SGLT2 Inhibitor Treatment Outcome in Nonalcoholic Fatty Liver Disease Complicated with Diabetes Mellitus: The Long-term Effects on Clinical Features and Liver Histopathology

Obesity and MASLD: Is weight loss the (only) key to treat metabolic liver disease?

Metabolic dysfunction-associated steatotic liver disease (MASLD) closely associates with obesity and type 2 diabetes. Lifestyle intervention and bariatric surgery aiming at substantial weight loss are cornerstones of MASLD treatment by improving histological outcomes and reducing risks of comorbidities. Originally developed as antihyperglycemic drugs, incretin (co-)agonists and SGLT2 inhibitors also reduce steatosis and cardiorenovascular events. Certain incretin agonists effectively improve histological features of MASLD, but not fibrosis. Of note, beneficial effects on MASLD may not necessarily require weight loss. Despite moderate weight gain, one PPARγ agonist improved adipose tissue and MASLD with certain benefit on fibrosis in post-hoc analyses. Likewise, the first THRβ-agonist was recently provisionally approved because of significant improvements of MASLD and fibrosis. We here discuss liver-related and metabolic effects induced by different MASLD treatments and their association with weight loss. Therefore, we compare results from clinical trials on drugs acting via weight loss (incretin (co)agonists, SGLT2 inhibitors) with those exerting no weight loss (pioglitazone; resmetirom). Furthermore, other drugs in development directly targeting hepatic lipid metabolism (lipogenesis inhibitors, FGF21 analogs) are addressed. Although THRβ-agonism may effectively improve hepatic outcomes, MASLD treatment concepts should consider all cardiometabolic risk factors for effective reduction of morbidity and mortality in the affected people.

Effects of luseogliflozin on suspected MASLD in patients with diabetes: a pooled meta-analysis of phase III clinical trials

BACKGROUND

Luseogliflozin, a sodium-glucose cotransporter 2 inhibitor, potentially exerts pleiotropic effects on the liver. However, the sufficient evidence is still lacking. We aimed to investigate the effects of luseogliflozin on hepatic steatosis, fibrosis, and cardiometabolic risk factors in diabetic patients by a pooled meta-analysis.

METHODS

In this pooled meta-analysis, we enrolled diabetic patients who participated in phase III clinical trials of luseogliflozin (luseogliflozin group n = 302, placebo group n = 191). The primary outcomes were changes in fatty liver index (FLI) and Hepamet fibrosis score (HFS) after 24 weeks. The secondary outcomes were changes in cardiometabolic risk factors after 24 weeks. Statistical analysis was performed using propensity scoring analysis by the inverse probability of treatment weighting method.

RESULTS

Primary outcomes: Luseogliflozin significantly decreased FLI compared to placebo after 24 weeks (adjusted coefficient - 5.423, 95%CI - 8.760 to - 2.086, P = 0.0016). There was no significant difference in changes in HFS between the two groups. However, luseogliflozin significantly decreased HFS compared to placebo in diabetic patients with ALT > 30 U/L (adjusted coefficient - 0.039, 95%CI - 0.077 to - 0.001, P = 0.0438) and with FIB-4 index > 1.3 (adjusted coefficient - 0.0453, 95%CI - 0.075 to - 0.016, P = 0.0026). Secondary outcom8es: Luseogliflozin significantly decreased HbA1c level, HOMA-IR value, BMI, and uric acids level, and increased HDL cholesterol level compared to placebo.

CONCLUSIONS

This pooled meta-analysis demonstrated that 24-week treatment with luseogliflozin improved hepatic steatosis and fibrosis indexes in diabetic patients, especially those with liver injury. Furthermore, luseogliflozin improved various cardiometabolic risk factors. Thus, luseogliflozin may be useful for improving MASLD in diabetic patients.

Review of current and new drugs for the treatment of metabolic-associated fatty liver disease

In the past 3 decades, metabolic-associated fatty liver disease (MAFLD) has emerged as a widespread liver condition, with its global prevalence on the rise. It ranks as a leading contributor to hepatocellular carcinoma (HCC) and necessitates liver transplantation. Under the multiple parallel hits model, the pathogenesis of MAFLD stems from various liver stressors, notably nutrient overload and sedentary lifestyles. While medical management for MAFLD is well-established, encompassing non-pharmaceutical and pharmaceutical interventions, determining the most effective pharmaceutical therapy has remained elusive. This review discusses diabetic medications for MAFLD treatment, emphasizing recent studies and emerging drugs while reviewing other nondiabetic agents. Emerging evidence suggests that combination therapies hold promise for resolving MAFLD and metabolic steatohepatitis (MASH) while managing side effects. Ongoing trials play a pivotal role in elucidating the effects of mono, dual, and triple receptor agonists in individuals with MASH. With the rising burden of MAFLD/MASH and its severe consequences, the need for effective treatments is more pressing than ever. This review provides a comprehensive overview of the current landscape of pharmaceutical interventions for MAFLD and MASH, shedding light on the potential of newer drugs especially diabetic medications and the importance of ongoing research in this field.

