Visceral adiposity and insulin resistance are independent predictors of the presence of non-cirrhotic NAFLD-related portal hypertension

Spleen volume is independently associated with non-alcoholic fatty liver disease, liver volume and liver fibrosis

Non-alcoholic fatty liver disease (NAFLD) can lead to irreversible liver damage manifesting in systemic effects (e.g., elevated portal vein pressure and splenomegaly) with increased risk of deadly outcomes. However, the association of spleen volume with NAFLD and related type 2-diabetes (T2D) is not fully understood. The UK Biobank contains comprehensive health-data of 500,000 participants, including clinical data and MR images of >40,000 individuals. The present study estimated the spleen volume of 37,066 participants through automated deep learning-based image segmentation of neck-to-knee MR images. The aim was to investigate the associations of spleen volume with NAFLD, T2D and liver fibrosis, while adjusting for natural confounders. The recent redefinition and new designation of NAFLD to metabolic dysfunction-associated steatotic liver disease (MASLD), promoted by major organisations of studies on liver disease, was not employed as introduced after the conduct of this study. The results showed that spleen volume decreased with age, correlated positively with body size and was smaller in females compared to males. Larger spleens were observed in subjects with NAFLD and T2D compared to controls. Spleen volume was also positively and independently associated with liver fat fraction, liver volume and the fibrosis-4 score, with notable volumetric increases already at low liver fat fractions and volumes, but not independently associated with T2D. These results suggest a link between spleen volume and NAFLD already at an early stage of the disease, potentially due to initial rise in portal vein pressure.

Liver stiffness as a cornerstone in heart disease risk assessment

Metabolic dysfunction-associated steatotic liver disease (MASLD) typically presents with hepatic fibrosis in advanced disease, resulting in increased liver stiffness. A subset of patients further develops liver cirrhosis and hepatocellular carcinoma. Cardiovascular disease is a common comorbidity in patients with MASLD and its prevalence is increasing in parallel. Recent evidence suggests that especially liver stiffness, whether or not existing against a background of MASLD, is associated with heart diseases. We conducted a narrative review on the role of liver stiffness in the prediction of highly prevalent heart diseases including heart failure, cardiac arrhythmias (in particular atrial fibrillation), coronary heart disease, and aortic valve sclerosis. Research papers were retrieved from major scientific databases (PubMed, Web of Science) until September 2023 using 'liver stiffness' and 'liver fibrosis' as keywords along with the latter cardiac conditions. Increased liver stiffness, determined by vibration-controlled transient elastography or hepatic fibrosis as predicted by biomarker panels, are associated with a variety of cardiovascular diseases, including heart failure, atrial fibrillation, and coronary heart disease. Elevated liver stiffness in patients with metabolic liver disease should lead to considerations of cardiac workup including N-terminal pro-B-type natriuretic peptide/B-type natriuretic peptide determination, electrocardiography, and coronary computed tomography angiography. In addition, patients with MASLD would benefit from heart disease case-finding strategies in which liver stiffness measurements can play a key role. In conclusion, increased liver stiffness should be a trigger to consider a cardiac workup in metabolically compromised patients.

Portal hypertension in patients with nonalcoholic fatty liver disease: Current knowledge and challenges

Portal hypertension (PH) has traditionally been observed as a consequence of significant fibrosis and cirrhosis in advanced non-alcoholic fatty liver disease (NAFLD). However, recent studies have provided evidence that PH may develop in earlier stages of NAFLD, suggesting that there are additional pathogenetic mechanisms at work in addition to liver fibrosis. The early development of PH in NAFLD is associated with hepatocellular lipid accumulation and ballooning, leading to the compression of liver sinusoids. External compression and intra-luminal obstacles cause mechanical forces such as strain, shear stress and elevated hydrostatic pressure that in turn activate mechanotransduction pathways, resulting in endothelial dysfunction and the development of fibrosis. The spatial distribution of histological and functional changes in the periportal and perisinusoidal areas of the liver lobule are considered responsible for the pre-sinusoidal component of PH in patients with NAFLD. Thus, current diagnostic methods such as hepatic venous pressure gradient (HVPG) measurement tend to underestimate portal pressure (PP) in NAFLD patients, who might decompensate below the HVPG threshold of 10 mmHg, which is traditionally considered the most relevant indicator of clinically significant portal hypertension (CSPH). This creates further challenges in finding a reliable diagnostic method to stratify the prognostic risk in this population of patients. In theory, the measurement of the portal pressure gradient guided by endoscopic ultrasound might overcome the limitations of HVPG measurement by avoiding the influence of the pre-sinusoidal component, but more investigations are needed to test its clinical utility for this indication. Liver and spleen stiffness measurement in combination with platelet count is currently the best-validated non-invasive approach for diagnosing CSPH and varices needing treatment. Lifestyle change remains the cornerstone of the treatment of PH in NAFLD, together with correcting the components of metabolic syndrome, using nonselective beta blockers, whereas emerging candidate drugs require more robust confirmation from clinical trials.

Relative Recovery of Non-Alcoholic Fatty Liver Disease (NAFLD) in Diet-Induced Obese Rats

Consumption of a high-carbohydrate diet has a critical role in the induction of weight gain and obesity-related pathologies. This study tested the hypothesis that a carbohydrate-rich diet induces weight gain, ectopic fat deposition, associated metabolic risks and development of non-alcoholic fatty liver disease (NAFLD), which are partially reversible following carbohydrate reduction. Sprague Dawley (SD) rats were fed a carbohydrate-enriched cafeteria diet (CAF) or normal chow (NC) ad libitum for 16-18 weeks. In the reversible group (REV), the CAF was replaced with NC for a further 3 weeks (18-21 weeks). Animals fed the CAF diet showed significantly increased body weight compared to those fed NC, accompanied by abnormal changes in their systemic insulin and triglycerides, elevation of hepatic triglyceride and hepatic steatosis. In the REV group, when the CAF diet was stopped, a modest, non-significant weight loss was associated with improvement in systemic insulin and appearance of the liver, with lower gross fatty deposits and hepatic triglyceride. In conclusion, a carbohydrate-enriched diet led to many features of metabolic syndrome, including hyperinsulinemia, while a dietary reduction in this macronutrient, even for a short period, was able to restore normoinsulinemia, and reversed some of the obesity-related hepatic abnormalities, without significant weight loss.

Portal Hypertension in Nonalcoholic Fatty Liver Disease: Challenges and Paradigms

Portal hypertension in cirrhosis is defined as an increase in the portal pressure gradient (PPG) between the portal and hepatic veins and is traditionally estimated by the hepatic venous pressure gradient (HVPG), which is the difference in pressure between the free-floating and wedged positions of a balloon catheter in the hepatic vein. By convention, HVPG≥10 mmHg indicates clinically significant portal hypertension, which is associated with adverse clinical outcomes. Nonalcoholic fatty liver disease (NAFLD) is a common disorder with a heterogeneous clinical course, which includes the development of portal hypertension. There is increasing evidence that portal hypertension in NAFLD deserves special considerations. First, elevated PPG often precedes fibrosis in NAFLD, suggesting a bidirectional relationship between these pathological processes. Second, HVPG underestimates PPG in NAFLD, suggesting that portal hypertension is more prevalent in this condition than currently believed. Third, cellular mechanoresponses generated early in the pathogenesis of NAFLD provide a mechanistic explanation for the pressure-fibrosis paradigm. Finally, a better understanding of liver mechanobiology in NAFLD may aid in the development of novel pharmaceutical targets for prevention and management of this disease.

