Effects of lixisenatide on elevated liver transaminases: systematic review with individual patient data meta-analysis of randomised controlled trials on patients with type 2 diabetes

Hepatic glucose metabolism in the steatotic liver

The liver is central in regulating glucose homeostasis, being the major contributor to endogenous glucose production and the greatest reserve of glucose as glycogen. It is both a target and regulator of the action of glucoregulatory hormones. Hepatic metabolic functions are altered in and contribute to the highly prevalent steatotic liver disease (SLD), including metabolic dysfunction-associated SLD (MASLD) and metabolic dysfunction-associated steatohepatitis (MASH). In this Review, we describe the dysregulation of hepatic glucose metabolism in MASLD and MASH and associated metabolic comorbidities, and how advances in techniques and models for the assessment of hepatic glucose fluxes in vivo have led to the identification of the mechanisms related to the alterations in glucose metabolism in MASLD and comorbidities. These fluxes can ultimately increase hepatic glucose production concomitantly with fat accumulation and alterations in the secretion and action of glucoregulatory hormones. No pharmacological treatment has yet been approved for MASLD or MASH, but some antihyperglycaemic drugs approved for treating type 2 diabetes have shown positive effects on hepatic glucose metabolism and hepatosteatosis. A deep understanding of how MASLD affects glucose metabolic fluxes and glucoregulatory hormones might assist in the early identification of at-risk individuals and the use or development of targeted therapies.

The role of glucagon-like peptide-1 receptor agonists in nonalcoholic fatty liver disease

INTRODUCTION

Nonalcoholic fatty liver disease (NAFLD) is a highly prevalent disease, associated with obesity, type 2 diabetes mellitus and dyslipidemia, which can lead to liver cirrhosis and hepatocellular carcinoma in some patients. Apart from lifestyle modifications, which are the cornerstone for its management, several drugs are under evaluation, including glucagon-like peptide-1 receptor agonists (GLP-R1RAs). In this review, we summarized major clinical data concerning the effects of GLP-1RAs on NAFLD, trying to highlight existing knowledge and to elucidate areas of uncertainty, thus providing clues to potential clinical implications and research.

AREAS COVERED

Selected clinical studies on GLP-R1As in NAFLD are presented in this narrative review.

EXPERT OPINION

There is evidence that treatment with GLP-R1As in NAFLD has beneficial effects on NAFLD, i.e. improvement in liver function tests and histological improvement in hepatic steatosis and inflammation, but not fibrosis. Further research is required toward the early use of GLP-R1Αs, i.e. in NAFLD patients without fibrosis to evaluate whether they may prevent the progression to fibrosis, or in patients with advanced disease in combination with other medications, which may have additive or even synergistic effects on NAFLD.

Glucagon-like Peptide-1 Receptor Agonists in Patients with Type 2 Diabetes Mellitus and Nonalcoholic Fatty Liver Disease-Current Background, Hopes, and Perspectives

Nonalcoholic fatty liver disease (NAFLD) represents the most common chronic liver disease worldwide, reaching one of the highest prevalences in patients with type 2 diabetes mellitus (T2DM). For now, no specific pharmacologic therapies are approved to prevent or treat NAFLD. Glucagon-like peptide-1 receptor agonists (GLP-1RAs) are currently evaluated as potential candidates for NAFLD treatment in patients with T2DM. Some representatives of this class of antihyperglycemic agents emerged as potentially beneficial in patients with NAFLD after several research studies suggested they reduce hepatic steatosis, ameliorate lesions of nonalcoholic steatohepatitis (NASH), or delay the progression of fibrosis in this population. The aim of this review is to summarize the body of evidence supporting the effectiveness of GLP-1RA therapy in the management of T2DM complicated with NAFLD, describing the studies that evaluated the effects of these glucose-lowering agents in fatty liver disease and fibrosis, their possible mechanistic justification, current evidence-based recommendations, and the next steps to be developed in the field of pharmacological innovation.

GLP-1 Receptor Agonists in Non-Alcoholic Fatty Liver Disease: Current Evidence and Future Perspectives

To date, non-alcoholic fatty liver disease (NAFLD) is the most frequent liver disease, affecting up to 70% of patients with diabetes. Currently, there are no specific drugs available for its treatment. Beyond their anti-hyperglycemic effect and the surprising role of cardio- and nephroprotection, GLP-1 receptor agonists (GLP-1 RAs) have shown a significant impact on body weight and clinical, biochemical and histological markers of fatty liver and fibrosis in patients with NAFLD. Therefore, GLP-1 RAs could be a weapon for the treatment of both diabetes mellitus and NAFLD. The aim of this review is to summarize the evidence currently available on the role of GLP-1 RAs in the treatment of NAFLD and to hypothesize potential future scenarios.

Potential Roles of Glucagon-Like Peptide 1 Receptor Agonists (GLP-1 RAs) in Nondiabetic Populations

Glucagon-like peptide 1 receptor agonists (GLP-1 RAs) have been observed in several large cardiovascular outcome trials to significantly reduce the incidence of major cardiovascular event (MACE) with type 2 diabetic patients. The clinical trials of GLP-1 RAs, including lixisenatide, exenatide, liraglutide, semaglutide, albiglutide, and dulaglutide, are associated with a significantly 14% lower risk of MACE in patients with T2DM and a history of CV disease, and with a nonsignificantly 6% lower risk in patients without history of CV disease. Some of the interpretation with GLP-1 RA trials suggested the possible role of glucagon-like peptide-1 receptor agonists (GLP-1 RAs) in primary prevention of cardiovascular diseases in nondiabetic individual, echoed by a recent editorial redefining the role of GLP-1 RAs being beyond glycaemic control. The narrative review provides an in-depth insight into GLP-1 RA use guideline in different countries and regions of the world and examines the safety and concern of GLP-1 RA use. The narrative review draws the comparison of GLP-1 RA use between diabetic and nondiabetic individual in terms of cardiovascular and metabolic benefits and points out the direction of future clinical trials of GLP-1 RAs in nondiabetic individuals. The focus of the review is on GLP-1 RAs' preventive roles in nondiabetic individuals with cardiovascular disease, chronic kidney diseases, obesity, dyslipidaemia, hypertension, nonalcoholic fatty liver diseases, polycystic ovarian syndrome (PCOS), and perioperative complications of bariatric surgery, albeit in small studies and subset analysis of clinical trials of diabetic patients.

Anti-obesity Medications for the Management of Nonalcoholic Fatty Liver Disease

PURPOSE OF REVIEW

Obesity is closely associated with nonalcoholic fatty liver disease (NAFLD), a highly prevalent disease without any approved medication. The aim of this review was to summarize the evidence on the effect of anti-obesity medications on NAFLD, especially focusing on hepatic histology.

RECENT FINDINGS

Orlistat and some glucagon-like peptide-1 receptor analogs, including liraglutide and semaglutide, have beneficial effects on hepatic steatosis and inflammation, but not fibrosis. Other anti-obesity medications, including lorcaserin, setmelanotide, phentermine hydrochloric, phentermine/topiramate, and naltrexone/bupropion, have been minimally investigated in NAFLD. Furthermore, medications like sodium-glucose cotransporter-2 inhibitors and farnesoid X receptor have shown beneficial effects in both NAFLD and obesity, but they have not been licensed for either disease. Liraglutide, semaglutide, and orlistat may be currently used in selected patients with obesity and NAFLD. Further research is warranted, since targeting obesity may provide additional benefits on its comorbidities, including NAFLD.

Non-alcoholic fatty liver disease, metabolic syndrome, and type 2 diabetes mellitus: where do we stand today?

