Efficacy and safety of anti-hyperglycaemic drugs in patients with non-alcoholic fatty liver disease with or without diabetes: An updated systematic review of randomized controlled trials.

AIM: There are no approved drugs for the treatment of non-alcoholic fatty liver disease (NAFLD). However, many randomized controlled trials (RCT) have examined the effect of anti-hyperglycaemic agents on NAFLD in patients with and without type 2 diabetes mellitus (T2DM), since both T2DM and insulin resistance are closely linked to this burdensome liver disease. METHODS: We systematically searched publication databases using predefined keywords to identify head-to-head or placebo-controlled RCTs (published until September 30, 2019) of NAFLD individuals testing the efficacy of anti-hyperglycaemic drugs to specifically treat NAFLD or non-alcoholic steatohepatitis (NASH). Outcomes of interest included changes in serum liver enzyme levels, liver fat, liver fibrosis, or histologic resolution of NASH. RESULTS: We included 29 RCTs involving a total of 2,617 individuals (∼45% had T2DM) that have used metformin (n=6 studies), glitazones (n=8 studies), glucagon-like peptide-1 receptor agonists (n=6 studies), dipeptidyl peptidase-4 inhibitors (n=4 studies) or sodium-glucose cotransporter-2 inhibitors (n=7 studies) to treat NAFLD. Although most anti-hyperglycaemic drugs improved serum liver enzyme levels, only glitazones (especially pioglitazone) and liraglutide showed an improvement of histologic features of NAFLD, with a mild beneficial effect also on liver fibrosis for pioglitazone only. CONCLUSION: RCT evidence supports the efficacy of some anti-hyperglycaemic agents (especially pioglitazone) in patients with NAFLD or NASH, though weight gain with pioglitazone may warrant caution. Further well-designed RCTs are needed to better characterize the efficacy and safety of monotherapy and combination therapy with anti-hyperglycaemic agents in patients with NAFLD.

Docosahexaenoic acid enrichment in NAFLD is associated with improvements in hepatic metabolism and hepatic insulin sensitivity: a pilot study.

This corrects the article DOI: 10.1038/ejcn.2017.9.

Docosahexaenoic acid enrichment in NAFLD is associated with improvements in hepatic metabolism and hepatic insulin sensitivity: a pilot study.

BACKGROUND/OBJECTIVE: Treatment of subjects with non-alcoholic fatty liver disease (NAFLD) with omega-3 polyunsaturated fatty acids (FAs) suggests high levels of docosahexaenoic acid (DHA) tissue enrichment decrease liver fat content. We assessed whether changes in erythrocyte DHA enrichment (as a surrogate marker of changes in tissue enrichment) were associated with alterations in hepatic de novo lipogenesis (DNL), postprandial FA partitioning and hepatic and peripheral insulin sensitivity in a sub-study of the WELCOME trial (Wessex Evaluation of fatty Liver and Cardiovascular markers in NAFLD (non-alcoholic fatty liver disease) with OMacor thErapy). SUBJECTS/METHODS: Sixteen participants were randomised to 4 g/day EPA+DHA (n=8) or placebo (n=8) for 15-18 months and underwent pre- and post-intervention measurements. Fasting and postprandial hepatic FA metabolism was assessed using metabolic substrates labelled with stable-isotope tracers (2H2O and [U13C]palmitate). Insulin sensitivity was measured by a stepped hyperinsulinaemic-euglycaemic clamp using deuterated glucose. Participants were stratified according to change in DHA erythrocyte enrichment (< or ⩾2% post intervention). RESULTS: Nine participants were stratified to DHA⩾2% (eight randomised to EPA+DHA and one to placebo) and seven to the DHA<2% group (all placebo). Compared with individuals with erythrocyte <2% change in DHA abundance, those with ⩾2% enrichment had significant improvements in hepatic insulin sensitivity, reduced fasting and postprandial plasma triglyceride concentrations, decreased fasting hepatic DNL, as well as greater appearance of 13C from dietary fat into plasma 3-hydroxybutyrate (all P<0.05). CONCLUSIONS: The findings from our pilot study indicate that individuals who achieved a change in erythrocyte DHA enrichment ⩾2% show favourable changes in hepatic FA metabolism and insulin sensitivity, which may contribute to decreasing hepatic fat content.

Type 2 Diabetes and Hepatocellular Carcinoma: Risk Factors and Pathogenesis.

PURPOSE OF REVIEW: This review aims to assess the epidemiological evidence for a link between type 2 diabetes and hepatocellular carcinoma and to investigate possible pathophysiological mechanisms. RECENT FINDINGS: The presence of type 2 diabetes significantly increases the risk of developing hepatocellular carcinoma, and treatment with metformin may be associated with a lower risk. Treatment with insulin and sulphonylureas may be associated with increased risk. The pathophysiology underlying development of hepatocellular carcinoma in this context is complex and is likely to involve increased proinflammatory mediators, oxidative stress, JNK-1 activation, increased IGF-1 activity, altered gut microbiota and immunomodulation. Hepatocellular carcinoma incidence is increasing and this is likely to be linked to the increasing incidence of type 2 diabetes, obesity and the metabolic syndrome. These conditions increase the risk of developing hepatocellular carcinoma, and a greater understanding of the underlying pathophysiology may help with the development of novel treatments.

