 receptors, recent literature data are supportive of an anti-inflammatory profile characterized by the immunosuppression of dendritic cells, inhibition of fibroblast proliferation and of cytokines and ATP secretion. Moreover, modulation of its activity appears to mediate the positive inotropic effect of ATP and mitigate endothelial dysfunction, thus rendering this receptor a promising therapeutic target in the cardiovascular disease armamentarium. The aim of the present review is to summarize the current available knowledge on P2Y11-related purinergic signaling in the setting of inflammation and cardio-metabolic diseases.

Noninvasive assessment of hepatic steatosis and fibrosis in patients with severe obesity

PURPOSE

In morbid obesity nonalcoholic fatty liver disease (NAFLD) is endemic. Aim of this study is to evaluate the diagnostic accuracy of the most common noninvasive methods for identify NAFLD and fibrosis in a cohort of morbid obese population.

METHODS

Ninety morbid obese patients undergoing bariatric surgery (BS) and intraoperative liver biopsy were evaluated preoperatively with Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) and serum biomarkers for steatosis and fibrosis and liver stiffness measurement (LSM) using acoustic radiation force impulse (ARFI) elastography. All nondiabetic patient (n = 77) underwent OGTT and calculation of Oral Glucose Insulin Sensitivity index (OGIS).

RESULTS

In the entire cohort prevalence of NAFLD was 77%, NASH 24%, moderate/severe steatosis 50%, and significant fibrosis 14%. New cut-offs were evaluated for all steatosis score assessed in this population. In all patients with moderate/severe steatosis HOMA IR was significantly greater than 3.5. ALT, GGT, Triglycerides, HOMA IR, and ARFI increased with fibrosis grade (p 0.03, p 0.008, p 0.04, p 0.05, respectively) and AST to Platelet ratio (APRI) was the only noninvasive fibrosis score significantly increased in significant fibrosis (p 0.04). A combination of 1/OGIS and VAI was able to discriminate NASH from simple steatosis (NAFL) (p 0.02).

CONCLUSIONS

In morbid obese subjects, we calculated new cut-offs of the most common steatosis indexes and found that a score based on insulin resistance (1/OGIS) and abdominal obesity (VAI) could represent a way to identify morbid obese subjects at risk of NASH.

Liver parameters as part of a non-invasive model for prediction of all-cause mortality after myocardial infarction

INTRODUCTION

Liver parameters are associated with cardiovascular disease risk and severity of stenosis. It is unclear whether liver parameters could predict the long-term outcome of patients after acute myocardial infarction (AMI). We performed an unbiased analysis of the predictive value of serum parameters for long-term prognosis after AMI.

MATERIAL AND METHODS

In a retrospective, observational, single-center, cohort study, 569 patients after AMI were enrolled and followed up until 6 years for major adverse cardiovascular events, including cardiac death. Patients were classified into non-survivors (n = 156) and survivors (n = 413). Demographic and laboratory data were analyzed using ensemble feature selection (EFS) and logistic regression. Correlations were performed for serum parameters.

RESULTS

Age (73; 64; p < 0.01), alanine aminotransferase (ALT; 93 U/l; 40 U/l; p < 0.01), aspartate aminotransferase (AST; 162 U/l; 66 U/l; p < 0.01), C-reactive protein (CRP; 4.7 U/l; 1.6 U/l; p < 0.01), creatinine (1.6; 1.3; p < 0.01), γ-glutamyltransferase (GGT; 71 U/l; 46 U/l; p < 0.01), urea (29.5; 20.5; p < 0.01), estimated glomerular filtration rate (eGFR; 49.6; 61.4; p < 0.01), troponin (13.3; 7.6; p < 0.01), myoglobin (639; 302; p < 0.01), and cardiovascular risk factors (hypercholesterolemia p < 0.02, family history p < 0.01, and smoking p < 0.01) differed significantly between non-survivors and survivors. Age, AST, CRP, eGFR, myoglobin, sodium, urea, creatinine, and troponin correlated significantly with death (r = -0.29; 0.14; 0.31; -0.27; 0.20; -0.13; 0.33; 0.24; 0.12). A prediction model was built including age, CRP, eGFR, myoglobin, and urea, achieving an AUROC of 77.6% to predict long-term survival after AMI.

