Association between nonalcoholic fatty liver disease and carotid artery inflammation evaluated by 18F-fluorodeoxyglucose positron emission tomography

Noninvasive Liver Fibrosis Indices as Indicators of Microvascular and Macrovascular Complications in Type 2 Diabetes

Objective: Nonalcoholic fatty liver disease (NAFLD) is more prevalent in patients with obesity, diabetes, and metabolic syndrome, which are risk factors for nonalcoholic steatohepatitis and liver fibrosis. NAFLD is related to cardiovascular outcomes in diabetes. We aimed to investigate the relationship between diabetic complications and NAFLD fibrosis score (NFS) and Fibrosis-4 score (FIB-4). Methods: Three hundred patients with type 2 diabetes mellitus (T2DM) were retrospectively evaluated according to NAFLD diagnosis on ultrasound in outpatient clinic. Risk of advanced fibrosis was estimated using FIB-4 and NFS. Diabetic complications of the patients were noted. Results: Presence of diabetic retinopathy is related to FIB-4 (P = 0.001) and NFS (P < 0.001) scores. NFS score (P = 0.037), not FIB-4 (P = 0.517), is related to diabetic nephropathy. Among macrovascular complications, only coronary artery disease is related to NFS and FIB-4 scores (P = 0.037 and P = 0.004, respectively). Although we cannot establish any association between fasting blood glucose, glycosylated hemoglobin (HbA1c) values and noninvasive liver fibrosis scores (P > 0.05), diabetes duration, and age positively correlated with the FIB-4 score (P = 0.033, P = 0.001). In logistic regression analysis, NFS > 0.676 values are associated with increased rates of diabetic retinopathy, independent of age, sex, HbA1c, and duration diabetes (odds ratio: 1.155, P = 0.030). FIB-4 has no relation with microvascular complications according to logistic regression analysis (P > 0.05 for all). Neither FIB-4 nor NFS has an effect on the presence of macrovascular complications (P > 0.05 for all). Conclusion: Our findings suggest that increase in NFS score is associated with the presence of diabetic retinopathy, independent of confounding factors. Further studies are needed on the applicability of noninvasive fibrosis scores in monitoring the presence of diabetic microvascular and macrovascular complications.

Fatty liver disease - non alcoholic to metabolic - A transition of concepts!!

Metabolic dysfunction associated fatty liver disease (MAFLD) was a concept suggested lately. Initially, the only criterion for the diagnosis of MAFLD was the absence of alcohol intake. With rising prevalence and studies assessing this condition, certain "positive criteria" were put forth. Experts from 22 countries proposed a simple yet comprehensive definition for the condition independent of other liver diseases. The presence of hepatic steatosis in addition to diabetes mellitus type 2, metabolic dysregulation, and obesity is generally observed. Criteria to define MAFLD-associated cirrhosis were also proposed. Reaching an agreement on MAFLD criteria will help define a protocol (for example: for International classification of Diseases (ICD) - coding), which will improve clinical care and advance the clinical and scientific field of liver research. As it is a condition that increases the risk of diabetes mellitus, chronic kidney disease (CKD), cirrhosis, hepatocellular carcinoma, and cardiac disorders it is important to recognize it at an early stage which makes it essential part of family medicine and primary care.

Machine learning prediction of hepatic steatosis using body composition parameters: A UK Biobank Study

