Postprandial effects of dark chocolate on portal hypertension in patients with cirrhosis: results of a phase 2, double-blind, randomized controlled trial

Mechanisms and implications of recompensation in cirrhosis

Decompensated cirrhosis has long been considered the irreversible end stage of liver disease, characterised by further decompensating events until death or liver transplantation. However, the observed clinical improvements after effective antiviral treatments for HBV and HCV and after sustained alcohol abstinence have changed this paradigm, leading to the concept of "recompensation" of cirrhosis. Recompensation of cirrhosis was recently defined by Baveno VII as (i) cure of the primary liver disease aetiology; (ii) disappearance of signs of decompensation (ascites, encephalopathy and portal hypertensive bleeding) off therapy; and (iii) stable improvement of liver function tests (bilirubin, international normalised ratio and albumin). Achieving these recompensation criteria is linked to a significant survival benefit. However, apart from aetiological therapies, no interventions/treatments that facilitate recompensation are available, the molecular mechanisms underlying recompensation remain incompletely understood, and early predictors of recompensation are lacking. Moreover, current recompensation criteria are based on expert opinion and may be refined in the future. Herein, we review the available evidence on cirrhosis recompensation, provide guidance on the clinical management of recompensated patients and discuss future challenges related to cirrhosis recompensation.

Pathophysiology and therapeutic options for cirrhotic portal hypertension

Portal hypertension represents the primary non-neoplastic complication of liver cirrhosis and has life-threatening consequences, such as oesophageal variceal bleeding, ascites, and hepatic encephalopathy. Portal hypertension occurs due to increased resistance of the cirrhotic liver vasculature to portal blood flow and is further aggravated by the hyperdynamic circulatory syndrome. Existing knowledge indicates that the profibrogenic phenotype acquired by sinusoidal cells is the initial factor leading to increased hepatic vascular tone and fibrosis, which cause increased vascular resistance and portal hypertension. Data also suggest that the phenotype of hepatic cells could be further impaired due to the altered mechanical properties of the cirrhotic liver itself, creating a deleterious cycle that worsens portal hypertension in the advanced stages of liver disease. In this Review, we discuss recent discoveries in the pathophysiology and treatment of cirrhotic portal hypertension, a condition with few pharmacological treatment options.

5-MTHF enhances the portal pressure reduction achieved with propranolol in patients with cirrhosis: A randomized placebo-controlled trial

BACKGROUND & AIMS

β-blockers reduce hepatic venous pressure gradient (HVPG) by decreasing portal inflow, with no reduction in intrahepatic vascular resistance. 5-Methyltetrahydrofolate (5-MTHF) can prevent oxidative loss of tetrahydrobiopterin (BH4), a cofactor for endothelial nitric oxide synthase coupling. It also converts homocysteine (tHcy) into methionine and enables the degradation of asymmetric dimethylarginine (ADMA), an inhibitor of endothelial nitric oxide synthase. The aim of this study was to evaluate the effects of 5-MTHF in combination with propranolol on HVPG and nitric oxide bioavailability markers in patients with cirrhosis and portal hypertension.

METHOD

Sixty patients with cirrhosis and HVPG ≥12 mmHg were randomized 1:1 to receive treatment with 5-MTHF+propranolol or placebo+propranolol for 90 days under double-blind conditions. HVPG and markers of nitric oxide bioavailability (BH4, ADMA and tHcy) were measured again at the end of treatment.

RESULTS

Groups were similar in terms of baseline clinical and hemodynamic data and nitric oxide bioavailability markers. HVPG decreased in both groups, but the magnitude of the change was significantly greater in the group treated with 5-MTHF+propranolol compared to placebo+propranolol (percentage decrease, 20 [29-9] vs. 12.5 [22-0], p = 0.028), without differences in hepatic blood flow. At the end of treatment, 5-MTHF+propranolol (vs. placebo+propranolol) was associated with higher BH4 (1,101.4 ± 1,413.3 vs. 517.1 ± 242.8 pg/ml, p <0.001), lower ADMA (109.3 ± 52.7 vs. 139.9 ± 46.7 μmol/L, p = 0.027) and lower tHcy (μmol/L, 11.0 ± 4.6 vs. 15.4 ± 7.2 μmol/L, p = 0.010) plasma levels.

CONCLUSION

In patients with cirrhosis and portal hypertension, 5-MTHF administration significantly enhanced the HVPG reduction achieved with propranolol. This effect appears to be mediated by improved nitric oxide bioavailability in the hepatic microcirculation.

CLINICAL TRIAL EUDRACT NUMBER

2014-002018-21.

IMPACT AND IMPLICATIONS

Currently, the pharmacological prevention of cirrhosis complications due to portal hypertension, such as esophageal varices rupture, is based on the use of β-blockers, but some patients still present with acute variceal bleeding, mainly due to an insufficient reduction of portal pressure. In this study, we sought to demonstrate that the addition of folic acid to β-blockers is more effective in reducing portal pressure than β-blockers alone. This finding could represent the basis for validation studies in larger cohorts, which could impact the future prophylactic management of variceal bleeding in cirrhosis. Enhancing the benefit of β-blockers with a safe, accessible, cost-effective drug could improve clinical outcomes in cirrhosis, which in turn could translate into a reduction in the rates and costs of hospitalization, and ultimately into improved survival.

Emerging Therapeutic Targets for Portal Hypertension

Purpose of Review

Portal hypertension is responsible of the main complications of cirrhosis, which carries a high mortality. Recent treatments have improved prognosis, but this is still far from ideal. This paper reviews new potential therapeutic targets unveiled by advances of key pathophysiologic processes.

