Treatment of Nonalcoholic Fatty Liver Disease (NAFLD) in patients with Type 2 Diabetes Mellitus

Restoration of lysosomal acidification rescues autophagy and metabolic dysfunction in non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is the most common liver disease in the world. High levels of free fatty acids in the liver impair hepatic lysosomal acidification and reduce autophagic flux. We investigate whether restoration of lysosomal function in NAFLD recovers autophagic flux, mitochondrial function, and insulin sensitivity. Here, we report the synthesis of novel biodegradable acid-activated acidifying nanoparticles (acNPs) as a lysosome targeting treatment to restore lysosomal acidity and autophagy. The acNPs, composed of fluorinated polyesters, remain inactive at plasma pH, and only become activated in lysosomes after endocytosis. Specifically, they degrade at pH of ~6 characteristic of dysfunctional lysosomes, to further acidify and enhance the function of lysosomes. In established in vivo high fat diet mouse models of NAFLD, re-acidification of lysosomes via acNP treatment restores autophagy and mitochondria function to lean, healthy levels. This restoration, concurrent with reversal of fasting hyperglycemia and hepatic steatosis, indicates the potential use of acNPs as a first-in-kind therapeutic for NAFLD.

Liraglutide on type 2 diabetes mellitus with nonalcoholic fatty liver disease: A systematic review and meta-analysis of 16 RCTs

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is a common comorbidity of type 2 diabetes mellitus (T2DM). Our aim is to investigate the effects of liraglutide on T2DM with NAFLD.

METHODS

Relevant articles published from the earliest publication to March 2022 were selected from several databases. The Cochrane Collaboration's RevMan software was used for the analysis.

RESULTS

Sixteen studies are selected for this meta-analysis, which includes totally 634 patients in the treatment group and 630 patients in the control group. As a result, 14 studies show that fasting plasma glucose levels of the experimental group are lower than that of the control group; 15 studies show that glycosylated hemoglobin A1c levels of the experimental group are lower than that of the control group; 13 studies show that triglyceride levels of the experimental group are lower than that of the control group; twelve studies show that total cholesterol levels of the experimental group are lower than that of the control group; 10 studies show that alanine aminotransferase levels of the experimental group is lower than that of the control group; 10 studies show that no significant difference in changes in aspartate transaminase between 2 groups; 13 studies show that low density lipoprotein cholesterol levels of the experimental group is lower than that of the control group; 9 studies show that no significant difference in changes in high density lipoprotein cholesterol between 2 groups; 7 studies mentioned adverse effects and the difference is significant.

CONCLUSION

Liraglutide is potentially curative for T2DM with NAFLD.

Identifying advanced MAFLD in a cohort of T2DM and clinical features

BACKGROUND

MAFLD is the most common cause of chronic liver disease, affecting 25% of the global population. Patients with T2DM have an increased risk of developing MAFLD. In addition, patients with T2DM have a higher risk of advanced forms of steatohepatitis and fibrosis. Identifying those patients is critical in order to refer them to specialist and appropriate management of their disease.

AIMS AND OBJECTIVES

To estimate advanced fibrosis prevalence in a cohort of patients with T2DM and to identify possible predictors.

METHODS

subjects with T2DM during regular health check-up were enrolled. Demographic and general characteristics were measured, including metabolic parameters and homeostasis model assessment of insulin resistance (HOMA2-IR). Four non-invasive fibrosis scores (NAFLD fibrosis scores, FIB-4, APRI, Hepamet fibrosis score) were measure and compared with transient elastography (TE).

RESULTS

96 patients (21%) presented risk of significant fibrosis (≥F2) measured by TE and 45 patients (10%) presented with risk of advanced fibrosis F3-F4. Liver fibrosis was related to BMI, AC, HOMA2-IR. The results of the non-invasive fibrosis scores have been validated with the results obtained in the TE. It is observed that the index with the greatest area under the curve (AUC) is APRI (AUC=0.729), with a sensitivity of 62.2% and a specificity of 76.1%. However, the test with better positive likelihood ratio (LR+) in our study is NAFLD fibrosis score.

CONCLUSIONS

Our results show that in a general T2DM follow up, 10% of patients were at risk of advanced fibrosis. We found a positive correlation between liver fibrosis and BMI, AC and HOMA2-IR. Non-invasive fibrosis markers can be useful for screening, showing NAFLD Fibrosis score a better LHR+ compared to TE. Further studies are needed to validate these results and elucidate the best screening approach to identify those patients at risk of advanced MAFLD.

Nonalcoholic Fatty Liver Disease and Cardiovascular Risk: A Scientific Statement From the American Heart Association

Nonalcoholic fatty liver disease (NAFLD) is an increasingly common condition that is believed to affect >25% of adults worldwide. Unless specific testing is done to identify NAFLD, the condition is typically silent until advanced and potentially irreversible liver impairment occurs. For this reason, the majority of patients with NAFLD are unaware of having this serious condition. Hepatic complications from NAFLD include nonalcoholic steatohepatitis, hepatic cirrhosis, and hepatocellular carcinoma. In addition to these serious complications, NAFLD is a risk factor for atherosclerotic cardiovascular disease, which is the principal cause of death in patients with NAFLD. Accordingly, the purpose of this scientific statement is to review the underlying risk factors and pathophysiology of NAFLD, the associations with atherosclerotic cardiovascular disease, diagnostic and screening strategies, and potential interventions.

