Clinical trial: insulin-sensitizing agents may reduce consequences of insulin resistance in individuals with non-alcoholic steatohepatitis

Metformin and the Liver: Unlocking the Full Therapeutic Potential

Metformin is a highly effective medication for managing type 2 diabetes mellitus. Recent studies have shown that it has significant therapeutic benefits in various organ systems, particularly the liver. Although the effects of metformin on metabolic dysfunction-associated steatotic liver disease and metabolic dysfunction-associated steatohepatitis are still being debated, it has positive effects on cirrhosis and anti-tumoral properties, which can help prevent the development of hepatocellular carcinoma. Furthermore, it has been proven to improve insulin resistance and dyslipidaemia, commonly associated with liver diseases. While more studies are needed to fully determine the safety and effectiveness of metformin use in liver diseases, the results are highly promising. Indeed, metformin has a terrific potential for extending its full therapeutic properties beyond its traditional use in managing diabetes.

Altered lipid metabolism and the development of metabolic-associated fatty liver disease

PURPOSE OF REVIEW

An increasing amount of research has underscored the significant role of lipoproteins in the pathogenesis of metabolic-associated fatty liver disease (MAFLD). This comprehensive review examines the intricate relationship between lipoprotein abnormalities and the development of MAFLD.

RECENT FINDINGS

Atherogenic dyslipidemia seen in insulin resistance states play a significant role in initiating and exacerbating hepatic lipid accumulation. There are also specific genetic factors (PNPLA3, TM6SF2, MBOAT7, HSD17B13, GCKR-P446L) and transcription factors (SREBP-2, FXR, and LXR9) that increase susceptibility to both lipoprotein disorders and MAFLD. Most monogenic primary lipid disorders do not cause hepatic steatosis unless accompanied by metabolic stress. Hepatic steatosis occurs in the presence of secondary systemic metabolic stress in conjunction with predisposing environmental factors that lead to insulin resistance. Identifying specific aberrant lipoprotein metabolic factors promoting hepatic fat accumulation and subsequently exacerbating steatohepatitis will shed light on potential targets for therapeutic interventions.

SUMMARY

The clinical implications of interconnection between genetic factors and an insulin resistant environment that predisposes MAFLD is many fold. Potential therapeutic strategies in preventing or mitigating MAFLD progression include lifestyle modifications, pharmacological interventions, and emerging therapies targeting aberrant lipoprotein metabolism.

Effects of Shenling Baizhu powder on intestinal microflora metabolites and liver mitochondrial energy metabolism in nonalcoholic fatty liver mice

Background & purpose

Non-alcoholic fatty liver disease (NAFLD) is characterised by the excessive accumulation of triglycerides in the liver. Shenling Baizhu powder (SLBZP) is formulated from various natural medicinal plants that protect the liver and are used to treat intestinal diseases. SLBZP improves the symptoms of NAFLD. However, its mechanism of action remains unclear. Herein, we investigated the ameliorative effect of SLBZP on model mice with high-fat-diet (HFD)-induced NAFLD. Additionally, we evaluated the impact of SLBZP on the intestinal flora and its metabolites and mitochondrial energy metabolism in NAFLD.

Methods

We used HFD to establish a mouse model of NAFLD. Different drug interventions were administered. We measured serum biochemical indices. Liver sections were visualised with hematoxylin-eosin and oil red O staining. 16S rDNA amplicon sequencing technology was used to analyse the diversity and abundance of the intestinal flora. Short-chain fatty acids (SCFAs) in the intestinal contents were detected using GC-MS. Liver tissue was sampled to detect mitochondrial membrane functional indices. Western blotting was used to determine the levels of mitochondrial pathway-related proteins, namely, uncoupling protein 2 (UCP2), adenosine monophosphate-activated protein kinase (AMPK) and inhibitory factor 1 (IF1) of F1Fo ATP synthesis/hydrolase, in the liver.

Results

The spleen-invigorating classic recipe of SLBZP reduced liver lipid deposition in mice with HFD-induced NAFLD. Additionally, SCFAs produced by intestinal flora metabolism regulated the UCP2/AMPK/IF1 signalling pathway involved in liver mitochondrial energy metabolism to improve the liver mitochondrial membrane permeability, respiratory state and oxidative phosphorylation efficiency of mice with NAFLD. Finally, SLBZP increased the liver ATP level.

Conclusion

Our results suggest that the therapeutic effect of SLBZP on NAFLD is related to the regulation of hepatic mitochondrial energy metabolism by intestinal flora and its metabolites and is possibly associated with the UCP2/AMPK/IF1 signalling pathway.

Effect of metformin on nonalcoholic fatty liver based on meta-analysis and network pharmacology

BACKGROUND

Whether metformin is related to nonalcoholic fatty liver disease (NAFLD) is controversial. Our aim was to investigate the relationship between metformin and NAFLD that may predict the metformin potential of these lesions and new prevention strategies in NAFLD patients.

METHODS

The meta-analysis was analyzed by Revman 5.3 softwares systematically searched for works published through July 29, 2022. Network pharmacology research based on databases, Cytoscape 3.7.1 software and R software respectively.

RESULTS

The following variables were associated with metformin in NAFLD patients: decreased of alanine aminotransferase (ALT) level (mean difference [MD] = -10.84, 95% confidence interval [CI] = -21.85 to 0.16, P = .05); decreased of aspartate amino transferase (AST) level (MD = -4.82, 95% CI = -9.33 to -0.30, P = .04); decreased of triglyceride (TG) level (MD = -0.17, 95% CI = -0.26 to -0.08, P = .0002); decreased of total cholesterol (TC) level (MD = -0.29, 95% CI = -0.47 to -0.10, P = .003); decreased of insulin resistance (IR) level (MD = -0.42, 95% CI = -0.82 to -0.02, P = .04). In addition, body mass index (BMI) (MD = -0.65, 95% CI = -1.46 to 0.16, P = .12) had no association with metformin in NAFLD patients. 181 metformin targets and 868 NAFLD disease targets were interaction analyzed, 15 core targets of metformin for the treatment of NAFLD were obtained. The effect of metformin on NAFLD mainly related to cytoplasm and protein binding, NAFLD, hepatitis B, pathway in cancer, toll like receptor signaling pathway and type 2 diabetes mellitus (T2DM). The proteins of hypoxia inducible factor-1 (HIF1A), nuclear factor erythroid 2-related factor (NFE2L2), nitric oxide synthase 3 (NOS3), nuclear receptor subfamily 3 group C member 1 (NR3C1), PI3K catalytic subunit alpha (PIK3CA), and silencing information regulator 2 related enzyme 1 (SIRT1) may the core targets of metformin for the treatment of NAFLD.

CONCLUSION

Metformin might be a candidate drug for the treatment of NAFLD which exhibits therapeutic effect on NAFLD patients associated with ALT, AST, TG, TC and IR while was not correlated with BMI. HIF1A, NFE2L2, NOS3, NR3C1, PIK3CA, and SIRT1 might be core targets of metformin for the treatment of NAFLD.

Correlation between long-term use of metformin and incidence of NAFLD among patients with type 2 diabetes mellitus: A real-world cohort study

BACKGROUND AND AIMS

Studies have demonstrated that the short-term use of metformin benefits liver function among patients with type 2 diabetes mellitus (T2DM). However, few studies have reported on the effects of long-term metformin treatment on liver function or liver histology. This study investigated the correlation between metformin use and the incidence of nonalcoholic fatty liver disease (NAFLD) among patients with T2DM.

METHODS

This population-based study investigated the risk of NAFLD among patients with T2DM who received metformin treatment between 2001-2018. Metformin users and metformin nonusers were enrolled and matched to compare the risk of NAFLD.

RESULTS

After 3 years, the patients who received <300 cDDD of metformin and those with metformin use intensity of <10 and 10-25 DDD/month had odds ratios (ORs) of 1.11 (95% confidence interval [CI] = 1.06-1.16), 1.08 (95% CI = 1.02-1.13), and 1.18 (95% CI = 1.11-1.26) for NAFLD, respectively. Moreover, metformin users who scored high on the Diabetes Complications and Severity Index (DCSI) were at high risk of NAFLD. Patients with comorbid hyperlipidemia, hyperuricemia, obesity, and hepatitis C were also at high risk of NAFLD.

CONCLUSION

Patients with T2DM who received metformin of <300 cDDD or used metformin at an intensity of <10 and 10-25 DDD/month were at a high risk of developing NAFLD. The results of this study also indicated that patients with T2DM receiving metformin and with high scores on the DCSI were at a high risk of developing NAFLD.