Recent Findings

Recent research highlighted the importance of suppressing etiologic factors and a safe lifestyle and outlined new mechanisms modulating portal pressure. These include intrahepatic abnormalities linked to inflammation, fibrogenesis, vascular occlusion, parenchymal extinction, and angiogenesis; impaired regeneration; increased hepatic vascular tone due to sinusoidal endothelial dysfunction with insufficient NO availability; and paracrine liver cell crosstalk. Moreover, pathways such as the gut-liver axis modulate splanchnic vasodilatation and systemic inflammation, exacerbate liver fibrosis, and are being targeted by therapy. We have summarized studies of new agents addressing these targets.

Summary

New agents, alone or in combination, allow acting in complementary mechanisms offering a more profound effect on portal hypertension while simultaneously limiting disease progression and favoring regression of fibrosis and of cirrhosis. Major changes in treatment paradigms are anticipated.

Investigational drugs in early clinical development for portal hypertension

INTRODUCTION

Advanced chronic liver disease is considered a reversible condition after removal of the primary aetiological factor. This has led to a paradigm shift in which portal hypertension (PH) is a reversible complication of cirrhosis. The pharmacologic management of PH is centered on finding targets to modify the natural history of cirrhosis and PH.

AREAS COVERED

This paper offers an overview of the use of pharmacological strategies in early clinical development that modify PH. Papers included were selected from searching clinical trials sites and PubMed from the last 10 years.

EXPERT OPINION

A paradigm shift has generated a new concept of PH in cirrhosis as a reversible complication of a potentially curable disease. Decreasing portal pressure to prevent decompensation and further complications of cirrhosis that may lead liver transplantation or death is a goal. Therapeutic strategies also aspire achieve total or partial regression of fibrosis thus eliminating the need for treatment or screening of PH.

Intercellular crosstalk of liver sinusoidal endothelial cells in liver fibrosis, cirrhosis and hepatocellular carcinoma

Intercellular crosstalk among various liver cells plays an important role in liver fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). Capillarization of liver sinusoidal endothelial cells (LSECs) precedes fibrosis and accumulating evidence suggests that the crosstalk between LSECs and other liver cells is critical in the development and progression of liver fibrosis. LSECs dysfunction, a key event in the progression from fibrosis to cirrhosis, and subsequently obstruction of hepatic sinuses and increased intrahepatic vascular resistance (IHVR) contribute to development of portal hypertension (PHT) and cirrhosis. More importantly, immunosuppressive tumor microenvironment (TME), which is closely related to the crosstalk between LSECs and immune liver cells like CD8+ T cells, promotes advances tumorigenesis, especially HCC. However, the connections within the crosstalk between LSECs and other liver cells during the progression from liver fibrosis to cirrhosis to HCC have yet to be discussed. In this review, we first summarize the current knowledge of how different crosstalk between LSECs and other liver cells, including hepatocytes, hepatic stellate cells (HSCs), macrophoges, immune cells in liver and extra cellular matrix (ECM) contribute to the physiological function and the progrssion from liver fibrosis to cirrhosis, or even to HCC. Then we examine current treatment strategies for LSECs crosstalk in liver fibrosis, cirrhosis and HCC.

Interaction of Microbiome, Diet, and Hospitalizations Between Brazilian and American Patients With Cirrhosis

BACKGROUND & AIMS

Gut microbiota are affected by diet, country, and affect outcomes in cirrhosis. Western diets are associated with dysbiosis. Comparisons with other diets is needed. We aimed to compare cirrhosis patients from the United States with cirrhosis patients from Brazil with respect to diet, microbiota, and impact on hospitalizations.

METHODS

Healthy controls and compensated/decompensated outpatients with cirrhosis from the United States and Brazil underwent dietary recall and stool for 16S ribosomal RNA sequencing. Demographics and medications/cirrhosis details were compared within and between countries. Patients with cirrhosis were followed up for 90-day hospitalizations. Regression for Shannon diversity was performed within cirrhosis. Regression for hospitalizations adjusting for clinical and microbial variables was performed.

RESULTS

Model for end-stage liver disease (MELD), diabetes, ascites, and albumin were similar, but more Americans were men, had higher hepatic encephalopathy and alcohol/hepatitis C etiology, with lower nonalcoholic fatty liver disease than Brazilians. Brazilians had higher cereal, rice, and yogurt intake vs the United States. As disease progressed, cereals, rice/beans, coffee, and chocolate consumption was reduced. Microbial diversity was higher in Brazilians. Within cirrhosis, high diversity was related to Brazilian origin (P < .0001), age, and cereal intake (P = .05), while high MELD scores (P = .009) and ascites (P = .05) did the reverse. Regardless of stage, beneficial taxa and taxa associated with grant and yogurt intake were higher (Ruminococcaceae, Christensenellacae, and Prevotellaceae), while pathobionts (Porphyromonadaceae, Sutterellaceae, and Enterobacteriaceae) were lower in Brazilians. More Americans were hospitalized vs Brazilians (P = .002). On regression, MELD (P = .001) and ascites (P = .001) were associated with higher hospitalizations, while chocolate (P = .03) and Brazilian origin (P = .001) were associated with lower hospitalizations with/without microbiota inclusion.

CONCLUSIONS

Brazilian cirrhotic patients follow a diet richer in cereals and yogurt, which is associated with higher microbial diversity and beneficial microbiota and could contribute toward lower hospitalizations compared with a Western-diet-consuming American cohort.