Non-alcoholic fatty liver disease (NAFLD), metabolic syndrome (MetS), and type 2 diabetes (T2DM) are metabolic disorders that belong to a highly prevalent disease cluster with a significant impact on public health worldwide. MetS is a complex condition characterized by metabolism perturbations that include glucose intolerance, insulin resistance, dyslipidaemia, associated pro-inflammatory state, and arterial hypertension. Because the components of MetS commonly co-occur, the management of these disorders cannot be considered separate issues. Thus NAFLD, recognized as a hepatic manifestation of MetS, is frequently associated with T2DM. This review analyses the underlying connections between these diseases and the risks associated with their co-occurrence. The effective management of NAFLD associated with MetS and T2DM involves an early diagnosis and optimal treatment of each condition leading to improvement in glycaemic and lipid regulation, liver steatosis, and arterial hypertension. The net effect of such treatment is the prevention of atherosclerotic cardiovascular diseases and liver fibrosis.

SGLT-2 inhibitors and GLP-1 receptor agonists in metabolic dysfunction-associated fatty liver disease

Metabolic dysfunction-associated fatty liver disease (MAFLD) is a chronic condition that affects nearly one billion people globally, characterized by triacylglycerol accumulation in the liver as a consequence of metabolic abnormalities (obesity and impaired glucose regulation). Low-grade inflammation, oxidative stress, mitochondrial dysfunction, and dysbiosis in gut microbiota are involved in the etiology of MAFLD, and both cardiovascular events and hepatic complications are the long-term consequences. In the absence of approved therapies for this condition, sodium-glucose cotransporter 2 inhibitors (SGLT-2 Is) and glucagon-like peptide 1 receptor agonists (GLP-1 RAs) have the specific advantage of lowering body weight and providing cardiovascular benefits. Here, we discuss potential roles for SGLT-2 Is and GLP-1 RAs in the prevention and treatment of intrahepatic triacylglycerol accumulation and associated inflammation and/or fibrosis.

Management of Diabetes in Candidates for Liver Transplantation and in Transplant Recipients

Diabetes is common in patients waitlisted for liver transplantation because of end-stage liver disease or hepatocellular cancer as well as in posttransplant phase (posttransplantation diabetes mellitus). In both conditions, the presence of diabetes severely affects disease burden and long-term clinical outcomes; careful monitoring and appropriate treatment are pivotal to reduce cardiovascular events and graft and recipients' death. We thoroughly reviewed the epidemiology of diabetes in the transplant setting and the different therapeutic options, from lifestyle intervention to antidiabetic drug use-including the most recent drug classes available-and to the inclusion of bariatric surgery in the treatment cascade. In waitlisted patients, the old paradigm that insulin should be the treatment of choice in the presence of severe liver dysfunction is no longer valid; novel antidiabetic agents may provide adequate glucose control without the risk of hypoglycemia, also offering cardiovascular protection. The same evidence applies to the posttransplant phase, where oral or injectable noninsulin agents should be considered to treat patients to target, limiting the impact of disease on daily living, without interaction with immunosuppressive regimens. The increasing prevalence of liver disease of metabolic origin (nonalcoholic fatty liver) among liver transplant candidates, also having a higher risk of noncirrhotic hepatocellular cancer, is likely to accelerate the acceptance of new drugs and invasive procedures, as suggested by international guidelines. Intensive lifestyle intervention programs remain however mandatory, both before and after transplantation. Achievement of adequate control is mandatory to increase candidacy, to prevent delisting, and to improve long-term outcomes.

AGL9: A Novel Hepatoprotective Peptide from the Larvae of Edible Insects Alleviates Obesity-Induced Hepatic Inflammation by Regulating AMPK/Nrf2 Signaling

In this study, we investigated the anti-obesity properties of the novel peptide Ala-Gly-Leu-Gln-Phe-Pro-Val-Gly-Arg (AGL9), isolated from the enzymatic hydrolysate of Allomyrinadichotoma larvae. To investigate the preventive effects of AGL9 against hepatic steatosis and its possible mechanisms of action, we established an nonalcoholic fatty liver disease (NAFLD) model by feeding C57BL/6 mice a high-fat diet. NAFLD mice were administered 100 mg/kg AGL9 and 60 mg/kg orlistat via gavage (10 mL/kg) for 5 weeks, followed by the collection of blood and liver tissues. We found that AGL9 normalized the levels of serum alanine aminotransferase, aspartate aminotransferase, triglyceride, total cholesterol, high-density lipoprotein, very low-density lipoprotein (LDL)/LDL, adiponectin, and leptin in these mice. Additionally, AGL9 activated the protein-level expression of 5′ AMP-activated protein kinase and acetyl-CoA carboxylase phosphorylation and the transcript-level expression of sterol regulatory element-binding protein-1c, fatty acid synthase, superoxide dismutase, glutathione peroxidase, glucocorticoid receptor, nuclear respiratory factor 2, tumor necrosis factor-α, interleukin-1β, interleukin-6, and monocyte chemoattractant protein-1 in hepatocytes. These results showed that AGL9 exhibited hepatoprotective effects by attenuating lipid deposition, oxidative stress, and inflammation via inhibition of AMPK/Nrf2 signaling, thereby reducing the production of hepatic proinflammatory mediators and indicating AGL9 as a potential therapeutic strategy for NAFLD.

Liver-targeting drugs and their effect on blood glucose and hepatic lipids

The global epidemic of non-alcoholic fatty liver disease (NAFLD) and steatohepatitis (NASH) and the high prevalence among individuals with type 2 diabetes has attracted the attention of clinicians specialising in liver disorders. Many drugs are in the pipeline for the treatment of NAFLD/NASH, and several glucose-lowering drugs are now being tested specifically for the treatment of liver disease. Among these are nuclear hormone receptor agonists (e.g. peroxisome proliferator-activated receptor agonists, farnesoid X receptor agonists and liver X receptor agonists), fibroblast growth factor-19 and -21, single, dual or triple incretins, sodium-glucose cotransporter inhibitors, drugs that modulate lipid or other metabolic pathways (e.g. inhibitors of fatty acid synthase, diacylglycerol acyltransferase-1, acetyl-CoA carboxylase and 11β-hydroxysteroid dehydrogenase type-1) or drugs that target the mitochondrial pyruvate carrier. We have reviewed the metabolic effects of these drugs in relation to improvement of diabetic hyperglycaemia and fatty liver disease, as well as peripheral metabolism and insulin resistance.

Liraglutide in patients with non-alcoholic fatty liver disease: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

A few randomized controlled trials (RCTs) have assessed the use of liraglutide as a treatment option in patients with non-alcoholic fatty liver disease (NAFLD). We aimed at critically appraising and summarizing these RCTs, providing precise effect estimates regarding the safety and efficacy of liraglutide in NAFLD.

METHODS

We searched major databases and grey literature from their inception to May 2019, for RCTs comparing liraglutide with placebo or active comparator in patients with NAFLD. We defined as primary efficacy outcomes the observed changes in hepatic fat content (HFC) and alanine aminotransferase levels (ALT). Metabolic outcomes of interest and major safety endpoints were also assessed.

RESULTS

We included five trials with 371 randomised participants in total. Liraglutide produced a non-significant decrease in HFC and ALT levels, compared to control. It induced a significant reduction in body mass index, primarily driven by reduction in patients with type 2 diabetes, while it did not affect significantly glycated hemoglobin levels and Homeostatic Model Assessment of Insulin Resistance. We also showed that liraglutide significantly decreased serum triglyceride levels, also driven by the observed reduction in patients with type 2 diabetes, however it did not significantly affect the rest lipid parameters. Liraglutide was associated with increased incidence of gastrointestinal adverse events, while, no other safety issues were identified.

CONCLUSION

Our results do not substantiate the use of liraglutide in patients with NAFLD yet, despite its promising role.