Effects of Hepatic Impairment on the Pharmacokinetic Profile and Safety of Lobeglitazone

In this open-label, single-dose, parallel-group study, we compared the pharmacokinetic profile and safety of lobeglitazone, a thiazolidinedione acting as an agonist for peroxisome proliferator-activated receptors, in patients with hepatic impairment (HI) and healthy matched controls for age, sex, and body weight. After a single oral dose of lobeglitazone (0.5 mg), the lobeglitazone (parent drug) and M7 (major metabolite) plasma concentrations and pharmacokinetic parameters were analyzed and compared between the HI patient groups and healthy matched control groups. The geometric mean ratio (GMR; 90% confidence interval [CI]) for maximum concentration (C_max ) and area under the plasma concentration-time curve from time 0 extrapolated to infinity (AUC_inf ) of lobeglitazone was 1.06 (0.90-1.24) and 1.07 (0.82-1.40), respectively, for mild HI vs control A. The GMR (90%CI) of C_max and AUC_inf was 0.70 (0.56-0.88) and 1.00 (0.72-1.37), respectively, for moderate HI vs control B. For M7, the GMR (90%CI) of C_max and AUC_inf was 1.09 (0.75-1.57) and 1.18 (0.71-1.97), respectively, for mild HI vs control A and 1.50 (0.95-2.38) and 1.79 (1.06-3.04), respectively, for moderate HI vs control B. Notable adverse events or tolerability issues were not observed. Lobeglitazone may be safely used in patients with mild or moderate HI without dose adjustment.

Computational Analysis of Gly482Ser Single-Nucleotide Polymorphism in PPARGC1A Gene Associated with CAD, NAFLD, T2DM, Obesity, Hypertension, and Metabolic Diseases

Peroxisome proliferator-activated receptor-gamma coactivator 1-alpha (PPARGC1A) regulates the expression of energy metabolism's genes and mitochondrial biogenesis. The essential roles of PPARGC1A encouraged the researchers to assess the relation between metabolism-related diseases and its variants. To study Gly482Ser (+1564G/A) single-nucleotide polymorphism (SNP) after PPARGC1A modeling, we substitute Gly482 for Ser482. Stability prediction tools showed that this substitution decreases the stability of PPARGC1A or has a destabilizing effect on this protein. We then utilized molecular dynamics simulation of both the Gly482Ser variant and wild type of the PPARGC1A protein to analyze the structural changes and to reveal the conformational flexibility of the PPARGC1A protein. We observed loss flexibility in the RMSD plot of the Gly482Ser variant, which was further supported by a decrease in the SASA value in the Gly482Ser variant structure of PPARGC1A and an increase of H-bond with the increase of β-sheet and coil and decrease of turn in the DSSP plot of the Gly482Ser variant. Such alterations may significantly impact the structural conformation of the PPARGC1A protein, and it might also affect its function. It showed that the Gly482Ser variant affects the PPARGC1A structure and makes the backbone less flexible to move. In general, molecular dynamics simulation (MDS) showed more flexibility in the native PPARGC1A structure. Essential dynamics (ED) also revealed that the range of eigenvectors in the conformational space has lower extension of motion in the Gly482Ser variant compared with WT. The Gly482Ser variant also disrupts PPARGC1A interaction. Due to this single-nucleotide polymorphism in PPARGC1A, it became more rigid and might disarray the structural conformation and catalytic function of the protein and might also induce type 2 diabetes mellitus (T2DM), coronary artery disease (CAD), and nonalcoholic fatty liver disease (NAFLD). The results obtained from this study will assist wet lab research in expanding potent treatment on T2DM.

Effects of Liraglutide on Nonalcoholic Fatty Liver Disease in Patients with Type 2 Diabetes Mellitus: A Systematic Review and Meta-Analysis

INTRODUCTION

Nonalcoholic fatty liver disease (NAFLD) is a common comorbidity of type 2 diabetes mellitus (T2DM), and no approved therapies are currently available. A meta-analysis was performed to investigate the effects of liraglutide on NAFLD in patients with T2DM.

METHODS

Medline (via PubMed), Embase (via Elsevier), and the Cochrane Central Register of Controlled Trials (CENTRAL) (via Cochrane Library) from inception to April 2020 were searched. After screening the literature and extracting data, we assessed the risk of bias of the eligible studies. The Cochrane Collaboration's RevMan software program was used for the statistical analysis.

RESULTS

Eleven trials involving 535 patients were included for the final analysis. Compared to the placebo or control group, liraglutide decreased liver fat (LF) (insulin: mean difference MD - 2.50, 95% confidence interval [CI] - 4.30 to - 0.70), body mass index (BMI) (placebo: MD - 1.13, 95% CI - 2.03 to - 0.23; pioglitazone: MD - 4.10, 95% CI - 6.27 to - 1.93; metformin: MD - 1.07, 95% CI - 2.06 to - 0.08; insulin: MD - 1.01, 95% CI - 1.60 to - 0.43), lipoproteins, including high-density (insulin: MD - 0.10, 95% CI - 0.15 to - 0.05) and low-density lipoproteins (MD - 0.26, 95% CI - 0.43 to - 0.10), glycated hemoglobin A1c (HbA1c) (placebo: MD - 0.86; 95% CI - 1.22 to - 0.51; insulin: MD - 0.22, 95% CI - 0.41 to  - 0.04), total cholesterol (placebo: MD - 0.34, 95% CI - 0.65 to - 0.03; metformin: MD  0.09, 95% CI 0.01-0.18), and triglycerides (placebo: MD - 0.29, 95% CI - 0.57 to - 0.01; insulin: MD - 0.80, 95% CI - 1.03 to - 0.57). Liraglutide may be associated with increased gastrointestinal reactions compared to pioglitazone.