Non-alcoholic fatty liver disease (NAFLD) has emerged as the most prevalent chronic liver disease worldwide, yet detection has remained largely based on surrogate serum biomarkers, elastography or biopsy. In this study, we used a total of 2959 participants from the UK biobank cohort and established the association of dual-energy X-ray absorptiometry (DXA)-derived body composition parameters and leveraged machine learning models to predict NAFLD. Hepatic steatosis reference was based on MRI-PDFF which has been extensively validated previously. We found several significant associations with traditional measurements such as abdominal obesity, as defined by waist-to-hip ratio (OR = 2.50 (male), 3.35 (female)), android-gynoid ratio (OR = 3.35 (male), 6.39 (female)) and waist circumference (OR = 1.79 (male), 3.80 (female)) with hepatic steatosis. Similarly, A Body Shape Index (Quantile 4 OR = 1.89 (male), 5.81 (female)), and for fat mass index, both overweight (OR = 6.93 (male), 2.83 (female)) and obese (OR = 14.12 (male), 5.32 (female)) categories were likewise significantly associated with hepatic steatosis. DXA parameters were shown to be highly associated such as visceral adipose tissue mass (OR = 8.37 (male), 19.03 (female)), trunk fat mass (OR = 8.64 (male), 25.69 (female)) and android fat mass (OR = 7.93 (male), 21.77 (female)) with NAFLD. We trained machine learning classifiers with logistic regression and two histogram-based gradient boosting ensembles for the prediction of hepatic steatosis using traditional body composition indices and DXA parameters which achieved reasonable performance (AUC = 0.83-0.87). Based on SHapley Additive exPlanations (SHAP) analysis, DXA parameters that had the largest contribution to the classifiers were the features predicted with significant association with NAFLD. Overall, this study underscores the potential utility of DXA as a practical and potentially opportunistic method for the screening of hepatic steatosis.

Nonalcoholic Fatty Liver Disease (NAFLD) and Cardiovascular Risk: Is Imaging Helpful?

Nonalcoholic Fatty Liver Disease (NAFLD) is proving to be a globally prevalent condition. Moreover, NAFLD may be an independent risk factor associated with higher cardiovascular (CVD) morbidity and mortality. Further studies are needed to assess whether NAFLD needs to be included in the atherosclerotic risk score algorithms or whether patients with NAFLD need to be screened early on to assess their CVD risk especially since imaging such as positron emission tomography can be used to assess both NAFLD and CV disease at the same time. Therefore employing cardiovascular imaging modalities to investigate the incidence, extent, and nature of atherosclerotic lesions in NAFLD may be beneficial. Additionally, whether treating NAFLD halts the progression of CVD on imaging remains to be seen. Further research to delineate NAFLD and CVD associations, deciphering screening imaging modalities, and investigating targeted interventions could improve CVD morbidity and mortality in NAFLD.

Effects of diet-induced hypercholesterolemia and gold nanoparticles treatment on peripheral tissues

Cholesterol is a lipid molecule of great biological importance to animal cells. Dysregulation of cholesterol metabolism leads to raised blood total cholesterol levels, a clinical condition called hypercholesterolemia. Evidence has shown that hypercholesterolemia is associated with the development of liver and heart disease. One of the mechanisms underlying heart and liver alterations induced by hypercholesterolemia is oxidative stress. In this regard, in several experimental studies, gold nanoparticles (AuNP) displayed antioxidant properties. We hypothesized that hypercholesterolemia causes redox system imbalance in the liver and cardiac tissues, and AuNP treatment could ameliorate it. Young adult male Swiss mice fed a regular rodent diet or a high cholesterol diet for eight weeks and concomitantly treated with AuNP (2.5 μg/kg) or vehicle by oral gavage. Hypercholesterolemia increased the nitrite concentration and glutathione (GSH) levels and decreased the liver's superoxide dismutase (SOD) activity. Also, hypercholesterolemia significantly enhanced the reactive oxygen species (ROS) and GSH levels in cardiac tissue. Notably, AuNP promoted the redox system homeostasis, increasing the SOD activity in hepatic tissue and reducing ROS levels in cardiac tissue. Overall, our data showed that hypercholesterolemia triggered oxidative stress in mice's liver and heart, which was partially prevented by AuNP treatment.

Non-alcoholic fatty liver disease increases risk of carotid atherosclerosis and ischemic stroke: An updated meta-analysis with 135,602 individuals

BACKGROUND/AIMS

Non-alcoholic fatty liver disease (NAFLD) is associated with the development of cardiovascular disease. While existing studies have examined cardiac remodeling in NAFLD, there has been less emphasis on the development of carotid atherosclerosis and stroke. We sought to conduct a meta-analysis to quantify the prevalence, risk factors, and degree of risk increment of carotid atherosclerosis and stroke in NAFLD.

