Effect of incretin therapies compared to pioglitazone and gliclazide in non-alcoholic fatty liver disease in diabetic patients not controlled on metformin alone: An observational, pilot study

Metformin induces pyroptosis in leptin receptor-defective hepatocytes via overactivation of the AMPK axis

Metformin is the biguanide of hepatic insulin sensitizer for patients with non-alcohol fatty liver disease (NAFLD). Findings regarding its efficacy in restoring blood lipids and liver histology have been contradictory. In this study, we explore metformin's preventive effects on NAFLD in leptin-insensitive individuals. We used liver tissue, serum exosomes and isolated hepatocytes from high-fat diet (HFD)-induced Zucker diabetic fatty (ZDF) rats and leptin receptor (Lepr) knockout rats to investigate the correlation between hepatic Lepr defective and liver damage caused by metformin. Through immunostaining, RT-PCR and glucose uptake monitoring, we showed that metformin treatment activates adenosine monophosphate (AMP)-activated protein kinase (AMPK) and its downstream cytochrome C oxidase (CCO). This leads to overactivation of glucose catabolism-related genes, excessive energy repertoire consumption, and subsequent hepatocyte pyroptosis. Single-cell RNA sequencing further confirmed the hyper-activation of glucose catabolism after metformin treatment. Altogether, we showed that functional Lepr is necessary for metformin treatment to be effective, and that long-term metformin treatment might promote NAFLD progression in leptin-insensitive individuals. This provides important insight into the clinical application of metformin.

A randomized triple-blind controlled clinical trial evaluation of sitagliptin in the treatment of patients with non-alcoholic fatty liver diseases without diabetes

The current study aimed to evaluate the efficacy of sitagliptin vs. placebo in treating non-alcoholic fatty liver disease (NAFLD). In a triple-blind randomized clinical trial, we assigned 120 eligible subjects with NAFLD to receive daily dosing of 50 mg sitagliptin (n = 60) or the placebo (n = 60) for 56 weeks and lifestyle modification in both groups. Laboratory and anthropometric outcomes were measured, and liver stiffness was assessed using a fibroscan. The primary outcome measures were changes from baseline in fibrosis scores and liver transferases. Out of 120 patients randomized into sitagliptin and placebo groups, 76 patients completed the trial, of whom 44 were in the sitagliptin and 32 in the placebo groups. Patients receiving sitagliptin showed a significant decrease in the fibrosis scores (P = 0.001). The reductions in the alanine aminotransferase (AST) (P = 0.036) and aspartate AST (P < 0.001) levels were also statistically significant. The effect of sitagliptin in reducing fibrosis scores was significantly greater in normal-weight and overweight individuals than in obese individuals (p = 0.036, and p = 0.018, respectively), whereas the effects of sitagliptin on AST levels were greater among overweight/obese patients (p = 0.028, and p = 0.016, respectively). Sitagliptin reduced fibrosis scores and liver enzymes in NAFLD patients after 56 weeks of therapy. The changes in fibrosis scores were more prominent in patients with normal weight and overweight than obese patients, whereas the effects on AST levels were greater among overweight/obese patients. Other randomized trials with larger sample sizes and longer treatment durations may be required before precise results can be reached.

Clinical Trial Registration

[https://www.irct.ir/trial/46140], identifier [IRCT20140430017505N2].

The role of nursing care in the type 2 diabetes treatment associated with chronic liver diseases

OBJECTIVE

Diabetes is the fifth leading cause of death in the People's Republic of China. The aim of the article is to compare the effects of nursing care on the laboratory findings and ultrasound results of diabetic patients with chronic liver diseases (CLD) who were treated with antiglycemic drugs.

METHODS

Diabetic were patients treated with metformin hydrochloride in combination with gliclazide, pioglitazone hydrochloride, sitagliptin, exenatide or liraglutide. Non-alcoholic fatty liver disease (NAFLD) was evaluated by abdominal ultrasound, and fibrosis stages were evaluated at baseline and 8 months. All the patients were equally divided into two groups depending on the therapeutic approach.