Insight into increased risk of portal vein thrombosis in nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is one of the leading chronic liver diseases with increased morbidity and mortality rates for extrahepatic diseases (including cardiovascular disease, portal vein thrombosis, etc.). There is an increased risk of thrombosis in both the portal and systemic circulation in patients with NAFLD, independent of traditional liver cirrhosis. However, increased portal pressure, the most critical factor, is frequently observed in NAFLD patients, predisposing them to portal vein thrombosis (PVT). It has been reported that there is an 8.5% incidence of PVT among patients with non-cirrhotic NAFLD in a prospective cohort study. Based on the prothrombotic status of NAFLD itself, patients combined with cirrhosis may accelerate the development of PVT and lead to a poor prognosis. Moreover, PVT has been shown to complicate the procedure and adversely affect the outcome during liver transplantation surgery. NAFLD is in a prothrombotic state, and its underlying mechanisms have not been fully understood so far. Particularly noteworthy is that gastroenterologists currently overlook the higher risk of PVT in NAFLD. We investigate the pathogenesis of NAFLD complicated with PVT from the perspective of primary, secondary, and tertiary hemostasis, and also summarize relevant studies in humans. Some treatment options that may affect NAFLD and its PVT are also explored to improve patient-oriented outcomes.

Heart Uptake of [18F]Fluoro-4-Thia-Oleate in a Non-Alcoholic Fatty Liver Disease Mouse Model

The world-wide high incidence of non-alcoholic fatty liver disease (NAFLD) is of concern for its progression to insulin resistance, steatohepatitis and cardiovascular disease (CVD). The increased uptake of fatty acids in critical organs plays a major role in NAFLD progression. Male Ceacam1−/− mice that develop NAFLD, insulin resistance and CVD on normal chow are a potential model for studying the dysregulation of fatty acid uptake. [18F]fluoro-4-thia-oleate ([18F]FTO) was chosen as a fatty acid reporter because of its higher uptake and retention in the heart in an animal model of CVD. Male wild-type (WT) or Ceacam1−/− mice fasted 4−6 h were administered [18F]FTO i.v., and dynamic PET scans were conducted in an MR/PET small animal imaging system along with terminal tissue biodistributions. Quantitative heart image analysis revealed significantly higher uptake at 35 min in Ceacam1−/− (6.0 ± 1.0% ID/cc) vs. WT (3.9 ± 0.6% ID/cc) mice (p = 0.006). Ex vivo heart uptake/retention (% ID/organ) was 2.82 ± 0.45 for Ceacam1−/− mice vs. 1.66 ± 0.45 for WT mice (p < 0.01). Higher kidney and pancreas uptake/retention in Ceacam1−/− was also evident, and the excretion of [18F]FTO into the duodenum was observed for both WT and Ceacam1−/− mice starting at 10 min. This study suggests that the administration of [18F]FTO as a marker of fatty acid uptake and retention may be an important tool in analyzing the effect of NAFLD on lipid dysregulation in the heart.

Nonalcoholic Fatty Liver Disease and Chronic Kidney Disease: Epidemiology, Pathogenesis, and Clinical and Research Implications

Nonalcoholic fatty liver disease (NAFLD) has become the most common cause of chronic liver disease worldwide, affecting up to ~30% of adult populations. NAFLD defines a spectrum of progressive liver conditions ranging from simple steatosis to nonalcoholic steatohepatitis (NASH), cirrhosis, and hepatocellular carcinoma, which often occur in close and bidirectional associations with metabolic disorders. Chronic kidney disease (CKD) is characterized by anatomic and/or functional renal damage, ultimately resulting in a reduced glomerular filtration rate. The physiological axis linking the liver and kidneys often passes unnoticed until clinically significant portal hypertension, as a major complication of cirrhosis, becomes apparent in the form of ascites, refractory ascites, or hepatorenal syndrome. However, the extensive evidence accumulated since 2008 indicates that noncirrhotic NAFLD is associated with a higher risk of incident CKD, independent of obesity, type 2 diabetes, and other common renal risk factors. In addition, subclinical portal hypertension has been demonstrated to occur in noncirrhotic NAFLD, with a potential adverse impact on renal vasoregulation. However, the mechanisms underlying this association remain unexplored to a substantial extent. With this background, in this review we discuss the current evidence showing a strong association between NAFLD and the risk of CKD, and the putative biological mechanisms underpinning this association. We also discuss in depth the potential pathogenic role of the hepatorenal reflex, which may be triggered by subclinical portal hypertension and is a poorly investigated but promising research topic. Finally, we address emerging pharmacotherapies for NAFLD that may also beneficially affect the risk of developing CKD in individuals with NAFLD.

Portal Hypertension in Nonalcoholic Fatty Liver Disease: From Pathogenesis to Clinical Practice

Portal hypertension in nonalcoholic fatty liver disease (NAFLD) mostly occur in cirrhotic stage. However, several experimental and clinical studies showed evidence of portal hypertension in NAFLD without significant or advance fibrosis. This early development of portal hypertension in NAFLD is associated with liver sinusoidal contraction by hepatocellular lipid accumulation and ballooning, which is also accompanied by capillarization and dysfunction of liver sinusoidal endothelial cells. Both of these impaired mechanical and molecular components can cause an increase in intrahepatic vascular resistance which lead to the increase of portal pressure in the absence of significant liver fibrosis. Extrahepatic factors such as insulin resistance and gut dysbiosis may also contribute to liver sinusoidal endothelial dysfunction and early portal hypertension in NAFLD. The clinical impact of early portal hypertension in NAFLD is still unclear. However, clinical tools for diagnosis and monitoring of portal hypertension in NAFLD are being investigated to predict high-risk patients and to guide therapy.

Overlooked subclinical portal hypertension in non-cirrhotic NAFLD: Is it real and how to measure it?

Clinical and experimental advances related to the detection, magnitude and pathobiology of subclinical portal hypertension in non-alcoholic fatty liver disease (NAFLD), primarily observed in the presence of non-alcoholic steatohepatitis (NASH), prompt us to revisit current disease paradigms. Hepatic venous pressure gradient (HVPG) has been reported to underestimate portal pressure in NASH-related cirrhosis, while inaccuracy is more likely in non-cirrhotic livers, indicating a potential need for new and preferably non-invasive methods of measurement. Although clinically significant portal hypertension (HVPG ≥10 mmHg) retains its prognostic significance in NASH, subclinical portal hypertension (HVPG 6.0-9.5 mmHg) has been repeatedly detected in patients with NAFLD in the absence of cirrhosis or even significant fibrosis whereas the impact of these findings on disease outcomes remains unclear. Mechanocrine signalling pathways in various types of liver cell reveal a molecular basis for the adverse effects of subclinical portal hypertension and suggest a bidirectional relationship between portal pressure and fibrosis. These findings may guide efforts to improve risk assessment and identify novel therapeutic targets in NAFLD.

Determination of “indeterminate score” measurements in lean nonalcoholic fatty liver disease patients from western Saudi Arabia

BACKGROUND

Noninvasive measures to estimate liver fibrosis in lieu of biopsy in nonalcoholic liver disease (NAFLD) can broadly differentiate high vs low degrees of condition extent. However, an “indeterminate score” necessitates further clinical investigation and biopsy becomes essential, highlighting the need for identification of other noninvasive factors with accuracy for this midlevel extent and its prognosis. Lean NAFLD cases are of particular interest regarding this issue, as they present as otherwise healthy, and will benefit greatly from the less invasive assessment.

AIM

To estimate the agreement of two noninvasive assessment tools in lean NAFLD patients, and assess factors related to indeterminate scores.