METHODS

Embase and Medline were searched for articles relating to NAFLD, carotid atherosclerosis, and stroke. Proportional data was analysed using a generalized linear mixed model. Pairwise meta-analysis was conducted to obtain odds ratio or weighted mean difference for comparison between patients with and without NAFLD.

RESULTS

From pooled analysis of 30 studies involving 7,951 patients with NAFLD, 35.02% (95% confidence interval [CI], 27.36-43.53%) had carotid atherosclerosis with an odds ratio of 3.20 (95% CI, 2.37-4.32; P<0.0001). Pooled analysis of 25,839 patients with NAFLD found the prevalence of stroke to be 5.04% (95% CI, 2.74-9.09%) with an odds ratio of 1.88 (95% CI, 1.23-2.88; P=0.02) compared to non-NAFLD. The degree of steatosis assessed by ultrasonography in NAFLD was closely associated with risk of carotid atherosclerosis and stroke. Older age significantly increased the risk of developing carotid atherosclerosis, but not stroke in NAFLD.

CONCLUSION

This meta-analysis shows that a stepwise increment of steatosis of NAFLD can significantly increase the risk of carotid atherosclerosis and stroke development in NAFLD. Patients more than a third sufferred from carotid atherosclerosis and routine assessment of carotid atherosclerosis is quintessential in NAFLD.

Non-alcoholic fatty liver disease and risk of fatal and non-fatal cardiovascular events: an updated systematic review and meta-analysis

BACKGROUND

Studies have reported a significant association between non-alcoholic fatty liver disease (NAFLD) and increased incidence of cardiovascular disease (CVD). However, the magnitude of the risk and whether this risk changes with the severity of NAFLD remains uncertain. We performed a meta-analysis of observational studies to quantify the magnitude of the association between NAFLD and risk of incident CVD events.

METHODS

We systematically searched PubMed, Scopus, and Web of Science from database inception to July 1, 2021, to identify eligible observational studies examining the risk of incident CVD events amongst adult (age ≥18 years) individuals with and without NAFLD and in which NAFLD was diagnosed by imaging, International Classification of Diseases codes, or liver biopsy. The primary outcomes were CVD death, non-fatal CVD events, or both. Data from selected studies were extracted, and meta-analysis was performed using random-effects models to obtain summary hazard ratios (HRs) with 95% CIs. The quality of the evidence was assessed with the Cochrane risk of bias tool. This study is registered on Open Science Framework, number osf.io/5z7gf.

FINDINGS

We identified 36 longitudinal studies with aggregate data on 5 802 226 middle-aged individuals (mean age 53 years [SD 7]) and 99 668 incident cases of fatal and non-fatal CVD events over a median follow-up of 6·5 years (IQR 5·0-10·2). NAFLD was associated with a moderately increased risk of fatal or non-fatal CVD events (pooled random-effects HR 1·45, 95% CI 1·31-1·61; I²=86·18%). This risk markedly increased across the severity of NAFLD, especially the stage of fibrosis (pooled random-effects HR 2·50, 95% CI 1·68-3·72; I²=73·84%). All risks were independent of age, sex, adiposity measures, diabetes, and other common cardiometabolic risk factors. Sensitivity analyses did not modify these results.

INTERPRETATION

NAFLD is associated with an increased long-term risk of fatal or non-fatal CVD events. CVD risk is further increased with more advanced liver disease, especially with higher fibrosis stage. These results provide evidence that NAFLD might be an independent risk factor for CVD morbidity and mortality.

FUNDING

None.

Gut-flora metabolites is not associated with synchronous carotid artery plaque and non-alcoholic fatty liver disease in asymptomatic adults: A STROBE-compliant article