The Potential of Dietary Bioactive Compounds against SARS-CoV-2 and COVID-19-Induced Endothelial Dysfunction

COVID-19 is an endothelial disease. All the major comorbidities that increase the risk for severe SARS-CoV-2 infection and severe COVID-19 including old age, obesity, diabetes, hypertension, respiratory disease, compromised immune system, coronary artery disease or heart failure are associated with dysfunctional endothelium. Genetics and environmental factors (epigenetics) are major risk factors for endothelial dysfunction. Individuals with metabolic syndrome are at increased risk for severe SARS-CoV-2 infection and poor COVID-19 outcomes and higher risk of mortality. Old age is a non-modifiable risk factor. All other risk factors are modifiable. This review also identifies dietary risk factors for endothelial dysfunction. Potential dietary preventions that address endothelial dysfunction and its sequelae may have an important role in preventing SARS-CoV-2 infection severity and are key factors for future research to address. This review presents some dietary bioactives with demonstrated efficacy against dysfunctional endothelial cells. This review also covers dietary bioactives with efficacy against SARS-CoV-2 infection. Dietary bioactive compounds that prevent endothelial dysfunction and its sequelae, especially in the gastrointestinal tract, will result in more effective prevention of SARS-CoV-2 variant infection severity and are key factors for future food research to address.

Chronic liver disease and oxidative stress - a narrative review

Introduction: Oxidative stress underlies the pathophysiology of various etiologies of chronic liver disease and contributes to the development of hepatocarcinogenesis.Areas covered: This review focuses on the impact of oxidative stress in various etiologies of chronic liver disease such as alcoholic liver disease (ALD), nonalcoholic steatohepatitis (NASH), hepatitis B virus (HBV), and hepatitis C virus (HCV) infection. The efficacy of antioxidants in laboratory, animal, and clinical studies in chronic liver disease is also reviewed.Expert opinion: Currently, there are limited targeted pharmacotherapeutics for NASH and no pharmacotherapeutics for ALD and antioxidant supplementation may be useful in these conditions to improve liver function and reverse fibrosis. Antioxidants may also be used in patients with HBV or HCV infection to supplement antiviral therapies. Specific genotypes of antioxidant and prooxidant genes render patients more susceptible to liver cirrhosis and hepatocellular carcinoma while other individual characteristics like age, genotype, and metabolomic profiling can influence the efficacy of antioxidants on CLD. More research needs to be done to establish the safety, efficacy, and dosage of antioxidants and to establish the ideal patient profile that will benefit the most from antioxidant treatment.

Role of liver sinusoidal endothelial cells in liver diseases

Liver sinusoidal endothelial cells (LSECs) form the wall of the hepatic sinusoids. Unlike other capillaries, they lack an organized basement membrane and have cytoplasm that is penetrated by open fenestrae, making the hepatic microvascular endothelium discontinuous. LSECs have essential roles in the maintenance of hepatic homeostasis, including regulation of the vascular tone, inflammation and thrombosis, and they are essential for control of the hepatic immune response. On a background of acute or chronic liver injury, LSECs modify their phenotype and negatively affect neighbouring cells and liver disease pathophysiology. This Review describes the main functions and phenotypic dysregulations of LSECs in liver diseases, specifically in the context of acute injury (ischaemia-reperfusion injury, drug-induced liver injury and bacterial and viral infection), chronic liver disease (metabolism-associated liver disease, alcoholic steatohepatitis and chronic hepatotoxic injury) and hepatocellular carcinoma, and provides a comprehensive update of the role of LSECs as therapeutic targets for liver disease. Finally, we discuss the open questions in the field of LSEC pathobiology and future avenues of research.

Regression of portal hypertension: underlying mechanisms and therapeutic strategies

Portal hypertension is the main non-neoplastic complication of chronic liver disease, being the cause of important life-threatening events including the development of ascites or variceal bleeding. The primary factor in the development of portal hypertension is a pathological increase in the intrahepatic vascular resistance, due to liver microcirculatory dysfunction, which is subsequently aggravated by extra-hepatic vascular disturbances including elevation of portal blood inflow. Evidence from pre-clinical models of cirrhosis has demonstrated that portal hypertension and chronic liver disease can be reversible if the injurious etiological agent is removed and can be further promoted using pharmacological therapy. These important observations have been partially demonstrated in clinical studies. This paper aims at providing an updated review of the currently available data regarding spontaneous and drug-promoted regression of portal hypertension, paying special attention to the clinical evidence. It also considers pathophysiological caveats that highlight the need for caution in establishing a new dogma that human chronic liver disease and portal hypertension is reversible.

Primary prevention of bleeding from esophageal varices in patients with liver cirrhosis: An update and review of the literature

All patients with liver cirrhosis and portal hypertension should be stratified by risk groups to individualize different therapeutic strategies to increase the effectiveness of treatment. In this regard, the development of primary prophylaxis of variceal bleeding and its management according to the severity of portal hypertension may be promising. This paper is to describe the modern principles of primary prophylaxis of esophageal variceal bleeding in patients with liver cirrhosis. The PubMed and EMbase databases, Web of Science, Google Scholar, and the Cochrane Database of Systematic Reviews were used to search for relevant publications from 1999 to 2019. The results suggested that depending on the severity of portal hypertension, patients with cirrhosis should be divided into those who need preprimary prophylaxis, which aims to prevent the formation of esophageal varices, and those who require measures that aim to prevent esophageal variceal bleeding. In subclinical portal hypertension, therapy should be etiological and pathogenetic. Cirrhosis with clinically significant portal hypertension should receive nonselective β-blockers if they have small esophageal varices and risk factors for variceal bleeding. Nonselective β-blockers are the first-line drugs for the primary prevention of bleeding from medium to large-sized esophageal varices. Endoscopic band ligation is indicated for the patients who are intolerant to nonselective β-blockers or in the case of contraindications to pharmacological therapy. In summary, the stratification of cirrhotic patients by the severity of portal hypertension and an individual approach to the choice of treatment may increase the effectiveness of therapy as well as improve survival rate of these patients.