METHODS

Ultrasound-diagnosed NAFLD patients, without sign of other chronic liver disease (n = 1262), were enrolled from a tertiary private medical centre between 2016-2019. After grouping by body mass index (obese, overweight, and lean), each participant underwent FibroScan. NAFLD fibrosis score (NFS) was used for subclassification (lower, higher, and indeterminate). No patient underwent liver biopsy. The kappa statistic was used to assess inter-rater agreement between the three groups on liver fibrosis degree assessed via FibroScan and NFS. Indeterminate score among the three groups was assessed to identify factors that predict its determination.

RESULTS

The NAFLD study cohort was composed of lean (159/1262, 12.6%), overweight (365/1262, 29%) and obese (737/1262, 58.4%) individuals. The lean patients were significantly younger (49.95 ± 15.3 years, P < 0.05), with higher serum high density lipoprotein (52.56 ± 16.27 mg/dL, P < 0.001) and lower prevalences of type 2 diabetes mellitus, hypertension and hyperlipidaemia. All groups showed a predominance of lower fibrosis degree. The lean NAFLD patients showed a significantly lower NFS (P < 0.001). Degree of agreement between FibroScan and NFS was fair between the lean and obese NAFLD categories, and moderate in the overweight category. NFS was predictive of indeterminate score. Age was a factor among all the body mass index (BMI) categories; other associated factors, but with less strength, were serum alanine aminotransferase in the overweight category and BMI in the obese category.

CONCLUSION

Lean NAFLD patients showed lower degree and prevalence of liver fibrosis by NFS; however, follow-up biopsy is still needed.

Correlation of serum betatrophin levels with disease severity and the emergence of insulin resistance in cirrhotic patients

Background

Insulin resistance (IR) is frequently associated with chronic liver disease. There has been an increased interest in betatrophin protein and its involvement in the compensatory response to IR. We aimed to investigate the correlation of serum betatrophin levels with disease severity and the emergence of IR in cirrhotic patients. This study included 27 cirrhotic patients and 30 healthy participants who served as a control group. IR was assessed by the Homeostasis Model Assessment (HOMA-IR). Serum insulin and betatrophin levels were measured using Enzyme-Linked Immunosorbent Assay (ELISA).

Results

IR was existing in 74% of cirrhotic patients (p < 0.001). Subjects with IR had higher serum betatrophin levels than those without IR (p = 0.04). Serum betatrophin levels were significantly higher in cirrhotic patients than controls (p < 0.001). In addition, Child-Pugh class C patients had higher serum betatrophin levels than those with Child-Pugh class B cirrhosis (p = 0.01). Moreover, the highest serum betatrophin levels were detected in patients with tense ascites followed by those with moderate and mild ascites (p = 0.01). In the cirrhosis group, serum betatrophin levels correlated positively with fasting blood glucose levels (p < 0.001), fasting insulin levels (p = 0.006), HOMA-IR (p = 0.006), Child-Pugh score (p = 0.023), MELD score (p < 0.001), and INR (p = 0.005), and correlated negatively with platelets count (p = 0.01).

Conclusion

Cirrhotic patients have higher serum betatrophin levels; moreover, these levels are positively correlated with disease severity as well as the emergence of insulin resistance.

Nonalcoholic fatty liver disease and portal hypertension

Nonalcoholic fatty liver disease (NAFLD) is a substantial and growing problem worldwide and has become the second most common indication for liver transplantation as it may progress to cirrhosis and develop complications from portal hypertension primarily caused by advanced fibrosis and erratic tissue remodeling. However, elevated portal venous pressure has also been detected in experimental models of fatty liver and in human NAFLD when fibrosis is far less advanced and cirrhosis is absent. Early increases in intrahepatic vascular resistance may contribute to the progression of liver disease. Specific pathophenotypes linked to the development of portal hypertension in NAFLD include hepatocellular lipid accumulation and ballooning injury, capillarization of liver sinusoidal endothelial cells, enhanced contractility of hepatic stellate cells, activation of Kupffer cells and pro-inflammatory pathways, adhesion and entrapment of recruited leukocytes, microthrombosis, angiogenesis and perisinusoidal fibrosis. These pathological events are amplified in NAFLD by concomitant visceral obesity, insulin resistance, type 2 diabetes and dysbiosis, promoting aberrant interactions with adipose tissue, skeletal muscle and gut microbiota. Measurement of the hepatic venous pressure gradient by retrograde insertion of a balloon-tipped central vein catheter is the current reference method for predicting outcomes of cirrhosis associated with clinically significant portal hypertension and guiding interventions. This invasive technique is rarely considered in the absence of cirrhosis where currently available clinical, imaging and laboratory correlates of portal hypertension may not reflect early changes in liver hemodynamics. Availability of less invasive but sufficiently sensitive methods for the assessment of portal venous pressure in NAFLD remains therefore an unmet need. Recent efforts to develop new biomarkers and endoscopy-based approaches such as endoscopic ultrasound-guided measurement of portal pressure gradient may help achieve this goal. In addition, cellular and molecular targets are being identified to guide emerging therapies in the prevention and management of portal hypertension.

Potential mechanisms linking gut microbiota and portal hypertension

Gut microbiota is the largest collection of commensal micro-organisms in the human body, engaged in reciprocal cellular and molecular interactions with the liver. This mutually beneficial relationship may break down and result in dysbiosis, associated with disease phenotypes. Altered composition and function of gut microbiota has been implicated in the pathobiology of nonalcoholic fatty liver disease (NAFLD), a prevalent condition linked to obesity, insulin resistance and endothelial dysfunction. NAFLD may progress to cirrhosis and portal hypertension, which is the result of increased intrahepatic vascular resistance and altered splanchnic circulation. Gut microbiota may contribute to rising portal pressure from the earliest stages of NAFLD, although the significance of these changes remains unclear. NAFLD has been linked to lower microbial diversity and weakened intestinal barrier, exposing the host to bacterial components and stimulating pathways of immune defence and inflammation. Moreover, disrupted host-microbial metabolic interplay alters bile acid signalling and the release of vasoregulatory gasotransmitters. These perturbations become prominent in cirrhosis, increasing the risk of clinically significant portal hypertension and leading to bacterial translocation, sepsis and acute-on-chronic liver failure. Better understanding of the gut-liver axis and identification of novel microbial molecular targets may yield specific strategies in the prevention and management of portal hypertension.

The potential role of vascular alterations and subsequent impaired liver blood flow and hepatic hypoxia in the pathophysiology of non-alcoholic steatohepatitis

Non-alcoholic fatty liver disease (NAFLD) covers a spectrum of disease ranging from steatosis to steatohepatitis (NASH) and fibrosis, but the underlying pathophysiological mechanisms remain largely unknown. As there is currently no approved pharmacological therapy and the prevalence of NAFLD keeps increasing, understanding of its pathophysiology is crucial. We hypothesise that vascular alterations in early NAFLD play a role in the progression of the disease by inducing an increased intrahepatic vascular resistance and consequently relative hypoxia in the liver. Evidence of the detrimental effects of hypoxia in NAFLD has already been observed in liver surgery, where the outcomes of steatotic livers after ischaemia-reperfusion are worse than in healthy livers, and in obstructive sleep apnoea, which is an independent risk factor of NAFLD. Moreover, early histological damage in NAFLD is situated in the pericentral zone, which is also the first zone to be affected by a decreased oxygen tension because of the unique hepatic vacsular anatomy that causes the pericentral oxygen tension to be the lowest. Angiogenesis is also a characteristic of NAFLD, driven by hypoxia-induced mechanisms, as demonstrated in both animal models and in humans with NAFLD. Relative hypoxia is most probably induced by impaired blood flow to the liver, caused by increased intrahepatic vascular resistance. An increased intrahepatic vascular resistance early in the development of disease has been convincingly demonstrated in several animal models of NAFLD, whereas an increased portal pressure, a consequence of increased intrahepatic vascular resistance, has been proven in patients with NAFLD. Animal studies demonstrated a decreased intrahepatic effect of vasodilators and an increased reactivity to vasoconstrictors that results in an increased intrahepatic vascular resistance, thus the presence of a functional component. Pharmacological products that target vasoregulation can hence improve the intrahepatic vascular resistance and this might prevent or reverse progression of NAFLD, representing an important therapeutic option to study. Some of the drugs currently under evaluation in clinical trials for NASH have interesting properties related to the hepatic vasculature. Some other interesting drugs have been tested in animal models but further study in patients with NAFLD is warranted. In summary, in this paper we summarise the evidence that leads to the hypothesis that an increased intrahepatic vascular resistance and subsequent parenchymal hypoxia in early NAFLD is an important pathophysiological driving mechanism for the progression of the disease.