Synchronous non-alcoholic fatty liver disease (NAFLD) and carotid artery plaque formation increase the risk of mortality in patients with cardiovascular disease (CVD). Metabolic status and host gut flora are associated with NAFLD and CVD, but the risk factors require further evaluation.To evaluate the risk factors associated with NAFLD and CVD, including gut-flora-related examinations.This cross-sectional study included 235 subjects aged over 40 years who underwent abdominal ultrasound examination and carotid artery ultrasound examination on the same day or within 12 months of abdominal ultrasound between January 2018 and December 2019. All subjects underwent blood tests, including endotoxin and trimethylamine-N-oxide.The synchronous NAFLD and carotid artery plaque subjects had a higher proportion of men and increased age compared with those without NAFLD and no carotid artery plaque. The synchronous NAFLD and carotid artery plaque group had increased body mass index (BMI), blood pressure, hemoglobin A1C (5.71% vs 5.42%), triglyceride (TG) (164.61 mg/dL vs 102.61 mg/dL), and low-density lipoprotein (135.27 mg/dL vs 121.42 mg/dL). In multiple logistic regression analysis, increased BMI, mean systolic blood pressure, and TG > 110 mg/dL were independent risk factors for synchronous NAFLD and carotid artery plaque formation. Endotoxin and trimethylamine-N-oxide levels were not significantly different between the 2 groups.Host metabolic status, such as elevated BMI, TG, and systolic blood pressure, are associated with synchronous NAFLD and carotid artery plaque in asymptomatic adults. Aggressive TG control, blood pressure control, and weight reduction are indicated in patients with NAFLD.

Dysregulated lipid metabolism links NAFLD to cardiovascular disease

Background

Non-alcoholic fatty liver disease (NAFLD) is rapidly becoming a global health problem. Cardiovascular diseases (CVD) are the most common cause of mortality in NAFLD patients. NAFLD and CVD share several common risk factors including obesity, insulin resistance, and type 2 diabetes (T2D). Atherogenic dyslipidemia, characterized by plasma hypertriglyceridemia, increased small dense low-density lipoprotein (LDL) particles, and decreased high-density lipoprotein cholesterol (HDL-C) levels, is often observed in NAFLD patients.

Scope of review

In this review, we highlight recent epidemiological studies evaluating the link between NAFLD and CVD risk. We further focus on recent mechanistic insights into the links between NAFLD and altered lipoprotein metabolism. We also discuss current therapeutic strategies for NAFLD and their potential impact on NAFLD-associated CVD risk.

Major conclusions

Alterations in hepatic lipid and lipoprotein metabolism are major contributing factors to the increased CVD risk in NAFLD patients, and many promising NASH therapies in development also improve dyslipidemia in clinical trials.

Clinical considerations in the management of non-alcoholic steatohepatitis cirrhosis pre- and post-transplant: A multi-system challenge

Non-alcoholic steatohepatitis (NASH) is the most common chronic liver disease worldwide, and the fastest growing indication for liver transplantation in the United States. NASH is now the leading etiology for liver transplantation in women, the second leading indication for men, and the most common cause amongst recipients aged 65 years and older. Patients with end-stage liver disease related to NASH represent a unique and challenging patient population due the high incidence of associated comorbid diseases, including obesity, type 2 diabetes (T2D), and hypertension. These challenges manifest in the pre-liver transplantation period with increased waitlist times and waitlist mortality. Furthermore, these patients carry considerable risk of morbidity and mortality both before after liver transplantation, with high rates of T2D, cardiovascular disease, chronic kidney disease, poor nutrition, and disease recurrence. Successful transplantation for these patients requires identification and management of their comorbidities in the face of liver failure. Multidisciplinary evaluations include a thorough pre-transplant workup with a complete cardiac evaluation, control of diabetes, nutritional support, and even, potentially, consultation with a bariatric surgeon. This article provides a comprehensive review of the conditions and challenges facing patients with NASH cirrhosis undergoing liver transplantation and provides recommendations for evaluation and management to optimize them before liver transplantation to produce successful outcomes.

Extra-hepatic manifestations and complications of nonalcoholic fatty liver disease

This review article aims to synthesize the evidence regarding nonalcoholic fatty liver disease (NAFLD) as a systemic disorder. We critically discuss the metabolic syndrome and its components; the cardiovascular and the endocrine system; chronic respiratory disorders; the musculoskeletal system; the skin; and extra-hepatic tumors. We conclude that, while some of these extra-hepatic conditions clearly predispose to the development of secondary forms of NAFLD (typically hypothyroidism-induced NAFLD), others result from pre-existent NAFLD (e.g., certain extra-hepatic tumors) and others (such as Type 2 Diabetes) have, with NAFLD, mutual and bidirectional associations. Analyzed data imply that NAFLD is not merely a hepatic disease. It is also and possibly more importantly, a systemic disorder requiring a special awareness, a multidisciplinary approach and a multidimensional vision.