Cirrhotic portal hypertension: From pathophysiology to novel therapeutics

Portal hypertension and bleeding from gastroesophageal varices is the major cause of morbidity and mortality in patients with cirrhosis. Portal hypertension is initiated by increased intrahepatic vascular resistance and a hyperdynamic circulatory state. The latter is characterized by a high cardiac output, increased total blood volume and splanchnic vasodilatation, resulting in increased mesenteric blood flow. Pharmacological manipulation of cirrhotic portal hypertension targets both the splanchnic and hepatic vascular beds. Drugs such as angiotensin converting enzyme inhibitors and angiotensin II type receptor 1 blockers, which target the components of the classical renin angiotensin system (RAS), are expected to reduce intrahepatic vascular tone by reducing extracellular matrix deposition and vasoactivity of contractile cells and thereby improve portal hypertension. However, these drugs have been shown to produce significant off-target effects such as systemic hypotension and renal failure. Therefore, the current pharmacological mainstay in clinical practice to prevent variceal bleeding and improving patient survival by reducing portal pressure is non-selective -blockers (NSBBs). These NSBBs work by reducing cardiac output and splanchnic vasodilatation but most patients do not achieve an optimal therapeutic response and a significant proportion of patients are unable to tolerate these drugs. Although statins, used alone or in combination with NSBBs, have been shown to improve portal pressure and overall mortality in cirrhotic patients, further randomized clinical trials are warranted involving larger patient populations with clear clinical end points. On the other hand, recent findings from studies that have investigated the potential use of the blockers of the components of the alternate RAS provided compelling evidence that could lead to the development of drugs targeting the splanchnic vascular bed to inhibit splanchnic vasodilatation in portal hypertension. This review outlines the mechanisms related to the pathogenesis of portal hypertension and attempts to provide an update on currently available therapeutic approaches in the management of portal hypertension with special emphasis on how the alternate RAS could be manipulated in our search for development of safe, specific and effective novel therapies to treat portal hypertension in cirrhosis.

Pharmacological management of portal hypertension and its complications in children: lessons from adults and opportunities for the future

INTRODUCTION

Portal hypertension (PHT) and its complications in children are thought to be distinct from adult PHT in several areas, including the underlying bio-physiology of a child in which PHT develops, but also because of the pediatric-specific etiologies that drive disease progression. And yet pharmacologic approaches to PHT in children are mainly based on adult data, modified for pediatric practice. This reality has been driven by a lack of data specific to children.

AREAS COVERED

The authors discuss current therapeutic approaches to PHT in children, including management of acute gastrointestinal variceal bleed, pharmacotherapy in prophylaxis, and established and emerging therapies to combat systemic co-morbidities that result from PHT. The few areas where pediatric-specific data exist are highlighted and the many gaps in knowledge that remain unresolved are underscored.

EXPERT OPINION

Despite decades of experience, optimal management of pediatric PHT remains undefined. In large part, this can be directly linked to a lack of basic understanding related to the unique pathophysiology and natural history that defines PHT in children. As a result, meaningful research into the utility and effectiveness of pharmacotherapy in children with PHT remains in its infancy. Large, multi-center, prospective studies will be needed to begin to establish an infrastructure on which a pediatric-specific research agenda can be built.

The sweet side of dark chocolate for chronic kidney disease patients

Chocolate is a widely appreciated foodstuff with historical appreciation as a food from the gods. In addition to its highly palatable taste, it is a rich source of (poly)phenolics, which have several proposed salutogenic effects, including neuroprotective anti-inflammatory, anti-oxidant and cardioprotective capabilities. Despite the known benefits of this ancient foodstuff, there is a paucity of information on the effects of chocolate in the context of chronic kidney disease (CKD). This review focusses on the potential salutogenic contribution of chocolate intake, to mitigate inflammatory and oxidative burden in CKD, its potential, for cardiovascular protection and on the maintenance of diversity in gut microbiota, as well as clinical perspectives, on regular chocolate intake by CKD patients.

Cognition and hospitalizations are linked with salivary and faecal microbiota in cirrhosis cohorts from the USA and Mexico

BACKGROUND & AIMS

Gut microbiota are affected by diet and ethnicity, which impacts cognition and hospitalizations in cirrhosis.

AIM

Study interactions of diet with microbiota and impact on hospitalizations and cognition in American and Mexican cohorts.

METHODS

Controls and age-balanced patients with compensated/decompensated cirrhosis were included and followed for 90-day hospitalizations. A subset underwent minimal hepatic encephalopathy (MHE) testing. Parameters such as dietary, salivary and faecal microbiota (diversity, taxa analysis, cirrhosis dysbiosis ratio CDR:high = good) between/within countries were analysed. Regression analyses for hospitalizations and MHE were performed.

RESULTS

In all, 275 age-balanced subjects (133 US [40 Control, 50 Compensated, 43 Decompensated] and 142 Mexican [41 Control, 49 Compensated, 52 Decompensated]) were enrolled. MELD/cirrhosis severity was comparable. Diet showed lower protein and animal fat intake in all decompensated patients, but this was worse in Mexico. Diversity was lower in stool and saliva in decompensated patients, and worse in Mexican cohorts. Prevotellaceae were lower in decompensated cirrhosis, particularly those with lower animal fat/protein consumption across countries. Hospitalizations were higher in Mexico vs the USA (26% vs 14%, P = .04). On regression, Prevotellaceae, Ruminococcaceae and Lachnospiraceae lowered hospitalization risk independent of MELD and ascites. MHE testing was performed in 120 (60/country and 20/subgroup) subjects and MHE rate was similar. MELD and decompensation increased while CDR and Prevotellaceae decreased the risk of MHE.

CONCLUSIONS

Changes in diet and microbiota, especially related to animal fat and protein intake and Prevotellaceae, are associated with MHE and hospitalizations in Mexican patients with cirrhosis compared to an American cohort. Nutritional counselling to increase protein intake in cirrhosis could help prevent these hospitalizations.