Systemic and organ-specific anti-inflammatory effects of sodium-glucose cotransporter-2 inhibitors

Inflammation plays an essential role and is a common feature in the pathogenesis of many chronic diseases. The exact mechanisms through which sodium-glucose cotransporter-2 (SGLT2) inhibitors achieve their much-acclaimed clinical benefits largely remain unknown. In this review, we detail the systemic and tissue- or organ-specific anti-inflammatory effects of SGLT2 inhibitors using evidence from animal and human studies. We discuss the potential pathways through which SGLT2 inhibitors exert their anti-inflammatory effects, including oxidative stress, mitochondrial, and inflammasome pathways. Finally, we highlight the need for further investigation of the extent of the contribution of the anti-inflammatory effects of SGLT2 inhibition to improvements in cardiometabolic and renal outcomes in clinical studies.

Management of type 2 diabetes in patients with compensated liver cirrhosis: Short of evidence, plenty of potential

BACKGROUND AND AIMS

Treatment of type 2 diabetes (T2D) in patients with compensated cirrhosis is challenging due to hypoglycemic risk, altered pharmacokinetics, and the lack of robust evidence on the risk/benefit ratio of various drugs. Suboptimal glycemic control accelerates the progression of cirrhosis, while the frequent coexistence of nonalcoholic fatty liver disease (NAFLD) with T2D highlights the need for a multifactorial therapeutic approach.

METHODS

A literature search was performed in Medline, Google Scholar and Scopus databases till July 2023, using relevant keywords to extract studies regarding the management of T2D in patients with compensated cirrhosis.

RESULTS

Metformin, sodium-glucose co-transporter-2 inhibitors (SGLT2i), and glucagon-like peptide-1 receptor agonists (GLP-1 RA) are promising treatment options for patients with T2D and compensated liver cirrhosis, offering good glycemic control with minimal risk of hypoglycemia, while their pleiotropic actions confer benefits on NAFLD and body weight, and decrease cardiorenal risk. Sulfonylureas cause hypoglycemia, thus should be avoided, while in specific studies, dipeptidyl peptidase-4 inhibitors have been correlated with increased risk of decompensation and variceal bleeding. Despite the benefits of thiazolidinediones in nonalcoholic steatohepatitis, concerns about edema and weight gain limit their use in compensated cirrhosis. Insulin does not exert hepatotoxic effects and can be administered safely in combination with other drugs; however, the risk of hypoglycemia should be considered.

CONCLUSIONS

The introduction of new hepatoprotective diabetes drugs into clinical practice, including tirzepatide, SGLT2i, and GLP-1 RA, sets the stage for future trials to investigate the ideal therapeutic regimen for people with T2D and compensated cirrhosis.

The role of anti-diabetic drugs in NAFLD. Have we found the Holy Grail? A narrative review

PURPOSE

Non-alcoholic fatty liver disease (NAFLD) has become a leading cause of liver disease, affecting 30% of the global population. NAFLD prevalence is particularly high in obese individuals and patients with type 2 diabetes mellitus (T2DM). NAFLD ranges from simple fat deposition in the liver to necroinflammation and fibrosis (non-alcoholic steatohepatitis (NASH)), NASH-cirrhosis, and/or hepatocellular carcinoma. Insulin resistance plays a key role in NAFLD pathogenesis, alongside dysregulation of adipocytes, mitochondrial dysfunction, genetic factors, and changes in gut microbiota. Since insulin resistance is also a major predisposing factor of T2DM, the administration of anti-diabetic drugs for the management of NAFLD seems reasonable.

METHODS

In this review we provide the NAFLD-associated mechanisms of action of some of the most widely used anti-diabetic drugs, namely metformin, pioglitazone, sodium-glucose transport protein-2 inhibitors (SGLT2i), glucagon-like peptide 1 receptor analogs (GLP1 RAs), and dipeptyl-peptidase-4 inhibitors (DPP4i) and present available data regarding their use in patients with NAFLD, with and without T2DM.

RESULTS

Both metformin and DPP4i have shown rather contradictory results, while pioglitazone seems to benefit patients with NASH and is thus the only drug approved for NASH with concomitant significant liver fibrosis by all major liver societies. On the other hand, SGLT2i and GLP1 RAs seem to be beneficiary in patients with NAFLD, showing both remarkable results, with SGLT2i proving to be more efficient in the only head-to-head study so far.

CONCLUSION

In patients with NAFLD and diabetes, pioglitazone, GLP1 RAs, and SGLT2i seem to be logical treatment options. Larger studies are needed before these drugs can be recommended for non-diabetic individuals.