CONCLUSIONS

Non-invasive parameters, including liver and renal markers, can predict long-term outcome of patients after AMI.

Hepatocyte-derived extracellular vesicles promote endothelial inflammation and atherogenesis via microRNA-1

BACKGROUND & AIMS

Clinical evidence has indicated a close link between non-alcoholic fatty liver disease (NAFLD) and cardiovascular disease (CVD). However, the underlying mechanism remains to be elucidated. This study aimed to explore a potential role of hepatocyte-derived extracellular vesicles (EVs) in endothelial inflammation and atherogenesis in the context of NAFLD.

METHODS

EVs were isolated, quantified and characterized from steatotic hepatocytes. An endothelial cell-specific PCR array was used to screen the functional properties of EVs. Profiling of global microRNA expression was conducted in EVs. The expression level and biological function of microRNA-1 (miR-1) was determined by quantitative PCR, immunoblot and reporter gene assays, respectively. The in vivo effect of miR-1 on atherogenesis was investigated in apolipoprotein E (ApoE)-deficient mice administered with a miR-1-specific inhibitor, antagomiR-1.

RESULTS

Steatotic hepatocytes released more EVs, which had significantly altered miRNA expression profiles compared to the EVs released by control hepatocytes. Endothelial cells co-cultured with steatotic hepatocytes, or treated with their EVs or miR-1, expressed significantly more proinflammatory molecules, as well as exhibiting increased NF-κB activity and reduced Kruppel-like factor 4 (KLF4) expression. EV-induced endothelial inflammation was prevented by either downregulation or inhibition of miR-1. While miR-1 treatment suppressed KLF4 expression and reporter gene activity, overexpression of KLF4 dramatically abolished the miR-1-induced endothelial inflammation. Moreover, not only did the miR-1 inhibitor reduce endothelial inflammation in vitro, but it also attenuated atherogenesis in ApoE-deficient mice.

CONCLUSION

Steatotic hepatocyte-derived EVs promote endothelial inflammation and facilitate atherogenesis by miR-1 delivery, KLF4 suppression and NF-κB activation. The findings illustrate an important role of hepatocyte-derived EVs in distant communications between the liver and vasculature, suggesting a new mechanism underlying the link between NAFLD and CVD.

LAY SUMMARY

Non-alcoholic fatty liver disease (NAFLD), a condition highly prevalent in obese and/or diabetic patients, is emerging as an independent risk factor of cardiovascular disease. Herein, we demonstrated that extracellular vesicles, released by hepatocytes under NAFLD conditions, cause vascular endothelial inflammation and promote atherosclerosis. Within these toxic vesicles, we identified a small molecular cargo that acted as a potent inducer of endothelial inflammation. By inhibiting this cargo's function, a specific gene-based inhibitor profoundly attenuated atherogenesis in mice, uncovering a novel mechanism which may be used to prevent or treat cardiovascular disease in patients with NAFLD.

Noninvasive tool for the diagnosis of NAFLD in association with atherosclerotic cardiovascular risk

Background

Whether the severity of liver histology in non-alcoholic fatty liver disease (NAFLD) is associated with more pronounced cardiovascular disease is unsettled. There is a need to develop a noninvasive tool to help its diagnosis in association with atherosclerotic cardiovascular disease. We aimed to evaluate the diagnostic performance of NAFLD-liver fat score (NAFLD-LFS) and carotid intima-media thickness (CIMT) in magnetic resonance imaging-proved NAFLD. The study comprised 60 patients with NAFLD during the period from October 2015 to June 2017, diagnosed by clinical features, laboratory tests, and magnetic resonance study. Thirty healthy subjects served as controls. All included individuals were subjected to anthropometric measurements and measurement of NAFLD-LFS and CIMT.