Pharmacologic Management of Portal Hypertension

Terlipressin, somatostatin, or octreotide are recommended as pharmacologic treatment of acute variceal hemorrhage. Nonselective β-blockers decrease the risk of variceal hemorrhage and hepatic decompensation, particularly in those 30% to 40% of patients with good hemodynamic response. Carvedilol, statins, and anticoagulants are promising agents in the management of portal hypertension. Recent advances in the pharmacologic treatment of portal hypertension have mainly focused on modifying an increased intrahepatic resistance through nitric oxide and/or modulation of vasoactive substances. Several novel pharmacologic agents for portal hypertension are being evaluated in humans.

Hepatic microcirculation and mechanisms of portal hypertension

The liver microcirculatory milieu, mainly composed of liver sinusoidal endothelial cells (LSECs), hepatic stellate cells (HSCs) and hepatic macrophages, has an essential role in liver homeostasis, including in preserving hepatocyte function, regulating the vascular tone and controlling inflammation. Liver microcirculatory dysfunction is one of the key mechanisms that promotes the progression of chronic liver disease (also termed cirrhosis) and the development of its major clinical complication, portal hypertension. In the present Review, we describe the current knowledge of liver microcirculatory dysfunction in cirrhotic portal hypertension and appraise the preclinical models used to study the liver circulation. We also provide a comprehensive summary of the promising therapeutic options to target the liver microvasculature in cirrhosis.

Advances in therapeutic options for portal hypertension

Portal hypertension represents one of the major clinical consequences of chronic liver disease, having a deep impact on patients' prognosis and survival. Its pathophysiology defines a pathological increase in the intrahepatic vascular resistance as the primary factor in its development, being subsequently aggravated by a paradoxical increase in portal blood inflow. Although extensive preclinical and clinical research in the field has been developed in recent decades, no effective treatment targeting its primary mechanism has been defined. The present review critically summarizes the current knowledge in portal hypertension therapeutics, focusing on those strategies driven by the disease pathophysiology and underlying cellular mechanisms.

Diet affects gut microbiota and modulates hospitalization risk differentially in an international cirrhosis cohort

The relative ranking of cirrhosis-related deaths differs between high-/middle-income countries. Gut microbiome is affected in cirrhosis and is related to diet. Our aim was to determine the effect of differing dietary habits on gut microbiota and clinical outcomes. Outpatient compensated/decompensated patients with cirrhosis and controls from Turkey and the United States underwent dietary and stool microbiota analysis. Patients with cirrhosis were followed till 90-day hospitalizations. Shannon diversity and multivariable determinants (Cox and binary logistic) of microbial diversity and hospitalizations were studied within/between groups. Two hundred ninety-six subjects (157 U.S.: 48 controls, 59 compensated, 50 decompensated; 139 Turkey: 46 controls, 50 compensated, 43 decompensated) were included. Patients with cirrhosis between cohorts had similar Model for End-Stage Liver Disease (MELD) scores. American patients with cirrhosis had more men, greater rifaximin/lactulose use, and higher hepatitis C/alcohol etiologies. Coffee intake was higher in Americans whereas tea, fermented milk, and chocolate intake were higher in Turkey. The entire Turkish cohort had a significantly higher microbial diversity than Americans, which did not change between their controls and patients with cirrhosis. In contrast, microbial diversity changed in the U.S.-based cohort and was the lowest in decompensated patients. Coffee, tea, vegetable, chocolate, and fermented milk intake predicted a higher diversity whereas MELD score, lactulose use, and carbonated beverage use predicted a lower microbial diversity. The Turkish cohort had a lower risk of 90-day hospitalizations. On Cox and binary logistic regression, microbial diversity was protective against 90-day hospitalizations, along with coffee/tea, vegetable, and cereal intake.

CONCLUSION

In this study of patients with cirrhosis and healthy controls from the United States and Turkey, a diet rich in fermented milk, vegetables, cereals, coffee, and tea is associated with a higher microbial diversity. Microbial diversity was associated with an independently lower risk of 90-day hospitalizations. (Hepatology 2018;68:234-247).

Predictors of clinical outcomes in cirrhosis patients

PURPOSE OF REVIEW

The current review aims to explain the different systems available to clinicians for predicting clinical outcomes in patients with cirrhosis.

RECENT FINDINGS

Cirrhosis is the final stage of chronic liver disease and is associated with high morbidity and mortality. The most commonly utilized tools to predict outcomes in patients with cirrhosis include the following: assessing severity of portal hypertension using hepatic venous pressure gradient (HVPG) measurements, using scoring systems such as the Model for End-stage Liver Disease (MELD) and Child-Pugh-Turcotte (CPT) scores, and recently, clinical staging systems based on cirrhosis-related clinical complications. Assessing portal pressure with HVPG measurements provides valuable prognostic information, yet is costly, time-consuming, and invasive. MELD and CPT scores can be calculated quickly and not only assess liver function, but also yield predictive information. However, they represent only one point in time, and do not take into account the full clinical picture. Clinical staging systems have traditionally been focused on compensated and decompensated stages, with newer models assessing the influence of cirrhosis-related complications. However, these are not commonly utilized.

SUMMARY

Predicting clinical outcomes in patients with cirrhosis is challenging, and is likely best accomplished with a combination of objective data (such as MELD and HVPG provide) in addition to the clinical course of cirrhosis.

Novel treatment options for portal hypertension

Portal hypertension is most frequently associated with cirrhosis and is a major driver for associated complications, such as variceal bleeding, ascites or hepatic encephalopathy. As such, clinically significant portal hypertension forms the prelude to decompensation and impacts significantly on the prognosis of patients with liver cirrhosis. At present, non-selective β-blockers, vasopressin analogues and somatostatin analogues are the mainstay of treatment but these strategies are far from satisfactory and only target splanchnic hyperemia. In contrast, safe and reliable strategies to reduce the increased intrahepatic resistance in cirrhotic patients still represent a pending issue. In recent years, several preclinical and clinical trials have focused on this latter component and other therapeutic avenues. In this review, we highlight novel data in this context and address potentially interesting therapeutic options for the future.