Severe steatosis induces portal hypertension by systemic arterial hyporeactivity and hepatic vasoconstrictor hyperreactivity in rats

Non-alcoholic fatty liver disease (NAFLD) has become the most prevalent chronic liver disease. The presence of portal hypertension has been demonstrated in NAFLD prior to development of inflammation or fibrosis, and is a result of extrahepatic and intrahepatic factors, principally driven by vascular dysfunction. An increased intrahepatic vascular resistance potentially contributes to progression of NAFLD via intralobular hypoxia. However, the exact mechanisms underlying vascular dysfunction in NAFLD remain unknown. This study investigates systemic hemodynamics and both aortic and intrahepatic vascular reactivity in a rat model of severe steatosis. Wistar rats were fed a methionine-choline-deficient diet, inducing steatosis, or control diet for 4 weeks. In vivo hemodynamic measurements, aortic contractility studies, and in situ liver perfusion experiments were performed. The mean arterial blood pressure was lower and portal blood pressure was higher in steatosis compared to controls. The maximal contraction force in aortic rings from steatotic rats was markedly reduced compared to controls. While blockade of nitric oxide (NO) production did not reveal any differences, cyclooxygenase (COX) blockade reduced aortic reactivity in both controls and steatosis, whereas effects were more pronounced in controls. Effects could be attributed to COX-2 iso-enzyme activity. In in situ liver perfusion experiments, exogenous NO donation or endogenous NO stimulation reduced the transhepatic pressure gradient (THPG), whereas NO synthase blockade increased the THPG only in steatosis, but not in controls. Alpha-1-adrenergic stimulation and endothelin-1 induced a significantly more pronounced increase in THPG in steatosis compared to controls. Our results demonstrate that severe steatosis, without inflammation or fibrosis, induces portal hypertension and signs of a hyperdynamic circulation, accompanied by extrahepatic arterial hyporeactivity and intrahepatic vascular hyperreactivity. The arterial hyporeactivity seems to be NO-independent, but appears to be mediated by specific COX-2-related mechanisms. Besides, the increased intrahepatic vascular resistance in steatosis appears not to be NO-related but rather to vasoconstrictor hyperreactivity.

Restoration of a healthy intestinal microbiota normalizes portal hypertension in a rat model of nonalcoholic steatohepatitis

Portal hypertension (PH) drives most of the clinical complications in chronic liver diseases. However, its progression in nonalcoholic steatohepatitis (NASH) and its association with the intestinal microbiota (IM) have been scarcely studied. Our aim was to investigate the role of the IM in the mechanisms leading to PH in early NASH. The experimental design was divided in two stages. In stage 1, Sprague-Dawley rats were fed for 8 weeks a high-fat, high-glucose/fructose diet (HFGFD) or a control diet/water (CD). Representative rats were selected as IM donors for stage 2. In stage 2, additional HFGFD and CD rats underwent intestinal decontamination, followed by IM transplantation with feces from opposite-diet donors (heterologous transplant) or autologous fecal transplant (as controls), generating four groups: CD-autotransplanted, CD-transplanted, HFGFD-autotransplanted, HFGFD-transplanted. After IM transplantation, the original diet was maintained for 12-14 days until death. HFGFD rats developed obesity, insulin resistance, NASH without fibrosis but with PH, intrahepatic endothelial dysfunction, and IM dysbiosis. In HFGFD rats, transplantation with feces from CD donors caused a significant reduction of PH to levels comparable to CD without significant changes in NASH histology. The reduction in PH was due to a 31% decrease of intrahepatic vascular resistance compared to the HFGFD-autotransplanted group (P < 0.05). This effect occurs through restoration of the sensitivity to insulin of the hepatic protein kinase B-dependent endothelial nitric oxide synthase signaling pathway.

CONCLUSION

The IM exerts a direct influence in the development of PH in rats with diet-induced NASH and dysbiosis; PH, insulin resistance, and endothelial dysfunction revert when a healthy IM is restored. (Hepatology 2018;67:1485-1498).

Nonalcoholic Fatty Liver Disease and Associated Metabolic Risks of Hypertension in Type 2 Diabetes: A Cross-Sectional Community-Based Study

The mechanisms facilitating hypertension in diabetes still remain to be elucidated. Nonalcoholic fatty liver disease (NAFLD), which is a higher risk factor for insulin resistance, shares many predisposing factors with diabetes. However, little work has been performed on the pathogenesis of hypertension in type 2 diabetes (T2DM) with NAFLD. The aim of this study is to investigate the prevalence of hypertension in different glycemic statuses and to analyze relationships between NAFLD, metabolic risks, and hypertension within a large community-based population after informed written consent. A total of 9473 subjects aged over 45 years, including 1648 patients with T2DM, were enrolled in this cross-sectional study. Clinical and biochemical parameters of all participants were determined. The results suggested that the patients with prediabetes or T2DM were with higher risks to have hypertension. T2DM with NAFLD had significantly higher levels of blood pressure, triglyceride, uric acid, and HOMA-IR than those without NAFLD. Data analyses suggested that hypertriglyceridemia [OR = 1.773 (1.396, 2.251)], NAFLD [OR = 2.344 (1.736, 3.165)], hyperuricemia [OR = 1.474 (1.079, 2.012)], and insulin resistance [OR = 1.948 (1.540, 2.465)] were associated with the higher prevalence of hypertension independent of other metabolic risk factors in type 2 diabetes. Further studies are needed to focus on these associations.

Incidence of insulin resistance and diabetes in patients with portosystemic shunts without liver dysfunction

Objective To investigate the incidence of insulin resistance (IR) and diabetes in patients with chronic hepatic schistosomiasis japonica (HSJ) and portosystemic shunts (PSS). Methods Pre- and post-contrasted computed tomography images obtained from patients with HSJ and control subjects were reviewed by two radiologists who identified and graded any shunting vessels. Anthropometric measurements, hepatic enzymes, lipid profile, blood levels of albumin, glucose, insulin and homeostasis model assessment (HOMA-2) index of all participants were also assessed. Results Fifty-two patients with HSJ and 30 control subjects were involved in the study. The coronary, short gastric and perisplenic veins were the most common shunting vessels. There were no significant differences between patients and controls in terms of body mass index or liver function. The degree of shunting vessels, blood glucose, oral glucose tolerance test_120/0, insulin, HOMA-2 index, glycosylated haemoglobin, cholesterol, high- and low-density lipoprotein, and C-reactive protein were significantly higher in the patients with IR. A positive correlation was found between the degree of the shunting vessels and the HOMA-2 index. Conclusions Patients with chronic HSJ and PSS without liver dysfunction had a high incidence of IR and diabetes. The study showed that PSS and IR are related and therefore patients with PSS should be screened for IR and vice versa.