Management of Cardiometabolic Complications in Patients With Nonalcoholic Fatty Liver Disease: A Review of the Literature With Recommendations

Nonalcoholic fatty liver disease (NAFLD) comprises a spectrum of liver conditions characterized by significant lipid deposition within hepatocytes. As an overarching diagnosis, NAFLD contains a continuum of progressive liver diseases ranging from isolated liver steatosis to necroinflammatory states leading to end-stage liver disease. Nonalcoholic fatty liver and nonalcoholic steatohepatitis are distinguished by their histologic patterns, with the former exhibiting steatosis without fibrosis or inflammation. This important distinction provides clinicians a timeline within the NAFLD staging to target appropriate interventions against modifiable risk factors. NAFLD is likely formed in response to metabolic imbalances that damage the livers adaptive capacity. Metabolic conditions leading to steatosis mirror common cardiovascular risk factors, including dyslipidemia, diabetes mellitus, and obesity. Acknowledging the common risk factors for development and progression of NAFLD, it is unsurprising the first-line management focuses on the treatment of metabolic syndrome with an emphasis on weight reduction in obese populations. The purpose of this review is to provide a detailed summary of the literature as well as outline the current treatment recommendations for patients with NAFLD with a detailed focus on pharmacologic antiobesity interventions.

Fibrosis progression rate in a systematic review of placebo-treated nonalcoholic steatohepatitis

BACKGROUND & AIMS

Liver fibrosis is the critical determinant of liver-related outcomes in persons with nonalcoholic fatty liver disease. The rate that fibrosis develops determines the time taken to reach cirrhosis and consequent clinical outcomes. Estimates of the fibrosis progression rate (FPR) are uncertain having been defined in small observational series that rely largely on nonstandardised repeat biopsy in selected patients. The aim of this study was to evaluate the FPR in placebo-treated participants with nonalcoholic steatohepatitis (NASH) in randomised controlled trials (RCTs).

METHODS

Systematic review and meta-analysis of RCTs in NASH with data on fibrosis change extracted. Calculated fibrosis progression rates were pooled in meta-analysis. The pooled estimate was then used to model the proportion of hypothetical cohorts starting with no fibrosis at the age of 30 who develop cirrhosis.

RESULTS

A total of 35 trials including 1419 placebo-treated participants who underwent repeat liver biopsy were evaluated. Considering all trials, the overall FPR was 0.00 stages per year, increasing to 0.03 stages per year in both trials at low risk of bias and trials including >50 placebo-treated participants. This estimate was markedly lower than the value derived from previously pooled analyses of observational data. Using a FPR of 0.03 resulted in a substantial reduction in the proportion of patients developing cirrhosis compared with the FPR derived from observational studies (13% vs 28%).

CONCLUSIONS

The FPR in placebo-treated participants in RCTs is lower than that described from observational data. Slower fibrosis progression predicts fewer persons with NASH will progress to cirrhosis than previously estimated.

What proportion of people have a follow-up biopsy in randomized trials of treatments for non-alcoholic steatohepatitis?: A systematic review and meta-analysis

Background and aim

Trials of treatments for non-alcoholic steatohepatitis require endpoint assessment with liver biopsies. Previous large-scale trials have calculated their sample size expecting high retention but on average did not achieve this. We aimed to quantify the proportion of participants with a valid follow-up biopsy.

Methods

We conducted a systematic review of MEDLINE and Embase until May 2020 and included randomized clinical trials of any intervention in non-alcoholic steatohepatitis with at least 1-year follow-up. We were guided by Cochrane methods to run a meta-analysis with generalized linear mixed models with random effects.

Results

Forty-one trials (n = 6,695) were included. The proportion of participants with a valid follow-up biopsy was 82% (95%CI: 78%-86%, I² = 92%). There was no evidence of a difference by location, trial length, or by allocated treatment group. Reasons for missing follow-up biopsies were, in ranked order, related to participants (95 per 1,000 participants (95%CI: 69–129, I² = 92%), medical factors, protocol, trial conduct, and other/unclear. Biopsy-related serious adverse events occurred in 16 per 1,000 participants (95% CI: 8–33, I² = 54%). No biopsy-related deaths were reported.

Conclusions

The proportion of participants with a valid follow-up biopsy in therapeutic trials in non-alcoholic steatohepatitis is on average 82%, with around 1 in 10 participants declining a follow-up biopsy. These findings can inform adequately-powered trials.

Non-Alcoholic Fatty Liver Disease and Cardiovascular Comorbidities: Pathophysiological Links, Diagnosis, and Therapeutic Management

Non-alcoholic fatty liver disease (NAFLD) has a growing prevalence in recent years. Its association with cardiovascular disease has been intensively studied, and certain correlations have been identified. The connection between these two entities has lately aroused interest regarding therapeutic management. In order to find the best therapeutic options, a detailed understanding of the pathophysiology that links (NAFLD) to cardiovascular comorbidities is needed. This review focuses on the pathogenic mechanisms that are behind these two diseases and on the therapeutic management available at this time.

What Are the Current Pharmacological Therapies for Nonalcoholic Fatty Liver Disease?

Of the currently available drugs tested to treat nonalcoholic fatty liver disease (NAFLD), the most efficacious drugs are pioglitazone (an insulin sensitizer) and vitamin E (an antioxidant). By targeting insulin resistance, the key pathogenic mechanism underlying metabolic syndrome and NAFLD, pioglitazone maybe the preferred drug to treat NAFLD. As we await the results of research trials into multiple new drugs to treat NAFLD, when should we use the currently available patients to treat NAFLD at the present time? To date, no drug has been approved by regulatory agency specifically to treat NAFLD. However, many drugs have been approved to treat other components of metabolic syndrome such as diabetes mellitus and dyslipidemia. Are we underutilizing the currently available drugs to treat NAFLD? Herein, we review the benefits and concerns of the use of these currently available drugs to treat NAFLD and suggest clinical scenarios, wherein the clinician should consider using these drugs.

TCTP participates in hepatic metabolism by regulating gene expression involved in insulin resistance

Translationally controlled tumor protein (TCTP) has various cellular functions and molecular interactions, many related to its growth-promoting and antiapoptotic properties. Recently, TCTP expression was reported to increases in insulin-resistant mice fed with high-fat diet. TCTP is a multifunctional protein, but its role in liver metabolism is unclear. Here, we investigated the function and mechanism of TCTP in HepG2 cells. Knock-down of TCTP led to 287 differentially expressed genes (DEGs) that were highly associated with cellular apoptosis and signal response, TNF and NF-κB signaling pathways, glycolysis/gluconeogenesis, insulin resistance, FoxO and insulin signaling pathways, adipocytokine and AMPK signaling pathways. shTCTP downregulated the expression of the key gluconeogenesis enzyme phosphoenolpyruvate carboxykinase (PCK1). Furthermore, TCTP regulated the alternative splicing of genes enriched in the phospholipid biosynthetic process and glycerophospholipid metabolism. We further showed that shTCTP down-regulated the intracellular levels of triglyceride and total cholesterol. Our results showed that TCTP regulates the liver cell transcriptome at both the transcriptional and alternative splicing levels. The TCTP regulatory network predicts the biological functions of TCTP in glucose and lipid metabolism, and also insulin resistance, which may be associated with liver metabolism and diseases such as nonalcoholic fatty liver disease.

Standardisation of diet and exercise in clinical trials of NAFLD-NASH: Recommendations from the Liver Forum

Lifestyle modification is the foundation of treatment recommendations for non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH). The design of clinical trials in NASH may be impeded by the lack of a systematic approach to identify and evaluate how lifestyle changes and/or modifications influence clinical trial outcomes and associated endpoints. Furthermore, there are additional uncertainties regarding the methods that can be utilised to better characterise and quantify lifestyle variables - which can influence disease activity and alter trial endpoints - to allow for comparisons of trial outcomes across different phases of research and/or within drug-classes. This summary by the Liver Forum's Standard of Care Working Group reviews currently available clinical data, identifies the barriers and challenges associated with the standard of care in NAFLD/NASH clinical trials, defines available assessments of lifestyle changes, and proposes approaches to better understand and define the influence of diet and exercise on NASH treatment in the context of different pharmacologic interventions. The ultimate objective is to propose tangible solutions which enable investigators, sponsors, and regulatory authorities to meaningfully interpret clinical trial outcomes and the impact of lifestyle modification on such outcomes as they pertain to phase I-IV clinical trials.

In-vitro Synergistic Effect of Metformin and Berberine on High Glucose-induced Lipogenesis

Metformin and berberine have been reported to have lipid lowering effects. This study aims to investigate lipid lowering effects of berberine and Metformin, alone and in combination, in HepG2 cells to determine whether berberine and Metformin work synergistically and elucidate their mechanisms. HepG2 cells were treated with 33 mM glucose in the presence of various concentrations of berberine and Metformin, alone and in combination, for 24 h. The cytotoxic effects of these compounds were determined by MTT assay. Oil red O staining, triglyceride measurement, and gene expression analyses were performed to evaluate the effects of these compounds on hepatocytes lipogenesis. Berberine at doses 20 µM and 40 µM and Metformin at doses 1 mM and 2 mM reduced total lipid content and triglyceride level in HepG2 cells. Metformin (mM) and berberine (µM) at combination ratios of 2:40, 1:20, 0.5:10, and 0.25:5 exhibited a synergistic lipid-lowering effect on HepG2 cells. These ratios could significantly decrease total lipid content and triglyceride level in HepG2 cells. The lowest dose of the combination [Metformin (0.25 mM) and berberine (5 μM)] also synergistically reduced the expression of the FAS and SREBP-1c genes in HepG2 cells treated with high glucose. The combination of Metformin and berberine exerted synergistic lipid-lowering effects on HepG2 cells by reducing total lipid content, triglyceride level, and the expression of the genes involved in lipogenesis.