CONCLUSION

These findings revealed that liraglutide decreased LF, BMI, lipids, or HbA1c in T2DM patients complicated with NAFLD, indicating its potential therapeutic efficacy.

Effects of SGLT2 inhibitor ipragliflozin alone and combined with pioglitazone on fluid retention in type 2 diabetic mice with NASH

Several antidiabetic agents, including thiazolidinediones and sodium-glucose cotransporter (SGLT) 2 inhibitors, attenuate the symptoms of nonalcoholic steatohepatitis (NASH). However, thiazolidinediones have serious side effects such as fluid retention and increased risk of congestive heart failure. We examined the effects of SGLT2 inhibitor ipragliflozin, pioglitazone, and ipragliflozin + pioglitazone on fluid retention in type 2 diabetic mice with NASH. Four-week repeated administration of pioglitazone caused significant increases in heart weight (31% increase in 30 mg/kg pioglitazone-treated group compared to vehicle-treated group) concomitant with fluid retention, as estimated by a decrease in plasma osmolality and increase in water intake/urine volume ratio. In addition, pioglitazone significantly increased (by 1.5 to 2-fold) mRNA expression of α, β, and γ subtypes of ENaC and AQP2 and 3 subtypes in the renal medulla. Thus, pioglitazone-induced fluid retention may arise from enhanced reabsorption of sodium and water associated with increased expression of these channels in the kidney. In contrast, ipragliflozin alone did not induce these symptoms and did not affect ENaC or AQP expression. Combination treatment with ipragliflozin + pioglitazone attenuated these symptoms by ipragliflozin-induced osmotic diuresis. These findings demonstrate that treatment with ipragliflozin monotherapy or coadministered with pioglitazone may be a potential therapeutic option for the treatment of type 2 diabetes with NASH without fluid retention as a side effect.

Unexpected Pleiotropic Effects of SGLT2 Inhibitors: Pearls and Pitfalls of This Novel Antidiabetic Class

Sodium-glucose co-transporter 2 (SGLT2) inhibitors facilitate urine glucose excretion by reducing glucose reabsorption, leading to ameliorate glycemic control. While the main characteristics of type 2 diabetes mellitus are insufficient insulin secretion and insulin resistance, SGLT2 inhibitors have some favorable effects on pancreatic β-cell function and insulin sensitivity. SGLT2 inhibitors ameliorate fatty liver and reduce visceral fat mass. Furthermore, it has been noted that SGLT2 inhibitors have cardio-protective and renal protective effects in addition to their glucose-lowering effect. In addition, several kinds of SGLT2 inhibitors are used in patients with type 1 diabetes mellitus as an adjuvant therapy to insulin. Taken together, SGLT2 inhibitors have amazing multifaceted effects that are far beyond prediction like some emerging magical medicine. Thereby, SGLT2 inhibitors are very promising as relatively new anti-diabetic drugs and are being paid attention in various aspects. It is noted, however, that SGLT2 inhibitors have several side effects such as urinary tract infection or genital infection. In addition, we should bear in mind the possibility of diabetic ketoacidosis, especially when we use SGLT2 inhibitors in patients with poor insulin secretory capacity.

Ugonin J improves metabolic disorder and ameliorates nonalcoholic fatty liver disease by regulating the AMPK/AKT signaling pathway

Closely associated with visceral obesity, hepatic steatosis resulting from non-alcoholic fatty liver disease (NAFLD) exacerbates insulin resistance. Developing effective drugs to treat NAFLD is imperative. Here, we investigated the pharmacological mechanism of ugonin J (UJ) in controlling metabolic disorder and ameliorating NAFLD pathophysiology in diet-induced obese mice. The effects of UJ were assessed in 5-week-old C57BL/6 J mice fed a high-fat diet (HFD) for 12 weeks. UJ treatment averted HFD-induced body weight gain by reducing fat deposition in adipose tissues and reduced HFD-induced hyperlipidemia and hepatic inflammation. UJ also improved HFD-induced glucose tolerance and insulin resistance. Moreover, the mode of action of UJ was analyzed in palmitate (PA)-induced steatotic human HuS-E/2 hepatocytes and in hyperglycemia-simulating rat BRIN-BD11 pancreatic β cells. In PA-induced steatotic human hepatocytes, UJ treatment promoted lipid clearance via pAMPK, pACC and CPT-1 upregulation and SREBP-1c downregulation. Interestingly, UJ upregulated Akt activity in hepatocytes and increased insulin secretion from β cells in acute insulin secretion tests. Taken together, UJ improved adipocyte hypertrophy, hyperinsulinemia, hyperglycemia, hyperlipidemia and fat deposition in livers. UJ also reduced fatty acid accumulation by modulating key metabolic regulators. Our findings demonstrated the therapeutic potential of UJ for the treatment of NAFLD and diet-induced metabolic disorders.

