Glitazones for human nonalcoholic steatohepatitis

Effects of the Mediterranean diet on cardiovascular risk factors in non-alcoholic fatty liver disease patients: A systematic review and meta-analysis

BACKGROUND & AIMS

We aimed to investigate the effect of the Mediterranean diet (MedDiet) on cardiovascular risk factors in patients with non-alcoholic fatty liver disease (NAFLD).

METHOD

A systematic search was performed in Scopus, Web of Science, Cochrane library and PubMed databases to find randomized controlled trials (RCTs) related to the effect of the MedDiet in patients with NAFLD, up to July, 2019. There was no language and time limitation. Meta-analyses were performed using both the random and fixed effects model where appropriate, and I2 index was used to evaluate the heterogeneity.

RESULTS

Primary search yielded 467 publications. Five RCTs were eligible. Our meta-analysis indicated that the MedDiet resulted in a significant decrease in serum levels of triglyceride and total cholesterol, and a decrease in body weight and HOMA-IR in comparison to a control diet, in NAFLD patients. Whereas, there were no significant improvement in the MedDiet group compared with the control group regarding other variables such as liver enzymes and blood pressure.

CONCLUSIONS

This meta-analysis indicated the advantageous effects of the MedDiet on some cardiovascular risks factors, as compared with a control diet. It seems that the MedDiet can be considered as an appropriate strategy to reduce cardiovascular risk factors in NAFLD patients.

Anti-NASH Drug Development Hitches a Lift on PPAR Agonism

Non-alcoholic fatty liver disease (NAFLD) affects one-third of the population worldwide, of which a substantial number of patients suffer from non-alcoholic steatohepatitis (NASH). NASH is a severe condition characterized by steatosis and concomitant liver inflammation and fibrosis, for which no drug is yet available. NAFLD is also generally conceived as the hepatic manifestation of the metabolic syndrome. Consequently, well-established drugs that are indicated for the treatment of type 2 diabetes and hyperlipidemia are thought to exert effects that alleviate the pathological features of NASH. One class of these drugs targets peroxisome proliferator-activated receptors (PPARs), which are nuclear receptors that play a regulatory role in lipid metabolism and inflammation. Therefore, PPARs are now also being investigated as potential anti-NASH druggable targets. In this paper, we review the mechanisms of action and physiological functions of PPARs and discuss the position of the different PPAR agonists in the therapeutic landscape of NASH. We particularly focus on the PPAR agonists currently under evaluation in clinical phase II and III trials. Preclinical strategies and how refinement and optimization may improve PPAR-targeted anti-NASH drug testing are also discussed. Finally, potential caveats related to PPAR agonism in anti-NASH therapy are stipulated.

Linking Nonalcoholic Fatty Liver Disease to Hepatocellular Carcinoma: From Bedside to Bench and Back

Aims and background

Nonalcoholic fatty liver disease (NAFLD) and hepatocellular carcinoma (HCC) are two major causes of liver disease worldwide. Epidemiological and clinical data have clearly demonstrated that NAFLD and its associated metabolic abnormalities are a risk factor for HCC. Traditionally, the mechanisms whereby NAFLD acts as a risk for HCC are believed to include replicative senescence of steatotic hepatocytes and compensatory hyperplasia of progenitor cells as a reaction to chronic hepatic injury. Recent years have witnessed significant advances in our understanding of the mechanisms underlying the link between NAFLD and HCC.

Methods

In the present review, we provide an update on the pathophysiological pathways linking NAFLD and its associated metabolic derangements to malignant hepatic transformation, with a special focus on insulin resistance, adipokines, inflammation, and angiogenesis. We will also discuss the potential therapeutic implications that such molecular links carry.

Results

Although treating NAFLD could reduce the risk of malignant hepatic transformation, no long-term studies focusing on this issue have been conducted thus far. Insulin resistance, inflammation as well as derangements in adipokines and angiogenic factors associated with NAFLD are closely intertwined with the risk of developing HCC.

Conclusions

Traditional therapeutic approaches in NAFLD including metformin and statins may theoretically reduce the risk of HCC by acting on common pathophysiological pathways shared by NAFLD and HCC.

Treatment efficacy of a probiotic preparation for non-alcoholic steatohepatitis: A pilot trial

OBJECTIVE

To evaluate the therapeutic effect of a probiotic cocktail containing Lactobacilli, Bifidobacteria and Streptococcus thermophilus on non-alcoholic steatohepatitis (NASH).

METHODS

In this open-label trial, 75 patients with NASH fed a low-fat/low-calorie diet were randomly divided into the control group and experimental group, with the latter receiving the probiotic cocktail once daily for 12 weeks.

RESULTS

All patients were diagnosed with fatty liver by ultrasound examination and had elevated levels of γ-glutamyl transferase (GGT) and alanine aminotransferase (ALT), and slightly increased body mass index (BMI) and cholesterol levels. BMI and serum cholesterol were reduced by the low-fat/low-calorie diet but ALT was not. However, the short-term (12-week) treatment with the probiotic cocktail caused a significant (by >20%) reduction of serum ALT compared with controls, indicating mitigation of inflammation. Accordingly, liver stiffness was decreased in the probiotic-treated group compared with the control group (P < 0.05). Moreover, a more significant decrease in the BMI and serum cholesterol was observed in the probiotic-treated group compared with control (P < 0.05). However, the reduction of GGT as a steatosis marker was insignificant. The composition of stool microbiota in probiotic-treated patients demonstrated a shift towards a normal pattern for all bacterial species examined. No adverse events were observed in any patient during the trial.