Metabolic Inflammation-A Role for Hepatic Inflammatory Pathways as Drivers of Comorbidities in Nonalcoholic Fatty Liver Disease?

Nonalcoholic fatty liver disease (NAFLD) is a global and growing health concern. Emerging evidence points toward metabolic inflammation as a key process in the fatty liver that contributes to multiorgan morbidity. Key extrahepatic comorbidities that are influenced by NAFLD are type 2 diabetes, cardiovascular disease, and impaired neurocognitive function. Importantly, the presence of nonalcoholic steatohepatitis and advanced hepatic fibrosis increase the risk for systemic comorbidity in NAFLD. Although the precise nature of the crosstalk between the liver and other organs has not yet been fully elucidated, there is emerging evidence that metabolic inflammation-in part, emanating from the fatty liver-is the engine that drives cellular dysfunction, cell death, and deleterious remodeling within various body tissues. This review describes several inflammatory pathways and mediators that have been implicated as links between NAFLD and type 2 diabetes, cardiovascular disease, and neurocognitive decline.

Molecular imaging of carotid artery atherosclerosis with PET: a systematic review

PURPOSE

To conduct a systematic review of articles on PET imaging of carotid atherosclerosis with emphasis on clinical usefulness and comparison with other imaging modalities.

METHODS

Research articles reporting carotid artery PET imaging with different radiotracers until 30 November 2018 were systematically searched for in Medline/PubMed, Scopus, Embase, Google Scholar, and Cochrane Library. Duplicates were removed, and editorials, case studies, and investigations on feasibility or reproducibility of PET imaging and of patients with end-stage diseases or immunosuppressive medications were omitted. After quality assessment of included articles using Joanna Briggs Institute checklists, all eligible articles were reviewed.

RESULTS

Of 1718 primary hits, 53 studies comprising 4472 patients, aged 47-91 years (78.8% males), were included and grouped under the following headlines: diagnostic performance, risk factors, laboratory findings, imaging modalities, and treatment. ¹⁸F-fluorodeoxyglucose (FDG) (49/53) and ¹⁸F-sodium fluoride (NaF) (5/53) were the most utilized tracers to visualize carotid wall inflammation and microcalcification, respectively. Higher carotid FDG uptake was demonstrated in patients with than without symptomatic carotid atherosclerosis. Normal carotid arteries presented with the lowest FDG uptake. In symptomatic atherosclerosis, carotid arteries ipsilateral to a cerebrovascular event had higher FDG uptake than the contralateral carotid artery. FDG uptake was significantly associated with age, male gender, and body mass index in healthy individuals, and in addition with arterial hypertension, hypercholesterolemia, and diabetes mellitus in patients. Histological assessment indicated a strong correlation between microcalcification and NaF uptake in symptomatic patients. Histological evidence of calcification correlated inversely with FDG uptake, which was associated with increased macrophage and CD68 count, both accounting for increased local inflammatory response.

CONCLUSION

FDG-PET visualizes the inflammatory part of carotid atherosclerosis enabling risk stratification to a certain degree, whereas NaF-PET seems to indicate long-term consequences of ongoing inflammation by demonstrating microcalcification allowing discrimination of atherosclerotic from normal arteries and suggesting clinically significant carotid atherosclerosis.

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.

Hypertension, diabetes, atherosclerosis and NASH: Cause or consequence?