Canagliflozin and Metabolic Associated Fatty Liver Disease in Patients With Diabetes Mellitus: New Insights From CANVAS

CONTEXT

Metabolic dysfunction-associated fatty liver disease (MAFLD) is highly prevalent among patients with type 2 diabetes mellitus (T2DM); however, there is still no approved pharmacological treatment. Sodium-glucose cotransporter 2 (SGLT-2) inhibitors have been suggested to beneficially modify liver-related outcomes in patients with diabetes.

OBJECTIVE

We aimed to investigate the effects of the SGLT-2 inhibitor canagliflozin on liver-related outcomes in patients with advanced T2DM and high cardiovascular risk.

METHODS

We performed a secondary post hoc analysis of 2 large double-blind randomized controlled trials, CANVAS (NCT01032629) and CANVAS-R (NCT01989754), which included patients with T2DM and high cardiovascular risk who were randomized to receive either canagliflozin or placebo once daily. The primary endpoint was a composite of improvement of alanine aminotransferase (ALT) levels >30% or normalization of ALT levels. Secondary endpoints included change in noninvasive tests of fibrosis and weight reduction of >10%.

RESULTS

In total, 10 131 patients were included, with a median follow-up of 2.4 years (mean age 62 years; mean duration of diabetes 13.5 years; 64.2% male). Of those patients, 8967 (88.5%) had MAFLD according to hepatic steatosis index and 2599 (25.7%) exhibited elevated liver biochemistry at baseline. The primary composite endpoint occurred in 35.2% of patients receiving canagliflozin and in 26.4% with placebo (adjusted odds ratio [aOR] 1.51; 95% CI, 1.38-1.64; P < .001). Canagliflozin led to improvements in some noninvasive tests of fibrosis (NFS, APRI, FNI). Significant weight reduction of >10% (within 6 years) was achieved in 12.7% with canagliflozin compared to 4.1% with placebo (aOR 3.45; 95% CI, 2.91-4.10; P < .001).

CONCLUSION

In patients with T2DM, treatment with canagliflozin vs placebo resulted in improvements in liver biochemistry and metabolism and might beneficially affect liver fibrosis.

Role of inflammasomes and cytokines in immune dysfunction of liver cirrhosis

Liver cirrhosis develops as a result of persistent inflammation and liver injury. The prolonged inflammation triggers the buildup of fibrous tissue and regenerative nodules within the liver, leading to the distortion of the hepatic vascular structure and impaired liver function. Cirrhosis disrupts the ability of liver function to maintain homeostasis and hepatic immunosurveillance which causes immunological dysfunction in the body. In pathological conditions, the production of cytokines in the liver is carefully regulated by various cells in response to tissue stimulation. Cytokines and inflammasomes are the key regulators and systematically contribute to the development of cirrhosis which involves an inflammatory response. However, the crosstalk role of different cytokines in the cirrhosis progression is poorly understood. Tumour necrosis factor-alpha (TNF-α), interleukin-1 (IL-1), interleukin-6 (IL-6), and interferon-gamma (IFN-γ), among others, are proinflammatory cytokines that contribute to liver cell necrosis, which in turn causes the development of fibrosis. While IL-10 exhibits a potent anti-inflammatory effect on the liver by inhibiting immune cell activation and neutralizing pro-inflammatory cytokine activity. Inflammasomes have also been implicated in the profibrotic processes of liver cirrhosis, as well as the production of chemokines such as CCL2/MCP-1. It is evident that inflammasomes have a role in the proinflammatory response seen in chronic liver illnesses. In conclusion, cirrhosis significantly impacts the immune system, leading to immunological dysfunction and alterations in both innate and acquired immunity. Proinflammatory cytokines like TNF-α, IL-1β, IL-6, and IFNγ are upregulated in cirrhosis, contributing to liver cell necrosis and fibrosis development. Managing cytokine-mediated inflammation and fibrosis is a key therapeutic approach to alleviate portal hypertension and its associated liver complications. This review attempted to focus largely on the role of immune dysfunction mediated by different cytokines and inflammasomes involved in the progression, regulation and development of liver cirrhosis.

Sodium-glucose cotransporter-2 inhibitors in patients with type 2 diabetes mellitus and moderate to severe hepatic fibrosis: A retrospective study

BACKGROUND

Sodium-glucose cotransporter-2 inhibitors (SGLT2i) have been shown to decrease hepatic transaminases, steatosis, and in some studies, hepatic fibrosis. However, the safety and efficacy of SGLT2i has not been tested in patients who have moderate to severe hepatic fibrosis.

METHODS

In a retrospective study of sixty patients with moderate to severe hepatic fibrosis (kPa estimated by Fibroscan > 10), SGLT2i were prescribed on top of other oral anti-hyperglycemic medications. The safety and efficacy of SGLT2i were evaluated. Using the Fibroscan, CAP scores (decibel/meter), and liver stiffness measurement (LSM) (kPa, kilopascals) were examined before and after treatment.