Changes in Hepatic Venous Pressure Gradient Induced by Physical Exercise in Cirrhosis: Results of a Pilot Randomized Open Clinical Trial

OBJECTIVES

Exercise has been scarcely studied in patients with cirrhosis, and prior evidence showed hepatic venous pressure gradient (HVPG) to be increased in response to exercise. The aim of this study was to investigate the effects of a supervised physical exercise program (PEP) in patients with cirrhosis.

METHODS

In an open-label, pilot clinical trial, patients with cirrhosis were randomized to PEP (cycloergometry/kinesiotherapy plus nutritional therapy, n=14) or control (nutritional therapy, n=15); for 14 weeks. Primary outcomes were: the effect of PEP in HVPG, and quality of life (chronic liver disease questionnaire, CLDQ). As secondary outcomes we investigated changes in physical fitness (cardiopulmonary exercise testing), nutritional status (phase angle-bioelectrical impedance), ammonia levels, and safety.

RESULTS

Twenty-two patients completed the study (11 each). HVPG decreased in subjects allocated to PEP (-2.5 mm Hg (interquartile range: -5.25 to 2); P=0.05), and increased in controls (4 mm Hg (0-5); P=0.039), with a significant between-groups difference (P=0.009). No major changes were noted in CLDQ in both groups. There was significant improvement in ventilatory efficiency (VE/VCO2) in PEP group (-1.9 (-3.12 to -0.1); P=0.033), but not in controls (-0.4 (-5.7 to 1.4); P=0.467). Phase angle improvement and a less-pronounced exercise-induced hyperammonemia were noted only in PEP group. No episodes of variceal bleeding or hepatic encephalopathy were observed.

CONCLUSIONS

A supervised PEP in patients with cirrhosis decreases the HVPG and improves nutritional status with no changes in quality of life. Further studies evaluating physical training in cirrhosis are eagerly awaited in order to better define the benefits of sustained exercise. ClinicalTrials.gov:NCT00517738.

Insulin resistance is associated with esophageal varices in alcoholic liver disease patients

BACKGROUND AND AIM

Insulin resistance plays an important role in chronic liver disease, where it has been associated with the progression of fibrosis and correlated with portal hypertension in cirrhotic patients with mixed etiology. However, the impact of insulin resistance in alcoholic liver disease remains mostly unknown. The aim of this study was to evaluate the association between insulin resistance, portal hypertension, severity of liver disease, and mortality in patients with alcoholic cirrhosis.

PATIENTS AND METHODS

A total of 106 consecutive alcoholic cirrhotic patients undergoing hepatic venous pressure gradient measurement at Erasme Hospital were included. Insulin resistance was estimated using the homeostatic model assessment-2 index.

RESULTS

The median model for end-stage liver disease (MELD) score was 15 (9-21) and the mean hepatic venous pressure gradient was16.3±6 mmHg. Twenty-six percent of the patients had compensated cirrhosis. Insulin resistance was significantly associated with portal hypertension in compensated cirrhotic patients and with the presence of esophageal varices, but was not associated with the MELD score and mortality. MELD score was the only independent covariate associated with mortality at 6 (P<0.001) and 12 months (P<0.001).

CONCLUSION

Insulin resistance is associated with the presence of esophageal varices, suggesting that the presence of insulin resistance could be harmful to alcoholic liver disease patients.

Effect of coexisting diabetes mellitus and chronic kidney disease on mortality of cirrhotic patients with esophageal variceal bleeding

BACKGROUND

Esophageal variceal bleeding (EVB) is a serious and common complication of cirrhosis. Diabetes mellitus (DM) and chronic kidney disease (CKD) increase mortality in patients with cirrhosis. However, whether coexisting DM and CKD increase mortality in cirrhotic patients with EVB remains unclear.

METHODS

We enrolled cirrhotic patients hospitalized with the first presentation of EVB from 2005 through 2010 using Longitudinal Health Insurance Database 2005. The hazard ratios (HRs) of 42-day and one-year EVB mortality were calculated using Cox regression model.

RESULTS

We identified 888 patients hospitalized with the first presentation of EVB. Among the cirrhotic patients with EVB, all-cause mortality at 42-day and one-year were 21.3 and 45.0 %, respectively. The respective HRs for the 42-day and one-year mortality were 1.80 (95 % confidence interval [CI], 1.10-2.97) and 1.52 (95 % CI, 1.06-2.17) for patients with CKD and 0.79 (95 % CI, 0.57-1.10) and 0.88 (95 % CI, 0.71-1.09) for patients with DM. Specifically, coexisting CKD and DM increased the 42-day and one-year mortality with respective HRs of 1.99 (95%CI, 1.03-3.84) and 1.84 (95%CI, 1.14-2.98) compared with those without CKD and DM. The HRs for 42-day and 1-year mortality in female patients with DM and CKD were 4.03 (95%CI, 1.40-11.59) and 2.84 (95%CI, 1.31-6.14) respectively, and were 2.93 (95%CI, 1.14-7.57) and 2.42 (95%CI, 1.28-4.57) in male patients with DM and CKD.

CONCLUSION

We identified that coexisting DM and CKD increased risk of mortality at 42 days and 1 year following EVB.

Probe-based confocal laser endomicroscopy quantitative morphometric markers associated with portal hypertension in duodenal mucosa

BACKGROUND & AIMS

Early detection of portal hypertension (PH) may help to prevent the morbidity of late-stage cirrhosis by stratifying disease severity and enabling disease-modifying interventions in potentially reversible conditions like non-alcoholic fatty liver disease and alcoholic hepatitis. This study seeks to correlate morphometric features by confocal endomicroscopy with established surrogate clinical markers of PH.

METHODS

Patients with and without PH scheduled for upper endoscopy at VA Boston participated in this IRB-approved study. Real-time probe-based confocal endomicroscopy (pCLE) was performed in the duodenum. Vascular and epithelial morphometry was performed off-line, in a blinded manner, using image-processing software.

RESULTS

Morphometric analysis of pCLE images from 16 patients with PH and 15 control patients was performed. Statistically significant differences were observed among control and PH patients for average vessel diameter (AVD: 11.7 μm vs. 17.1 μm), average vessel branching (AVB: 0.11 vs. 0.31 bifurcations per image frame), and average columnar cell height (ACCH: 40.0 μm vs. 52.0 μm). Spearman correlations comparing AVD, AVB and ACCH to portal gastropathy scores (0.86, 0.44 and 0.70) and to grade of oesophageal varices (0.88, 0.41 and 0.66) were statistically significant. Similarly, Pearson correlations of AVD and ACCH to spleen size (0.72 and 0.57), platelet count (-0.69 and -0.40) and the platelet count/spleen size ratio (-0.69 and -0.41) were also found to be statistically significant.

CONCLUSIONS

Duodenal pCLE reveals microvascular dilatation and altered epithelial cell volume/morphology in PH. These morphometric pCLE markers correlate with surrogate markers of PH. Additional studies will define the correlation between microscopic vascular patterns, epithelial cell volume and the hepatic venous pressure gradient.

Peripheral and Hepatic Vein Cytokine Levels in Correlation with Non-Alcoholic Fatty Liver Disease (NAFLD)-Related Metabolic, Histological, and Haemodynamic Features

BACKGROUND

Haemodynamic impairment, inflammatory mediators and glucose metabolism disturbances have been implicated in the pathogenesis of Non-Alcoholic Fatty Liver Disease (NAFLD).