Effect of Weight Loss Medications on Hepatic Steatosis and Steatohepatitis: A Systematic Review

Non-alcoholic fatty liver disease (NAFLD) is a common comorbidity in individuals with obesity. Although multiple pharmacotherapeutics are in development, currently there are limited strategies specifically targeting NAFLD. This systematic review summarizes the existing literature on hepatic effects of medications used for weight loss. Glucagon-like peptide 1 (GLP-1) agonists are the best-studied in this regard, and evidence consistently demonstrates reduction in liver fat content, sometimes accompanied by improvements in histological features of steatohepatitis and reductions in serum markers of hepatic injury such as alanine aminotransferase (ALT). It remains unclear whether these benefits are independent of the weight loss caused by these agents. Literature is limited regarding effects of orlistat, but a small number of reports suggest that orlistat reduces liver fat content and improves histologic features of NASH, benefits which may also be driven primarily by weight loss. A sizeable body of literature on hepatic effects of metformin yields mixed results, with a probability of modest benefit, but no consistent signal for strong benefit. There are insufficient data on hepatic effects of topiramate, phentermine, naltrexone, bupropion, and lorcaserin. Finally, a few studies to date suggest that sodium-glucose co-transporter-2 (SGLT2) inhibitors may reduce liver fat content and cause modest reductions in ALT, but further study is needed to better characterize these effects. Based on available data, GLP-1 agonists have the strongest evidence base demonstrating beneficial effects on NAFLD, but it is not clear if any weight loss medication has effects on NAFLD superior to those of nutritional modification and exercise alone.

Pentoxifylline with metformin treatment improves biochemical parameters in patients with nonalcoholic steatohepatitis

Background

The progression of the nonalcoholic fatty liver disease to nonalcoholic steatohepatitis (NASH) is multifactorial, and there is still a lack of approved medications for its treatment. The study aimed to evaluate the impact of combined treatment with Pentoxifylline and Metformin on biochemical parameters in patients with Nash. Setting: Outpatient hepatology clinic.

Methods

A prospective trial was conducted. The first cohort included patients with biopsy-proven Nash, while the second cohort consisted of patients with biopsy-confirmed NAFLD. Blood tests were checked at baseline and every three months. Pentoxifylline at a dosage of 400 mg t.i.d. and Metformin at the dosage of 500 mg t.i.d. were introduced for six months in Nash group. The impact of the treatment was assessed based on biochemical results after combined treatment with low-cost medications.

Results

All 33 Nash patients completed 24 weeks of treatment. We observed significant improvement (p<0.05) of median values after treatment for the following parameters: serum uric acid levels decreased by 51.0 mmol/L, calcium decreased for 0.27 mmoL/L, magnesium showed an increase of 0.11 mmoL/L. Insulin resistance improved as a reduction of HOMA - IR by 1.3 was detected. A significant decrease of median in liver enzymes, alanine aminotransferase, aspartate aminotransferase and gamma-glutamyltransferase by 24.0 U/L, 9.1 U/L, 10.8 U/L respectively, was noted.

Conclusions

Pentoxifylline and Metformin may provide possible treatment option in Nash. Some new potential benefit of the therapy in improving liver function whilst decreasing cardiovascular risk was perceived.

Exploration and Development of PPAR Modulators in Health and Disease: An Update of Clinical Evidence

Peroxisome proliferator-activated receptors (PPARs) are nuclear receptors that govern the expression of genes responsible for energy metabolism, cellular development, and differentiation. Their crucial biological roles dictate the significance of PPAR-targeting synthetic ligands in medical research and drug discovery. Clinical implications of PPAR agonists span across a wide range of health conditions, including metabolic diseases, chronic inflammatory diseases, infections, autoimmune diseases, neurological and psychiatric disorders, and malignancies. In this review we aim to consolidate existing clinical evidence of PPAR modulators, highlighting their clinical prospects and challenges. Findings from clinical trials revealed that different agonists of the same PPAR subtype could present different safety profiles and clinical outcomes in a disease-dependent manner. Pemafibrate, due to its high selectivity, is likely to replace other PPARα agonists for dyslipidemia and cardiovascular diseases. PPARγ agonist pioglitazone showed tremendous promises in many non-metabolic disorders like chronic kidney disease, depression, inflammation, and autoimmune diseases. The clinical niche of PPARβ/δ agonists is less well-explored. Interestingly, dual- or pan-PPAR agonists, namely chiglitazar, saroglitazar, elafibranor, and lanifibranor, are gaining momentum with their optimistic outcomes in many diseases including type 2 diabetes, dyslipidemia, non-alcoholic fatty liver disease, and primary biliary cholangitis. Notably, the preclinical and clinical development for PPAR antagonists remains unacceptably deficient. We anticipate the future design of better PPAR modulators with minimal off-target effects, high selectivity, superior bioavailability, and pharmacokinetics. This will open new possibilities for PPAR ligands in medicine.

Rosiglitazone ameliorates bile duct ligation-induced liver fibrosis by down-regulating NF-κB-TNF-α signaling pathway in a PPARγ-dependent manner

Liver fibrosis is a major cause of morbidity and mortality worldwide. One of its therapeutic targets is peroxisome proliferator-activated receptor γ (PPARγ), with its ligands including rosiglitazone being tested in pre-clinical and clinical studies. However, the effects of rosiglitazone on bile duct ligation (BDL)-induced liver fibrosis and the involved mechanisms remain unknown. Herein, we used floxed control (PPARγ^fl/fl) and hepatocyte-specific PPARγ deficient (HepPPARγ KO) mice to conduct BDL to induce liver fibrosis and treated the animals with rosiglitazone. After one week of BDL, mice in BDL group displayed liver injury evidenced by increased collagen content, fibrosis area, necrosis area and apoptotic cells, and elevated alkaline phosphatase and alanine transaminase activities in serum. Interestingly, rosiglitazone ameliorated BDL-induced liver injury in PPARγ^fl/fl mice but not in HepPPARγ KO mice. Mechanistically, rosiglitazone reduced BDL-induced collagen content by downregulating fibrotic related genes including transforming growth factor β1, α-smooth muscle actin and collagen type I α1, and decreased inflammation cytokine tumor necrosis factor α level by inhibiting phosphorylation of nuclear factor-κB in a PPARγ-dependent manner. Based on findings above, we demonstrated that rosiglitazone can ameliorate BDL-induced liver fibrosis in mice and confirmed its critical functions on fibrosis by regulating NF-κB-TNF-α pathway in a PPARγ-dependent manner.

Of mice and men: Is there a future for metformin in the treatment of hepatic steatosis?

Non-alcoholic fatty liver disease (NAFLD) encompasses a spectrum of liver diseases, of which the first stage is steatosis. It is one of the most common liver diseases in developed countries and there is a clear association between type 2 diabetes (T2DM) and NAFLD. It is estimated that 70% of people with T2DM have NAFLD and yet there is currently no licensed pharmacological agent to treat it. Whilst lifestyle modification may ameliorate liver fat, it is often difficult to achieve or sustain; thus, there is great interest in pharmacological treatments for NAFLD. Metformin is the first-line medication in the management of T2DM and evidence from animal and human studies has suggested that it may be useful in reducing liver fat via inhibition of lipogenesis and increased fatty acid oxidation. Findings from the majority of studies undertaken in rodent models clearly suggest that metformin may be a powerful therapeutic agent specifically to reduce liver fat accumulation; data from human studies are less convincing. In the present review we discuss the evidence for the specific effects of metformin treatment on liver fat accumulation in animal and human studies, as well as the underlying proposed mechanisms, to try and understand and reconcile the difference in findings between rodent and human work in this area.

Rates of and Factors Associated With Placebo Response in Trials of Pharmacotherapies for Nonalcoholic Steatohepatitis: Systematic Review and Meta-analysis

BACKGROUND & AIMS

It is important to know the extent of the placebo effect in designing randomized controlled trials for patients with nonalcoholic steatohepatitis (NASH), to accurately calculate sample size and define treatment endpoints.

METHODS

We performed a systematic review and meta-analysis of the placebo groups from randomized controlled trials of adults with NASH that provided histologic and/or magnetic resonance image-based assessments. We identified trials through a comprehensive search of MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and Scopus, from each database's inception through January 2, 2018.