Results

On doing ultrasonography, 30 cases showed mild, 24 showed moderate, and 6 cases showed severe steatosis. NAFLD-LFS at a cutoff value of − 1.628 showed a sensitivity of 96.7%, specificity 100%, positive predictive value 100%, negative predictive value 93.8%, and accuracy 97.8%. CIMT at a cutoff value of 0.6 had a sensitivity of 70%, specificity 53.3%, positive predictive value 75%, negative predictive value 47.1%, and accuracy 64.4%. The combination of CIMT at cutoff 0.7 and NAFLD-LFS at cutoff − 1.628 showed sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of 100%.

Conclusion

CIMT combined with NAFLD-LFS can produce a simple noninvasive tool for diagnosis of NAFLD.

Liver Transplantation for Nonalcoholic Steatohepatitis: Pathophysiology of Recurrence and Clinical Challenges

Nonalcoholic steatohepatitis is the fastest-growing indication for the liver transplant and a leading cause of hepatocellular carcinoma among patients listed for liver transplantation in the USA. Post-transplant nonalcoholic hepatic steatosis and steatohepatitis are frequent complications of liver transplantation. Nonalcoholic steatohepatitis poses a significant challenge in both pre- and post-transplant period due to its association with metabolic syndrome, coronary artery disease, chronic kidney disease, and obstructive sleep apnea. While optimal therapy is not yet available in the post-liver transplant setting, lifestyle interventions continue to remain as the mainstay of therapy for post-transplant nonalcoholic steatohepatitis. Early recognition with protocol biopsies and noninvasive modalities, along with modification of known risk factors, are the most effective methods to curtail the progression of nonalcoholic steatohepatitis in the absence of FDA-approved pharmacologic therapy.

Factors influencing subclinical atherosclerosis in patients with biopsy-proven nonalcoholic fatty liver disease

Although the presence of nonalcoholic fatty liver disease (NAFLD) is known to be related to subclinical atherosclerosis, the relationship between the severity of NAFLD and subclinical atherosclerosis is not clear. This study aimed to clarify the factors related to subclinical arteriosclerosis, including the histopathological severity of the disease and PNPLA3 gene polymorphisms, in NAFLD patients. We measured brachial-ankle pulse wave velocity (baPWV) as an index of arterial stiffness in 153 biopsy-proven NAFLD patients. The baPWV values were significantly higher in the advanced fibrosis group than in the less advanced group (median, 1679 cm/s vs 1489 cm/s; p = 5.49×10⁻⁴). Multiple logistic regression analysis revealed that older age (≥55 years) (p = 8.57×10⁻³; OR = 3.03), hypertension (p = 1.05×10⁻³; OR = 3.46), and advanced fibrosis (p = 9.22×10⁻³; OR = 2.94) were independently linked to baPWV ≥1600 cm/s. NAFLD patients were categorized into low-risk group (number of risk factors = 0), intermediate-risk group (= 1), and high-risk group (≥2) based on their risk factors, including older age, hypertension, and biopsy-confirmed advanced fibrosis. The prevalence of baPWV ≥1600 cm/s was 7.1% (3/42) in the low-risk group, 30.8% (12/39) in the intermediate-risk group, and 63.9% (46/72) in the high-risk group. Non-invasive liver fibrosis markers and scores, including the FIB-4 index, NAFLD fibrosis score, hyaluronic acid, Wisteria floribunda agglutinin positive Mac-2-binding protein, and type IV collagen 7s, were feasible substitutes for invasive liver biopsy. Older age, hypertension, and advanced fibrosis are independently related to arterial stiffness, and a combination of these three factors may predict risk of arteriosclerosis in NAFLD patients.

Cardiovascular Risk in Fatty Liver Disease: The Liver-Heart Axis-Literature Review