RESULTS

The mean age of the T2DM patients was 54.7 ± 10.3 years, and the mean duration of T2DM was 8.3 ± 7.1 years. SGLT2i were given from 3 to 36 months. After treatment, a decrease in glycated hemoglobin (HbA1c), and hepatic transaminases (SGOT and SGPT) was recorded. Upon follow up, CAP and kPa scores decreased significantly. Importantly, no adverse drug reaction, such as balanoposthitis, vulvovaginitis, urosepsis, and postural drop in blood pressure, were reported in any patient.

CONCLUSION

In this retrospective cohort study, patient with T2DM and moderate to severe hepatic fibrosis, use of SGLT2i is safe with respect to common adverse effects & may have contributed to improved hepatic profile.

Study on inflammation and fibrogenesis in MAFLD from 2000 to 2022: a bibliometric analysis

Chronic inflammation and fibrosis are significant factors in the pathogenesis of metabolic-associated fatty liver disease (MAFLD). In this study, we conducted a bibliometric analysis of publications on inflammation and fibrogenesis in MAFLD, with a focus on reporting publication trends. Our findings indicate that the USA and China are the most productive countries in the field, with the University of California San Diego being the most productive institution. Over the past 23 years, Prof. Diehl AM has published 25 articles that significantly contributed to the research community. Notably, the research focus of the field has shifted from morbid obesity and adiponectin to metabolic syndrome, genetics, and microbiome. Our study provides a comprehensive and objective summary of the historical characteristics of research on inflammation and fibrogenesis in MAFLD, which will be of interest to scientific researchers in this field.

Nonalcoholic Fatty Liver Disease and Chronic Kidney Disease Cross Talk

Nonalcoholic fatty liver disease is a multisystem condition with effects beyond the liver. The identification of chronic kidney disease as an independent mediator of nonalcoholic fatty liver disease or associated entity with shared cardiometabolic risk factors remains controversial and continues to draw scientific interest. With increasing prevalence of nonalcoholic fatty liver disease and lack of Food and Drug Administration approved therapies, these shared cardiometabolic risk factors have drawn significant attention. In this article, we review shared pathophysiological mechanisms between nonalcoholic fatty liver disease and chronic kidney disease along with current treatment strategies that might be useful for both disease processes.

Non-Alcoholic Fatty Liver Disease and Extrahepatic Cancers: A Wolf in Sheep’s Clothing?

Non-alcoholic fatty liver disease (NAFLD) is now considered the main driver and leading cause of chronic liver disease globally. The umbrella term NAFLD describes a range of liver conditions closely related to insulin resistance, metabolic syndrome, diabetes mellitus, obesity, and dyslipidemia. At the same time, several malignancies, including hepatocellular carcinoma and colorectal cancer, are considered to be common causes of death among patients with NAFLD. At first, our review herein aims to investigate the role of NAFLD in developing colorectal neoplasms and adenomatous polyps based on the current literature. We will also explore the connection and the missing links between NAFLD and extrahepatic cancers. Interestingly, any relationship between NAFLD and extrahepatic malignancies could be attributable to several shared metabolic risk factors. Overall, obesity, insulin resistance, metabolic syndrome, and related disorders may increase the risk of developing cancer. Therefore, early diagnosis of NAFLD is essential for preventing the progression of the disease and avoiding its severe complications. In addition, cancer screening and early detection in these patients may improve survival and reduce any delays in treatment.

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.

Favorable impact of long-term SGLT2 inhibitor for NAFLD complicated by diabetes mellitus: A 5-year follow-up study

The aim of this study was to determine the impact at 5 years of sodium‐glucose cotransporter 2 inhibitor (SGLT2i) in nonalcoholic fatty liver disease (NAFLD) with type 2 diabetes mellitus (T2DM) on liver histopathology and clinical features. In this retrospective study, the histological impacts at 5 years after the start of SGLT2i in NAFLD with T2DM were investigated. Six patients with NAFLD and T2DM were treated for the long term with canagliflozin of SGLT2i, and liver biopsies were obtained at the points of the pretreatment, 24 weeks, 3 years, and 5 years after the start of treatment. The primary outcome was liver histopathological changes at 5 years (defined as decrease in NAFLD activity score of one point or more without worsening in fibrosis stage, compared with the pretreatment). The additional treatment of glucagon‐like peptide 1 receptor agonist (GLP‐1RA) was performed in 2 patients after the point of 3 years, and evaluated as histological worsening. As the primary outcome, histological improvement, no change, and worsening were 50%, 17%, and 33% at 5 years, respectively. Overall, the scores of steatosis, lobular inflammation, ballooning, and fibrosis stage decreased at 5 years in 67%, 33%, 0%, and 33%, respectively. As the secondary outcomes, homeostasis model assessment of insulin resistance and serum ferritin decreased significantly at 5 years. None developed 3‐point major adverse cardiovascular events. Two patients with the addition of GLP‐1RA on SGLT2i did not show the worsening of steatosis, ballooning, and fibrosis stage at 5 years compared with 3 years. Conclusion: A 5‐year follow‐up study with SGLT2i indicated the favorable histological impact on NAFLD with T2DM.