Effects of anti-diabetic treatments in type 2 diabetes and fatty liver disease

Introduction: Nonalcoholic fatty liver disease (NAFLD) and type 2 diabetes mellitus (T2DM) are significant non-communicable diseases that often affect individuals concurrently. In individuals with both T2DM and NAFLD, there is evidence that anti-diabetic therapies may demonstrate potential combined beneficial metabolic and reduced hepatic inflammatory effects.Areas covered: A PubMed and Google Scholar search was performed to find relevant literature. Included studies focused on individuals with T2DM and NAFLD receiving anti-diabetic treatments including bariatric surgery, insulin sensitizers, incretin mimetics, and SGLT2 inhibitors. Additional articles highlight investigational treatments.Expert opinion: In individuals with T2DM and NAFLD, 5-10% weight loss or bariatric surgery if unable to lose weight or maintain weight loss are appropriate. GLP-1 receptor agonists and SGLT2 inhibitors result in weight loss, appear safe and may provide beneficial hepatic outcomes. Whether their effects are related to favorable weight changes or intrinsic hepatic effects is unclear. Thiazolidinediones have advantageous anti-hyperglycemic and hepatic effects but individuals must be monitored for weight gain and edema. Metformin and DPP-4 inhibitor beneficial hepatic effects remain debated. There are opportunities to standardize markers and imaging of NAFLD. Studies powered to evaluate the possible cardiovascular benefits of anti-diabetic therapies in individuals with T2DM and NAFLD are needed.

Effects of antidiabetic agents on steatosis and fibrosis biomarkers in type 2 diabetes: A real-world data analysis

BACKGROUND & AIMS

There is intense research for drugs able to reduce disease progression in nonalcoholic fatty liver disease. We aimed to test the impact of novel antidiabetic drugs (dipeptidyl-peptidase-4 inhibitors - DPP-4Is, glucagon-like peptide-1 receptor agonists - GLP-1RAs, sodium-glucose cotransporter-2 inhibitors - SGLT-2Is) on non-invasive biomarkers of steatosis (fatty liver index, FLI) and fibrosis (Fibrosis-4 score, FIB-4) in patients with type 2 diabetes (T2D).

METHODS

Clinical, anthropometric and biochemical parameters were retrospectively analysed in 637 consecutive T2D patients switched from metformin w/wo sulfonylureas and/or pioglitazone to DPP-4Is, GLP-1RAs and SGLT-2Is in a tertiary care setting. 165 patients maintained on original treatments served as controls. The effects on FLI and FIB-4 at 6- and 12-month follow-up were analysed by logistic regression after adjustment for baseline differences, computed by propensity scores, and additional adjustment for changes in glycosylated hemoglobin (HbA1c) and body mass index.

RESULTS

Body mass index, HbA1c and aminotrasferases significantly decreased following switching to GLP-1RAs and SGLT2-Is, compared with both controls and DPP-4Is, whereas only HbA1c was reduced on DPP-4Is. FLI and FIB-4 were reduced on GLP-1RA and SGLT-2I; logistic regression analysis confirmed a significant improvement of both biomarkers after adjustment for propensity score. The shift of FIB-4 values towards the category ruling out advanced fibrosis was maintained after additional adjustment for confounders. These effects were confirmed in a sensitivity analysis on effect size.

CONCLUSIONS

Glucagon-like peptide-1 receptor agonists and SGLT-2Is improve biomarkers of steatosis and fibrosis, in keeping with beneficial effects on liver disease progression, and should be considered the treatment of choice in T2D.

NAFLD in type 2 diabetes mellitus: Still many challenging questions

Epidemiologic data consistently show that in patients with type 2 diabetes (T2DM) the prevalence of non-alcoholic fatty liver disease (NAFLD), including advanced fibrosis, is double compared to the general population, and it associates with high risk of liver-related morbidity (advanced fibrosis, hepatocellular carcinoma) and mortality, but also with other systemic consequences, such as cardiovascular (CV) disease, chronic kidney disease, and overall mortality. There are still many answers that need to be clarified regarding NAFLD in T2DM, including deciphering the complex pathogenetic mechanisms, the intertwined relationships with the extrahepatic organs and tissues (mainly heart, kidneys, adipose tissue, gut), the prognostic value of NAFLD for CV risk stratification, and more importantly, what would be the most appropriate screening algorithm, diagnostic method and therapeutic approach. We advocate here for proactive action, in order to identify NAFLD in a timely manner, and suggest a simple algorithm to be used in clinical practice, based on risk stratification and on experts' opinions. We discuss the current therapeutic options for NAFLD in T2DM, for which a multifactorial approach is needed, that concomitantly addresses the liver and the cardio-reno-metabolic disturbances.

Glucagon-Like Peptide-1 Receptor Agonists for Treatment of Nonalcoholic Fatty Liver Disease and Nonalcoholic Steatohepatitis: An Updated Meta-Analysis of Randomized Controlled Trials

To assess the efficacy of glucagon-like peptide-1 receptor agonists (GLP-1 RAs) for treatment of nonalcoholic fatty liver disease (NAFLD) or steatohepatitis (NASH), we performed a systematic review and meta-analysis of randomized controlled trials (RCTs). Three large electronic databases were systematically searched (up to 15 December 2020) to identify placebo-controlled or active-controlled RCTs using different GLP-1 RAs. We included eleven placebo-controlled or active-controlled phase-2 RCTs (involving a total of 936 middle-aged individuals) that used liraglutide (n = 6 RCTs), exenatide (n = 3 RCTs), dulaglutide (n = 1 RCT) or semaglutide (n = 1 RCT) to specifically treat NAFLD or NASH, detected by liver biopsy (n = 2 RCTs) or imaging techniques (n = 9 RCTs). Compared to placebo or reference therapy, treatment with GLP-1 RAs for a median of 26 weeks was associated with significant reductions in the absolute percentage of liver fat content on magnetic resonance-based techniques (pooled weighted mean difference: −3.92%, 95% confidence intervals (CI) −6.27% to −1.56%) and serum liver enzyme levels, as well as with greater histological resolution of NASH without worsening of liver fibrosis (pooled random-effects odds ratio 4.06, 95% CI 2.52–6.55; for liraglutide and semaglutide only). In conclusion, treatment with GLP-1 RAs (mostly liraglutide and semaglutide) is a promising treatment option for NAFLD or NASH that warrants further investigation.

Glucagon-Like Peptide-1 Receptor Agonists for Treatment of Nonalcoholic Fatty Liver Disease and Nonalcoholic Steatohepatitis: An Updated Meta-Analysis of Randomized Controlled Trials

To assess the efficacy of glucagon-like peptide-1 receptor agonists (GLP-1 RAs) for treatment of nonalcoholic fatty liver disease (NAFLD) or steatohepatitis (NASH), we performed a systematic review and meta-analysis of randomized controlled trials (RCTs). Three large electronic databases were systematically searched (up to 15 December 2020) to identify placebo-controlled or active-controlled RCTs using different GLP-1 RAs. We included eleven placebo-controlled or active-controlled phase-2 RCTs (involving a total of 936 middle-aged individuals) that used liraglutide (n = 6 RCTs), exenatide (n = 3 RCTs), dulaglutide (n = 1 RCT) or semaglutide (n = 1 RCT) to specifically treat NAFLD or NASH, detected by liver biopsy (n = 2 RCTs) or imaging techniques (n = 9 RCTs). Compared to placebo or reference therapy, treatment with GLP-1 RAs for a median of 26 weeks was associated with significant reductions in the absolute percentage of liver fat content on magnetic resonance-based techniques (pooled weighted mean difference: −3.92%, 95% confidence intervals (CI) −6.27% to −1.56%) and serum liver enzyme levels, as well as with greater histological resolution of NASH without worsening of liver fibrosis (pooled random-effects odds ratio 4.06, 95% CI 2.52–6.55; for liraglutide and semaglutide only). In conclusion, treatment with GLP-1 RAs (mostly liraglutide and semaglutide) is a promising treatment option for NAFLD or NASH that warrants further investigation.