AIM

To investigate the cytokine profile in NAFLD patients in peripheral (P) and hepatic venous (HV) blood and to compare with histology, haemodynamic and metabolic parameters.

METHODS

40 obese patients with an indication for a transjugular liver biopsy were enrolled. Besides an extended liver and metabolic work-up, interleukin (IL) 1B, IL4, IL6, IL10, IL23, tumour necrosis factor (TNF) α and interferon (INF) γ were measured in plasma obtained from P and HV blood by means of multiplex immunoassay. The T helper (Th)1/Th2, the macrophage M1/M2 and the IL10/IL17a ratios were calculated.

RESULTS

A decrease of the P-IL10/IL17-ratio and an increase of the P-M1/M2-ratio (p<0.05) were observed in NASH versus no-NASH patients. A P-M1/M2-ratio increase was detected also in patients with portal hypertension in comparison with patients without it (p<0.05). Moreover diabetic patients showed an increase of the P-Th1/Th2-ratio in comparison with non-diabetic ones (p<0.05). The P-M1/M2 ratio positively correlated with steatosis grade (r = 0.39, p = 0.02) and insulin (r = 0.47, p = 0.003). The HV-M1/M2 ratio positively correlated with fasting insulin and Hepatic Venous Pressure Gradient (r = 0.47, p = 0.003). IL6 correlated with the visceral fat amount (r = 0.36, p = 0.02). The P- and HV-IL10/IL17 ratios negatively correlated with fasting insulin (respectively r = -0.4, p = 0.005 and r = 0.4, p = 0.01).

CONCLUSIONS

A proinflammatory cytokine state is associated with more disturbed metabolic, histological, and haemodynamic features in NAFLD obese patients. An increase of the M1/M2 ratio and a decrease of the IL10/IL17 ratio play a key role in this process.

Intimate association of visceral obesity with non-alcoholic fatty liver disease in healthy Asians: A case-control study

BACKGROUND AND AIM

To identify factors associated with non-alcoholic fatty liver disease (NAFLD) in healthy Asian subjects.

METHODS

A propensity score-matched case-control study was designed. To investigate the effects of demographic and clinical factors on the presence of NAFLD, a baseline-category logit model was used. Potential living liver donors with no hepatic steatosis (< 5%: n = 1353, group 1) were considered the baseline category, and subjects with mild (5-33%: n = 724, group 2) and moderate/severe (> 33%: n = 116, group 3) hepatic steatosis were defined as cases. Age and gender were matched between cases and controls, which resulted in 83 matched subjects in each of the three groups. The area of abdominal (visceral and subcutaneous) fat was directly measured in all subjects by unenhanced computed tomography.

RESULTS

Serum aspartate aminotransferase, alanine aminotransferase (ALT), gamma-glutamyltranspeptidase, total cholesterol and triglyceride levels, and visceral fat amount were directly correlated with the grade of hepatic steatosis, and high-density lipoprotein cholesterol levels were inversely correlated with it (all P values < 0.05). In a multivariate model, visceral fat amount was significantly correlated with both mild (group 2) and moderate to severe (group 3) NAFLD, with respective odds ratios (ORs) of 1.03 relative to group 1 (Ps < 0.05). Body mass index (BMI), ALT, and subcutaneous fat were significant predictors of only moderate to severe NAFLD (ORs of 0.54, 1.20, and 1.02, respectively, for group 3 vs group 1; Ps < 0.05).

CONCLUSIONS

Our results indicate that visceral adiposity makes non-obese subjects more susceptible to NAFLD, compared with subcutaneous fat and BMI.

Plasma betatrophin levels in patients with liver cirrhosis

AIM: To investigate the plasma levels of betatrophin in patients with cirrhosis.

METHODS: Forty patients diagnosed at the clinic with liver cirrhosis according to biological, ultrasonographic, or histological criteria were included. The severity of cirrhosis was classified according to Pugh’s modification of Child’s classification and MELD score. Insulin resistance (IR) was assessed by the Homeostasis Model Assessment. A total of 20 patients showed a MELD score higher than 14. The control group consisted in 15 sex-and aged-matched subjects. Fasting blood samples were obtained for subsequent analysis. Serum insulin was determined by Liaison automated immune chemiluminiscence assay (DiaSorin S.p.A.) using a sandwich assay. The sensitivity of the assay was 0.2 μU/mL. The intra and interassay variation coefficients were < 4% and < 10%, respectively. The normal values were between 2 and 17 μU/mL. Human active betatrophin was analyzed by specific quantitative sandwich ELISA (Aviscera Bioscience^®). The sensitivity of the assay was 0.4 ng/mL, and the intra and interassay reproducibility were < 6% and < 10%, respectively.

RESULTS: Plasma betatrophin levels were significantly increased in patients with cirrhosis compared with those in healthy subjects (P = 0.0001). Betatrophin levels were also associated with disease severity, being higher in Child-Pugh C patients compared to Child-Pugh B (P < 0.0005) and in patients who displayed a MELD score higher than 14 points compared to patients with lower punctuation (P = 0.01). In addition, we found a positive correlation between plasma betatrophin levels and the severity of cirrhosis according to Child-Pugh classification (r = 0.53; P < 0.01) or MELD score (r = 0.45; P < 0.01). In the overall cohort, a moderate correlation between serum betatrophin and plasmatic bilirrubin (r = 0.39; P < 0.01) has been observed, as well as an inverse correlation between betatrophin and albumin (r = -0.41; P < 0.01) or prothrombin time (r = -0.44; P <0.01). Moreover, insulin resistance was observed in 82.5% of the cirrhotic patients. In this group of patients, betatrophin levels were significantly higher than those in the group of patients without IR (P < 0.05).

CONCLUSION: Plasma betatrophin is increased in patients with cirrhosis. This increase is related to the severity of cirrhosis, as well as with the emergence of insulin resistance.

Multigenerational Undernutrition Increases Susceptibility to Obesity and Diabetes that Is Not Reversed after Dietary Recuperation

People in developing countries have faced multigenerational undernutrition and are currently undergoing major lifestyle changes, contributing to an epidemic of metabolic diseases, though the underlying mechanisms remain unclear. Using a Wistar rat model of undernutrition over 50 generations, we show that Undernourished rats exhibit low birth-weight, high visceral adiposity (DXA/MRI), and insulin resistance (hyperinsulinemic-euglycemic clamps), compared to age-/gender-matched control rats. Undernourished rats also have higher circulating insulin, homocysteine, endotoxin and leptin levels, lower adiponectin, vitamin B12 and folate levels, and an 8-fold increased susceptibility to Streptozotocin-induced diabetes compared to control rats. Importantly, these metabolic abnormalities are not reversed after two generations of unrestricted access to commercial chow (nutrient recuperation). Altered epigenetic signatures in insulin-2 gene promoter region of Undernourished rats are not reversed by nutrient recuperation, and may contribute to the persistent detrimental metabolic profiles in similar multigenerational undernourished human populations.