According to the World Health Organization, cardiovascular disease (CVD) remains the leading cause of death worldwide, accounting for approximately 18 million deaths per year. Nevertheless, the worldwide prevalence of metabolic diseases, such as type 2 diabetes mellitus, obesity, and non-alcoholic fatty liver disease (NAFLD), also known to be common risk factors for CVD, have dramatically increased over the last decades. Chronic alcohol consumption is a major cause of chronic liver diseases (CLD) as well as being a major health care cost expenditure accounting for the spending of tremendous amounts of money annually. NAFLD has become one of the major diseases plaguing the world while standing as the most common cause of liver disease in the Western countries by representing about 75% of all CLD. Currently, the most common cause of death in NAFLD remains to be CVD. Several mechanisms have been suggested to be responsible for associating FLD with CVD through several mechanisms including low-grade systemic inflammation, oxidative stress, adipokines, endoplasmic reticulum stress, lipotoxicity and microbiota dysbiosis which may also be influenced by other factors such as genetic and epigenetic variations. Despite of all this evidence, the exact mechanisms of how FLD can causally contribute to CVD are not fully elucidated and much remains unknown. Moreover, the current literature supports the increasing evidence associating FLD with several cardiovascular (CV) adverse events including coronary artery disease, increased subclinical atherosclerosis risk, structural alterations mainly left ventricular hypertrophy, increased epicardial fat thickness, valvular calcifications including aortic valve sclerosis and mitral annular calcification and functional cardiac modifications mainly diastolic dysfunction in addition to cardiac arrhythmias such as atrial fibrillation and ventricular arrythmias and conduction defects including atrioventricular blocks and bundle branch blocks. Patients with FLD should be evaluated and managed accordingly in order to prevent further complications. Possible management methods include non-pharmacological strategies including life style modifications, pharmacological therapies as well as surgical management. This review aims to summarize the current state of knowledge regarding the pathophysiological mechanisms linking FLD with an increased CV risk, in addition to associated CV adverse events and current management modalities.

Nonalcoholic fatty liver disease and alcoholic liver disease: metabolic diseases with systemic manifestations

The progression of liver disease is portrayed by several common, overarching signs and symptoms. Classically, these include findings such as spider angiomata, jaundice, palmar erythema, and as cirrhosis decompensates, ascites, variceal hemorrhage (VH), hepatic encephalopathy (HE), and hepatocellular carcinoma (HCC). Aside from these universal hallmarks among cirrhotics, patients with nonalcoholic fatty liver disease (NAFLD) and alcoholic liver disease (ALD) harbor their own distinct systemic associations and manifestations. NAFLD is tightly linked to metabolic syndrome, which appears to be a driving force for a multitude of comorbidities, such as insulin resistance, cardiovascular disease, chronic kidney disease (CKD), obstructive sleep apnea (OSA), as well as increased malignancy risk. ALD also maintains a variety of comorbidities congruent with systemic effects of chronic alcohol use. These findings are highlighted by cardiovascular conditions, neuronal damage, myopathy, nutritional deficiencies, chronic pancreatitis, in addition to increased malignancy risk. While a general, guideline-driven management for all cirrhotic patients remains imperative for minimizing risk of complications, a tailored treatment strategy is useful for patients with NAFLD and ALD who entertain their own constellation of unique systemic manifestations.

Brain involvement in non-alcoholic fatty liver disease (NAFLD): A systematic review

Non-alcoholic fatty liver disease (NAFLD) is associated with high cardiovascular morbidity and mortality which usually is considered to be related to cardiac involvement, while scarce attention is addressed to brain damage. Viceversa NAFLD is associated with asymptomatic brain lesions, alterations in cerebral perfusion and activity, cognitive impairment and brain aging and with increased risk and severity of both ischemic and haemorrhagic stroke. Besides known metabolic risk factors, NAFLD is characterized by a pro inflammatory state, which contributes to atherosclerosis and microglia activation, endothelial dysfunction, pro-coagulant state and platelets activation, which in turn promote both micro and macrovascular damage eventually responsible for clinical and subclinical cerebrovascular alterations. A better knowledge of the association between NAFLD and brain alterations could lead to an improved management of risk factors underpinning both liver and cerebral disease, possibly preventing the progression of asymptomatic brain lesions to clinical cerebrovascular accidents.