How to Face Chronic Liver Disease: The Sinusoidal Perspective

Liver microcirculation plays an essential role in the progression and aggravation of chronic liver disease. Hepatic sinusoid environment, mainly composed by hepatocytes, liver sinusoidal endothelial cells, Kupffer cells, and hepatic stellate cells, intimately cooperate to maintain global liver function and specific phenotype of each cell type. However, continuous liver injury significantly deregulates liver cells protective phenotype, leading to parenchymal and non-parenchymal dysfunction. Recent data have enlightened the molecular processes that mediate hepatic microcirculatory injury, and consequently, opened the possibility to develop new therapeutic strategies to ameliorate liver circulation and viability. The present review summarizes the main cellular components of the hepatic sinusoid, to afterward focus on non-parenchymal cells phenotype deregulation due to chronic injury, in the specific clinical context of liver cirrhosis and derived portal hypertension. Finally, we herein detail new therapies developed at the bench-side with high potential to be translated to the bedside.

Advances in the treatment of portal hypertension in cirrhosis

Non-selective beta-blockers and handling of esophageal varices has been key elements in the treatment of portal hypertension in recent decades. Liver vein catheterization has been essential in diagnosis and monitoring of portal hypertension, but ongoing needs for noninvasive tools has led to research in areas of both biomarkers, and transient elastography, which displays promising results in discerning clinically significant portal hypertension. Novel research into the areas of hepatic stellate cell function and the dynamic components of portal hypertension has revealed promising areas of treatment modalities, targeting intestinal decontamination, angiogenesis, inflammation and oxidative stress. Future studies may reveal if these initiatives lead to developments of new drugs for treatment of portal hypertension.

Emerging therapies for portal hypertension in cirrhosis

INTRODUCTION

Counteracting splanchnic vasodilatation and increased portal-collateral blood flow has been the mainstay for the treatment of portal hypertension (PH) over the past three decades. However, there is still large room for improvement in the treatment of PH.

AREAS COVERED

The basic mechanism leading to portal hypertension is the increased hepatic vascular resistance to portal blood flow caused by liver structural abnormalities inherent to cirrhosis and increased hepatic vascular tone. Molecules modulating microvascular dysfunction which have undergone preclinical and clinical trials are summarized, potential drug development issues are addressed, and situations relevant to design of clinical trials are considered.

EXPERT OPINION

Experimental and clinical evidence indicates that molecules modulating liver microvascular dysfunction may allow for 30-40% reduction in portal pressure. Several agents could be utilized in the earlier stages of cirrhosis (antifibrotics, antiangiogenics, etiological therapies) may allow reduction of fibrosis and halt progression of PH. This 'nip at the bud' policy, by combining therapies with existing agents used in advanced phase of cirrhosis and novel agents which could be used in early phase of cirrhotic spectrum, which are likely to hit the market soon would be the future strategy for PH therapy.

[Aspects of pathogenetc pharmacotherapy for portal hypertension in liver cirrhosis]

The review of literature considers the principles of medical treatment for portal hypertension in liver cirrhosis, which are based on the current views of its development mechanisms. It describes both current pharmacotherapy methods for portal hypertension and drugs, the efficacy of which is being investigated.

Cocoa extract intake for 4 weeks reduces postprandial systolic blood pressure response of obese subjects, even after following an energy-restricted diet

Background

Cardiometabolic profile is usually altered in obesity. Interestingly, the consumption of flavanol-rich foods might be protective against those metabolic alterations.

Objective

To evaluate the postprandial cardiometabolic effects after the acute consumption of cocoa extract before and after 4 weeks of its daily intake. Furthermore, the bioavailability of cocoa extract was investigated.

Design

Twenty-four overweight/obese middle-aged subjects participated in a 4-week intervention study. Half of the volunteers consumed a test meal enriched with 1.4 g of cocoa extract (415 mg flavanols), while the rest of the volunteers consumed the same meal without the cocoa extract (control group). Glucose and lipid profile, as well as blood pressure and cocoa metabolites in plasma, were assessed before and at 60, 120, and 180 min post-consumption, at the beginning of the study (Postprandial 1) and after following a 4-week 15% energy-restricted diet including meals containing or not containing the cocoa extract (Postprandial 2).

Results

In the Postprandial 1 test, the area under the curve (AUC) of systolic blood pressure (SBP) was significantly higher in the cocoa group compared with the control group (p=0.007), showing significant differences after 120 min of intake. However, no differences between groups were observed at Postprandial 2. Interestingly, the reduction of postprandial AUC of SBP (AUC_Postprandial 2-AUC_Postprandial 1) was higher in the cocoa group (p=0.016). Furthermore, cocoa-derived metabolites were detected in plasma of the cocoa group, while the absence or significantly lower amounts of metabolites were found in the control group.

Conclusions

The daily consumption of cocoa extract within an energy-restricted diet for 4 weeks resulted in a greater reduction of postprandial AUC of SBP compared with the effect of energy-restricted diet alone and independently of body weight loss. These results suggest the role of cocoa flavanols on postprandial blood pressure homeostasis.