NAFLD and Cardiovascular Diseases: Epidemiological, Mechanistic and Therapeutic Considerations

Overwhelming evidence suggests an association of cardiovascular disease (CVD) with non-alcoholic fatty liver disease (NAFLD); however, the underlying mechanisms remain largely speculative. It is, however, likely that common mechanisms contribute to the development of CVD and NAFLD, with lifestyle factors such as smoking, sedentary lifestyle with poor nutrition habits and physical inactivity being major candidates. These behavioral factors, on a predisposing genetic background, trigger changes in gut microbiota, inflammation, dyslipidemia and oxidative stress, leading to metabolic syndrome, diabetes and obesity as well as atherosclerosis. Treatment options to counteract both the progression and development of CVD and NAFLD include lifestyle interventions, optimal medical therapy of comorbid conditions and, as final possibility, bariatric surgery. As no causal pharmacotherapy of NAFLD is available, further research is urgently needed to address the unmet need of a growing population with NAFLD and CVD.

A look to the future in non-alcoholic fatty liver disease: Are glucagon-like peptide-1 analogues or sodium-glucose co-transporter-2 inhibitors the answer?

The increasing prevalence of diabetes and non-alcoholic fatty liver disease (NAFLD) is a growing public health concern associated with significant morbidity, mortality and economic cost, particularly in those who progress to cirrhosis. Medical treatment is frequently limited, with no specific licensed treatments currently available for people with NAFLD. Its association with diabetes raises the possibility of shared mechanisms of disease progression and treatment. With the ever-growing interest in the non-glycaemic effects of diabetes medications, studies and clinical trials have investigated hepatic outcomes associated with the use of drug classes used for people with type 2 diabetes (T2D), such as glucagon-like peptide-1 (GLP-1) analogues or sodium-glucose co-transporter-2 (SGLT2) inhibitors. Studies exploring the use of GLP-1 analogues or SGLT2 inhibitors in people with NAFLD have observed improved measures of hepatic inflammation, liver enzymes and radiological features over short periods. However, these studies tend to have variable study populations and inconsistent reported outcomes, limiting comparison between drugs and drug classes. As these drugs appear to improve biomarkers of NAFLD, clinicians should consider their use in patients with NAFLD and T2D. However, further evidence with greater participant numbers and longer trial durations is required to support specific licensing for people with NAFLD. Larger trials would allow reporting of major adverse hepatic events, akin to cardiovascular and renal outcome trials, to be determined. This would provide a more meaningful evaluation of the impact of these drugs in NAFLD. Nevertheless, these drugs represent a future potential therapeutic avenue in this difficult-to-treat population and may beget significant health and economic impacts.

Comparative effectiveness of glucagon-like peptide-1 receptor agonists versus dipeptidyl peptidase-4 inhibitors on noninvasive indices of hepatic steatosis and fibrosis in patients with type 2 diabetes mellitus

BACKGROUND AND AIMS

Nonalcoholic fatty liver disease (NAFLD) is highly prevalent in patients with type 2 diabetes mellitus (T2DM). There is currently no approved treatment for NAFLD. The main aim was the evaluation of the effect of glucagon-like peptide-1 receptor agonists (GLP-1 RA) vs. dipeptidyl peptidase-4 inhibitor (DPP-4i) treatment on noninvasive indices of hepatic steatosis and fibrosis in patients with T2DM.

METHODS

In this retrospective study, three noninvasive indices of hepatic steatosis [HSI, NAFLD ridge score, and triglycerides (TG) to high-density lipoprotein cholesterol (HDL-C) ratio] and five of fibrosis (APRI, FIB-4, NAFLD fibrosis score, BAAT and BARD) were calculated before and after (6-18 months) the addition of a DPP-4i (n = 152) or a GLP-1 RA (n = 37) in patients with T2DM.

RESULTS

Regarding steatosis indices, NAFLD ridge score was significantly decreased in the GLP-1 RA group (baseline: 0.90 ± 0.34, follow-up: 0.67 ± 0.24; p = 0.001), but not in the DPP-4i group (p = 0.25); the difference for group∗time interaction was significant (p = 0.02). HSI showed a trend between groups, being significantly different at baseline and follow-up (p < 0.001) with no significant difference in group∗time interaction. Indices of fibrosis were not essentially changed within or between groups.

CONCLUSIONS

NAFLD ridge score was significantly decreased after the addition of GLP-1 RA in patients with T2DM. This study warrants further prospective clinical trials.

Glucagon-Like Peptide 1 Receptor Agonists and Heart Failure

With worsening epidemiological trends for both the incidence and prevalence of type 2 diabetes mellitus (T2DM) and heart failure (HF) worldwide, it is critical to implement optimal prevention and treatment strategies for patients with these comorbidities, either alone or concomitantly. Several guidelines and consensus statements have recommended glucagon-like peptide-1 receptor agonists and sodium-glucose cotransporter type 2 inhibitors as add-ons to lifestyle interventions with or without metformin in those at high atherosclerotic cardiovascular disease risk. However, these recommendations are either silent about HF or fail to differentiate between the prevention of HF in those at risk versus the treatment of individuals with manifest HF. Furthermore, these documents do not differentiate among those with different HF phenotypes. This distinction, even though important, may not be critical for sodium-glucose cotransporter type 2 inhibitors in view of the consistent data for benefit for both atherosclerotic cardiovascular disease– and HF-related outcomes that have emerged from the regulatory-mandated cardiovascular outcome trials for all sodium-glucose cotransporter type 2 inhibitors and the recent DAPA-HF trial (Dapagliflozin in Patients with Heart Failure and Reduced Ejection Fraction)demonstrating the benefit of dapagliflozin on HF-related outcomes in patients with HF with reduced ejection fraction with or without T2DM. However, the distinction may be crucial for glucagon-like peptide-1 receptor agonists and other antihyperglycemic agents. Indeed, in several of the new statements, glucagon-like peptide-1 receptor agonists are suggested treatment not only for patients with T2DM and atherosclerotic cardiovascular disease, but also in those with manifest HF, despite a lack of evidence for the latter recommendation. Although glucagon-like peptide-1 receptor agonists may be appropriate to use in patients at risk for HF, mechanistic insights and observations from randomized trials suggest no clear benefit on HF-related outcomes and even uncertainty regarding the safety in those with HF with reduced ejection fraction. Conversely, theoretical rationales suggest that these agents may benefit patients with HF with preserved ejection fraction. Considering that millions of patients with T2DM have HF, these concerns have public health implications that necessitate the thoughtful use of these therapies. Achieving this aim will require dedicated trials with these drugs in both patients who have HF with reduced ejection fraction and HF with preserved ejection fraction with T2DM to assess their efficacy, safety, and risk-benefit profile.

Glucagon-like peptide-1 receptor agonists in non-alcoholic fatty liver disease: An update

Non-alcoholic fatty liver disease (NAFLD) is the predominant cause of chronic liver disease worldwide. NAFLD progresses in some cases to non-alcoholic steatohepatitis (NASH), which is characterized, in addition to liver fat deposition, by hepatocyte ballooning, inflammation and liver fibrosis, and in some cases may lead to hepatocellular carcinoma. NAFLD prevalence increases along with the rising incidence of type 2 diabetes mellitus (T2DM). Currently, lifestyle interventions and weight loss are used as the major therapeutic strategy in the vast majority of patients with NAFLD. Glucagon-like peptide-1 receptor agonists (GLP-1RAs) are used in the management of T2DM and do not have major side effects like hypoglycemia. In patients with NAFLD, the GLP-1 receptor production is down-regulated. Recently, several animal and human studies have emphasized the role of GLP-1RAs in ameliorating liver fat accumulation, alleviating the inflammatory environment and preventing NAFLD progression to NASH. In this review, we summarize the updated literature data on the beneficial effects of GLP-1RAs in NAFLD/NASH. Finally, as GLP-1RAs seem to be an attractive therapeutic option for T2DM patients with concomitant NAFLD, we discuss whether GLP-1RAs should represent the first line pharmacotherapy for these patients.