A Review of Cardiovascular Toxicity of Microcystins

The mortality rate of cardiovascular diseases (CVD) in China is on the rise. The increasing burden of CVD in China has become a major public health problem. Cyanobacterial blooms have been recently considered a global environmental concern. Microcystins (MCs) are the secondary products of cyanobacteria metabolism and the most harmful cyanotoxin found in water bodies. Recent studies provide strong evidence of positive associations between MC exposure and cardiotoxicity, representing a threat to human cardiovascular health. This review focuses on the effects of MCs on the cardiovascular system and provides some evidence that CVD could be induced by MCs. We summarized the current knowledge of the cardiovascular toxicity of MCs, with regard to direct cardiovascular toxicity and indirect cardiovascular toxicity. Toxicity of MCs is mainly governed by the increasing level of reactive oxygen species (ROS), oxidative stress in mitochondria and endoplasmic reticulum, the inhibition activities of serine/threonine protein phosphatase 1 (PP1) and 2A (PP2A) and the destruction of cytoskeletons, which finally induce the occurrence of CVD. To protect human health from the threat of MCs, this paper also puts forward some directions for further research.

Nonalcoholic Fatty Liver Disease Is Associated With Arterial Distensibility and Carotid Intima-Media Thickness: (from the Multi-Ethnic Study of Atherosclerosis)

Nonalcoholic fatty liver disease (NAFLD) is considered a potential independent risk factor for cardiovascular disease (CVD). The Multi-Ethnic Study of Atherosclerosis cohort enrolled 6,814 adults without previous CVD. We excluded 2,692 participants who had missing variables, were heavy drinkers, or history of steroid use and/or chronic liver disease. NAFLD was defined using noncontrast cardiac CT and a liver/spleen Hounsfield Unit attenuation ratio <1. Ultrasound-measured carotid arterial compliance and stiffness, was expressed as distensibility coefficient and Young's modulus. Common and internal carotid intima-media thickness (CIMT) and coronary artery calcium (CAC) >0 were used as markers of subclinical CVD. A multivariate robust linear regression and logistic regression analysis were done to evaluate the association of NAFLD and this subclinical CVD markers. Our analysis of 4,123 participants showed 55% were female with a mean age of 63 (±10) years, 39% white, 10% Chinese, 28% black, and 23% were Hispanic. The prevalence of NAFLD was 17% (n = 729). Patients with NAFLD had higher distensibility coefficient and higher CIMT. Multivariate linear regression analysis showed the presence of NAFLD was associated with both the common carotid and internal carotid IMT and logCAC. Logistic analysis showed an independent association with CAC > 0 (odds ratio [OR] 1.44 95% confidence interval [CI] 1.18, 1.75) and CIMT > 1 mm (OR 1.30 95% 1.08, 1.56). When stratified by race the association with CIMT > 1 mm was significant in whites (OR 1.37 95% 1.00, 1.90) and Hispanic (OR 1.53 95% 1.08, 2. 17) and CAC > 0 was significant in Hispanics (OR 1.52 95% 1.06, 2.19). In conclusion, NAFLD is modestly associated with carotid IMT and coronary artery calcification in a multiethnic population.

The hepatokine Tsukushi is released in response to NAFLD and impacts cholesterol homeostasis

Nonalcoholic fatty liver disease (NAFLD) prevails in obesity and is linked to several health complications including dyslipidemia and atherosclerosis. How exactly NAFLD induces atherogenic dyslipidemia to promote cardiovascular diseases is still elusive. Here, we identify Tsukushi (TSK) as a hepatokine induced in response to NAFLD. We show that both endoplasmic reticulum stress and inflammation promote the expression and release of TSK in mice. In humans, hepatic TSK expression is also associated with steatosis, and its circulating levels are markedly increased in patients suffering from acetaminophen-induced acute liver failure (ALF), a condition linked to severe hepatic inflammation. In these patients, elevated blood TSK levels were associated with decreased transplant-free survival at hospital discharge, suggesting that TSK could have a prognostic significance. Gain- and loss-of-function studies in mice revealed that TSK impacts systemic cholesterol homeostasis. TSK reduces circulating HDL cholesterol, lowers cholesterol efflux capacity, and decreases cholesterol-to-bile acid conversion in the liver. Our data identify the hepatokine TSK as a blood biomarker of liver stress that could link NAFLD to the development of atherogenic dyslipidemia and atherosclerosis.