RESULTS

We identified 39 randomized controlled trials, comprising 1463 patients who received placebo. Histologic assessment data (the nonalcoholic fatty liver disease activity scores, NAS) were available from 956 patients; magnetic resonance spectroscopy data were available from 295 patients and magnetic resonance proton density fat fraction measurements from 61 patients. Overall, 25% of patients given placebo had an improvement in NAS by 2 or more points (95% CI, 21%-29%) with a small amount of heterogeneity (I₂ = 27%). There were improvements by at least 1 point in steatosis scores of 33% ± 3% of patients, in hepatocyte ballooning scores of 30% ± 3% of patients, in lobular inflammation scores of 32% ± 3% of patients, and in fibrosis scores of 21% ± 3% of patients, with a moderate amount of heterogeneity among trials (I₂ range, 51%-63%). Patients given placebo had a statistically significant improvement in NAS (by 0.72 ± 0.19), with a large amount of heterogeneity (I₂ = 96%). Univariate and multivariate meta-regression showed that trials with a higher baseline NAS, those conducted in South America, and those in which patients had a decrease in body mass index, were associated with greater improvements in NAS among patients given placebo. Patients given placebo had significant reductions in intrahepatic triglyceride, measured by magnetic resonance spectroscopy (by 1.45% ± 0.54%) with moderate heterogeneity (I₂ = 40%), and in magnetic resonance proton density fat fraction (by 2.43 ± 0.89), without heterogeneity (I₂ = 0). Mean serum levels of alanine and aspartate aminotransferases decreased significantly (by 11.7 ± 3.8 U/L and 5.9 ± 2.1 U/L, respectively; P < .01 for both).

CONCLUSIONS

In a meta-analysis of randomized controlled trials of NASH, patients given placebo have significant histologic, radiologic, and biochemical responses. The placebo response should be considered in designing trials of agents for treatment of NASH.

Post-translational regulation of lipogenesis via AMPK-dependent phosphorylation of insulin-induced gene

Insulin-induced gene (Insig) negatively regulates SREBP-mediated de novo fatty acid synthesis in the liver. However, the upstream regulation of Insig is incompletely understood. Here we report that AMPK interacts with and mediates phosphorylation of Insig. Thr222 phosphorylation following AMPK activation is required for protein stabilization of Insig-1, inhibition of cleavage and processing of SREBP-1, and lipogenic gene expression in response to metformin or A769662. AMPK-dependent phosphorylation ablates Insig’s interaction with E3 ubiquitin ligase gp78 and represses its ubiquitination and degradation, whereas AMPK deficiency shows opposite effects. Interestingly, activation of AMPK by metformin causes an augmentation of Insig stability and reduction of lipogenic gene expression, and leads to the attenuation of hepatic steatosis in HFHS diet-fed mice. Moreover, hepatic overexpression of Insig-1 rescues hepatic steatosis in liver-specific AMPKα2 knockout mice fed with HFHS diet. These findings uncover a novel effector of AMPK. Targeting Insig may have the therapeutic potential for treating fatty liver disease and related disorders.

Insulin-related gene (Insig) negatively regulates hepatic fatty acid synthesis, a process involved in development of non-alcoholic fatty liver disease (NAFLD). Here, the authors show that AMPK activation by metformin promotes Insig phosphorylation, stabilizing it and inhibiting lipogenic gene expression. This is protective against steatosis in diabetic mice.

Long-term treatment with metformin in the prevention of fatty liver in Zucker diabetic fatty rats

BACKGROUND

Treatment with metformin, the biguanide of hepatic insulin sensitizer, in patients with non-alcoholic fatty liver disease (NAFLD) has been reported with contradictory findings regarding the effectiveness on blood lipids and liver histology. In this study, we aimed to explore the preventive effects of metformin on NAFLD in Zucker diabetic fatty (ZDF) rats.

METHODS

Male ZDF rats and Zucker lean rats aged 4-8 weeks were subjected to vehicle or metformin treatment for 6 months. Liver cDNA microarray assay, and protein semiquantitative and histological examinations were performed.

RESULTS

Data demonstrated that ZDF rats developed hyperglycemia, hyperlipidemia, liver deficiency and hepatocyte degeneration. The metformin treatment significantly reduced post-load blood glucose levels, but not blood lipid profiles or liver enzyme levels. Hepatocyte degeneration was not attenuated after the treatment. The metformin-treated ZDF rats showed activation of AMP-activated protein kinase by Western blot and overexpression of cytochrome c oxidase by immunofluorescent microscopy. Gene expression microarray assay demonstrated that a panel of genes participating in glucose and lipid metabolisms were changed in the ZDF rats, and most of the altered genes involved in glucose and cholesterol metabolisms, but not those in fatty acid metabolisms, were corrected by the metformin treatment. No genes associated with inflammation, apoptosis, fibrosis, or cell death were overexpressed in the metformin-treated ZDF rats.

CONCLUSIONS

These results suggest that long-term metformin treatment presents no preventive effect for NAFLD in ZDF rats.

Antidiabetic Drugs in NAFLD: The Accomplishment of Two Goals at Once? Pharmaceuticals (Basel). 2018;11:121. [PMID: 30413050 PMCID: PMC6316860 DOI: 10.3390/ph11040121]

Non-Alcoholic Fatty Liver Disease (NAFLD) is the most common cause of chronic liver disease in Western countries, accounting for 20–30% of general population and reaching a prevalence of 55% in patients with type 2 diabetes mellitus (T2DM). Insulin resistance plays a key role in pathogenic mechanisms of NAFLD. Many drugs have been tested but no medications have yet been approved. Antidiabetic drugs could have a role in the progression reduction of the disease. The aim of this review is to summarize evidence on efficacy and safety of antidiabetic drugs in patients with NAFLD. Metformin, a biguanide, is the most frequently used drug in the treatment of T2DM. To date 15 randomized controlled trials (RCTs) and four meta-analysis on the use of metformin in NAFLD are available. No significant improvement in histological liver fibrosis was shown, but it can be useful in the treatment of co-factors of NAFLD, like body weight, transaminase or cholesterol levels, and HbA1c levels. A possible protective role in various types of cancer has been reported for Metformin. Thiazolidinediones modulate insulin sensitivity by the activation of PPAR-γ. The RCTs and the meta-analysis available about the role of these drugs in NAFLD show an improvement in ballooning, lobular inflammation, and perhaps fibrosis, but some side effects, in particular cardiovascular, were showed. GLP-1 analogues stimulate insulin secretion by pancreatic beta cell and inhibit glucagon release; Liraglutide is the most used drug in this class and significantly improves steatosis, hepatocyte ballooning and transaminase levels. Scanty data about the role of DPP-4 and SGLT inhibitors were published. No data about insulin effects on NAFLD are available but it was showed a possible association between insulin use and the development of solid neoplasms, in particular HCC. In conclusion, antidiabetic drugs seem to be promising drugs, because they are able to treat both NAFLD manifestations and diabetes, preventing worsening of hepatic damage, but data are still conflicting. All antidiabetic drugs can be safely used in patients with compensated cirrhosis, while insulin is the preferred drug in decompensated Child C cirrhosis.

Evaluation of metformin therapy using controlled attenuation parameter and transient elastography in patients with non-alcoholic fatty liver disease

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is among the most common causes of liver disease worldwide. There is growing evidence on pathogenesis and pathophysiology of NAFLD. However, there is still no universally accepted pharmacotherapy protocol.

METHODS

The study was conducted on 42 patients with NAFLD. They were randomized to dietary treatment alone (n = 21) or to diet and metformin therapy (n = 21). Liver ultrasonography, controlled attenuation parameter (CAP), liver stiffness (LS), complete blood count, anthropometric and biochemical parameters were obtained before treatment (baseline), and after 3 and 5 months of the therapy.

RESULTS

Patients treated with diet and metformin exhibited significantly decreased CAP values at 3 and 5 months of the therapy compared to baseline (319 dB/m vs. 285 dB/m; p < 0.05; 319 dB/m vs. 295 dB/m; p < 0.05 respectively). Five months of diet and the metformin therapy resulted in significant reduction of LS value (6.2 kPa vs. 5.2 kPa; p <  0.05), while patients treated with diet alone had no significant changes in liver CAP and LS measurements.

CONCLUSIONS

Metformin therapy combined with dietary treatment seems to be effective for the reduction of hepatic steatosis and fibrosis. However, considering limitations of the study and inconsistent results of previous investigations in this area, there is a need for further research on metformin efficacy in this group of patients.

Pharmacological interventions for non-alcoholic fatty liver disease: a systematic review and network meta-analysis

AIM

Several drugs have been used for treating non-alcoholic fatty liver disease (NAFLD). The present study is a network meta-analysis of such drugs.

DESIGN, SETTING AND PATIENTS

Randomised clinical trials comparing drug interventions in patients with NAFLD were analysed. OR and weighted mean difference (95 % CI) were the effect estimates for categorical and numerical outcomes, respectively. Random-effects model was used to generate pooled estimates. Surface under the cumulative ranking curve was used to rank the treatments.