Design and rationale of the WELCOME trial: A randomised, placebo controlled study to test the efficacy of purified long chainomega-3 fatty acid treatment in non-alcoholic fatty liver disease [corrected].

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) represents a range of liver conditions from simple fatty liver to progressive end stage liver disease requiring liver transplantation. NAFLD is common in the population and in certain sub groups (e.g. type 2 diabetes) up to 70% of patients may be affected. NAFLD is not only a cause of end stage liver disease and hepatocellular carcinoma, but is also an independent risk factor for type 2 diabetes and cardiovascular disease. Consequently, effective treatments for NAFLD are urgently needed. OBJECTIVES: The WELCOME study is testing the hypothesis that treatment with high dose purified long chain omega-3 fatty acids will have a beneficial effect on a) liver fat percentage and b) two histologically validated algorithmically-derived biomarker scores for liver fibrosis. DESIGN: In a randomised double blind placebo controlled trial, 103 participants with NAFLD were randomised to 15-18months treatment with either 4g/day purified long chain omega-3 fatty acids (Omacor) or 4g/day olive oil as placebo. Erythrocyte percentage DHA and EPA enrichment (a validated proxy for hepatic enrichment) was determined by gas chromatography. Liver fat percentage was measured in three discrete liver zones by magnetic resonance spectroscopy (MRS). We also measured body fat distribution, physical activity and a range of cardiometabolic risk factors. METHODS: Recruitment started in January 2010 and ended in June 2011. We identified 178 potential participants, and randomised 103 participants who met the inclusion criteria. The WELCOME study was approved by the local ethics committee (REC: 08/H0502/165; www.clinicalTrials.gov registration number NCT00760513).

Omega-3 fatty acids, hepatic lipid metabolism, and nonalcoholic fatty liver disease.

Long-chain omega-3 fatty acids belong to a family of polyunsaturated fatty acids that are known to have important beneficial effects on metabolism and inflammation. Such effects may confer a benefit in specific chronic noncommunicable diseases that are becoming very prevalent in Westernized societies [e.g., nonalcoholic fatty liver disease (NAFLD)]. Typically, with a Westernized diet, long-chain omega-6 fatty acid consumption is markedly greater than omega-3 fatty acid consumption. The potential consequences of an alteration in the ratio of omega-6 to omega-3 fatty acid consumption are increased production of proinflammatory arachidonic acid-derived eicosanoids and impaired regulation of hepatic and adipose function, predisposing to NAFLD. NAFLD represents a spectrum of liver fat-related conditions that originates with ectopic fat accumulation in liver (hepatic steatosis) and progresses, with the development of hepatic inflammation and fibrosis, to nonalcoholic steatohepatitis (NASH). If the adipose tissue is inflamed with widespread macrophage infiltration, the production of adipokines may act to exacerbate liver inflammation and NASH. Omega-3 fatty acid treatment may have beneficial effects in regulating hepatic lipid metabolism, adipose tissue function, and inflammation. Recent studies testing the effects of omega-3 fatty acids in NAFLD are showing promise and suggesting that these fatty acids may be useful in the treatment of NAFLD. To date, further research is needed in NAFLD to (a) establish the dose of long-chain omega-3 fatty acids as a treatment, (b) determine the duration of therapy, and (c) test whether there is benefit on the different component features of NAFLD (hepatic fat, inflammation, and fibrosis).

Non-alcoholic fatty liver disease and cardiovascular risk: metabolic aspects and novel treatments.

Non-alcoholic fatty liver disease (NAFLD) is usually a silent disease that occurs in a very high proportion of people with features of the metabolic syndrome, including overweight, insulin resistance and type 2 diabetes. Because obesity and type 2 diabetes are now extremely common in Westernised societies, it is likely that the prevalence of NAFLD increases markedly in the future. Although previously it was thought that NAFLD was harmless, it is now recognised that NAFLD can be a progressive liver condition that increases risk of cirrhosis, end-stage liver disease and hepatocellular carcinoma. Additionally, liver fat accumulation causes insulin resistance and increases risk of type 2 diabetes. Increasing evidence now shows NAFLD is a risk factor for cardiovascular disease (CVD). The purpose of this review is to briefly discuss the pathogenesis of NAFLD, to describe the relationship between NAFLD and CVD and the mechanisms linking both conditions and to discuss some of the treatment options (including lifestyle, nutrition and drugs) that may influence both NAFLD and risk of CVD.