Cardiometabolic risk in obese children

Obesity in childhood remains a significant and prevalent public health concern. Excess adiposity in youth is a marker of increased cardiometabolic risk (CMR) in adolescents and adults. Several longitudinal studies confirm the strong association of pediatric obesity with the persistence of adult obesity and the future development of cardiovascular disease, diabetes, and increased risk of death. The economic and social impact of childhood obesity is further exacerbated by the early onset of the chronic disease burden in young adults during their peak productivity years. Furthermore, rising prevalence rates of severe obesity in youth from disadvantaged and/or minority backgrounds have prompted the creation of additional classification schemes for severe obesity to improve CMR stratification. Current guidelines focus on primary obesity prevention efforts, as well as screening for clustering of multiple CMR factors to target interventions. This review summarizes the scope of the pediatric obesity epidemic, the new severe obesity classification scheme, and examines the association of excess adiposity with cardiovascular and metabolic risk. We will also discuss potential questions for future investigation.

Derivation and validation of a cardiovascular risk score for prediction of major acute cardiovascular events in non-alcoholic fatty liver disease; the importance of an elevated mean platelet volume

BACKGROUND

Atherosclerotic cardiovascular disease is a key cause of morbidity in non-alcoholic fatty liver disease (NAFLD) but appropriate means to predict major acute cardiovascular events (MACE) are lacking.

AIM

To design a bespoke cardiovascular risk score in NAFLD.

METHODS

A retrospective derivation (2008-2016, 356 patients) and a prospective validation (2016- 2017, 111 patients) NAFLD cohort study was performed. Clinical and biochemical data were recorded at enrolment and mean platelet volume (MPV), Qrisk2 and Framingham scores were recorded one year prior to MACE (Cardiovascular death, acute coronary syndrome, stroke and transient ischaemic attack).

RESULTS

The derivation and validation cohorts were well-matched, with MACE prevalence 12.6% and 12%, respectively. On univariate analysis, age, diabetes, advanced fibrosis, collagen proportionate area >5%, MPV and liver stiffness were associated with MACE. After multivariate analysis, age, diabetes and MPV remained independently predictive of MACE. The "NAFLD CV-risk score" was generated using binary logistic regression: 0.06*(Age) + 0.963*(MPV) + 0.26*(DM¹ ) - 16.44; ¹ Diabetes mellitus: 1: present; 2: absent. (AUROC 0.84). A cut-off of -3.98 gave a sensitivity 97%, specificity 27%, PPV 16%, and NPV 99%. An MPV alone of >10.05 gave a sensitivity 97%, specificity 59%, PPV 24% and NPV 97% (AUROC 0.83). Validation cohort AUROCs were comparable at 0.77 (NAFLD CV-risk) and 0.72 (MPV). In the full cohort, the NAFLD CV-risk score and MPV outperformed both Qrisk2 and Framingham scores.

CONCLUSIONS

The NAFLD CV risk score and MPV accurately predict 1-year risk of MACE, thereby allowing better identification of patients that require optimisation of their cardiovascular risk profile.

Crosstalk between nonalcoholic fatty liver disease and cardiometabolic syndrome

Nonalcoholic fatty liver disease (NAFLD) is a chronic condition characterized by fat accumulation combined with low-grade inflammation in the liver. A large body of clinical and experimental data shows that increased flux of free fatty acids from increased visceral adipose tissue and de novo lipogenesis can lead to NAFLD and insulin resistance. Thus, individuals with obesity, insulin resistance, and dyslipidaemia are at the greatest risk of developing NAFLD. Conversely, NAFLD is a phenotype of cardiometabolic syndrome. Notably, researchers have discovered a close association between NAFLD and impaired glucose metabolism and focused on the role of NAFLD in the development of type 2 diabetes. Moreover, recent studies provide substantial evidence for an association between NAFLD and atherosclerosis and cardiometabolic disorders. Even if NAFLD can progress into severe liver disorders including nonalcoholic steatohepatitis (NASH) and cirrhosis, the majority of subjects with NAFLD die from cardiovascular disease eventually. In this review, we propose a potential pathological link between NAFLD/NASH and cardiometabolic syndrome. The potential factors that can play a pivotal role in this link, such as inflammation, insulin resistance, alteration in lipid metabolism, oxidative stress, genetic predisposition, and gut microbiota are discussed.