Effects of steatosis on hepatic hemodynamics in patients with metabolic syndrome

The aim of our study was to assess the hemodynamic changes in hepatic and splenic circulation using B-mode ultrasonography and color Doppler ultrasonography, in a population of patients with metabolic syndrome divided with respect to the presence or absence of steatosis diagnosed by ultrasonography. One hundred forty-one patients were included in the study. The severity of non-alcoholic fatty liver disease was classified as mild, moderate or severe. Visceral fat thickness, longitudinal diameter of the spleen, diameter of the portal vein, mean maximum portal vein flow velocity, hepatic artery and splenic artery resistivity indexes and hepatic vein flow phasicity were measured. Non-alcoholic fatty liver disease was detected in 114 of 141 patients, with a prevalence of 80.8%. Patients with steatosis had significantly greater diameters of the portal vein, longitudinal diameters of the spleen, visceral fat thickness and hepatic artery and splenic artery resistivity indexes, whereas their portal vein flow velocities were significantly lower. Non-alcoholic fatty liver disease severity correlated positively with diameter of the portal vein, longitudinal diameter of the spleen and visceral fat thickness and negatively with hepatic artery and splenic artery resistivity indexes and reduced hepatic vein flow phasicity. Our patients with metabolic syndrome and non-alcoholic fatty liver disease had a flattened hepatic vein flow phasicity, greater portal vein diameter, reduction in portal vein flow velocity and intrahepatic arterial vasodilation. The vasodilation of the intrahepatic arterial system was likely activated both by the effect of insulin resistance and as a physiologic adaptation to restore hepatic flow. The increase in spleen volume might be related to the organomegaly typical of obese patients.

The Symptoms of Gastroesophageal Reflux Disease Correlate with High Body Mass Index, the Aspartate Aminotransferase/Alanine Aminotransferase Ratio and Insulin Resistance in Japanese Patients with Non-alcoholic Fatty Liver Disease

OBJECTIVE

This study was designed to compare the association between the body mass index (BMI) and symptoms of gastroesophageal reflux disease (GERD) in allegedly normal subjects undergoing regular medical checkups and subjects diagnosed with non-alcoholic fatty liver disease (NAFLD). Additionally, the correlation between the BMI and GERD symptoms was evaluated in subjects with NAFLD.

METHODS

This study included 50 patients with NAFLD and 228 normal subjects evaluated during regular medical checkups. The height, weight, BMI, frequency scale for the symptoms of GERD (FSSG), and serum concentrations of triglycerides and γ-GTP were compared between the two groups. In the NAFLD group, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) concentrations were measured and insulin resistance was calculated using the quantitative insulin sensitivity check index (QUICKI).

RESULTS

The total FSSG score moderately correlated with the BMI in the NAFLD group (r=0.342, p=0.015), but correlated negatively in the control group (r=-0.014, p=0.831). The FSSG score in the NAFLD group also negatively correlated with the AST/ALT ratio (r=-0.319) and insulin resistance calculated using the QUICKI score (r=-0.288). The BMI in the NAFLD group moderately correlated with the acid-reflux related score on the FSSG (r=0.389), and both the AST/ALT ratio (r=-0.344) and QUICKI score (r=-0.330) negatively correlated with the dyspepsia score on the FSSG.

CONCLUSION

Obesity evaluated by the BMI was a significant risk factor for the exacerbation of GERD symptoms in subjects with NAFLD.

Ratio of hepatic arterial flow to recipient body weight predicts biliary complications after deceased donor liver transplantation

OBJECTIVES

Adequate hepatic arterial (HA) flow to the bile duct is essential in liver transplantation. This study was conducted to determine if the ratio of directly measured HA flow to weight is related to the occurrence of biliary complications after deceased donor liver transplantation.

METHODS

A retrospective review of 2684 liver transplants carried out over a 25-year period was performed using data sourced from a prospectively maintained database. Rates of biliary complications (biliary leaks, anastomotic and non-anastomotic strictures) were compared between two groups of patients with HA flow by body weight of, respectively, <5 ml/min/kg (n = 884) and ≥5 ml/min/kg (n = 1800).

RESULTS

Patients with a lower ratio of HA flow to weight had higher body weight (92 kg versus 76 kg; P < 0.001) and lower HA flow (350 ml/min versus 550 ml/min; P < 0.001). A lower ratio of HA flow to weight was associated with higher rates of biliary complications at 2 months, 6 months and 12 months (19.8%, 28.2% and 31.9% versus 14.8%, 22.4% and 25.8%, respectively; P < 0.001).

CONCLUSIONS

A ratio of HA flow to weight of < 5 ml/min/kg is associated with higher rates of biliary complications. This ratio may be a useful parameter for application in the prevention and early detection of biliary complications.

Diabetes mellitus is associated with gastroesophageal variceal bleeding in cirrhotic patients

Diabetes mellitus (DM) has been reported to increase the risk of complications of liver cirrhosis of any etiology and subsequent survival. However, the impact of DM on the development of gastroesophageal variceal bleeding (GEVB) remains unclear. We aimed to elucidate whether DM is an independent risk factor for GEVB among cirrhotic patients. A total of 146 consecutive patients with liver cirrhosis (Child-Pugh Class A, n = 75; Class B, n = 40; and Class C, n = 31) were prospectively enrolled. Data on clinical and biochemical characteristics and history of ascites, GEVB, hepatic encephalopathy, and spontaneous bacterial peritonitis were retrospectively reviewed. Of these 146 patients, 37 (25%) had DM. Patients with DM had significantly higher ratio of Child-Pugh Class B/C (p = 0.043), renal insufficiency (p = 0.002), and history of GEVB (p = 0.006) compared with non-DM patients. GEVB was associated with Child-Pugh Class B/C (p = 0.001), ascites (p = 0.002), hepatic encephalopathy (p = 0.023), and low platelet counts (p < 0.001). Based on stepwise multiple logistic regression analysis, Child-Pugh class B/C [odds ratio (OR) = 4.90, p = 0.003] and DM (OR = 2.99, p = 0.022) were identified as independent predictors of GEVB. In the subgroup analysis, DM significantly correlated with GEVB in patients with Child-Pugh Class A (p = 0.042), but not in patients with Child-Pugh Class B/C (p = 0.128). DM is independently associated with GEVB in cirrhotic patients, especially in those with Child-Pugh Class A.

Prediction of non-alcoholic fatty-liver disease and liver fat content by serum molecular lipids

AIMS/HYPOTHESIS

We examined whether analysis of lipids by ultra-performance liquid chromatography (UPLC) coupled to MS allows the development of a laboratory test for non-alcoholic fatty-liver disease (NAFLD), and how a lipid-profile biomarker compares with the prediction of NAFLD and liver-fat content based on routinely available clinical and laboratory data.

METHODS

We analysed the concentrations of molecular lipids by UPLC-MS in blood samples of 679 well-characterised individuals in whom liver-fat content was measured using proton magnetic resonance spectroscopy ((1)H-MRS) or liver biopsy. The participants were divided into biomarker-discovery (n = 287) and validation (n = 392) groups to build and validate the diagnostic models, respectively.

RESULTS

Individuals with NAFLD had increased triacylglycerols with low carbon number and double-bond content while lysophosphatidylcholines and ether phospholipids were diminished in those with NAFLD. A serum-lipid signature comprising three molecular lipids ('lipid triplet') was developed to estimate the percentage of liver fat. It had a sensitivity of 69.1% and specificity of 73.8% when applied for diagnosis of NAFLD in the validation series. The usefulness of the lipid triplet was demonstrated in a weight-loss intervention study.

CONCLUSIONS/INTERPRETATION

The liver-fat-biomarker signature based on molecular lipids may provide a non-invasive tool to diagnose NAFLD, in addition to highlighting lipid molecular pathways involved in the disease.