Beneficial effect of anti-diabetic drugs for nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is the most common liver disorder and is associated with various metabolic diseases, including type 2 diabetes mellitus. There are no approved drugs for NAFLD, and the only approved treatment option is weight reduction. As insulin resistance plays an important role in the development of NAFLD, many anti-diabetic drugs have been evaluated for the treatment of NAFLD. Improvement of liver enzymes has been demonstrated by many anti-diabetic drugs, but histological assessment still remains insufficient. Pioglitazone could become the first-line therapy for T2DM patients with NAFLD, based on evidence of histological improvement in patients with biopsy-proven nonalcoholic steatohepatitis (NASH). Liraglutide, another promising alternative, is not yet recommended in patients with NAFLD/NASH due to limited evidence. Therefore, well-designed randomized controlled trials should be performed in the near future to demonstrate if and how anti-diabetic drugs can play a role in the treatment of NAFLD.

Gut-Pancreas-Liver Axis as a Target for Treatment of NAFLD/NASH

Non-alcoholic fatty liver disease (NAFLD) represents the most common form of chronic liver disease worldwide. Due to its association with obesity and diabetes and the fall in hepatitis C virus morbidity, cirrhosis in NAFLD is becoming the most frequent indication to liver transplantation, but the pathogenetic mechanisms are still not completely understood. The so-called gut-liver axis has gained enormous interest when data showed that its alteration can lead to NAFLD development and might favor the occurrence of non-alcoholic steatohepatitis (NASH). Moreover, several therapeutic approaches targeting the gut-pancreas-liver axis, e.g., incretins, showed promising results in NASH treatment. In this review, we describe the role of incretin hormones in NAFLD/NASH pathogenesis and treatment and how metagenomic/metabolomic alterations in the gut microbiota can lead to NASH in the presence of gut barrier modifications favoring the passage of bacteria or bacterial products in the portal circulation, i.e., bacterial translocation.

GLP-1 receptor agonists for NAFLD treatment in patients with and without type 2 diabetes: an updated meta-analysis

Aim: Recent randomized controlled trials (RCTs) have tested the efficacy of glucagon-like peptide-1 receptor agonists (GLP-1 RA) to specifically treat non-alcoholic fatty liver disease (NAFLD). We performed a meta-analysis of RCTs to investigate the efficacy of GLP-1 RAs for treatment of NAFLD or non-alcoholic steatohepatitis (NASH). Methods: We systematically searched PubMed and ClinicalTrials.Gov databases utilizing specific terms to identify placebo-controlled or head-to-head RCTs (last research on March 1, 2020) involving NAFLD patients with the aim to evaluate the efficacy of GLP-1 RAs to treat NAFLD/NASH. Primary outcomes were changes in serum liver enzymes, liver fat content, or histologic resolution of NASH. Weighted mean differences (WMD) were used to test the differences between the treatment arms. Results: Overall, we found 7 placebo-controlled or head-to-head RCTs involving 472 middle-aged individuals (66% men; 77% with established diabetes) followed for a median of 16 weeks that have used liraglutide or exenatide to treat NAFLD on imaging (n = 6) or biopsy (n = 1). Compared to placebo or reference therapy, treatment with GLP-1 RAs decreased serum alanine aminotransferase [n = 7 studies; WMD: -8.77 IU/L, 95% confidence intervals (CI) -17.69 to 0.14 IU/L; I2 = 87.3%] and gamma-glutamyltransferase levels (n = 4 studies; WMD: -10.17 IU/L, 95% CI -14.27 IU/L to -6.07 IU/L; I2 = 0%) and imaging-defined liver fat content (n = 4 studies; WMD: -6.23%, 95% CI -8.95% to -3.51%; I2 = 85.9%). In one RCT involving 55 patients with biopsy-proven NASH, a 48-week treatment with liraglutide also led to a greater histological resolution of NASH than placebo. Conclusions: GLP-1 RAs (mostly liraglutide) seem to be a promising treatment option for NAFLD or NASH.

Post-transplant diabetes mellitus and preexisting liver disease - a bidirectional relationship affecting treatment and management

Liver cirrhosis and diabetes mellitus (DM) are both common conditions with significant socioeconomic burden and impact on morbidity and mortality. A bidirectional relationship exists between DM and liver cirrhosis regarding both etiology and disease-related complications. Type 2 DM (T2DM) is a well-recognized risk factor for chronic liver disease and vice-versa, DM may develop as a complication of cirrhosis, irrespective of its etiology. Liver transplantation (LT) represents an important treatment option for patients with end-stage liver disease due to non-alcoholic fatty liver disease (NAFLD), which represents a hepatic manifestation of metabolic syndrome and a common complication of T2DM. The metabolic risk factors including immunosuppressive drugs, can contribute to persistent or de novo development of DM and NAFLD after LT. T2DM, obesity, cardiovascular morbidities and renal impairment, frequently associated with metabolic syndrome and NAFLD, may have negative impact on short and long-term outcomes following LT. The treatment of DM in the context of chronic liver disease and post-transplant is challenging, but new emerging therapies such as glucagon-like peptide-1 receptor agonists (GLP-1RAs) and sodium–glucose cotransporter 2 inhibitors (SGLT2i) targeting multiple mechanisms in the shared pathophysiology of disorders such as oxidative stress and chronic inflammation are a promising tool in future patient management.

Nonalcoholic Fatty Liver Disease in Adults: Current Concepts in Etiology, Outcomes, and Management

Nonalcoholic fatty liver disease (NAFLD) is a spectrum of disease, extending from simple steatosis to inflammation and fibrosis with a significant risk for the development of cirrhosis. It is highly prevalent and is associated with significant adverse outcomes both through liver-specific morbidity and mortality but, perhaps more important, through adverse cardiovascular and metabolic outcomes. It is closely associated with type 2 diabetes and obesity, and both of these conditions drive progressive disease toward the more advanced stages. The mechanisms that govern hepatic lipid accumulation and the predisposition to inflammation and fibrosis are still not fully understood but reflect a complex interplay between metabolic target tissues including adipose and skeletal muscle, and immune and inflammatory cells. The ability to make an accurate assessment of disease stage (that relates to clinical outcome) can also be challenging. While liver biopsy is still regarded as the gold-standard investigative tool, there is an extensive literature on the search for novel noninvasive biomarkers and imaging modalities that aim to accurately reflect the stage of underlying disease. Finally, although no therapies are currently licensed for the treatment of NAFLD, there are interventions that appear to have proven efficacy in randomized controlled trials as well as an extensive emerging therapeutic landscape of new agents that target many of the fundamental pathophysiological processes that drive NAFLD. It is highly likely that over the next few years, new treatments with a specific license for the treatment of NAFLD will become available.

Effects of newer antidiabetic drugs on nonalcoholic fatty liver and steatohepatitis: Think out of the box!