CONCLUSION

Short-term treatment with the probiotic cocktail caused significant improvement of liver inflammation without adverse events and, thus, may represent a promising candidate therapeutic approach for NASH.

PPARα gene expression correlates with severity and histological treatment response in patients with non-alcoholic steatohepatitis

BACKGROUND & AIMS

Peroxisome proliferator-activated receptors (PPARs) have been implicated in non-alcoholic steatohepatitis (NASH) pathogenesis, mainly based on animal data. Gene expression data in NASH patients are scarce. We studied liver PPARα, β/δ, and γ expression in a large cohort of obese patients assessed for presence of NAFLD at baseline and 1 year follow-up.

METHODS

Patients presented to the obesity clinic underwent a hepatic work-up. If NAFLD was suspected, liver biopsy was performed. Gene expression was studied by mRNA quantification. Patients were reassessed after 1 year.

RESULTS

125 patients were consecutively included in the study, of which 85 patients had paired liver biopsy taken at 1 year of follow-up. Liver PPARα expression negatively correlated with the presence of NASH (p=0.001) and with severity of steatosis (p=0.003), ballooning (p=0.001), NASH activity score (p=0.008) and fibrosis (p=0.003). PPARα expression was positively correlated to adiponectin (R(2)=0.345, p=0.010) and inversely correlated to visceral fat (R(2)=-0.343, p<0.001), HOMA IR (R(2)=-0.411, p<0.001) and CK18 (R(2)=-0.233, p=0.012). Liver PPARβ/δ and PPARγ expression did not correlate with any histological feature nor with glucose metabolism or serum lipids. At 1 year, correlation of PPARα expression with liver histology was confirmed. In longitudinal analysis, an increase in expression of PPARα and its target genes was significantly associated with histological improvement (p=0.008).

CONCLUSION

Human liver PPARα gene expression negatively correlates with NASH severity, visceral adiposity and insulin resistance and positively with adiponectin. Histological improvement is associated with an increase in expression of PPARα and its target genes. These data might suggest that PPARα is a potential therapeutic target in NASH.

4Ps medicine of the fatty liver: the research model of predictive, preventive, personalized and participatory medicine-recommendations for facing obesity, fatty liver and fibrosis epidemics

Relationship between adipose tissue and fatty liver, and its possible evolution in fibrosis, is supported by clinical and research experience. Given the multifactorial pathogenesis of non-alcoholic fatty liver disease (NAFLD), treatments for various contributory risk factors have been proposed; however, there is no single validated therapy or drug association recommended for all cases which can stand alone. Mechanisms, diagnostics, prevention and treatment of obesity, fatty liver and insulin resistance are displayed along with recommendations and position points. Evidences and practice can get sustainable and cost-benefit valuable outcomes by participatory interventions. These recommendations can be enhanced by comprehensive research projects, addressed to societal issues and innovation, market appeal and industry development, cultural acceptance and sustainability. The basis of participatory medicine is a greater widespread awareness of a condition which is both a disease and an easy documented and inclusive clue for associated diseases and unhealthy lifestyle. This model is suitable for addressing prevention and useful for monitoring improvement, worsening and adherence with non-invasive imaging tools which allow targeted approaches. The latter include health psychology and nutritional and physical exercise prescription expertise disseminated by continuous medical education but, more important, by concrete curricula for training undergraduate and postgraduate students. It is possible and recommended to do it by early formal teaching of ultrasound imaging procedures and of practical lifestyle intervention strategies, including approaches aimed to healthier fashion suggestions. Guidelines and requirements of research project funding calls should be addressed also to NAFLD and allied conditions and should encompass the goal of training by research and the inclusion of participatory medicine topics. A deeper awareness of ethics of competences in health professionals and the articulation of knowledge, expertise and skills of medical doctors, dieticians, health psychologists and sport and physical exercise graduates are the necessary strategy for detectin a suboptimal health status and achieving realistically beneficial lifestyle changes. “The devil has put a penalty on all things we enjoy in life. Either we suffer in health or we suffer in soul or we get fat” (Albert Einstein); the task of medical research and intervention is to make possible to enjoy life also without things that make sufferance in health and souls and which excessively increase body fat.

Should visceral fat, strictly linked to hepatic steatosis, be depleted to improve survival?

Numerous epidemiologic studies have implicated abdominal obesity as a major risk factor for insulin resistance, type 2 diabetes mellitus, cardiovascular disease, stroke, metabolic syndrome and its further expression, i.e., nonalcoholic fatty liver disease and death. Using novel models of visceral obesity, several studies have demonstrated that the relationship between visceral fat and longevity is causal, while the accrual of subcutaneous fat does not appear to play an important role in the etiology of disease risk. The need of reducing the visceral fat to improve survival, mainly taking into account the strict link between nonalcoholic fatty liver disease and the coronary artery disease is discussed.

Farnesoid X receptor targeting to treat nonalcoholic steatohepatitis

Nonalcoholic fatty liver disease (NAFLD) is a highly prevalent chronic liver condition evolving in a proportion of patients into nonalcoholic steatohepatitis (NASH), an aggressive form of NAFLD associated with increased cardiovascular mortality and significant risk of progressive liver disease, including fibrosis, cirrhosis and hepatocellular carcinoma. At present, no specific therapies for NASH exist. In this review, we examine the evidence supporting activation of the farnesoid X receptor (FXR), a nuclear hormone receptor regulated by bile acids (BAs), for the treatment of NASH. We also discuss the potential of the semi-synthetic BA derivative obeticholic acid (OCA), a first-in-class FXR agonist, as a safe and effective drug to address this significant unmet medical need.