Calorie-Restricted Mediterranean and Low-Fat Diets Affect Fatty Acid Status in Individuals with Nonalcoholic Fatty Liver Disease

Lifestyle modifications are the main support of nonalcoholic fatty liver disease (NAFLD) therapy. Weight loss is one of the primary goals in NAFLD, but the effects of different calorie-restricted diets remain unclear. Thus, we evaluated the effects of two calorie-restricted diets—the Mediterranean diet (Med diet) and low-fat diet—on liver status, cardiometabolic markers, and fatty acid profiles in patients with NAFLD. Twenty-four overweight/moderately obese men were randomly assigned to consume one of these diets. Lipid levels, glucose, insulin, liver enzymes, steatosis, and fatty acid profiles of serum and erythrocytes phospholipids were assessed. After 3 months, all participants had a significant weight loss (>9%), with improvements in waist circumference, body fat %, index of visceral adiposity (VAI), lipid accumulation product, fatty liver (FLI), and hepatic steatosis (HSI) index (p < 0.001). Both diets significantly lowered triglycerides, total and LDL-cholesterol, liver enzymes, fasting glucose, insulin, and HOMA-IR index. Fatty acid profiles were enhanced after both diets, with a significantly decreased n-6/n-3 ratio. Participants on the Med diet had higher levels of HDL-cholesterol and monounsaturated and n-3 docosahexaenoic acids in serum phospholipids and lower levels of saturated fatty acids, triglycerides, TG/HDL ratio, and FLI when compared to participants on the low-fat diet. Our results indicate that dietary patterns and calorie restriction represent central therapeutic issues in the improvement of obesity-related cardiometabolic alterations that are involved in the mechanism of hepatic steatosis. The Med diet may contribute to disease treatment even more than the low-fat diet since it leads to decreased saturated and increased monounsaturated and n-3 polyunsaturated fatty acid status and improved FLI in NAFLD patients.

REV-ERB agonism improves liver pathology in a mouse model of NASH

Non-alcoholic fatty liver disease (NAFLD) affects a significant number of people worldwide and currently there are no pharmacological treatments. NAFLD often presents with obesity, insulin resistance, and in some cases cardiovascular diseases. There is a clear need for treatment options to alleviate this disease since it often progresses to much more the much more severe non-alcoholic steatohepatitis (NASH). The REV-ERB nuclear receptor is a transcriptional repressor that regulates physiological processes involved in the development of NAFLD including lipogenesis and inflammation. We hypothesized that pharmacologically activating REV-ERB would suppress the progression of fatty liver in a mouse model of NASH. Using REV-ERB agonist SR9009 in a mouse NASH model, we demonstrate the beneficial effects of REV-ERB activation that led to an overall improvement of hepatic health by suppressing hepatic fibrosis and inflammatory response.

SGLT2 inhibitor ipragliflozin alone and combined with pioglitazone prevents progression of nonalcoholic steatohepatitis in a type 2 diabetes rodent model

Nonalcoholic steatohepatitis (NASH) has become the most common cause of chronic liver disease worldwide in recent years. The pathogenesis of NASH is closely linked to metabolic diseases such as insulin resistance, obesity, dyslipidemia, and type 2 diabetes. However, there is currently no pharmacological agent for preventing the progression of NASH. Sodium-glucose cotransporter (SGLT) 2 inhibitors increase urinary glucose excretion by inhibiting renal glucose reabsorption, and improve various pathological conditions of type 2 diabetes, including insulin resistance. In the present study, we examined the effects of ipragliflozin, a SGLT2-selective inhibitor, alone and in combination with pioglitazone on NASH in high-fat diet-fed KK/A^y type 2 diabetic mice. Type 2 diabetic mice with NASH exhibited steatosis, inflammation, and fibrosis in the liver as well as hyperglycemia, insulin resistance, and obesity, features that are observed in human NASH. Four-week repeated administration of ipragliflozin (0.1-3 mg/kg) led to significant improvements in hyperglycemia, insulin resistance, and obesity in addition to hyperlipidemia and liver injury including hepatic steatosis and fibrosis. Moreover, ipragliflozin reduced inflammation and oxidative stress in the liver. Repeated administration of pioglitazone (3-30 mg/kg) also significantly improved various parameters of diabetes and NASH, excluding obesity. Furthermore, combined treatment comprising ipragliflozin (1 mg/kg) and pioglitazone (10 mg/kg) additively improved these parameters. These findings indicate that the SGLT2-selective inhibitor ipragliflozin improves hyperglycemia as well as NASH in type 2 diabetic mice. Therefore, treatment with ipragliflozin monotherapy or coadministered with pioglitazone is expected to be a potential therapeutic option for the treatment of type 2 diabetes with NASH.

An in vitro model of hepatic steatosis using lipid loaded induced pluripotent stem cell derived hepatocyte like cells

Hepatic steatosis is a metabolic disease, characterized by selective and progressive accumulation of lipids in liver, leading to progressive non-alcoholic fatty liver disease (NAFLD), non-alcoholic steatohepatitis (NASH), and cirrhosis. The existing in vitro models of hepatic steatosis to elucidate the molecular mechanisms behind the onset of hepatic steatosis and to profile small molecule modulators uses lipid loaded primary hepatocytes, and cell lines like HepG2. The limitation of these models includes high variability between the different donor samples, reproducibility, and translatability to physiological context. An in vitro human hepatocyte derived model that mimics the pathophysiological changes seen in hepatic steatosis may provide an alternative tool for pre-clinical drug discovery research. We report the development of an in vitro experimental model of hepatic steatosis using human induced pluripotent stem cell (iPSC) derived hepatocytes like cells (HLC), loaded with lipids. Our data suggests that HLC carry some of the functional characteristics of primary hepatocytes and are amenable for development of an in vitro steatosis model using lipid loading method. The in vitro experimental model of hepatic steatosis was further characterized using biomarker analysis and validated using telmisartan. With some refinement and additional validation, our in vitro steatosis model system may be useful for profiling small molecule inhibitors and studying the mechanism of action of new drugs.