RESULTS

The first group of patients additionally received nursing care, and the second group adhered to the prescribed therapy on their own. In total 90 patients, or 55.6%, had NAFLD at baseline, and its course was dependent upon changes in the weight (P = 0.009) and waist circumference (P = 0.012). The proportions of patients who demonstrated an ultrasonographic improvement in the control group were: 24 (56.8%) with gliclazide, 15 (41.3%) with pioglitazone hydrochloride, 28 (66.1%) with sitagliptin, 16 (79%) with exenatide and 15 (66.7%) with liraglutide (P = 0.2). For the group that received nursing care an ultrasonographic improvement was in: 29 (68.16%) with gliclazide, 18 (49.56%) with pioglitazone hydrochloride, 33 (79.32%) with sitagliptin, 19 (94.8%) with exenatide and 21 80.04% with liraglutide (P = 0.2).

CONCLUSIONS

Outcomes from the type 2 diabetes treatment paralleling of CLD were presented. Treatment of type 2 diabetes with pioglitazone hydrochloride, gliclazide, sitagliptin, liraglutide and exenatide was proven effective.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Newer second-line glucose-lowering drugs versus thiazolidinediones on cirrhosis risk among older US adult patients with type 2 diabetes

AIMS

Type 2 diabetes (T2D) accelerates progression of chronic liver disease to cirrhosis, yet the effects of most glucose-lowering drugs (GLDs) on cirrhosis risk in T2D are unknown. To address this gap, we compared cirrhosis risk following initiation of newer second-line GLDs vs. thiazolidinediones (TZDs), which improve histology in non-alcoholic fatty liver disease.

MATERIALS AND METHODS

Using the US Medicare Fee-for-Service database (2007-2015) and an active comparator, new-user design, we estimated crude incidence rates (IRs) and propensity-score adjusted hazard ratios (aHR) for incident cirrhosis, comparing newer GLDs (dipeptidyl peptidase-4 inhibitors (DPP4i), glucagon-like peptide-1 receptor agonists (GLP1RA), and sodium-glucose co-transporter 2 inhibitors (SGLT2i)) vs. TZDs.

RESULTS

Among 239,549 total initiators, we observed 318, 151, and < 30 cirrhosis events when comparing DPP4i vs. TZD, GLP1RA vs. TZD, and SGLT2i vs. TZD, respectively. IRs ranged from 1.7 [95% CI, 0.8-3.6] to 3.6 [2.5-5.2] events per 1000 person-years. Point aHR estimates for cirrhosis were elevated among newer GLD initiators vs. TZD (DPP4i: 1.15 [0.89-1.50]; GLP1RA: 1.34 [0.82-2.20]; SGLT2i: 1.16, [0.44-3.08]), although estimates were imprecise due to short durations of drug exposure.

CONCLUSIONS

We observed mildly elevated cirrhosis risk with newer GLDs vs. TZD; however, uncertainty remains due to imprecise and statistically non-significant effect estimates.

One Year's Treatment with the Glucagon-Like Peptide 1 Receptor Agonist Liraglutide Decreases Hepatic Fat Content in Women with Nonalcoholic Fatty Liver Disease and Prior Gestational Diabetes Mellitus in a Randomized, Placebo-Controlled Trial