Additional Effect of Luseogliflozin on Semaglutide in Nonalcoholic Steatohepatitis Complicated by Type 2 Diabetes Mellitus: An Open-Label, Randomized, Parallel-Group Study

INTRODUCTION

Untreated nonalcoholic fatty liver may progress to nonalcoholic steatohepatitis (NASH) and cirrhosis and induce hepatocellular carcinoma and liver failure. Type 2 diabetes mellitus (T2DM), often complicated with nonalcoholic fatty liver disease (NAFLD), is a driver of NAFLD progression. Thus, efficacious treatment strategies for patients with coexisting NAFLD and T2DM are important for preventing NAFLD progression. Although previous studies have demonstrated that either sodium-glucose transporter 2 inhibitors (SGLT2is) or glucagon-like peptide 1 receptor agonists (GLP-1 RAs) benefit NASH patients with T2DM, the rate of NASH resolution has not sufficiently improved. Therefore, we developed a protocol for a randomized controlled trial to examine whether the addition of an SGLT2i to the treatment regimen of patients receving a GLP-1 RA (combination therapy), within the therapeutic dose range for T2DM, increases the rate of NASH resolution in patients with coexisting NASH and T2DM.

METHODS

This open-label, randomized, parallel-group study commenced in June 2021, will conclude recruitment in May 2023, and will end by March 2025. Sixty patients with NASH complicated by T2DM are enrolled at the Ehime University Hospital in Toon, Japan. Participants will be randomized into: (1) an intervention group receiving combination therapy with the SGLT2i luseogliflozin 2.5 mg, once daily (Taisho Pharmaceutical, Tokyo, Japan) and the GLP-1 RA semaglutide 0.5 mg, once per week (Novonordisk, Copenhagen, Denmark); and (2) a control group receiving monotherapy with the GLP-1 analog semaglutide. The primary endpoints, which will be ascertained by liver biopsy, are: (1) NASH resolution rate from baseline without worsening of liver fibrosis after 52 weeks of intervention; (2) rate of improvement from baseline of at least 1 point in the NAFLD activity score without worsening of liver fibrosis after 52 weeks of intervention; and (3) rate of improvement from baseline of at least one fibrosis stage without worsening of NASH after 52 weeks of intervention.

TRIAL REGISTRATION

University Hospital Medical Information Network Clinical Trial Registry (UMIN-CTR) number: UMIN000045003. Japan Registry of Clinical Trials registration number: jRCTs061210009.

SGLT2 Inhibitors: A Broad Impact Therapeutic Option for the Nephrologist

Since their introduction as antidiabetic drugs, SGLT2 inhibitors (SGLT2i) have come a long way, proving to be beneficial on cardiovascular and renal outcomes independently of diabetes status. The benefits go far beyond glycemic control, and both the cardio- and nephroprotection are underpinned by diverse mechanisms. From the activation of tubule glomerular feedback and the consequent reduction in hyperfiltration to the improvement of hypoxia and oxidative stress in the renal cortex, SGLT2i have also been shown to inhibit hepcidin and limit podocyte damage. Likewise, they improve cardiac metabolism and bioenergetics, and reduce necrosis and cardiac fibrosis and the production of adipokines, cytokines, and epicardial adipose tissue mass. In terms of outcomes, the efficacy has been demonstrated on blood pressure control, BMI, albuminuria, stroke, heart disease, and mortality rate due to cardiovascular events. Patients with chronic kidney disease and proteinuria, with or without diabetes, treated with some SGLT2i have a reduced risk of progression. The analysis of subgroups of individuals with specific diseases such as IgA nephropathy has confirmed this solid effect on renal outcomes. Given these overarching activities on such a broad pathophysiological background and the favorable safety profile that goes with the use of SGLT2i, it is now certain that they are changing our approach to clinical interventions for important outcomes with an impressive impact.

SGLT-2 Inhibitors in NAFLD: Expanding Their Role beyond Diabetes and Cardioprotection

Non-alcoholic fatty liver disease (NAFLD) is an ‘umbrella’ term, comprising a spectrum ranging from benign, liver steatosis to non-alcoholic steatohepatitis, liver fibrosis and eventually cirrhosis and hepatocellular carcinoma. NAFLD has evolved as a major health problem in recent years. Discovering ways to prevent or delay the progression of NAFLD has become a global focus. Lifestyle modifications remain the cornerstone of NAFLD treatment, even though various pharmaceutical interventions are currently under clinical trial. Among them, sodium-glucose co-transporter type-2 inhibitors (SGLT-2i) are emerging as promising agents. Processes regulated by SGLT-2i, such as endoplasmic reticulum (ER) and oxidative stress, low-grade inflammation, autophagy and apoptosis are all implicated in NAFLD pathogenesis. In this review, we summarize the current understanding of the NAFLD pathophysiology, and specifically focus on the potential impact of SGLT-2i in NAFLD development and progression, providing current evidence from in vitro, animal and human studies. Given this evidence, further mechanistic studies would advance our understanding of the exact mechanisms underlying the pathogenesis of NAFLD and the potential beneficial actions of SGLT-2i in the context of NAFLD treatment.