Non-alcoholic fatty liver disease (NAFLD) has become one of the most common forms of chronic liver disease worldwide and its prevalence is expected to continue rising. NAFLD has traditionally been considered a consequence of metabolic syndrome (MetS). However, the link between NAFLD and MetS components, especially type 2 diabetes mellitus (T2DM), hypertension (HTN), and cardiovascular disease (CVD) is more complex than previously thought. Indeed, the adverse effects of NAFLD extend far beyond the liver, with a large body of clinical evidence now suggesting that NAFLD may precede and/or promote the development of T2DM, HTN and atherosclerosis/CVD. The risk of developing these cardiometabolic diseases parallels the underlying severity of NAFLD. Accumulating evidence suggests that the presence and severity of NAFLD is associated with an increased risk of incident T2DM and HTN. Moreover, long-term prospective studies indicate that the presence and severity of NAFLD independently predicts fatal and nonfatal CVD events. In this review, we critically discuss the rapidly expanding body of clinical evidence that supports the existence of a bi-directional relationship between NAFLD and various components of MetS, particularly T2DM and HTN, as well as the current knowledge regarding a strong association between NAFLD and CVD morbidity and mortality. Finally, we discuss the most updated putative biological mechanisms through which NAFLD may contribute to the development of HTN, T2DM and CVD.

Vascular inflammation and metabolic activity in hematopoietic organs and liver in familial combined hyperlipidemia and heterozygous familial hypercholesterolemia

BACKGROUND

Familial dyslipidemias of either heterozygous (heFH) or combined (FCH) type lead to accelerated atherogenesis and increased cardiovascular risk.

OBJECTIVE

The aim of this study was to investigate in statin-naïve adult patients with familial dyslipidemias whether inflammatory activation and liver, spleen and bone marrow metabolic activity differ compared with normolipidemic subjects and between dyslipidemic groups.

METHODS

Fourteen patients with FCH, 14 with heFH, and 14 normolipidemic individuals were enrolled. Serum lipids, high-sensitivity C-reactive protein, and fibrinogen levels were measured, followed by ¹⁸F-fluorodeoxyglucose positron-emission tomography/computed tomography imaging. Radiotracer uptake in the aortic wall, spleen, bone marrow, and liver was quantified as tissue-to-background ratio (TBR).

RESULTS

Patients with heFH had significantly higher low-density lipoprotein levels compared with those with FCH and controls (P < .001). However, aortic TBRs were higher in FCH compared with heFH patients and controls (P = .02 and P < .001, respectively). FCH patients exhibited higher FDG uptake in the spleen compared with controls (P = .05). In addition, FCH exhibited higher bone marrow FDG uptake compared with heFH patients and controls (P = .03 and P = .02, respectively). FCH had higher liver uptake compared with heFH patients and controls (P < .001 for both). Significant correlations were observed between inflammatory biomarkers and imaging indices as well as between aortic TBR and FDG uptake of hematopoietic organs and liver.

CONCLUSIONS

Systemic, as well as vascular inflammation and spleen, bone marrow, and hepatic metabolic activity are increased in patients with FCH despite lower levels of low-density lipoprotein.

Hexim1 heterozygosity stabilizes atherosclerotic plaque and decreased steatosis in ApoE null mice fed atherogenic diet

Hexim-1 is an inhibitor of RNA polymerase II transcription elongation. Decreased Hexim-1 expression in animal models of chronic diseases such as left ventricular hypertrophy, obesity and cancer triggered significant changes in adaptation and remodeling. The main aim of this study was to evaluate the role of Hexim1 in lipid metabolism focused in the progression of atherosclerosis and steatosis. We used the C57BL6 apolipoprotein E (ApoE null) crossed bred to C57BL6Hexim1 heterozygous mice to obtain ApoE null - Hexim1 heterozygous mice (ApoE-HT). Both ApoE null backgrounds were fed high fat diet for twelve weeks. Then, we evaluated lipid metabolism, atherosclerotic plaque formation and liver steatosis. In order to understand changes in the transcriptome of both backgrounds during the progression of steatosis, we performed Affymetrix mouse 430 2.0 microarray. After 12 weeks of HFD, ApoE null and ApoE-HT showed similar increase of cholesterol and triglycerides in plasma. Plaque composition was altered in ApoE-HT. Additionally, liver triglycerides and steatosis were decreased in ApoE-HT mice. Affymetrix analysis revealed that decreased steatosis might be due to impaired inducible SOCS3 expression in ApoE-HT mice. In conclusion, decreased Hexim-1 expression does not alter cholesterol metabolism in ApoE null background after HFD. However, it promotes stable atherosclerotic plaque and decreased steatosis by promoting the anti-inflammatory TGFβ pathway and blocking the expression of the inducible and pro-inflammatory expression of SOCS3 respectively.