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in Western societies and a major cause of hepatic disease worldwide. Its more severe type, namely nonalcoholic steatohepatitis (NASH), may result in the development of cirrhosis and hepatocellular carcinoma. NAFLD, and especially NASH, are also associated with increased cardiovascular morbidity and mortality. Type 2 diabetes mellitus (T2DM) predisposes to NAFLD development and progression via insulin resistance and hyperglycemia. It has also been reported that the majority of T2DM patients have NAFLD/NASH, thus potentially further increasing their cardiometabolic risk. Current guidelines recommend to screen for NAFLD in all T2DM patients and vice-versa. Lifestyle remains the first-line therapeutic option for NAFLD/NASH. Among antidiabetic drugs, pioglitazone was shown to improve histological features of NASH. More recently, there is an increasing interest regarding the effects of newer anti-diabetic drugs, such as dipeptidyl peptidase 4 inhibitors (DPP-4i), sodium glucose cotransporter 2 inhibitors (SGLT2i), and glucagon-like peptide-1 receptor agonists (GLP-1 RAs) on NAFLD/NASH. The present narrative review considers the up-to-date data on the impact of DPP-4i, SGLT2i, and GLP-1 RAs on biochemical and/or histological markers of NAFLD/NASH. The potential clinical implications of these findings in daily practice are also discussed. Taking into consideration the global increasing prevalence of NAFLD/NASH, therapeutic options that can prevent or treat this disease will exert considerable benefits on human health.

Cardiovascular, renal and liver protection with novel antidiabetic agents beyond blood glucose lowering in type 2 diabetes: consensus article from the European Society of Hypertension Working Group on Obesity, Diabetes and the High-risk Patient

: The prevalence of type 2 diabetes (T2D) has increased over the past few decades. T2D has a strong genetic propensity that becomes overt when a patient is exposed to a typical Western lifestyle, gain weight and becomes obese, whereas weight loss protects from the development of T2D. Except of lifestyle modifications, the choice of the appropriate treatment is essential in the management of patients with T2D and appears critical for the obese population with T2D. The new pharmacological approach for the treatment of T2D, sodium-glucose cotransporter 2 inhibitors and glucagon-like peptide 1 receptor agonists, seems to be effective not only in the management of T2D but also for weight loss, reduction of blood pressure and improvement of nonalcoholic fatty liver disease. Sodium-glucose cotransporter 2 inhibitors and glucagon-like peptide 1 analogues reduced cardiovascular risk, prevented cardiovascular disease and mortality, thereby playing an important role in the treatment of obese patients with hypertension and T2D.

Consensus Recommendations on GLP-1 RA Use in the Management of Type 2 Diabetes Mellitus: South Asian Task Force

The advent of incretin mimetics such as glucagon-like peptide-1 receptor agonists (GLP-1 RAs) has enriched the armamentarium for diabetes management owing to their glycaemic as well as extra-glycaemic benefits. The approval status and availability of this class of drugs vary widely across the globe. Being a relatively newer class of drug with numerous benefits, several national and international guidelines are working towards addressing clinical questions pertaining to the optimal use of GLP-1 RAs for the management of diabetes. Although the newer class of drugs are associated with significant benefits such as patient-centric approach, these drugs demand the providers to be vigilant and knowledgeable about the medication. The South Asian population is at higher risk of type 2 diabetes mellitus (T2DM) because of their genetic predisposition and lifestyle changes. Hence, prevention and management of T2DM and its associated complications in this population are of paramount importance. The current report aims to present an overview of current knowledge on GLP-1 RAs based on pragmatic review of the available clinical evidence. In addition, this report is a consensus of expert endocrinologists representing South Asian countries including India, Pakistan, Bangladesh, Nepal, Sri Lanka, Afghanistan and the Maldives on essential recommendations related to the use of GLP-1 RAs in a real-world scenario.

From NASH to diabetes and from diabetes to NASH: Mechanisms and treatment options

The worldwide prevalence of non-alcoholic fatty liver disease (NAFLD) is estimated to have reached 25% or more in adults. NAFLD is prevalent in obese individuals, but may also affect non-obese insulin-resistant individuals. NAFLD is associated with a 2- to 3-fold increased risk of developing type 2 diabetes (T2D), which may be higher in patients with more severe liver disease - fibrosis increases this risk. In NAFLD, not only the close association with obesity, but also the impairment of many metabolic pathways, including decreased hepatic insulin sensitivity and insulin secretion, increase the risk of developing T2D and related comorbidities. Conversely, patients with diabetes have a higher prevalence of steatohepatitis, liver fibrosis and end-stage liver disease. Genetics and mechanisms involving dysfunctional adipose tissue, lipotoxicity and glucotoxicity appear to play a role. In this review, we discuss the altered pathophysiological mechanisms that underlie the development of T2D in NAFLD and vice versa. Although there is no approved therapy for the treatment of NASH, we discuss pharmacological agents currently available to treat T2D that could potentially be useful for the management of NASH.

Nonalcoholic Fatty Liver Disease and Diabetes: Part II: Treatment

Nonalcoholic fatty liver disease (NAFLD) and diabetes are common metabolic disorders that are often comorbid conditions. Among many proposed treatments, weight reduction is the only approved option for NAFLD to date. However, it is not easy to maintain weight loss by lifestyle modification alone; pharmacological treatments are helpful in this regard. Although many drugs have been investigated, pioglitazone could be a first-line therapy in patients with NAFLD and diabetes. Many more drugs are currently being developed and investigated, and it is likely that combination strategies will be used for future treatment of NAFLD and diabetes. Attention should be paid to the management of NAFLD and diabetes and efforts should be made to intervene early and individualize treatment of NAFLD in patients with diabetes.

The Effects of Hypoglycemic Agents on Non-alcoholic Fatty Liver Disease: Focused on Sodium-Glucose Cotransporter 2 Inhibitors and Glucagon-Like Peptide-1 Receptor Agonists

The only known, effective intervention for non-alcoholic fatty liver disease (NAFLD) is weight loss, and there is no approved pharmacotherapy. Recently, new hypoglycemic agents, such as sodium-glucose cotransporter 2 (SGLT2) inhibitors and glucagon-like peptide-1 receptor agonists (GLP-1RAs), and their effects on NAFLD have received substantial interest. Herein, we review the currently available human studies regarding the effects of SGLT2 inhibitors and GLP-1RAs on NAFLD/non-alcoholic steatohepatitis in patients with type 2 diabetes mellitus, and we describe the possible mechanisms explaining the positive effects of these agents on NAFLD.

Obesity and nonalcoholic fatty liver disease: From pathophysiology to therapeutics

The obesity epidemic is closely associated with the rising prevalence and severity of nonalcoholic fatty liver disease (NAFLD): obesity has been linked not only with simple steatosis (SS), but also with advanced disease, i.e., nonalcoholic steatohepatitis (NASH), NASH-related cirrhosis and hepatocellular carcinoma. As a consequence, apart from increasing all-cause mortality, obesity seems to increase liver-specific mortality in NAFLD patients. Given the lack of approved pharmacological interventions for NAFLD, targeting obesity is a rational option for its management. As the first step, lifestyle modification (diet and exercise) is recommended, although it is difficult to achieve and sustain. When the first step fails, adding pharmacotherapy is recommended. Several anti-obesity medications have been investigated in NAFLD (e.g., orlistat, glucagon-like peptide-1 analogs), other anti-obesity medications have not been investigated (e.g., lorcaserin, phentermine hydrochloric, phentermine/topiramate and naltrexone/bupropion), whereas some medications with weight-lowering efficacy have not been approved for obesity (e.g., sodium-glucose cotransporter-2 inhibitors, farnesoid X receptor ligands). If the combination of lifestyle modification and pharmacotherapy also fails, then bariatric surgery should be considered in selected morbidly obese individuals. This review summarizes best evidence linking obesity with NAFLD and presents related therapeutic options.