MAIN OUTCOME MEASURES

Proportion of responders was the primary outcome measure and non-alcoholic steatohepatitis scores, liver enzymes, lipid profile, body mass index, homeostatic model assessment of insulin resistance, intrahepatic fat and adverse events were the key secondary outcomes.

RESULTS

116 studies were included in the systematic review and 106 in the meta-analysis. Elafibranor, gemfibrozil, metadoxine, obeticholic acid, pentoxifylline, pioglitazone, probiotics, telmisartan, vildagliptin and vitamin E significantly increased the response rate than standard of care. Various other drugs were observed to modify the secondary outcomes favourably. Probiotics was found with a better response in children; and elafibranor, obeticholic acid, pentoxifylline and pioglitazone in patients with type 2 diabetes mellitus. The quality of evidence observed was either low or very low.

CONCLUSION

In patients with NAFLD, several drugs have been shown to have variable therapeutic benefit. However, the estimates and the inferences should be considered with extreme caution as it might change with the advent of future head-to-head clinical trials.

Association of non-alcoholic fatty liver disease with cardiovascular disease and subclinical atherosclerosis

Non-alcoholic fatty liver disease (NAFLD) refers to fatty infiltration of liver in the absence of significant alcohol intake, use of steatogenic medication, or hereditary disorders. It is a common cause of chronic liver disease with a worldwide estimated prevalence ranging from 6.3% to 33%. The NAFLD is considered a hepatic manifestation of the metabolic syndrome. Insulin resistance and increased oxidative stress are central to pathogenesis of NAFLD, and risk factors include metabolic syndrome, diabetes mellitus, obesity, lack of physical activity, smoking, and high fat diet. NAFLD is associated with higher mortality as compared to the general population with cardiovascular disease being the most common cause of death. The NAFLD is associated with a higher prevalence of subclinical atherosclerosis as evidenced by odds of higher coronary artery calcification, higher average and maximum carotid intima-media thickness. It is also associated with stiff arteries as evidenced by higher cardio-ankle vascular index and higher brachial-ankle pulse wave velocity. Increasing evidence has linked NAFLD with atherosclerotic cardiovascular diseases. The NAFLD is associated with a higher prevalence of coronary artery disease (CAD), more severe CAD, poor coronary collateral development, and higher incidence of coronary events. The NAFLD is also associated with ischemic stroke. Studies have shown that the association between NAFLD and atherosclerotic cardiovascular diseases is independent of shared risk factors.

Randomised clinical trial: a leucine-metformin-sildenafil combination (NS-0200) vs placebo in patients with non-alcoholic fatty liver disease

BACKGROUND

Sirtuin 1 (Sirt1) is suppressed in non-alcoholic fatty liver disease (NAFLD), while its' stimulation or overexpression results in reduced disease severity in pre-clinical NAFLD models. Leucine allosterically activates Sirt1 and synergise with other Sirt/AMPK/NO pathway activators. We developed a triple combination of leucine, metformin and sildenafil (NS-0200), which was effective in a mouse model of non-alcoholic steatohepatitis (NASH).

AIM

To report the results from a Phase 2, randomised clinical trial of of NS-0200 in 91 subjects with NAFLD (liver fat ≥15% by magnetic resonance imaging-proton-density fat fraction (MRI-PDFF)).

METHODS

Subjects were randomised to placebo, low-dose (1.1 g leucine/0.5 g metformin/0.5 mg sildenafil) or high-dose NS-0200 (1.1 g leucine/0.5 g metformin/1.0 mg sildenafil) b.d. for 16 weeks; change in hepatic fat was assessed via MRI-PDFF, and lipid metabolism was assessed via changes in the lipidomic signature. Seventy subjects completed the trial and met a priori compliance criteria. Analyses were conducted on the full cohort and on those with alanine aminotransferase (ALT) values above median (50 U/L; n = 35).

RESULTS

In the full cohort, active treatments did not separate from placebo. High dose NS-0200 reduced hepatic fat by 15.7% (relative change from baseline) in the high ALT group (P < 0.005) while low dose NS-0200 and placebo did not significantly change hepatic fat. Lipidomic analysis showed dose-responsive treatment effects in both overall and high ALT cohorts, with significant decreases in metabolically active lipids and up-regulation of fatty acid oxidation.

CONCLUSION

These data support further evaluation of high-dose NS-0200 for treating NASH, especially in those with elevated ALT (NCT 02546609).

The effect of antidiabetic medications on non-alcoholic fatty liver disease (NAFLD)

Non-alcoholic fatty liver disease (NAFLD) is the hepatic manifestation of the metabolic syndrome and is prevalent in more than 50% of patients with type II diabetes. At present, there is no approved therapy for NASH. Until now, the only proven effective interventions in improving biochemical and histological features of NASH, including fibrosis, are weight loss and physical activity even without weight loss. Because of the common epidemiological and pathophysiological features between NAFLD and T2DM, many antidiabetics drugs have been tested in patients with NAFLD over the years. Among these, pioglitazone and liraglutide seem to improve some histological features of NASH but have no clear effect on fibrosis. Metformin has been largely studied in the past years without convincing evidence of improving NAFLD. Data on other compounds such as DDP-4 and SGLT-2 inhibitors are limited. The rational and results of such studies are discussed in the present review.

Thiazolidinediones versus metformin on improving abnormal liver enzymes in patients with type 2 diabetes mellitus: a meta-analysis

Background

Liver enzyme abnormalities are common in patients with type 2 diabetes. Currently, the inverse relationship between elevated liver enzymes and antidiabetics intake may be explained by rigorous treatment and good control. However, few studies have directly explored the influence of antidiabetics on abnormal liver function, especially the comparison between two insulin sensitizers—thiazolidinediones and metformin.

Materials And Methods

Databases, including PubMed, Cochrane, CNKI, Wanfang and VIP were searched. Two reviewers performed independently. Meta-analysis was used when studies were homogeneous enough.

Results

Six studies, including 4726 patients with type 2 diabetes, were involved in this systematic review. Compared with metformin, thiazolidinediones significantly reduced the alanine transaminase, aspartate aminotransferase and gamma-glutamyl transpeptidase. Further subgroup analysis suggested that pioglitazone-treated participants showed vast improvement in decreasing alanine transaminase (MD = -13.70; 95% CI = -16.91 to -10.52; P < 0.00001; I² = 1%), aspartate aminotransferase (MD = -3.51; 95% CI = -5.74 to –1.28; P = 0.002; I² = 0%) and gamma-glutamyl transpeptidase (MD = -5.41; 95% CI = -9.40 to -1.42; P = 0.008; I² = 0%), while rosiglitazone exhibited no difference in lowering corresponding liver enzyme levels. Besides, thiazolidinediones similarly decreased fasting plasma glucose. However, thiazolidinediones were inferior to metformin in lowering HbA1C and alkaline phosphatase. Additionally, no significant publication bias was seen.

Conclusions

Thiazolidinediones may confer modest biological improvement of liver function in people with type 2 diabetes than metformin. But owing to the limited methodological quality, more clinical researches are warranted in the future.

The pharmacological management of NAFLD in children and adolescents

INTRODUCTION

Non-alcoholic fatty liver disease (NAFLD) represents a spectrum, including 'simple' steatosis, non-alcoholic steatohepatitis (NASH), and fibrosis. Increasing prevalence of NAFLD has followed the international rise in obesity and lifestyle modification is the mainstay therapy for children. To date, pharmacological trials have had varying efficacy but a large number of new agents are in early phase trials for adults. Areas covered: This review explores the effect of current and potential future paediatric NAFLD treatments in terms of histological and biochemical endpoints. The potential for the extension of adult treatments to children is discussed, as well as what limits the use of certain agents in children. Expert commentary: No drugs have yet to be licenced for NAFLD. Trial heterogeneity makes comparison of drugs between studies challenging. FXR agonists are yet to be trialled in children but may represent a safe and potentially efficacious therapy. Future treatments would likely encompass a multimodal approach that may include bariatric surgery.

Thiazolidinedione drugs in the treatment of type 2 diabetes mellitus: past, present and future

Thiazolidinedione (TZD) drugs used in the treatment of type 2 diabetes mellitus (T2DM) have proven effective in improving insulin sensitivity, hyperglycemia, and lipid metabolism. Though well tolerated by some patients, their mechanism of action as ligands of peroxisome proliferator-activated receptors (PPARs) results in the activation of several pathways in addition to those responsible for glycemic control and lipid homeostasis. These pathways, which include those related to inflammation, bone formation, and cell proliferation, may lead to adverse health outcomes. As treatment with TZDs has been associated with adverse hepatic, cardiovascular, osteological, and carcinogenic events in some studies, the role of TZDs in the treatment of T2DM continues to be debated. At the same time, new therapeutic roles for TZDs are being investigated, with new forms and isoforms currently in the pre-clinical phase for use in the prevention and treatment of some cancers, inflammatory diseases, and other conditions. The aims of this review are to provide an overview of the mechanism(s) of action of TZDs, a review of their safety for use in the treatment of T2DM, and a perspective on their current and future therapeutic roles.