Comparison of the effects of three kinds of glucose-lowering drugs on non-alcoholic fatty liver disease in patients with type 2 diabetes: A randomized, open-label, three-arm, active control study

Aims/Introduction

Non‐alcoholic fatty liver disease (NAFLD) is often observed in individuals with type 2 diabetes mellitus, and it is known that the presence of type 2 diabetes mellitus leads to the aggravation of NAFLD. The aim of this study was to compare the possible effects of three kinds of oral hypoglycemic agents on NAFLD in individuals with type 2 diabetes mellitus.

Materials and Methods

We carried out a prospective clinical trial (a randomized and open‐label study) in patients with type 2 diabetes mellitus and NAFLD. A total of 98 patients were randomly allocated either to the dapagliflozin (n = 32), pioglitazone (n = 33) or glimepiride (n = 33) group, and the patients took these drugs for 28 weeks. The primary end‐point was the change of the liver‐to‐spleen ratio on abdominal computed tomography.

Results

There was no difference in baseline clinical characteristics among the three groups. Dapagliflozin, pioglitazone and glimepiride ameliorated hyperglycemia similarly. Bodyweight and visceral fat area were significantly decreased only in the dapagliflozin group. Serum adiponectin levels were markedly increased in the pioglitazone group compared with the other two groups. Dapagliflozin and pioglitazone, but not glimepiride, significantly increased the liver‐to‐spleen ratio, and the effects of dapagliflozin and pioglitazone on the liver‐to‐spleen ratio were comparable.

Conclusions

The present study showed that the decrease of visceral fat area and the increase of adiponectin level contributed to the improvement of NAFLD in patients with type 2 diabetes mellitus. Furthermore, dapagliflozin and pioglitazone exerted equivalent beneficial effects on NAFLD in patients with type 2 diabetes mellitus, although it seemed that these two drugs had different mechanisms of action.

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

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

Therapeutic Effects of SGLT2 Inhibitor Ipragliflozin and Metformin on NASH in Type 2 Diabetic Mice

Background and aim: Sodium-glucose cotransporter (SGLT) 2 is responsible for most of the glucose reabsorption in the kidneys and has been proposed as a novel therapeutic target for the treatment of type 2 diabetes. In recent years, nonalcoholic steatohepatitis (NASH), the pathogenesis of which is strongly associated with insulin resistance, obesity, and type 2 diabetes, has become a considerable healthcare burden worldwide. However, there is currently no established pharmacotherapy for NASH. Here, we investigated the therapeutic effects of the SGLT2 selective inhibitor ipragliflozin alone and in combination with metformin on NASH in high fat and cholesterol diet-fed KK/A^y type 2 diabetic mice.Results: This diabetic model had hyperglycemia, insulin resistance, and obesity, and also exhibited steatosis, inflammation, and fibrosis in the liver, pathological features resembling those in human NASH. Four-week repeated administration of ipragliflozin significantly improved not only hyperglycemia, insulin resistance, and obesity but also hyperlipidemia and NASH-associated symptoms including hepatic steatosis and fibrosis. In addition, ipragliflozin attenuated inflammation and oxidative stress in the liver. Repeated administration of metformin also significantly improved symptoms of type 2 diabetes with NASH to a comparable degree to that by ipragliflozin. In addition, combination treatment with ipragliflozin and metformin additively improved these symptoms.Conclusions: These results demonstrate that the SGLT2 selective inhibitor ipragliflozin improves not only hyperglycemia but also NASH in type 2 diabetic mice, suggesting that treatment with ipragliflozin alone and in combination with metformin may be effective for treating type 2 diabetes with NASH.

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.

Concurrent nonalcoholic fatty liver disease and type 2 diabetes: diagnostic and therapeutic considerations

Introduction: The relationship between nonalcoholic fatty liver disease (NAFLD) and type 2 diabetes mellitus (T2DM) is complex and bidirectional. NAFLD increases the risk of incident diabetes and is very prevalent in T2DM patients and T2DM is an aggravating factor for NAFLD. Timely T2DM diagnosis and treatment in subjects with NAFLD and diagnosis, staging and treatment of NAFLD in those with T2DM are critical issues. Areas covered: PubMed/MEDLINE was searched for articles related to concomitant occurrence of NAFLD and T2DM between January 2013 and May 2019. Areas covered included epidemiological, diagnostic and therapeutic aspects. Expert opinion: there is a need for increased awareness on NAFLD adding liver disease as an end-organ complication of T2DM. Emphasis on use of simple non-invasive tools to triage patients with potentially severe liver disease should be made. Management of patients with NAFLD and T2DM relies on lifestyle optimization to achieve significant weight loss. Currently, there is no drug approved for treatment of NAFLD in patients with T2DM although Vitamin E and pioglitazone might be used in selected patients. Approved diabetic medications hold promise for NAFLD treatment and several liver-specific drugs are in evaluation clinical trials. A combination approach will likely represent the future of NAFLD therapeutics.