Multiple target tissue effects of GLP-1 analogues on non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH)

Accumulating experimental and clinical evidences over the last decade indicate that GLP-1 analogues have a series of central nervous system and peripheral target tissues actions which are able to significantly influence the liver metabolism. GLP-1 analogues pleiotropic effects proved to be efficacious in T2DM subjects not only reducing liver steatosis and ameliorating NAFLD and NASH, but also in lowering plasma glucose and liver inflammation, improving cardiac function and protecting from kidney dysfunction. While the experimental and clinical data are robust, the precise mechanisms of action potentially involved in these protective multi-target effects need further investigation. Here we present a systematic review of the most recent literature data on the multi-target effects of GLP-1 analogues on the liver, on adipose and muscular tissue and on the nervous system, all capable of influencing significant aspects of the fatty liver disease physiopathology. From this analysis, we can conclude that the multi-target beneficial action of the GLP-1 analogues could explain the positive effects observed in animal and human models on progression of NAFLD to NASH.

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.

Targeting incretin hormones and the ASK-1 pathway as therapeutic options in the treatment of non-alcoholic steatohepatitis

Non-alcoholic fatty liver disease (NAFLD) is currently one of the leading forms of chronic liver disease, and its rising frequency worldwide has reached epidemic proportions. NAFLD, particularly its progressive variant NASH (non-alcoholic steatohepatitis), can lead to advanced fibrosis, cirrhosis, and HCC. The pathophysiologic mechanisms that contribute to the development and progression of NAFLD and NASH are complex, and as such myriad therapies are under investigation targeting different pathophysiological mechanisms. Incretin-based therapies, including GLP-1RAs and DPP-4 inhibitors and the inhibition of ASK1 pathway have provided two such novel mechanisms in the management of this disease, and will remain focus of this review.

Future Perspectives on GLP-1 Receptor Agonists and GLP-1/glucagon Receptor Co-agonists in the Treatment of NAFLD

Along the obesity pandemic, the prevalence of non-alcoholic fatty liver disease (NAFLD), often regarded as the hepatic manifestation of the metabolic syndrome, increases worldwide representing now the prevalent liver disease in western countries. No pharmacotherapy is approved for the treatment of NAFLD and, currently, the cornerstone treatment is lifestyle modifications focusing on bodyweight loss, notoriously difficult to obtain and even more difficult to maintain. Thus, novel therapeutic approaches are highly demanded. Glucagon-like peptide-1 (GLP-1) receptor agonists (GLP-1RAs) are approved for the treatment of type 2 diabetes and obesity. They exert their body weight-lowering effect by reducing satiety and food intake. GLP-1RAs have also been shown to reduce liver inflammation and fibrosis. Furthermore, glucagon receptor agonism is being investigated for the treatment of NAFLD due to its appetite and food intake-reducing effects, as well as its ability to increase lipid oxidation and thermogenesis. Recent studies suggest that glucagon receptor signaling is disrupted in NAFLD, indicating that supra-physiological glucagon receptor agonism might represent a new NAFLD treatment target. The present review provides (1) an overview in the pathophysiology of NAFLD, including the potential involvement of GLP-1 and glucagon, (2) an introduction to the currently available GLP-1RAs and (3) outlines the potential of emerging GLP-1RAs and GLP-1/glucagon receptor co-agonists in the treatment of NAFLD.

Efficacy and safety of glucagon-like peptide-1 receptor agonists in non-alcoholic fatty liver disease: A systematic review and meta-analysis

BACKGROUND AND OBJECTIVE

New drugs are urgently needed for the treatment of non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH). The aim of this meta-analysis was to evaluate the efficacy and safety of glucagon-like peptide-1 receptor agonists (GLP-1RAs) in NAFLD/NASH.

METHODS

We searched the MEDLINE, Embase, and Cochrane Library Central to identify randomized controlled trials (RCTs) and observational studies that compared GLP-1RAs with a control treatment or baseline values with respect to efficacy and safety in patients with NAFLD/NASH. Mean differences (MDs) with 95% confidence intervals (CIs) and odds ratios (ORs) were pooled using a random-effect model.

RESULTS

Six studies were eligible and included. Among the 329 NAFLD/NASH patients included in these studies, 277 patients had type 2 diabetes (T2D). GLP-1RA treatment produced significant reductions relative to baseline in liver histology scores for steatosis (MD, 0.80; 95% CI, 0.49 to 1.11), lobular inflammation (MD, 0.22; 95% CI, 0.00 to 0.45), hepatocellular ballooning (MD, 0.41; 95% CI, 0.15 to 0.67) and fibrosis (MD, 0.35; 95% CI, 0.00 to 0.70). Compared with placebo and positive agents, GLP-1RAs significantly reduced gamma-glutamyl transpeptidase (GGT) levels (MD, 13.8 U/L; 95% CI, 7.4 to 20.3; P<0.001). The reported major adverse events associated with GLP-1RA treatment included mild to moderate gastrointestinal discomfort that resolved within a few weeks.

CONCLUSIONS

Our study suggests that in NASH patients, particularly patients with diabetes, GLP-1RAs may improve liver histology and reduce aminotransferase levels from baseline. Benefits of GLP-1RAs are considered to outweigh the risks in NAFLD/NASH patients with or without diabetes.

Pharmacological management of nonalcoholic fatty liver disease in type 2 diabetes

INTRODUCTION

The prevalence of nonalcoholic fatty liver disease (NAFLD) in patients with type 2 diabetes (T2D) is high and it is associated with poor prognosis. Hepatic steatosis results as a consequence of excessive hepatic lipid accumulation which correlates with insulin resistance and lipotoxicity, with subsequent oxidative stress, inflammation, apoptosis and fibrosis. Areas covered: This article presents the main pathophysiologic mechanisms and currently available drugs evaluated for their therapeutic effects on NAFLD/nonalcoholic steatohepatitis (NASH) and drugs under development that target relevant pathogenetic pathways. However, to date there is no particular drug approved for treatment of NAFLD in patients with T2D. Expert commentary: Early recognition and intervention are essential to ameliorate disease progression. Specific recommendations are still needed for NAFLD/NASH screening and diagnosis and therapeutic algorithm in patients with T2D. Lifestyle optimization with significant weight loss is a key intervention in patients with NAFLD and T2D. Pioglitazone, liraglutide, vitamin E, OCA and pentoxifylline have proven some histological improvements in NASH and omega 3-PUFAs were shown to decrease liver fat, but no specific recommendation can be made for treatment of NASH. Perhaps a combination of agents that target different pathogenic pathways are needed to better control disease progression, but more robust evidence for these agents is still needed.

Which treatment for type 2 diabetes associated with non-alcoholic fatty liver disease?

Type 2 diabetes (T2DM) and nonalcoholic fatty liver disease (NAFLD) are highly prevalent in the community, and share common pathogenic mechanisms. There is also evidence that T2DM may be favored by hepatic fat accumulation; in turn the presence of T2DM is a risk factor for liver disease progression. The treatment of T2DM has considerably changed in the past few years; new drug classes, promoting glucose-lowering through mechanisms different from classical insulin-sensitizing or insulin-secreting action, have been added to continuing lifestyle intervention. Metformin and pioglitazone may be safely used in the presence of liver fat, whereas sulfonylureas and insulin itself have been associated with NAFLD progression and adverse outcome. Drugs acting on the incretin axis and on Na-glucose co-transport at renal tubular level offer new hopes for a tailored treatment able to reduce the burden of hepatic triglyceride accumulation and liver disease progression.