Thiazolidinediones and Advanced Liver Fibrosis in Nonalcoholic Steatohepatitis: A Meta-analysis

IMPORTANCE

Nonalcoholic steatohepatitis (NASH) is projected to be the leading cause of liver transplantation by 2020. Advanced fibrosis (stage F3-F4) on liver biopsy independently predicts all-cause and liver-related mortality in NASH. There are no known efficacious treatments for advanced fibrosis related to NASH. Thiazolidinedione therapy has been extensively evaluated in NASH, and new randomized clinical trials (RCTs) of its efficacy have been completed.

OBJECTIVE

To synthesize the evidence about the association of thiazolidinedione therapy with advanced liver fibrosis in NASH.

DATA SOURCES

MEDLINE, Ovid MEDLINE In-Process, Cochrane Library, EMBASE, clinicaltrials.gov, PubMed, and Scopus databases (without language restrictions), as well as other registries and scientific meeting presentations, from database inception through August 15, 2016.

STUDY SELECTION

Randomized clinical trials evaluating the effect of thiazolidinedione therapy on histologic features of the liver in biopsy-proven NASH.

DATA EXTRACTION AND SYNTHESIS

Two investigators extracted study data independently and in duplicate and rated the risk of bias using the Cochrane Risk of Bias Tool.

MAIN OUTCOMES AND MEASURES

The primary outcome was a dichotomous improvement in advanced fibrosis on liver biopsy, defined as an improvement in fibrosis stage from F3-F4 to F0-F2. Secondary outcomes were at least a 1-point improvement in fibrosis of any stage and NASH resolution. This meta-analysis also evaluated adverse effects of thiazolidinedione therapy, including weight gain, lower limb edema, congestive heart failure, bone fractures, cancer, and anemia. With the use of random-effects models, dichotomous variables are presented as odds ratios (ORs) with 95% CIs, and continuous variables are presented as weighted mean differences with 95% CIs.

RESULTS

This study analyzed 8 RCTs (5 evaluating pioglitazone use and 3 evaluating rosiglitazone maleate use) enrolling 516 patients with biopsy-proven NASH for a duration of 6 to 24 months. Among all studies combined, thiazolidinedione therapy was associated with improved advanced fibrosis (OR, 3.15; 95% CI, 1.25-7.93; P = .01; I2 = 0%), fibrosis of any stage (OR, 1.66; 95% CI, 1.12-2.47; P = .01; I2 = 0%), and NASH resolution (OR, 3.22; 95% CI, 2.17-4.79; P < .001; I2 = 0%). Analyses restricted to RCTs enrolling patients without diabetes yielded similar results for improvement in advanced fibrosis (OR, 2.95; 95% CI, 1.04-10.90; P = .02; I2 = 0%), improvement in fibrosis of any stage (OR, 1.76; 95% CI, 1.02-3.03; P = .02; I2 = 0%), and NASH resolution (OR, 3.40; 95% CI, 1.95-5.93; P < .001; I2 = 0%). All effects were accounted for by pioglitazone use. Weight gain and lower limb edema occurred more frequently with thiazolidinedione therapy (initial body weight +2.70%; 95% CI, 1.96%-4.34%; P = .001). The small sample size of included RCTs prevented evaluation of more serious adverse effects of thiazolidinedione therapy.

CONCLUSIONS AND RELEVANCE

Pioglitazone use improves advanced fibrosis in NASH, even in patients without diabetes. Whether this finding translates to improvement in risk for clinical outcomes requires further study.

Pharmacological interventions for non-alcohol related fatty liver disease (NAFLD): an attempted network meta-analysis

BACKGROUND

Non-alcohol related fatty liver disease (commonly called non-alcoholic fatty liver disease (NAFLD)) is liver steatosis in the absence of significant alcohol consumption, use of hepatotoxic medication, or other disorders affecting the liver such as hepatitis C virus infection, Wilson's disease, and starvation. NAFLD embraces the full spectrum of disease from pure steatosis (i.e. uncomplicated fatty liver) to non-alcoholic steatohepatitis (NASH), via NASH-cirrhosis to cirrhosis. The optimal pharmacological treatment for people with NAFLD remains uncertain.

OBJECTIVES

To assess the comparative benefits and harms of different pharmacological interventions in the treatment of NAFLD through a network meta-analysis and to generate rankings of the available pharmacological treatments according to their safety and efficacy. However, it was not possible to assess whether the potential effect modifiers were similar across different comparisons. Therefore, we did not perform the network meta-analysis, and instead, assessed the comparative benefits and harms of different interventions using standard Cochrane methodology.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, Science Citation Index Expanded, the World Health Organization International Clinical Trials Registry Platform, and ClinicalTrials.com to August 2016.

SELECTION CRITERIA

We included only randomised clinical trials (irrespective of language, blinding, or publication status) in participants with NAFLD. We excluded trials which included participants who had previously undergone liver transplantation. We considered any of the various pharmacological interventions compared with each other or with placebo or no intervention.

DATA COLLECTION AND ANALYSIS

We calculated the odds ratio (OR) and rate ratio with 95% confidence intervals (CI) using both fixed-effect and random-effects models based on an available participant analysis with Review Manager. We assessed risk of bias according to the Cochrane risk of bias tool, controlled risk of random errors with Trial Sequential Analysis, and assessed the quality of the evidence using GRADE.

MAIN RESULTS

We identified 77 trials including 6287 participants that met the inclusion criteria of this review. Forty-one trials (3829 participants) provided information for one or more outcomes. Only one trial was at low risk of bias in all domains. All other trials were at high risk of bias in one or more domains. Overall, all the evidence was very low quality. Thirty-five trials included only participants with non-alcohol related steatohepatitis (NASH) (based on biopsy confirmation). Five trials included only participants with diabetes mellitus; 14 trials included only participants without diabetes mellitus. The follow-up in the trials ranged from one month to 24 months.We present here only the comparisons of active intervention versus no intervention in which two or more trials reported at least one of the following outcomes: mortality at maximal follow-up, serious adverse events, and health-related quality of life, the outcomes that determine whether a treatment should be used. Antioxidants versus no interventionThere was no mortality in either group (87 participants; 1 trial; very low quality evidence). None of the participants developed serious adverse events in the trial which reported the proportion of people with serious adverse events (87 participants; 1 trial; very low quality evidence). There was no evidence of difference in the number of serious adverse events between antioxidants and no intervention (rate ratio 0.89, 95% CI 0.36 to 2.19; 254 participants; 2 trials; very low quality evidence). None of the trials reported health-related quality of life. Bile acids versus no interventionThere was no evidence of difference in mortality at maximal follow-up (OR 5.11, 95% CI 0.24 to 107.34; 659 participants; 4 trials; very low quality evidence), proportion of people with serious adverse events (OR 1.56, 95% CI 0.84 to 2.88; 404 participants; 3 trials; very low quality evidence), or the number of serious adverse events (rate ratio 1.01, 95% CI 0.66 to 1.54; 404 participants; 3 trials; very low quality evidence) between bile acids and no intervention. None of the trials reported health-related quality of life. Thiazolidinediones versus no interventionThere was no mortality in either group (74 participants; 1 trial; very low quality evidence). None of the participants developed serious adverse events in the two trials which reported the proportion of people with serious adverse events (194 participants; 2 trials; very low quality evidence). There was no evidence of difference in the number of serious adverse events between thiazolidinediones and no intervention (rate ratio 0.25, 95% CI 0.06 to 1.05; 357 participants; 3 trials; very low quality evidence). None of the trials reported health-related quality of life. Source of fundingTwenty-six trials were partially- or fully-funded by pharmaceutical companies that would benefit, based on the results of the trial. Twelve trials did not receive any additional funding or were funded by parties with no vested interest in the results. The source of funding was not provided in 39 trials.

AUTHORS' CONCLUSIONS

Due to the very low quality evidence, we are very uncertain about the effectiveness of pharmacological treatments for people with NAFLD including those with steatohepatitis. Further well-designed randomised clinical trials with sufficiently large sample sizes are necessary.

The role of insulin resistance in nonalcoholic steatohepatitis and liver disease development--a potential therapeutic target?

Insulin resistance (IR) is defined by the inability of insulin to exert its metabolic actions, due to impaired activation of intracellular insulin signaling. This condition is caused by genetic defects or by environmental conditions, among which the most common is obesity. Systemic IR determines the development of hepatic fat accumulation, which can progress to nonalcoholic steatohepatitis, cirrhosis and hepatocellular carcinoma, and is a major determinant of liver disease independently of coexisting factors. Therefore, insulin-sensitizing drugs are currently under evaluation to improve steatohepatitis. Indeed, manipulation of nuclear hormone receptors is already under scrutiny for liver disease prevention by amelioration of IR, whereas NOTCH signaling inhibition represents a novel approach. Nevertheless, further research is warranted to better understand the mechanism linking IR to progressive fibrogenesis in the absence of inflammation and to identify novel drug targets.