Pathophysiology and a Rational Basis of Therapy

Portal hypertension is a common complication of chronic liver disease. Its relevance comes from the fact that it determines most complications leading to death or liver transplantation in patients with cirrhosis of the liver: bleeding from esophageal or gastric varices, ascites and renal dysfunction, sepsis and hepatic encephalopathy. Portal hypertension results from increased resistance to portal blood flow through the cirrhotic liver. This is caused by two mechanisms: (1) distortion of the liver vascular architecture due to the liver disease causing structural abnormalities (nodule formation, remodeling of liver sinusoids, fibrosis, angiogenesis and vascular occlusion), and (2) increased hepatic vascular tone due to sinusoidal endothelial dysfunction, which results in a defective production of endogenous vasodilators, mainly nitric oxide (NO), and increased production of vasoconstrictors (thromboxane A2, cysteinyl leukotrienes, angiotensin II, endothelins and an activated adrenergic system). Hepatic endothelial dysfunction occurs early in the course of chronic liver disease as a consequence of inflammation and oxidative stress, and determines loss of the normal phenotype of liver sinusoidal endothelial cells (LSECs) that become proliferative, prothrombotic, proinflammatory and vasoconstrictor. The cross-talk between LSECs and hepatic stellate cells (HSCs) induces activation of the latter, which in turn proliferate, migrate and increase collagen deposition around the sinusoids, contributing to fibrogenesis, architectural disruption and angiogenesis, which further increase the hepatic vascular resistance and worsen liver failure by interfering with the blood perfusion of the liver parenchyma. An additional factor further worsening portal hypertension is an increased blood flow through the portal system due to splanchnic vasodilatation. This is an adaptive response to decreased effective hepatocyte perfusion, and is maximal once portal pressure has increased sufficiently to promote the development of intrahepatic shunts and portal-systemic collaterals, including varices, through which portal blood flow bypasses the liver. In human portal hypertension collateralization and hyperdynamic circulation start at a portal pressure gradient >10 mm Hg. Rational therapy for portal hypertension aims at correcting these pathophysiological abnormalities: liver injury, fibrogenesis, increased hepatic vascular tone and splanchnic vasodilatation. Continuing liver injury may be counteracted specifically by etiological treatments (the best example being the direct-acting antivirals for hepatitis C viral infection), while architectural disruption and fibrosis can be ameliorated by a variety of antifibrotic drugs and antiangiogenic strategies. Several drugs in this category are currently under investigation in phase II-III randomized controlled trials. Sinusoidal endothelial dysfunction is ameliorated by statins as well as by other drugs increasing NO availability. It is of note that simvastatin has already been proven to be clinically effective in two randomized controlled trials. Splanchnic hyperemia can be counteracted by nonselective β-blockers (NSBBs), vasopressin analogs and somatostatin analogs, drugs that until recently were the only available treatments for portal hypertension, but that are not very effective in the initial stages of cirrhosis. There is experimental and clinical evidence indicating that a more effective reduction of portal pressure is obtained by combining agents acting on these different pathways. It is likely that the treatment of portal hypertension will evolve to use etiological treatments together with antifibrotic agents and/or drugs improving sinusoidal endothelial function in the initial stages of cirrhosis (preprimary prophylaxis), while NSBBs will be added in advanced stages of the disease.

Contemporary concepts of the medical therapy of portal hypertension under liver cirrhosis

Severe complications of liver cirrhosis are mostly related to portal hypertension. At the base of the pathogenesis of portal hypertension is the increase in hepatic vascular resistance to portal blood flow with subsequent development of hyperdynamic circulation, which, despite of the formation of collateral circulation, promotes progression of portal hypertension. An important role in its pathogenesis is played by the rearrangement of vascular bed and angiogenesis. As a result, strategic directions of the therapy of portal hypertension under liver cirrhosis include selectively decreasing hepatic vascular resistance with preserving or increasing portal blood flow, and correcting hyperdynamic circulation and pathological angiogenesis, while striving to reduce the hepatic venous pressure gradient to less than 12 mmHg or 20% of the baseline. Over the last years, substantial progress in understanding the pathophysiological mechanisms of hemodynamic disorders under liver cirrhosis has resulted in the development of new drugs for their correction. Although the majority of them have so far been investigated only in animal experiments, as well as at the molecular and cellular level, it might be expected that the introduction of the new methods in clinical practice will increase the efficacy of the conservative approach to the prophylaxis and treatment of portal hypertension complications. The purpose of the review is to describe the known methods of portal hypertension pharmacotherapy and discuss the drugs that may affect the basic pathogenetic mechanisms of its development.

New cellular and molecular targets for the treatment of portal hypertension

Portal hypertension (PH) is a common complication of chronic liver disease, and it determines most complications leading to death or liver transplantation in patients with liver cirrhosis. PH results from increased resistance to portal blood flow through the cirrhotic liver. This is caused by two mechanisms: (a) distortion of the liver vascular architecture and (b) hepatic microvascular dysfunction. Increment in hepatic resistance is latterly accompanied by splanchnic vasodilation, which further aggravates PH. Hepatic microvascular dysfunction occurs early in the course of chronic liver disease as a consequence of inflammation and oxidative stress and determines loss of the normal phenotype of liver sinusoidal endothelial cells (LSEC). The cross-talk between LSEC and hepatic stellate cells induces activation of the latter, which in turn proliferate, migrate and increase collagen deposition around the sinusoids, contributing to fibrogenesis, architectural disruption and angiogenesis. Therapy for PH aims at correcting these pathophysiological abnormalities: liver injury, fibrogenesis, increased hepatic vascular tone and splanchnic vasodilatation. Continuing liver injury may be counteracted specifically by etiological treatments, while architectural disruption and fibrosis can be ameliorated by a variety of anti-fibrogenic drugs and anti-angiogenic strategies. Sinusoidal endothelial dysfunction is ameliorated by statins and other drugs increasing NO availability. Splanchnic hyperemia can be counteracted by non-selective beta-blockers (NSBBs), vasopressin analogs and somatostatin analogs. Future treatment of portal hypertension will evolve to use etiological treatments together with anti-fibrotic agents and/or drugs improving microvascular function in initial stages of cirrhosis (pre-primary prophylaxis), while NSBBs will be added in advanced stages of the disease.