Novel Antidiabetic Strategies and Diabetologists' Views in Nonalcoholic Steatohepatitis

Nonalcoholic fatty liver disease (NAFLD) has become the most common chronic liver disease worldwide with high prevalence, especially in individuals with obesity and type 2 diabetes. Among individuals with type 2 diabetes, the severe insulin resistant subgroup has the greatest risk of NAFLD, likely due to dysfunctional adipose tissue mass but also genetic factors, and may progress earlier to inflammatory and profibrotic nonalcoholic steatohepatitis (NASH). NASH has been associated with increased liver-related as well as cardiovascular morbidity and mortality. International diabetes associations recommend certain screening and treatment strategies for NASH in type 2 diabetes, which, however, bear several limitations such as lack of accurate noninvasive diagnostic tools and targeted treatments. Currently, antihyperglycemic drug concepts based on glucagon-like peptide-1 receptor agonists and sodium glucose cotransporter 2 inhibitors offer metabolic as well as cardiorenal benefits and provide treatment options for both hyperglycemia and NASH in type 2 diabetes.

Advancements in the treatment of non-alcoholic fatty liver disease (NAFLD)

Non-alcoholic fatty liver disease (NAFLD) is a series of diseases, involving excessive lipid deposition in the liver and is often accompanied by obesity, diabetes, dyslipidemia, abnormal blood pressure, and other metabolic disorders. In order to more accurately reflect its pathogenesis, an international consensus renamed NAFLD in 2020 as metabolic (dysfunction) associated with fatty liver disease (MAFLD). The changes in diet and lifestyle are recognized the non-drug treatment strategies; however, due to the complex pathogenesis of NAFLD, the current drug therapies are mainly focused on its pathogenic factors, key links of pathogenesis, and related metabolic disorders as targets. There is still a lack of specific drugs. In clinical studies, the common NAFLD treatments include the regulation of glucose and lipid metabolism to protect the liver and anti-inflammation. The NAFLD treatments based on the enterohepatic axis, targeting gut microbiota, are gradually emerging, and various new metabolism-regulating drugs are also under clinical development. Therefore, this review article has comprehensively discussed the research advancements in NAFLD treatment in recent years.

Evidence-based clinical practice guidelines for nonalcoholic fatty liver disease/nonalcoholic steatohepatitis 2020

Nonalcoholic fatty liver disease (NAFLD) has become a serious public health issue not only in Western countries but also in Japan. Within the wide spectrum of NAFLD, nonalcoholic steatohepatitis (NASH) is a progressive form of disease that often develops into liver cirrhosis and increases the risk of hepatocellular carcinoma (HCC). While a definite diagnosis of NASH requires liver biopsy to confirm the presence of hepatocyte ballooning, hepatic fibrosis is the most important prognostic factor in NAFLD. With so many NAFLD patients, it is essential to have an effective screening method for NAFLD with hepatic fibrosis. As HCC with non-viral liver disease has increased markedly in Japan, effective screening and surveillance of HCC are also urgently needed. The most common death etiology in NAFLD patients is cardiovascular disease event. Gastroenterologists must, therefore, pay close attention to CVD when examining NAFLD patients. In the updated guidelines, we propose screening and follow-up methods for hepatic fibrosis, HCC, and CVD in NAFLD patients. Several drug trials are ongoing for NAFLD/NASH therapy, however, there is currently no specific drug therapy for NAFLD/NASH. In addition to vitamin E and thiazolidinedione derivatives, recent trials have focused on sodium glucose co-transporter 2 (SGLT2) inhibitors and glucagon-like peptide-1 (GLP-1) analogues, and effective therapies are expected to be developed. These practical guidelines for NAFLD/NASH were established by the Japanese Society of Gastroenterology in conjunction with the Japan Society of Hepatology. Clinical evidence reported internationally between 1983 and October 2018 was collected, and each clinical and background question was evaluated using the Grades of Recommendation Assessment, Development and Evaluation (GRADE) system. This English summary pro- vides the core essentials of these clinical practice guidelines, which include the definition and concept, screening systems for hepatic fibrosis, HCC and CVD, and current therapies for NAFLD/NASH in Japan.