Association between vascular inflammation and non-alcoholic fatty liver disease: Analysis by 18F-fluorodeoxyglucose positron emission tomography

BACKGROUND

Growing evidence suggests that non-alcoholic fatty liver disease (NAFLD) is associated with cardiovascular disease as well as metabolic syndrome. FDG-PET is a novel imaging technique that detects vascular inflammation, which may reflect rupture-prone vulnerable atherosclerotic plaques.

METHODS

Vascular inflammation was measured as the maximum target-to-background ratio (maxTBR), along with various cardiometabolic risk factors in 51 subjects with NAFLD, and compared with 100 age- and gender-matched subjects without NAFLD. The liver attenuation index (LAI), which was measured using computed tomography, was used as a parameter for the diagnosis of NAFLD.

RESULTS

After adjusting for age and sex, both maxTBR and LAI values were associated with several cardiometabolic risk parameters. Furthermore, there was a significant inter-relationship between LAI and maxTBR values (r=-0.227, P=0.005). Individuals with NAFLD had higher maxTBR values than those without NAFLD (P=0.026), although their carotid intima-media thickness (CIMT) values did not differ. The proportion of subjects with NAFLD showed a step-wise increment following the tertiles of maxTBR values (P for trend=0.015). In multiple logistic regression analysis, maxTBR tertiles were independently associated with NAFLD after adjusting for age, gender, systolic blood pressure, triglycerides, HDL-cholesterol, glucose, BUN, creatinine and homeostasis model assessment of insulin resistance (HOMA-IR) (P=0.030). However, their relationship was attenuated after further adjustment for waist circumference or high sensitive C-reactive protein.

CONCLUSION

Patients with NAFLD have an increased risk for vascular inflammation as measured via FDG-PET/CT even without difference in CIMT. (Clinical trials No. NCT01958411, http://www.clinicaltrials.gov/).

Immune Imbalances in Non-Alcoholic Fatty Liver Disease: From General Biomarkers and Neutrophils to Interleukin-17 Axis Activation and New Therapeutic Targets

Non-alcoholic fatty liver disease (NAFLD) is an increasing problem worldwide and is associated with negative outcomes such as cirrhosis, hepatocellular carcinoma, insulin resistance, diabetes, and cardiovascular events. Current evidence shows that the immune response has an important participation driving the initiation, maintenance, and progression of the disease. So, various immune imbalances, from cellular to cytokines levels, have been studied, either for better compression of the disease pathophysiology or as biomarkers for severity assessment and outcome prediction. In this article, we performed a thorough review of studies that evaluated the role of inflammatory/immune imbalances in the NAFLD. At the cellular level, we gave special focus on the imbalance between neutrophils and lymphocytes counts (the neutrophil-to-lymphocyte ratio), and that which occurs between T helper 17 (Th17) and regulatory T cells as emerging biomarkers. By extension, we reviewed the reflection of these imbalances at the molecular level through pro-inflammatory cytokines including those involved in Th17 differentiation (IL-6, IL-21, IL-23, and transforming growth factor-beta), and those released by Th17 cells (IL-17A, IL-17F, IL-21, and IL-22). We gave particular attention to the role of IL-17, either produced by Th17 cells or neutrophils, in fibrogenesis and steatohepatitis. Finally, we reviewed the potential of these pathways as new therapeutic targets in NAFLD.

Non-alcoholic fatty liver disease and risk of incident cardiovascular disease: A meta-analysis

BACKGROUND & AIMS

There have been many studies of the effects of non-alcoholic fatty liver disease (NAFLD) and the risk of cardiovascular disease (CVD), but these have produced conflicting results. We performed a meta-analysis of these studies to quantify the magnitude of the association between NAFLD (and NAFLD severity) and risk of CVD events.