Thiazolidinediones for nonalcoholic steatohepatitis: A meta-analysis of randomized clinical trials

The findings regarding the effects of thiazolidinediones (TZDs) in nonalcoholic steatohepatitis (NASH) patients have been inconsistent, and the assessment of different clinical variables for evaluating the effects of TZDs confound a direct comparison of the results of different randomized clinical trials (RCTs), especially with regard to lifestyle changes. In this paper, we performed a meta-analysis of randomized controlled trials to clarify the effects of TZD treatment with and without lifestyle changes on histological markers of NASH and clinical variables related to insulin resistance (IR), hyperlipidemia, and obesity. We searched the literature using the following MeSH terms: "nonalcoholic steatohepatitis," "non-alcoholic steatohepatitis," "thiazolidinedione," "pioglitazone," "rosiglitazone," "randomized," and "clinical trial." Five eligible RCTs were selected, in which patients were treated with either pioglitazone or rosiglitazone, with or without lifestyle changes. We compared the effects of TZD treatment on hepatic fibrosis, lobular inflammation, IR improvement, fasting serum insulin, adiposity, and dyslipidemia between the various studies using fixed and random effects models, and heterogeneity in clinical outcomes was assessed. Significant improvement in hepatic fibrosis did not occur among the patients treated with TZDs alone or in those who underwent both lifestyle changes and TZD therapy. Lobular inflammation decreased in NASH patients who received TZD treatment and in those who underwent both TZD therapy and lifestyle changes. Although TZD treatment resulted in no significant improvement in IR, NASH patients who underwent both lifestyle changes and TZD therapy experienced a significantly greater reduction in their fasting insulin level than that observed in the control patients, whereas patients treated with TZDs alone did not. Although TZD-treated patients experienced significantly greater weight gain than the control patients, TZD treatment had no significant impact on body-mass index, percentage of body fat, or serum levels of cholesterol and triglyceride. Our findings indicate that additional variables should be assessed to obtain a more comprehensive evaluation of the effects of TZD treatment on IR and comorbidity risk factors in NASH patients, and suggest that including lifestyle changes and additional insulin-sensitizing agents in TZD regimens might improve the benefits of TZD therapy for NASH.

Comparative efficacy of interventions on nonalcoholic fatty liver disease (NAFLD): A PRISMA-compliant systematic review and network meta-analysis

BACKGROUND

The prevalence of nonalcoholic fatty liver disease (NAFLD) has significantly increased over the last decades. Despite existence of several interventions, there remains unclear which interventions work the best.

METHODS

A systematic review and network meta-analysis of randomized trials comparing efficacy of all treatment options in NAFLD were performed to determine comparative efficacy and safety of interventions in the management of NAFLD. Several electronic databases were searched up to Nov 15, 2015. Outcomes include liver histological outcomes (i.e., fibrosis), all-cause mortality, cirrhosis, and safety. A network meta-analysis was applied to estimate pooled risk ratios (RR). Quality of evidence was assessed using GRADE criteria.

RESULTS

A total of 44 studies (n = 3802) were eligible. When compared with placebo, obeticholic acid (OCA) was the only intervention that significantly improved fibrosis with RR (95% CI) of 1.91 (1.15, 3.16), while pentoxyfylline (PTX) demonstrated improved fibrosis without statistical significance with RR (95% CI) of 2.27 (0.81, 6.36). Only thiazolidinedione (TZD) and vitamin E use resulted in significant increase in resolution of NASH, while OCA, TZD, and vitamin E significantly improved other outcomes including NAS, steatosis, ballooning, and inflammation outcomes. Quality of evidence varied from very low (i.e., metformin, PTX on mean change of ballooning grade) to high (OCA, TZD, vitamin E on improving histological outcomes). Limitations of this study were lack of relevant long-term outcomes (e.g., cirrhosis, death, safety), possible small study effect, and few head-to-head studies.

CONCLUSIONS

Our study suggests potential efficacy of OCA, TZD, and vitamin E in improving histologic endpoints in NAFLD. These findings are however based on a small number of studies. Additional studies are awaited to strengthen this network meta-analysis.

Sitagliptin vs. placebo for non-alcoholic fatty liver disease: A randomized controlled trial

BACKGROUND & AIMS

Uncontrolled studies show sitagliptin, an oral DPP-4 inhibitor, may improve alanine aminotransferase and liver histology in non-alcoholic fatty liver disease (NAFLD) patients. We aimed to compare sitagliptin vs. the efficacy of a placebo in reducing liver fat measured by MRI-derived proton density-fat fraction (MRI-PDFF).

METHODS

This randomized, double-blind, allocation-concealed, placebo-controlled trial included 50 NAFLD patients with prediabetes or early diabetes randomized to sitagliptin orally 100mg/day or placebo for 24weeks. Primary outcome was liver fat change measured by MRI-PDFF in colocalized regions of interest within each of nine liver segments. Additional advanced assessments included MR spectroscopy (MRS) for internal validation of MRI-PDFF's accuracy, and magnetic resonance elastography (MRE) and FIBROSpect® II to assess liver fibrosis.

RESULTS

Sitagliptin was not significantly better than placebo in reducing liver fat measured by MRI-PDFF (mean difference between sitagliptin and placebo arms: -1.3%, p=0.4). Compared to baseline, there were no significant differences in end-of-treatment MRI-PDFF for sitagliptin (18.1% to 16.9%, p=0.27) or placebo (16.6% to 14.0%, p=0.07). The groups had no significant differences for changes in alanine aminotransferase, aspartate aminotransferase, low-density lipoprotein, homeostatic model assessment insulin resistance, and MRE-derived liver stiffness. In both groups at baseline and post-treatment, MRI-PDFF and MRS showed robust correlation coefficients ranging from r(2)=0.96 to r(2)=0.99 (p<0.0001), demonstrating the strong internal validity of the findings. FIBROSpect® II showed no changes in the sitagliptin group but was significantly increased in the placebo group (p=0.03).

CONCLUSIONS

Sitagliptin was safe but not better than placebo in reducing liver fat in prediabetic or diabetic patients with NAFLD.

LAY SUMMARY

In a randomized, double-blind, placebo-controlled study, the anti-diabetic drug sitagliptin was no more effective than placebo for improving liver fat and liver fibrosis in patients with non-alcoholic fatty liver disease. This study demonstrates that non-invasive magnetic resonance imaging techniques, including magnetic resonance imaging-proton density-fat fraction and magnetic resonance elastography, can be used to assess treatment response in non-alcoholic fatty liver disease clinical trials.

Treating the patient with nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is becoming a worldwide health crisis. It is important for NPs to understand the spectrum of NAFLD. Although lifestyle modifications are the first-line treatment, the NP should be aware of current and future medication management to help the patient live a healthy life.

Practical combination therapy based on pathophysiology of type 2 diabetes

Type 2 diabetes is a complex, chronic, and progressive condition that often necessitates the use of multiple medications to achieve glycemic goals. Clinical guidelines generally recommend intensifying pharmacotherapy if glycemic goals are not achieved after 3 months of treatment. However, for many patients with type 2 diabetes, treatment intensification is delayed or does not occur. Initiating combination therapy early in the disease course has the potential to delay disease progression and improve patient outcomes. Guidelines generally provide a list of agents that may be used in combination regimens and emphasize individualization of treatment. The purpose of this review is to discuss the rationale for combination therapy, considering treatment effects on pathophysiologic aspects of type 2 diabetes and individual drug profiles. The combination of newer antidiabetes therapies with complementary mechanisms of action provides the opportunity to target multiple sites of tissue, organ, and cellular dysfunction.

Cost-effectiveness of non-invasive methods for assessment and monitoring of liver fibrosis and cirrhosis in patients with chronic liver disease: systematic review and economic evaluation

BACKGROUND

Liver biopsy is the reference standard for diagnosing the extent of fibrosis in chronic liver disease; however, it is invasive, with the potential for serious complications. Alternatives to biopsy include non-invasive liver tests (NILTs); however, the cost-effectiveness of these needs to be established.

OBJECTIVE

To assess the diagnostic accuracy and cost-effectiveness of NILTs in patients with chronic liver disease.

DATA SOURCES

We searched various databases from 1998 to April 2012, recent conference proceedings and reference lists.

METHODS

We included studies that assessed the diagnostic accuracy of NILTs using liver biopsy as the reference standard. Diagnostic studies were assessed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool. Meta-analysis was conducted using the bivariate random-effects model with correlation between sensitivity and specificity (whenever possible). Decision models were used to evaluate the cost-effectiveness of the NILTs. Expected costs were estimated using a NHS perspective and health outcomes were measured as quality-adjusted life-years (QALYs). Markov models were developed to estimate long-term costs and QALYs following testing, and antiviral treatment where indicated, for chronic hepatitis B (HBV) and chronic hepatitis C (HCV). NILTs were compared with each other, sequential testing strategies, biopsy and strategies including no testing. For alcoholic liver disease (ALD), we assessed the cost-effectiveness of NILTs in the context of potentially increasing abstinence from alcohol. Owing to a lack of data and treatments specifically for fibrosis in patients with non-alcoholic fatty liver disease (NAFLD), the analysis was limited to an incremental cost per correct diagnosis. An analysis of NILTs to identify patients with cirrhosis for increased monitoring was also conducted.