Association between PPARGC1A single nucleotide polymorphisms and increased risk of nonalcoholic fatty liver disease among Iranian patients with type 2 diabetes mellitus

Background/aim

Environmental and genetic factors may play a major role in the development of nonalcoholic fatty liver disease (NAFLD) among people with obesity and type 2 diabetes mellitus. Based on the fact that PGC-1α, as the protein encoded by the PPARGC1A gene, plays a key role in energy metabolism pathways, it has been hypothesized that polymorphisms within the PPARGC1A gene may be associated with increased risks of NAFLD. Thus, this study was designed to evaluate the Gly482Ser polymorphism (rs8192678) within the PPARGC1A gene and its association with the increased risk of NAFLD in Iranian patients with type 2 diabetes.

Materials and methods

A total of 145 NAFLD patients with a history of type 2 diabetes and 145 healthy control subjects were included in the study. Gly482Ser polymorphism genotyping was done using the amplification refractory mutation system-polymerase chain reaction (ARMS-PCR) technique.

Results

The results showed a significant difference between the PPARGC1A Gly482Ser polymorphism in NAFLD patients and the healthy controls. Accordingly, the AA genotype and A allele were increased in the NAFLD patients when compared to the healthy controls. However, no significant correlation was observed between the Gly482Ser polymorphism and the physiological and biochemical parameters.

Conclusion

Based on the results, the AA genotype, which is associated with the insertion of Ser, can be considered as a risk factor for the development of NAFLD in Iranian patients with diabetes type 2.

Cardio-Metabolic Disorders in Non-Alcoholic Fatty Liver Disease

With the progressive epidemics of obesity, non-alcoholic fatty liver disease (NAFLD) has become the most common cause of chronic liver disease in adults and children. The increasing prevalence and incidence of NAFLD with advanced fibrosis is concerning because patients appear to experience higher non-liver-related morbidity and mortality than the general population. Recent clinical evidence suggests that NAFLD is directly associated with an increased risk of cardio-metabolic disorders. This mini review describes briefly the current understanding of the pathogenesis of NAFLD, summarizing the link between NAFLD and cardio-metabolic complications, focusing mainly upon ischemic stroke, type 2 diabetes mellitus (DM), hypertension, chronic kidney disease (CKD) and cardiac arrhythmias. In addition, it describes briefly the current understanding of the pathogenesis of NAFLD.

Clinical workup of fatty liver for the primary care provider

Nonalcoholic fatty liver disease (NAFLD) is quickly emerging as a global epidemic in parallel with the rise in obesity and the Metabolic Syndrome. NAFLD, once seen simply as a passive consequence of the Metabolic Syndrome (MetS), has been found to interact with other features of MetS to exacerbate insulin resistance, diabetes, and cardiovascular disease. NAFLD is also becoming the top indication for liver transplant and an important risk factor for hepatocellular carcinoma. Treatment of this disorder is limited mainly to lifestyle modifications to promote weight loss along with consideration for off-label use of certain medications, but recent progression in clinical trials means more effective treatments are on the horizon. Therefore, the primary care provider must be prepared to recognize and determine the severity of this disorder in order to optimize management. In this review, we will discuss risk factors for NAFLD, workup and differential, and finally, offer recommendations on screening.

Saturated fatty acid combined with lipopolysaccharide stimulates a strong inflammatory response in hepatocytes in vivo and in vitro

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease and consumption of high-fat diet (HFD) is a risk factor for NAFLD. The HFD not only increases intake of saturated fatty acid (SFA) but also induces metabolic endotoxemia, an HFD-associated increase in circulating lipopolysaccharide (LPS). Although it is known that SFA or LPS promote hepatic inflammation, a hallmark of NAFLD, it remains unclear how SFA in combination with LPS stimulates host inflammatory response in hepatocytes. In this study, we performed both in vivo and in vitro experiments to investigate the effect of SFA in combination with LPS on proinflammatory gene expression in hepatocytes. Our animal study showed that feeding low-density lipoprotein-deficient mice HFD enriched with SFA and injection of low-dose LPS cooperatively stimulated IL-6 expression in livers. To understand how SFA and LPS interact to promote IL-6 expression, our in vitro studies showed that palmitic acid (PA), a major SFA, and LPS exerted synergistic effect on the expression of IL-6 in hepatocytes. Furthermore, coculture of hepatocytes with macrophages resulted in a greater IL-6 expression than culture of hepatocytes without macrophages in response to the combination of PA and LPS. Finally, we observed that LPS and PA increased ceramide production by cooperatively stimulating ceramide de novo synthesis, which played an essential role in the synergistic stimulation of proinflammatory gene expression by LPS and PA. Taken together, this study showed that SFA in combination with LPS stimulated a strong inflammatory response in hepatocytes in vivo and in vitro.

Obesity and type 2 diabetes: Also linked in therapeutic options

The prevalence of obesity has increased worldwide over the past decades. Obesity is associated with multiple comorbidities, such as type 2 diabetes, that generates a great impact on health and economy. Weight loss in these patients leads to glycemic control so it is a target to achieve. Lifestyle changes are not effective enough and recently other treatments have been developed such as bariatric/metabolic surgery, as well as drugs for type 2 diabetes and antiobesity drugs. The aim of this review is to compare the results in weight reduction and glycemic control of the different kinds of drugs with bariatric / metabolic surgery's results in type 2 diabetes.

Dapagliflozin significantly reduced liver fat accumulation associated with a decrease in abdominal subcutaneous fat in patients with inadequately controlled type 2 diabetes mellitus

AIMS

We examined dapagliflozin-induced changes in liver fat accumulation.