METHODS

We searched PubMed, Google scholar, and Web of Science databases using terms "NAFLD", "cardiovascular events", "cardiovascular mortality", "prognosis" and their combinations to identify observational studies published through January 2016. We included only observational studies conducted in adults >18years and in which NAFLD was diagnosed on imaging or histology. Data from selected studies were extracted and meta-analysis was then performed using random effects modelling.

RESULTS

A total of 16 unique, observational prospective and retrospective studies with 34,043 adult individuals (36.3% with NAFLD) and approximately 2,600 CVD outcomes (>70% CVD deaths) over a median period of 6.9years were included in the final analysis. Patients with NAFLD had a higher risk of fatal and/or non-fatal CVD events than those without NAFLD (random effect odds ratio [OR] 1.64, 95% CI 1.26-2.13). Patients with more 'severe' NAFLD were also more likely to develop fatal and non-fatal CVD events (OR 2.58; 1.78-3.75). Sensitivity analyses did not alter these findings. Funnel plot and Egger's test did not reveal significant publication bias.

CONCLUSIONS

NAFLD is associated with an increased risk of fatal and non-fatal CVD events. However, the observational design of the studies included does not allow to draw definitive causal inferences.

LAY SUMMARY

The data on whether NAFLD by itself is associated with increased cardiovascular events and death remains an issue of debate. The findings of this updated and large meta-analysis of observational studies indicate that NAFLD is significantly associated with an increased risk of fatal and non-fatal cardiovascular events. However, the observational design of the studies included does not allow us to prove that NAFLD causes cardiovascular disease. Clinicians who manage patients with NAFLD should not focus only on liver disease but should also consider the increased risk of cardiovascular disease and undertake early, aggressive risk factor modification.

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.

NAFLD and Increased Aortic Stiffness: Parallel or Common Physiopathological Mechanisms?

Non-alcoholic fatty liver disease (NAFLD) has become the leading cause of chronic liver diseases worldwide. Liver inflammation and fibrosis related to NAFLD contribute to disease progression and increasing liver-related mortality and morbidity. Increasing data suggest that NAFLD may be linked to atherosclerotic vascular disease independent of other established cardiovascular risk factors. Central arterial stiffness has been recognized as a measure of cumulative cardiovascular risk marker load, and the measure of carotid-femoral pulse wave velocity (cf-PWV) is regarded as the gold standard assessment of aortic stiffness. It has been shown that increased aortic stiffness predicts cardiovascular morbidity and mortality in several clinical settings, including type 2 diabetes mellitus, a well-known condition associated with advanced stages of NAFLD. Furthermore, recently-published studies reported a strong association between NAFLD and increased arterial stiffness, suggesting a possible link in the pathogenesis of atherosclerosis and NAFLD. We sought to review the published data on the associations between NAFLD and aortic stiffness, in order to better understand the interplay between these two conditions and identify possible common physiopathological mechanisms.

Carotid Plaques Correlates in Patients With Familial Hypercholesterolemia

Patients with familial hypercholesterolemia (FH) are at increased risk of premature cardiovascular disease. We compared factors associated with the presence of carotid plaques and carotid intima–media thickness (cIMT), markers of subclinical atherosclerosis, in 241 patients with FH (98, 40.7% men; mean age 41 ± 18.4 years). Patients with FH having carotid plaques (36.5%) had mean age, apolipoprotein (apo) B, glucose, apoA1, systolic blood pressure (SBP) and diastolic BP, waist/hip ratio (WHR), and body mass index higher than patients without plaques. Logistic regression revealed that apoB (odds ratio [OR] per 1 unit change 1.03, P = .005), high-density lipoprotein cholesterol (HDL-C; OR per 1 standard deviation [SD] change 0.59, P = .015), and non-HDL-C (OR per 1SD change 1.53, P = .04) were significantly associated with the presence of plaques. The cIMT correlated with obesity parameters, BP, apoB, glucose, high-sensitivity C-reactive protein, creatinine, γ-glutamyl transpeptidase, and alanine transaminase ( P < .001). Regression analysis revealed that cIMT was significantly associated with apoB, SBP, and WHR. These results confirm the role of apoB-containing lipoproteins and low HDL-C with the presence of carotid plaques and apoB, BP, and WHR with cIMT.