Loss of TDAG51 results in mature-onset obesity, hepatic steatosis, and insulin resistance by regulating lipogenesis

Regulation of energy metabolism is critical for the prevention of obesity, diabetes, and hepatic steatosis. Here, we report an important role for the pleckstrin homology-related domain family member, T-cell death-associated gene 51 (TDAG51), in the regulation of energy metabolism. TDAG51 expression was examined during adipocyte differentiation. Adipogenic potential of preadipocytes with knockdown or absence of TDAG51 was assessed. Weight gain, insulin sensitivity, metabolic rate, and liver lipid content were also compared between TDAG51-deficient (TDAG51(-/-)) and wild-type mice. In addition to its relatively high expression in liver, TDAG51 was also present in white adipose tissue (WAT). TDAG51 was downregulated during adipogenesis, and TDAG51(-/-) preadipocytes exhibited greater lipogenic potential. TDAG51(-/-) mice fed a chow diet exhibited greater body and WAT mass, had reduced energy expenditure, displayed mature-onset insulin resistance (IR), and were predisposed to hepatic steatosis. TDAG51(-/-) mice had increased hepatic triglycerides and SREBP-1 target gene expression. Furthermore, TDAG51 expression was inversely correlated with fatty liver in multiple mouse models of hepatic steatosis. Taken together, our findings suggest that TDAG51 is involved in energy homeostasis at least in part by regulating lipogenesis in liver and WAT, and hence, may constitute a novel therapeutic target for the treatment of obesity and IR.

Insulin resistance in patients with cirrhosis and portal hypertension

Insulin resistance (IR) is involved in the pathogenesis of endothelial dysfunction and is also present in patients with cirrhosis. Intrahepatic endothelial dysfunction plays a major role, increasing hepatic vascular resistance and promoting portal hypertension (PH). In addition, β-adrenergic agonists and insulin share several intracellular signaling pathways. Thus IR may influence the response to β-blockers. This study aimed at evaluating the relationship between IR and hepatic hemodynamics in patients with cirrhosis and with the portal pressure response to acute β-blockade. Forty-nine patients with cirrhosis and PH were included. Hepatic and systemic hemodynamics were measured, and IR was estimated by using the updated homeostasis model assessment (HOMA)-2 index. Patients with HOMA-2 > 2.4 were considered IR. In patients with hepatic venous pressure gradient (HVPG) ≥ 10 mmHg) [clinically significant PH (CSPH)], hemodynamic measurements were performed again 20 min after intravenous propranolol. Mean HOMA-2 index was 3 ± 1.4. Fifty-seven percent of patients had IR. A weak correlation between HOMA-2 index and HVPG was observed. Eighty-six percent of patients had CSPH. HOMA-2 index was an independent predictor of CSPH. However, in patients with CSPH, the correlation between HOMA-2 index and HVPG was lost. HVPG, but not IR, predicted the presence of esophageal varices. Response to propranolol was not different between patients with or without IR. In nondiabetic patients with cirrhosis, HOMA-2 index is directly associated with the presence of CSPH and indirectly with varices, but does not allow either grading HVPG or predicting its response to propranolol.

Hepatic left lobe volume is a sensitive index of metabolic improvement in obese women after gastric banding

BACKGROUND

Nonalcoholic fatty liver disease is a common finding in obese subjects. Increasing evidence has been provided suggesting that it represents the hepatic component of the metabolic syndrome.

OBJECTIVE

Aim of this longitudinal study was to evaluate the relationships between several anthropometric measures, including the hepatic left lobe volume (HLLV), and various indicators of the metabolic syndrome in a cohort of severely obese women before and after laparoscopic adjustable gastric banding (LAGB).

STUDY DESIGN AND RESULTS

Seventy-five obese women (mean age 45 ± 10 years and body mass index (BMI) 42.5 ± 4.8 kg m(-2)) underwent LAGB and completed an average (± s.d.) post-surgical follow-up of 24 ± 6 months. Determination of HLLV, subcutaneous and intra-abdominal fat (IAF) was based on ultrasound. The principal component statistical analysis applied to pre-operative measurements, highlighted HLLV as a parameter that clustered with serum insulin, IAF, serum glucose and uric acid, along with triglycerides (TGs), alkaline phosphatase and high-density lipoprotein cholesterol. After LAGB, the average reduction of BMI was 23%, 12% for subcutaneous fat (SCF), 42% for HLLV and 40% for visceral fat. Among body weight, BMI, SCF, IAF and HLLV, reduction of the latter was an independent predictor of reduction of serum transaminases and γ-Glutamyltransferase, glucose, insulin and TGs.

CONCLUSIONS

In severely obese women: (i) HLLV is a sensitive indicator of ectopic fat deposition, clustering with parameters defining the metabolic syndrome; (ii) weight loss achieved by LAGB is associated with a reduction of liver volume as estimated by HLLV; (iii) among various anthropometric parameters measured, reduction of HLLV that follows LAGB represents the best single predictor of improvement of various cardiometabolic risk factors.

Idiopathic noncirrhotic portal hypertension

Idiopathic noncirrhotic portal hypertension (INCPH) is characterized by an increased portal venous pressure gradient in the absence of a known cause of liver disease and portal vein thrombosis. In contrast to the high prevalence of this disorder in India, INCPH is a rare disease in the Western world. The etiology of INCPH can be divided in five categories: chronic infections, exposure to medication or toxins, thrombophilia, immunological disorders, and genetic disorders. Multifactorial etiology can also be encountered. Chronic abdominal infection is incriminated as the most important etiological factor in Eastern patients and thrombophilia in Western patients. The majority of patients with INCPH initially present with signs or complications of portal hypertension (mainly variceal bleeding and splenomegaly). These patients usually have preserved liver function. Liver function impairment occurs mainly in the context of intercurrent conditions. Patients with INCPH are often clinically and radiologically misdiagnosed as liver cirrhosis, so that a liver biopsy is indispensable to discriminate cirrhosis from INCPH. Histopathological characteristics of INCPH are heterogeneous, demonstrating overlap between several pathological entities (e.g., hepatoportal sclerosis, nodular regenerative hyperplasia, and incomplete septal cirrhosis). Even though hemodynamical changes in INCPH patients are not comparable to those in cirrhotics, prophylaxis and treatment of variceal bleeding are recommended to be similar. Anticoagulation therapy must be considered only in patients who develop portal vein thrombosis. INCPH has been considered a disorder with a relatively benign disease course. However, liver failure, hepatic encephalopathy, and hepatopulmonary syndrome can occur and are considered indications for liver transplantation.

Cafeteria diet is a robust model of human metabolic syndrome with liver and adipose inflammation: comparison to high-fat diet

Obesity has reached epidemic proportions worldwide and reports estimate that American children consume up to 25% of calories from snacks. Several animal models of obesity exist, but studies are lacking that compare high-fat diets (HFD) traditionally used in rodent models of diet-induced obesity (DIO) to diets consisting of food regularly consumed by humans, including high-salt, high-fat, low-fiber, energy dense foods such as cookies, chips, and processed meats. To investigate the obesogenic and inflammatory consequences of a cafeteria diet (CAF) compared to a lard-based 45% HFD in rodent models, male Wistar rats were fed HFD, CAF or chow control diets for 15 weeks. Body weight increased dramatically and remained significantly elevated in CAF-fed rats compared to all other diets. Glucose- and insulin-tolerance tests revealed that hyperinsulinemia, hyperglycemia, and glucose intolerance were exaggerated in the CAF-fed rats compared to controls and HFD-fed rats. It is well-established that macrophages infiltrate metabolic tissues at the onset of weight gain and directly contribute to inflammation, insulin resistance, and obesity. Although both high fat diets resulted in increased adiposity and hepatosteatosis, CAF-fed rats displayed remarkable inflammation in white fat, brown fat and liver compared to HFD and controls. In sum, the CAF provided a robust model of human metabolic syndrome compared to traditional lard-based HFD, creating a phenotype of exaggerated obesity with glucose intolerance and inflammation. This model provides a unique platform to study the biochemical, genomic and physiological mechanisms of obesity and obesity-related disease states that are pandemic in western civilization today.