METHODS

We prospectively recruited Japanese patients with inadequately controlled type 2 diabetes mellitus (T2DM) [hemoglobin A1c (HbA1c) >7.0%]. Dapagliflozin (5 mg/day) or non-sodium glucose cotransporter 2 inhibitors (SGLT2i) was added to the patients' treatment regimen for 6 months. Changes in liver fat accumulation were assessed by the liver-to-spleen (L/S) attenuation ratio using abdominal computed tomography (CT).

RESULTS

This study enrolled 55 Japanese T2DM patients. The L/S ratio significantly increased in the dapagliflozin group compared with the non-SGLT2i group. Abdominal subcutaneous fat area (SFA), visceral fat area, total fat area assessed by abdominal CT, aspartate aminotransferase, alanine aminotransferase (ALT), and γ-glutamyl transpeptidase decreased significantly only in the dapagliflozin group. Changes in the L/S ratio showed a significant negative relationship with changes in abdominal SFA, ALT, and non-esterified fatty acid. In sub-group analyses of non-insulin users, hepatic insulin extraction was assessed by the plasma C-peptide-to-insulin ratio, which was significantly increased in the dapagliflozin group but not in the non-SGLT2i group.

CONCLUSION

In patients with inadequately controlled T2DM, additional dapagliflozin-treatment significantly reduced the liver fat accumulation associated with a decrease in abdominal SFA.

Practical strategies for improving outcomes in T2DM: The potential role of pioglitazone and DPP4 inhibitors

T2DM is a complex disease underlined by multiple pathogenic defects responsible for the development and progression of hyperglycaemia. Each of these factors can now be tackled in a more targeted manner thanks to glucose-lowering drugs that have been made available in the past 2 to 3 decades. Recognition of the multiplicity of the mechanisms underlying hyperglycaemia calls for treatments that address more than 1 of these mechanisms, with more emphasis placed on the earlier use of combination therapies. Although chronic hyperglycaemia contributes to and amplifies cardiovascular risk, several trials have failed to show a marked effect from intensive glycaemic control. During the past 10 years, the effect of specific glucose-lowering agents on cardiovascular risk has been explored with dedicated trials. Overall, the cardiovascular safety of the new glucose-lowering agents has been proven with some of the trials summarized in this review, showing significant reduction of cardiovascular risk. Against this background, pioglitazone, in addition to exerting a sustained glucose-lowering effect, also has ancillary metabolic actions of potential interest in addressing the cardiovascular risk of T2DM, such as preservation of beta-cell mass and function. As such, it seems a logical agent to combine with other oral anti-hyperglycaemic agents, including dipeptidyl peptidase-4 inhibitors (DPP4i). DPP4i, which may also have a potential to preserve beta-cell function, is available as a fixed-dose combination with pioglitazone, and could, potentially, attenuate some of the side effects of pioglitazone, particularly if a lower dose of the thiazolidinedione is used. This review critically discusses the potential for early combination of pioglitazone and DPP4i.

Why Should be the Strategy of Type 2 Diabetes Treatment Radically Changed

Insulin resistance is a root cause of Type 2 Diabetes Mellitus (T2DM) appearing long time before the outbreak of hyperglycemia. On molecular level, a complex impairment of various biochemical processes occurs, the most important being the failure of phosphatidylinositol 3-kinase enzymatic chain responsible for activation of glucose transporters and endothelial nitric oxide (NO) synthesis. Therefore, in insulin resistant states the defect of glucose utilization is coupled with NO deficit and vasodilatory impairment, generating a huge body of residual cardiovascular risk. However, majority of drugs administered to treat T2DM (sulfonylureas, high doses of insulin) even amplify this malignant relationship, reflected by aggravated obesity, dyslipidemia and arterial hypertension. Early and tight glycemic control strategy is helpful to prevent cardiovascular complications in younger diabetics and harmful for long lasting diabetes in older patients, dying mostly from macrovascular complications (80%) for which hyperglycemia, responsible primarily for microvascular impairment, is a weak risk factor compared with hypercholesterolemia or high blood pressure. Glucocentric paradigm of T2DM treatment should be therefore revised in favor of pathophysiologic approaches with drugs selected to address multifactorial risk, affecting different components of diabetes pathophysiology, to achieve hypoglycemic goals without worsening obesity, insulin resistance, sympathetic overactivity and NO deficit, for example with dual or triple combinations (with dosage adjusted to glycemia) such as: metformin + SGLT2 inhibitor + GLP-1 agonist or metformin + SGLT2 inhibitor + pyoglitazone. Patients should be strongly advised to enhance physical activity, reduce body weight this being the most effective method to decrease insulin resistance, the key factor of extensive cardiovascular damage.

Comparison of Pioglitazone and Metformin Efficacy against Glucocorticoid Induced Atherosclerosis and Hepatic Steatosis in Insulin Resistant Rats

INTRODUCTION

Insulin Resistance is a major cause of Atherosclerosis (AS) and Non Alcoholic Fatty Liver Disease (NAFLD). These lipid alterations in blood vessels and liver may progress to cardiovascular abnormalities and cirrhosis respectively. Drugs like pioglitazone (PIO) and metformin (MET) are effective insulin sensitizers used in T2DM. But their efficacy and tolerability needs to be compared in IR associated abnormalities.

AIM

To compare the efficacy of PIO and MET in glucocorticoid induced AS, Hepatic Steatosis (HS) and IR in albino rats.