Endothelial dysfunction in cirrhosis: Role of inflammation and oxidative stress

This review describes the recent developments in the pathobiology of endothelial dysfunction (ED) in the context of cirrhosis with portal hypertension and defines novel strategies and potential targets for therapy. ED has prognostic implications by predicting unfavourable early hepatic events and mortality in patients with portal hypertension and advanced liver diseases. ED characterised by an impaired bioactivity of nitric oxide (NO) within the hepatic circulation and is mainly due to decreased bioavailability of NO and accelerated degradation of NO with reactive oxygen species. Furthermore, elevated inflammatory markers also inhibit NO synthesis and causes ED in cirrhotic liver. Therefore, improvement of NO availability in the hepatic circulation can be beneficial for the improvement of endothelial dysfunction and associated portal hypertension in patients with cirrhosis. Furthermore, therapeutic agents that are identified in increasing NO bioavailability through improvement of hepatic endothelial nitric oxide synthase (eNOS) activity and reduction in hepatic asymmetric dimethylarginine, an endogenous modulator of eNOS and a key mediator of elevated intrahepatic vascular tone in cirrhosis would be interesting therapeutic approaches in patients with endothelial dysfunction and portal hypertension in advanced liver diseases.

Acute effects of an oral supplement of (-)-epicatechin on postprandial fat and carbohydrate metabolism in normal and overweight subjects

Postprandial hyperglycemia, in particular when accompanied by excessive hypertriglyceridemia, is associated with increased cardiovascular risk, mainly in overweight or obese subjects, as it favors oxidative stress, systemic inflammation and endothelial dysfunction. Thus, treatments that favorably modulate metabolism by reducing steep increases in postprandial serum glucose and triglycerides, are of considerable interest. Evidence suggests that (-)-epicatechin (EPI) is responsible for reductions in cardiometabolic risk associated with chocolate consumption; these effects may be associated with favorable effects of EPI on postprandial metabolism. The aims of this study were to assess the effects of EPI on postprandial metabolism in normal-weight and overweight/obese subjects. Twenty adult volunteers (normal and overweight) underwent oral metabolic tolerance tests in the absence and presence of oral EPI (1 mg kg(-1)). Metabolic responses were examined using indirect calorimetry and determining blood glucose and triglycerides at 0, 2 and 4 hours after metabolic load ingestion. Results show that EPI increased postprandial lipid catabolism, as evidenced by a significant decrease in the respiratory quotient, which implies an increase in fat oxidation. The effect was associated with significantly lower postprandial plasma glucose and triglycerides concentrations. The effects were more prominent in overweight subjects. In conclusion, EPI modulates postprandial metabolism by enhancing lipid oxidation accompanied by reductions in glycemia and triglyceridemia.

Liver cirrhosis

Cirrhosis is an increasing cause of morbidity and mortality in more developed countries, being the 14th most common cause of death worldwide but fourth in central Europe. Increasingly, cirrhosis has been seen to be not a single disease entity, but one that can be subclassified into distinct clinical prognostic stages, with 1-year mortality ranging from 1% to 57% depending on the stage. We review the current understanding of cirrhosis as a dynamic process and outline current therapeutic options for prevention and treatment of complications of cirrhosis, on the basis of the subclassification in clinical stages. The new concept in management of patients with cirrhosis should be prevention and early intervention to stabilise disease progression and to avoid or delay clinical decompensation and the need for liver transplantation. The challenge in the 21st century is to prevent the need for liver transplantation in as many patients with cirrhosis as possible.

Pharmacologic management of portal hypertension

Progress in the knowledge of the pathophysiology of portal hypertension has disclosed new targets for therapy, resulting in a larger spectrum of drugs with a potential role for clinical practice. This review focuses on pharmacologic treatments already available for reducing portal pressure and summarizes drugs currently under investigation in this field.

Is it tea time for portal hypertension?

Portal hypertension is the main complication of cirrhosis and represents a leading cause of death in patients with chronic liver disease. Therapeutic agents to improve portal hypertension should ameliorate the underlying mechanisms of portal hypertension: the elevated hepatic resistance and the hyperdynamic circulation. In the present issue of Clinical Science, Hsu and co-workers show the beneficial effects of GTPs (green tea polyphenols) in improving portal hypertension. Long-term administration of GTPs inhibited the development of cirrhosis and portal hypertension by decreasing both hepatic resistance and splanchnic hyperdynamic circulation. The main underlying mechanism of the benefits of GTPs appears related to the down-regulation of splanchnic angiogenesis. The present study adds further evidence supporting the potential of natural compounds for an effective nutriceutical approach to the treatment of patients with cirrhosis of the liver.

Influence of acute coffee consumption on postprandial oxidative stress

Background:

Coffee has been reported to be rich in antioxidants, with both acute and chronic consumption leading to enhanced blood antioxidant capacity. High-fat feeding is known to result in excess production of reactive oxygen and nitrogen species, promoting a condition of postprandial oxidative stress.

Methods:

We tested the hypothesis that coffee intake following a high-fat meal would attenuate the typical increase in blood oxidative stress during the acute postprandial period. On 3 different occasions, 16 men and women consumed a high-fat milk shake followed by either 16 ounces of caffeinated or decaffeinated coffee or bottled water. Blood samples were collected before and at 2 and 4 hours following intake of the milk shake and analyzed for triglycerides (TAG), malondialdehyde (MDA), hydrogen peroxide (H₂O₂), and Trolox equivalent antioxidant capacity (TEAC).

Results:

Values for TAG and MDA (P < 0.001), as well as for H₂O₂ (P < 0.001), increased significantly following milk shake consumption, with values higher at 4 hours compared with 2 hours post consumption for TAG and H₂O₂ (P < 0.05). TEAC was unaffected by the milk shake consumption. Coffee had no impact on TAG, MDA, H₂O₂, or TEAC, with no condition or interaction effects noted for any variable (P > 0.05).

Conclusions:

Acute coffee consumption following a high-fat milk shake has no impact on postprandial oxidative stress.