Dapagliflozin attenuates steatosis in livers of high-fat diet-induced mice and oleic acid-treated L02 cells via regulating AMPK/mTOR pathway

Dapagliflozin (DAPA), a kind of sodium-glucose cotransporter 2(SGLT2) inhibitor is used to treat diabetes mellitus by inhibiting urine glucose reuptake. Recent clinical outcomes indicate that SGLT2 inhibitors may exert pharmacological activities against non-alcoholic fatty liver diseases. Nonetheless, the underlying molecular mechanisms are still poorly elucidated. In this study, we investigated the potential anti-fatty liver effects of DAPA in vivo and in vitro and assayed their underlying mechanisms. Male NIH (National Institutes of Health) mice were fed with a high-fat diet (HFD) and then treated with DAPA by gavage for 4 weeks. In the following experiments, L02 cells were treated with oleic acid (OA) and different concentrations of DAPA to assess lipid metabolism. Our results revealed that DAPA administration could remarkably suppress excessive fat accumulation in the liver tissues of HFD-fed mice and OA-treated L02 cells. Importantly, DAPA could downregulate the expression levels of proteins related to lipid synthesis and upregulate the expression levels of genes associated with fatty acid oxidation in vitro and in vivo. We also found that DAPA intervention could activate adenosine monophosphate-activated protein kinase (AMPK) phosphorylation but inhibit mammalian target of rapamycin (mTOR) phosphorylation in vitro and in vivo. AMPK activation might be mediated by increasing liver kinase B1 activity and decreasing ATP level. Furthermore, these ameliorative effects were completely eliminated by an AMPK inhibitor, compound C. This study suggested that DAPA might remarkably ameliorate hepatic steatosis mediated through the AMPK/mTOR pathway and thus could be a potential drug candidate for the treatment of fatty liver diseases.

Canagliflozin Improves Liver Function in Rats by Upregulating Asparagine Synthetase

INTRODUCTION

Canagliflozin (CANA) is a sodium-glucose cotransporter 2 inhibitor that was recently approved for treating diabetes. However, its effects on liver function are not well understood. The function of asparagine synthetase (ASNS) has been studied in several cancers but not in liver injury. Therefore, we investigated the connection between CANA and ASNS in alleviating damage (i.e., their hepatoprotective effect) in a rat liver injury model.

METHODS

The rat model of liver injury was established using carbon tetrachloride treatment. Rats with liver injury were administered CANA orally for 8 weeks daily. After week 8, peripheral blood was collected to measure serum alanine aminotransferase, aspartate aminotransferase, and lactate dehydrogenase levels. Liver histopathology was examined using hematoxylin and eosin staining to determine the degree of liver injury. Protein expression in the rat livers was examined using Western blotting.

RESULTS

CANA treatment decreased serum alanine aminotransferase, aspartate aminotransferase, and lactate dehydrogenase levels compared with those of the untreated group, demonstrating diminished liver injury. Mechanistically, CANA treatment activated AMP-activated protein kinase (AMPK), leading to increased nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) and activating transcription factor 4 (ATF4), which upregulated ASNS expression in liver-injured rats.

CONCLUSION

CANA significantly alleviated liver injury by activating the AMPK/Nrf2/ATF4 axis and upregulating ASNS expression, indicating its potential for treating patients with type 2 diabetes mellitus with impaired liver function.

Effect of ipragliflozin on liver function in Japanese type 2 diabetes mellitus patients: subgroup analysis of a 3-year post-marketing surveillance study (STELLA-LONG TERM)

The STELLA-LONG TERM prospective post-marketing surveillance study assessed ipragliflozin in Japanese patients with type 2 diabetes mellitus (T2DM). This subgroup analysis of patients with liver impairment used the final 3-year results. Data on patients, adverse drug reactions (ADRs), and changes in glycemic parameters and liver enzymes (aspartate aminotransferase [AST], alanine aminotransferase [ALT], gamma-glutamyl transpeptidase [γ-GTP] and alkaline phosphatase [ALP]) were collected, and the fatty liver index (FLI) was calculated. In the effectiveness analysis (n = 8,763), baseline liver function was normal in 2,605 patients (ALT <31/<21 U/L [men/women]) and abnormal in 3,277 (ALT ≥31/≥21 U/L). The abnormal liver function group had higher mean body weight and BMI than the normal liver function group (p < 0.001). In the safety analysis (n = 11,051), urinary tract infections, genital infections and hepatic disorders were more common in the abnormal than normal liver function group (2.25% vs. 1.07%; 1.78% vs. 1.14% and 1.85% vs. 1.01%). In the abnormal liver function group, there were significant (p < 0.001) decreases from baseline at 36 months in AST and ALT (from 38.8 and 53.7 U/L to 29.3 and 37.7 U/L, respectively), γ-GTP (from 75.4 to 51.7 U/L) and ALP (from 254.8 to 234.5 U/L), which were greater than in the normal liver function group. FLI reductions at 36 months were significant (p < 0.001) in subgroups with baseline FLI of ≥30 or ≥60. In conclusion, ipragliflozin improved liver function over 3 years in patients with impaired liver function, although ADRs occurred more frequently than in the normal liver function group.