MATERIALS AND METHODS

Male Wistar albino rats were randomized into four groups (n=6). Group 1 (Normal control) rats consumed 2% gum acacia orally for 12 days. Group 2 {dexamethasone (DEX) control} rats were administered 2% gum acacia orally for 12 days and DEX (8 mg/kg) intraperitoneally (i.p.) from 7th to 12th day during the study period. Group 3 and 4 (PIO and MET control) rats received oral administration of PIO (45 mg/kg) and MET (1000 mg/kg) for 12 days respectively. Both groups were treated with DEX (8 mg/kg/i.p.) from 7th to 12th day during the study period. On last day, fasting blood was collected and rats were sacrificed by cervical dislocation; aorta and liver tissues were isolated for the histopathological examination. Body weight, liver weight and liver volume were measured. Blood samples were processed for biochemical parameters. The data were analysed by One-way Analysis of variance (ANOVA) followed by Scheffe's multiple comparison post-hoc test. The statistical significance was assumed at p<0.05.

RESULTS

Our results established the possible role of DEX in the development of AS and HS. Histopathological examination of Group 2 rats treated with DEX showed a marked lipid accumulation in the aorta and liver. Administration of MET and PIO resulted in partial to complete restoration of DEX induced fatty changes in aorta and liver. Both drugs significantly (p<0.05) prevented the elevation of insulin, lipid, glucose levels, liver weight and liver volume in DEX treated rats. They had significantly (p<0.05) improved body weight and insulin sensitivity. However, PIO was highly significant (p<0.05) compared to MET in reducing DEX induced IR complications.

CONCLUSION

These findings suggest that PIO was more effective insulin sensitizer compared to MET in reducing AS, HS and IR induced by glucocorticoids.

Inhibition of exendin-4-induced steatosis by protein kinase A in cultured HepG2 human hepatoma cells

Nonalcoholic fatty liver is characterized by the abnormal accumulation of triglycerides within hepatocytes, resulting in a steatotic liver. Glucagon-like peptide 1 and its analog exendin-4 can ameliorate certain aspects of this syndrome by inducing weight loss and reducing hepatic triglyceride accumulation, but it is unclear whether these effects result from the effects of glucagon-like peptide 1 on the pancreas, or from direct action on the liver. This study investigated the direct action and putative cellular mechanism of exendin-4 on steatotic hepatocytes in culture. Steatosis was induced in cultured HepG2 human hepatoma cells by incubation in media supplemented with 2 mM each of linoleic acid and oleic acid. Steatotic hepatocytes were then pre-incubated in the protein kinase A inhibitor H89 for 30 min, then treated with exendin-4 over a period of 24 h. Cell viability and triglyceride content were characterized by a TUNEL assay and AdipoRed staining, respectively. Our results showed that steatotic cells maintained high levels of intracellular triglycerides (80%) compared to lean controls (25%). Exendin-4 treatment caused a significant reduction in intracellular triglyceride content after 12 h that persisted through 24 h, while protein kinase A inhibitors abolished the effects of exendin-4. The results demonstrate the exendin-4 induces a partial reduction in triglycerides in steatotic hepatocytes within 12 h via the GLP-1 receptor-mediated activation of protein kinase A. Thus, the reduction in hepatocyte triglyceride accumulation is likely driven primarily by downregulation of lipogenesis and upregulation of β-oxidation of free fatty acids.

Treatment of patients with type 2 diabetes and non-alcoholic fatty liver disease: current approaches and future directions

Non-alcoholic fatty liver disease (NAFLD) is reaching epidemic proportions in patients with type 2 diabetes. Patients with NAFLD are at increased risk of more aggressive liver disease (non-alcoholic steatohepatitis [NASH]) and at a higher risk of death from cirrhosis, hepatocellular carcinoma and cardiovascular disease. Dysfunctional adipose tissue and insulin resistance play an important role in the pathogenesis of NASH, creating the conditions for hepatocyte lipotoxicity. Mitochondrial defects are at the core of the paradigm linking chronic excess substrate supply, insulin resistance and NASH. Recent work indicates that patients with NASH have more severe insulin resistance and lipotoxicity compared with matched obese controls with only isolated steatosis. This review focuses on available agents and future drugs under development for the treatment of NAFLD/NASH in type 2 diabetes. Reversal of lipotoxicity with pioglitazone is associated with significant histological improvement, which occurs within 6 months and persists with continued treatment (or for at least 3 years) in patients with prediabetes or type 2 diabetes, holding potential to modify the natural history of the disease. These results also suggest that pioglitazone may become the standard of care for this population. Benefit has also been reported in non-diabetic patients. Recent promising results with glucagon-like peptide 1 receptor agonists have opened another new treatment avenue for NASH. Many agents in Phase 2-3 of development are being tested, aiming to restore glucose/lipid metabolism, ameliorate adipose tissue and liver inflammation, or to inhibit liver fibrosis. By targeting a diversity of relevant pathways, combination therapy in NASH will likely provide greater success in the future. In summary, increased clinical awareness and improved screening strategies (as currently done for diabetic retinopathy and nephropathy) are needed, to translate recent treatment progress into early treatment and improved quality of life for patients with type 2 diabetes and NASH. This review summarises a presentation given at the symposium 'The liver in focus' at the 2015 annual meeting of the EASD. It is accompanied by two other reviews on topics from this symposium (by John Jones, DOI: 10.1007/s00125-016-3940-5 , and by Hannele Yki-Järvinen, DOI: 10.1007/s00125-016-3944-1 ) and a commentary by the Session Chair, Michael Roden (DOI: 10.1007/s00125-016-3911-x ).