RESULTS

Given a cost-effectiveness threshold of £20,000 per QALY, treating everyone with HCV without prior testing was cost-effective with an incremental cost-effectiveness ratio (ICER) of £9204. This was robust in most sensitivity analyses but sensitive to the extent of treatment benefit for patients with mild fibrosis. For HBV [hepatitis B e antigen (HBeAg)-negative)] this strategy had an ICER of £28,137, which was cost-effective only if the upper bound of the standard UK cost-effectiveness threshold range (£30,000) is acceptable. For HBeAg-positive disease, two NILTs applied sequentially (hyaluronic acid and magnetic resonance elastography) were cost-effective at a £20,000 threshold (ICER: £19,612); however, the results were highly uncertain, with several test strategies having similar expected outcomes and costs. For patients with ALD, liver biopsy was the cost-effective strategy, with an ICER of £822.

LIMITATIONS

A substantial number of tests had only one study from which diagnostic accuracy was derived; therefore, there is a high risk of bias. Most NILTs did not have validated cut-offs for diagnosis of specific fibrosis stages. The findings of the ALD model were dependent on assuptions about abstinence rates assumptions and the modelling approach for NAFLD was hindered by the lack of evidence on clinically effective treatments.

CONCLUSIONS

Treating everyone without NILTs is cost-effective for patients with HCV, but only for HBeAg-negative if the higher cost-effectiveness threshold is appropriate. For HBeAg-positive, two NILTs applied sequentially were cost-effective but highly uncertain. Further evidence for treatment effectiveness is required for ALD and NAFLD.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42011001561.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Mechanism of Altered Metformin Distribution in Nonalcoholic Steatohepatitis

Metformin is an antihyperglycemic drug that is widely prescribed for type 2 diabetes mellitus and is currently being investigated for the treatment of nonalcoholic steatohepatitis (NASH). NASH is known to alter hepatic membrane transporter expression and drug disposition similarly in humans and rodent models of NASH. Metformin is almost exclusively eliminated through the kidney primarily through active secretion mediated by Oct1, Oct2, and Mate1. The purpose of this study was to determine how NASH affects kidney transporter expression and metformin pharmacokinetics. A single oral dose of [(14)C]metformin was administered to C57BL/6J (wild type [WT]) and diabetic ob/ob mice fed either a control diet or a methionine- and choline-deficient (MCD) diet. Metformin plasma concentrations were slightly increased in the WT/MCD and ob/control groups, whereas plasma concentrations were 4.8-fold higher in ob/MCD mice compared with WT/control. The MCD diet significantly increased plasma half-life and mean residence time and correspondingly decreased oral clearance in both genotypes. These changes in disposition were caused by ob/ob- and MCD diet-specific decreases in the kidney mRNA expression of Oct2 and Mate1, whereas Oct1 mRNA expression was only decreased in ob/MCD mice. These results indicate that the diabetic ob/ob genotype and the MCD disease model alter kidney transporter expression and alter the pharmacokinetics of metformin, potentially increasing the risk of drug toxicity.

Non-alcoholic fatty liver disease following liver transplantation: a clinical review

Non-alcoholic steatohepatitis (NASH) is rapidly becoming the leading indication for liver transplantation (LT) in the United States. While post-transplantation outcomes are similar to other indications for transplant, recent evidence has suggested that reduction in risk factors for post-transplant metabolic syndrome may impose a significant survival benefit in this patient population. Cardiovascular mortality is the leading cause of death following transplantation for NASH. While pre-transplant pharmacologic and surgical approaches have been utilized to reduce cardiovascular risk factors following transplantation, the effectiveness of these treatment approaches in the post-transplant setting is poorly defined. Studies are urgently needed in the treatment of this rapidly growing population.

Liver Injury Indicating Fatty Liver but Not Serologic NASH Marker Improves under Metformin Treatment in Polycystic Ovary Syndrome

Objective. Polycystic ovary syndrome (PCOS) is associated with obesity and insulin resistance (IR), key features of nonalcoholic steatohepatitis (NASH). Cytokeratin 18 fragments (M30) have been established as a serum marker for NASH. The insulin sensitizer metformin improves hepatic IR. This study evaluates the influence of MF on serologic NASH (sNASH) in patients with PCOS. Patients and Methods. In 89 patients, metabolic parameters, liver injury indicating fatty liver (LIFL), and M30 were assessed at baseline and after metformin treatment. Patients with initial IR were subdivided into dissolved (PCOS-exIR) and persistent IR (PCOS-PIR) after treatment and compared to an initially insulin sensitive PCOS group (PCOS-C). Results. Improvement of LIFL prevalence could be seen in PCOS-C and PCOS-exIR compared to PCOS-PIR (-19.4, resp., -12.0% versus 7.2%, Chi(2) = 29.5, P < 0.001) without change in sNASH prevalence. In PCOS-PIR, ALT levels increased significantly accompanied by a nominal, nonsignificant M30 increase. Conclusions. Metformin improves LIFL in subgroups of patients with PCOS without influencing sNASH. This could either indicate a missing effect of metformin on NAFLD or slowed disease progression. Further studies are needed to elucidate NAFLD in the context of PCOS and potential therapeutic options.

Review article: the management of paediatric nonalcoholic fatty liver disease

BACKGROUND

Paediatric nonalcoholic fatty liver disease (NAFLD) is a major public health concern given the recent increase in its prevalence and link to obesity and other metabolic comorbidities. Current treatment strategies involve lifestyle changes. Other surgical and pharmacologic interventions have been proposed; however, limited randomised controlled trials (RCTs) in the paediatric population restrict their use.

AIM

To review the current management of paediatric NAFLD, including lifestyle and pharmacologic interventions, and to formulate recommendations for study design for future studies.

METHODS

A MEDLINE, Pubmed and Cochrane Review database search used a combination of keywords, including NAFLD, nonalcoholic steatohepatitis (NASH), paediatric, treatments, lifestyle changes, bariatric surgery, orlistat, metformin, thiazolidinediones, vitamin E, cysteamine bitartrate, ursodeoxycholic acid (UDCA), probiotics, omega-3 fatty acids, pentoxyfylline, farnesoid X receptor agonist and toll-like receptor modifiers. The articles were selected based on their relevance to the review.

RESULTS

Lifestyle interventions involving diet and exercise remain first-line treatment for paediatric NAFLD. Bariatric surgery, orlistat, insulin sensitisers and UDCA have been evaluated but are not recommended as first or second-line therapy. Medications such as cysteamine bitartrate, probiotics, polyunsaturated fats and pentoxyfilline share beneficial effects in trials, however, there is a paucity of adequately powered RCTs in which liver histology is evaluated. Vitamin E has been shown to be effective and safe in improving NASH histology in children.

CONCLUSIONS

Lifestyle intervention should be first-line treatment for paediatric NAFLD. Vitamin E should be considered for those with biopsy-proven NASH or borderline NASH failing first-line therapy. Other therapeutics show promising results but require larger RCTs with convincing endpoints. Improved screening techniques, objective validated inclusion criteria and outcome measures as well as rigour in study design are necessary for propelling therapeutic discovery.

Liver transplantation for nonalcoholic fatty liver disease: New challenges and new opportunities

Nonalcoholic fatty liver disease (NAFLD) is becoming rapidly one of the most common indications for orthotopic liver transplantation in the world. Development of graft steatosis is a significant problem during the post-transplant course, which may happen as a recurrence of pre-existing disease or de novo NAFLD. There are different risk factors that might play a role in development of graft steatosis including post-transplant metabolic syndrome, immune-suppressive medications, genetics and others. There are few studies that assessed the effects of NAFLD on graft and patient survival; most of them were limited by the duration of follow up or by the number of patients. With this review article we will try to shed light on post-liver transplantation NAFLD, significance of the disease, how it develops, risk factors, clinical course and treatment options.

Metformin in the treatment of non-alcoholic fatty liver disease: safety, efficacy and mechanism

Non-alcoholic fatty liver disease (NAFLD) is the most common liver disease etiology worldwide. It encompasses a spectrum ranging from simple steatosis to non-alcoholic steatohepatitis. Although the physiopathology of NAFLD is partly known. Insulin-resistance plays a central role in the development and progression of NAFLD. Several studies have indicated that metformin, as an insulin sensitizer, effectively improves NAFLD and its related metabolic status. Metformin was effective in reducing enzyme levels in the short period, but very limited and controversial information are available on liver histology. Larger randomized controlled trials of sufficient duration using clearly defined histological endpoints are needed to fully assess the efficacy of this drug in modifying the natural history of NAFLD.