Novel antidiabetic medications for non-alcoholic fatty liver disease with type 2 diabetes mellitus

Liver-related diseases are the leading causes of death in patients with type 2 diabetes mellitus (T2DM) in Japan. Type 2 diabetes mellitus is closely associated with non-alcoholic fatty liver disease (NAFLD), which is the most prevalent chronic liver disease worldwide. Non-alcoholic steatohepatitis (NASH), a severe form of NAFLD, can lead to hepatocellular carcinoma and hepatic failure. Non-alcoholic steatohepatitis can be called "diabetic hepatopathy". There are no established pharmacotherapies for NAFLD/NASH patients with T2DM. Although metformin is established as the first-line therapy for T2DM, given its relative safety and beneficial effects on glycosylated hemoglobin, weight, and cardiovascular mortality, this agent is not recommended as specific therapy for NASH/NAFLD due to lack of clinical evidence. The effects of pioglitazone on NASH histology with T2DM have been extensively proved, but several concerns exist, such as body weight gain, fluid retention, cancer incidence, and bone fracture. In recent years, novel antidiabetic medications have been approved for T2DM, such as glucagon-like peptide 1 receptor agonists, dipeptidyl peptidase 4 inhibitors, and sodium/glucose cotransporter 2 inhibitors. A key clinical question for hepatologists is what kinds of antidiabetic medications are the most appropriate for the treatment of NAFLD accompanied by T2DM, to prevent progression of hepatic fibrosis resulting in HCC/liver-related mortality without increased risk of cardiovascular events. This review focuses on novel antidiabetic agents and future perspectives on the treatment of NAFLD/NASH with T2DM.

Pleiotropic effects of insulin and GLP-1 receptor agonists: Potential benefits of the association

The combination of basal insulin and glucagon-like peptide-1 receptor agonists (GLP-1RAs) is an emerging option for patients with type 2 diabetes (T2D). GLP-1RAs have been shown to improve glycaemic control with a low risk of hypoglycaemia and to promote body weight loss. However, GLP-1 receptors (GLP-1Rs) are widely expressed in extrapancreatic tissues and could sustain pleiotropic actions of GLP-1RAs beyond glycaemic control. The underlying molecular mechanisms maintaining these extrapancreatic actions of GLP-1 are complex, and involve GLP-1R signalling in both the brain and several peripheral tissues. The present review focuses specifically on the role of GLP-1RAs in the cardiovascular system and liver. Preclinical data in rodents and pilot studies in humans suggest that GLP-1RAs may have potential beneficial effects on heart function, blood pressure, postprandial lipaemia, liver steatosis and non-alcoholic steatohepatitis (NASH). Long-term studies are now warranted to determine the safety and clinical relevance of the association between insulin and GLP-1RAs in T2D.

[Lixisenatide in patients with type 2 diabetes and obesity: Beyond glycaemic control]

Objetivo

Evaluar la tolerancia a lixisenatida y sus efectos sobre el peso y el control metabólico de pacientes con diabetes tipo 2 y obesidad.

Diseño

Estudio prospectivo.

Emplazamiento

Consultas de atención especializada de Endocrinología y Nutrición en Almería, Granada y Málaga.

Participantes

Pacientes con diabetes tipo 2 y obesidad.

Intervenciones

Respuesta y tolerancia al tratamiento con lixisenatida.

Mediciones principales

Se analizaron datos clínicos y analíticos con medidas de cambio intrasujeto antes-después del tratamiento.

Resultados

Evaluamos 104 pacientes (51% mujeres) con diabetes tipo 2 y obesidad (Almería 18,3%; Granada 40,4%; Málaga 41,3%). Edad media 58,4 ± 10,5 años y duración media de diabetes 11,2 ± 6,7 años. El tiempo medio desde la visita basal a la revisión tras inicio de tratamiento con lixisenatida fue de 3,8 ± 1,6 meses. Encontramos mejoría significativa del peso (p < 0,001), índice de masa corporal (p < 0,001), circunferencia de cintura (p = 0,002), presión arterial sistólica (p < 0,001) y diastólica (p = 0,001), glucemia en ayunas (p < 0,001), HbA1c (p = 0,022), colesterol total (p < 0,001), colesterol LDL (p = 0,046) y triglicéridos (p = 0,020). No se observó alteración de cifras de amilasa en relación con el tratamiento con lixisenatida, y el 7,9% no lo toleraron.

Conclusiones

Lixisenatida consigue: 1) mejoría significativa de parámetros antropométricos y control glucémico (glucemia basal y HbA1c); 2) descenso significativo de la presión arterial y del perfil lipídico, y 3) seguridad y buena tolerancia en la mayoría de los pacientes. Además, encontramos una significativa intensificación del tratamiento antihipertensivo e hipolipemiante.

Non-alcoholic fatty liver disease and dyslipidemia: An update

Non-alcoholic fatty liver (NAFLD) is the most common liver disease worldwide, progressing from simple steatosis to necroinflammation and fibrosis (leading to non-alcoholic steatohepatitis, NASH), and in some cases to cirrhosis and hepatocellular carcinoma. Inflammation, oxidative stress and insulin resistance are involved in NAFLD development and progression. NAFLD has been associated with several cardiovascular (CV) risk factors including obesity, dyslipidemia, hyperglycemia, hypertension and smoking. NAFLD is also characterized by atherogenic dyslipidemia, postprandial lipemia and high-density lipoprotein (HDL) dysfunction. Most importantly, NAFLD patients have an increased risk for both liver and CV disease (CVD) morbidity and mortality. In this narrative review, the associations between NAFLD, dyslipidemia and vascular disease in NAFLD patients are discussed. NAFLD treatment is also reviewed with a focus on lipid-lowering drugs. Finally, future perspectives in terms of both NAFLD diagnostic biomarkers and therapeutic targets are considered.

Baseline ALT levels as a marker of glycemic response to treatment with GLP-1 receptor agonists

BACKGROUND AND OBJECTIVES

This study aimed to assess if ALT levels, as a marker of non-alcoholic fatty liver disease, may predict HbA1c response to treatment with GLP-1 receptor agonists (GLP-1 RAs).

PATIENTS AND METHODS

A retrospective, longitudinal, analytical study was conducted including patients with type 2 diabetes mellitus continuously treated with GLP-1 agonists (85% with liraglutide) for one year. Patients were divided into two groups according to baseline ALT levels, with 24 U/L (the median of the distribution) as the cut-off point. The dependent variable was HbA1c change (one-year follow-up minus baseline). The predictive value of ALT levels above 24 U/L and ALT change was analyzed using multivariate linear regression adjusted to age, gender, diabetes duration, type and dose of GLP-1 RA, baseline HbA1c, baseline body mass index (BMI), and change in BMI.

RESULTS

A total of 117 patients (48% females) aged 58.6 (SD 9.6) years were enrolled into the study. Treatment was associated with a change in ALT of -4.3 U/L (p=0.041) and a change in HbA1c of -1.1% (p<0.0001). Decreases in HbA1c (-1.41% vs -0.76%; p=0.045) and ALT (-9.25 vs 0.46 U/L; p=0.002) were significantly higher in patients with ALT levels above the median. In the multivariate analysis, both ALT>24 U/L (b=-0.74; 95%CI: -1.31 to -0.18; p=0.011) and ALT change (b=0.028; 95%CI: 0.010 to 0.046; p=0.003), were significant response predictors.

CONCLUSIONS

Elevated baseline transaminase values and decreased transaminase levels during follow-up are associated to a favorable glycemic response to GLP-1 RAs.

Incretin manipulation in diabetes management

Incretin-based therapies have revolutionized the medical management of type 2 diabetes mellitus (T2DM) in the 21^st century. Glucagon-like peptide-1 (GLP-1) suppresses appetite and gastric motility, and has trophic effects on pancreas, cardio-protective and renal effects. GLP-1 analogues and dipeptidyl peptidase-4 inhibitors form the incretin-based therapies. Significant reduction of hemoglobin A1c when used as monotherapy and in combination regimens, favorable effects on body weight, and low risk of hypoglycemia are their unique therapeutic benefits. Their safety and tolerability are comparable to other anti-diabetic medications. Concern about elevated risk of pancreatitis has been discarded by two recent meta-analyses. This article discusses the therapeutic manipulation of incretin system for the management of T2DM.