Emergence of SGLT2 Inhibitors as Powerful Antioxidants in Human Diseases

Sodium-glucose cotransporter 2 (SGLT2) inhibitors are a new class of oral glucose-lowering agents. Apart from their glucose-lowering effects, large clinical trials assessing certain SGLT2 inhibitors have revealed cardiac and renal protective effects in non-diabetic patients. These excellent outcomes motivated scientists and clinical professionals to revisit their underlying mechanisms. In addition to the heart and kidney, redox homeostasis is crucial in several human diseases, including liver diseases, neural disorders, and cancers, with accumulating preclinical studies demonstrating the therapeutic benefits of SGLT2 inhibitors. In the present review, we aimed to update recent advances in the antioxidant roles of SGLT2 inhibitors in common but debilitating human diseases. We anticipate that this review will guide new research directions and novel therapeutic strategies for diabetes, cardiovascular diseases, nephropathies, liver diseases, neural disorders, and cancers in the era of SGLT2 inhibitors.

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.

Evidence-based clinical practice guidelines for nonalcoholic fatty liver disease/nonalcoholic steatohepatitis 2020

Nonalcoholic fatty liver disease (NAFLD) has become a serious public health issue not only in Western countries but also in Japan. Within the wide spectrum of NAFLD, nonalcoholic steatohepatitis (NASH) is a progressive form of disease that often develops into liver cirrhosis and increases the risk of hepatocellular carcinoma (HCC). While a definite diagnosis of NASH requires liver biopsy to confirm the presence of hepatocyte ballooning, hepatic fibrosis is the most important prognostic factor in NAFLD. With so many NAFLD patients, it is essential to have an effective screening method for NAFLD with hepatic fibrosis. As HCC with non-viral liver disease has increased markedly in Japan, effective screening and surveillance of HCC are also urgently needed. The most common death etiology in NAFLD patients is cardiovascular disease (CVD) event. Gastroenterologists must, therefore, pay close attention to CVD when examining NAFLD patients. In the updated guidelines, we propose screening and follow-up methods for hepatic fibrosis, HCC, and CVD in NAFLD patients. Several drug trials are ongoing for NAFLD/NASH therapy, however, there is currently no specific drug therapy for NAFLD/NASH. In addition to vitamin E and thiazolidinedione derivatives, recent trials have focused on sodium glucose co-transporter 2 (SGLT2) inhibitors and glucagon-like peptide-1 (GLP-1) analogues, and effective therapies are expected to be developed. These practical guidelines for NAFLD/NASH were established by the Japanese Society of Gastroenterology in conjunction with the Japan Society of Hepatology. Clinical evidence reported internationally between 1983 and October 2018 was collected, and each clinical and background question was evaluated using the Grades of Recommendation Assessment, Development and Evaluation (GRADE) system. This English summary provides the core essentials of these clinical practice guidelines, which include the definition and concept, screening systems for hepatic fibrosis, HCC and CVD, and current therapies for NAFLD/NASH in Japan.

Liver Fibrosis in Non-alcoholic Fatty Liver Disease: From Liver Biopsy to Non-invasive Biomarkers in Diagnosis and Treatment

An increasing percentage of people have or are at risk to develop non-alcoholic fatty liver disease (NAFLD) worldwide. NAFLD comprises different stadia going from isolated steatosis to non-alcoholic steatohepatitis (NASH). NASH is a chronic state of liver inflammation that leads to the transformation of hepatic stellate cells to myofibroblasts. These cells produce extra-cellular matrix that results in liver fibrosis. In a normal situation, fibrogenesis is a wound healing process that preserves tissue integrity. However, sustained and progressive fibrosis can become pathogenic. This process takes many years and is often asymptomatic. Therefore, patients usually present themselves with end-stage liver disease e.g., liver cirrhosis, decompensated liver disease or even hepatocellular carcinoma. Fibrosis has also been identified as the most important predictor of prognosis in patients with NAFLD. Currently, only a minority of patients with liver fibrosis are identified to be at risk and hence referred for treatment. This is not only because the disease is largely asymptomatic, but also due to the fact that currently liver biopsy is still the golden standard for accurate detection of liver fibrosis. However, performing a liver biopsy harbors some risks and requires resources and expertise, hence is not applicable in every clinical setting and is unsuitable for screening. Consequently, different non-invasive diagnostic tools, mainly based on analysis of blood or other specimens or based on imaging have been developed or are in development. In this review, we will first give an overview of the pathogenic mechanisms of the evolution from isolated steatosis to fibrosis. This serves as the basis for the subsequent discussion of the current and future diagnostic biomarkers and anti-fibrotic drugs.