Prior gestational diabetes mellitus (pGDM) is associated with increased risk of nonalcoholic fatty liver disease (NAFLD). Treatment with glucagon-like peptide 1 (GLP-1) receptor agonists has shown beneficial effects in NAFLD patients. We evaluated the effect of the GLP-1 analogue liraglutide on NAFLD features in women with pGDM. Eighty-two overweight/obese, nondiabetic women with pGDM were included. We performed abdominal ultrasound, transient elastography with controlled attenuation parameter (CAP), and blood sampling at baseline and after 1 year. Thirty-seven women were randomized to liraglutide (1.8 mg once-daily) and 45 to placebo. Based on the ultrasound scan, 18 women (22%) had ultrasound-verified NAFLD at baseline and of these, 10 (56%) received liraglutide treatment. After 1 year, eight participants no longer had steatosis, four in each treatment group. The number of participants who developed NAFLD was similar in the two treatment groups; five in the liraglutide group and six in the placebo group (p = 0.74). Compared to placebo, liraglutide reduced the CAP-assessed intrahepatic fat content (−28 (−44;−11) vs. 2 (−13;18) dB/m, p < 0.01) and body weight (−4.7 (−6.4;−2.9) vs. −1.4 (−3;0.3) kg, p < 0.01). One-year’s liraglutide treatment had no effect on the presence of ultrasound-diagnosed NAFLD in overweight/obese nondiabetic women with pGDM, but reduced body weight and steatosis assessed by transient elastography with CAP.

Efficacy of Glucagon-Like Peptide-1 Analogs in Nonalcoholic Fatty Liver Disease: A Systematic Review

Background

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease. It is believed to be the hepatic manifestation of the metabolic syndrome. Many treatment approaches have been suggested so far, and several types of studies have been done to find treatment for NAFLD, the most promising of which are those with lifestyle interventions.

Objective

The aim of this systematic review was to evaluate the efficacy and safety of glucagon-like peptide-1 (GLP-1) analogs on the management of NAFLD.

Methods

The PubMed, MEDLINE, and Cochrane Central Library were searched to identify randomized controlled trials, single arm trials, and cohorts that compared GLP-1 analogs with a control treatment or baseline values with respect to efficacy and safety in patients living with NAFLD. The key outcomes were a change in serum transaminase, resolution of disease status measured by imaging or histological techniques, improvement in insulin resistance, and reduction in body weight.

Results

Initial searching retrieved 201 peer-reviewed articles and abstracts. Ten studies met all inclusion criteria. The review included a total of 590 participants with NAFLD. Following administration of GLP-1 analogs, a decrease in serum transaminases, improvement in liver histology and insulin resistance, and a reduction in body weight were observed. Compared with baseline, body weight, alanine aminotransferase, aspartate aminotransferase, and gamma glutamyltransferase were decreased by 5.5%, 59.5%, 52.8%, and 44.8%, respectively, due to GLP-1. Likewise, a reduction of proinflammatory cytokines and fibrosis markers and an enhancement of protective adipokines were observed in some of the studies.

Conclusion

The decrease in a key biochemical marker of liver injury following treatment with GLP-1 analogs, as well as improvements in imaging and histology, suggests that these agents may be effective alternatives for managing NAFLD.

Registration

CRD42018087262.

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

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

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

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

Effect of liraglutide on blood pressure: a meta-analysis of liraglutide randomized controlled trials

BACKGROUND

Several clinical trials have studied the effects of glucagon-like peptide-1 receptor agonists (GLP-1RAs) on glycometabolism and cardiovascular risk factors since they were identified. Because of their cardiovascular benefits and efficacy in lowering glucose, GLP-1RAs are becoming increasingly important in clinical therapy for patients with or without pathoglycaemia. The aim of this study was to assess the effect of the GLP-1RA liraglutide on blood pressure based on randomised controlled trials (RCTs).

METHODS

We searched PubMed for RCTs published from 2009 to 2018 comparing the effect of liraglutide on blood pressure with that of placebo in individuals with or without pathoglycaemia. RCTs in humans that included data describing blood pressure changes from baseline to the end of the trial were selected for inclusion in the meta-analysis.

RESULTS

A total of 18 RCTs that enrolled 7616 individuals in the liraglutide group and 6046 individuals in the control group were included in this meta-analysis. Compared with placebo, liraglutide reduced systolic blood pressure (SBP) by 3.18 mmHg (95% CI -4.32, - 2.05), P < 0.00001, but had no significant effect on diastolic blood pressure (DBP). Subgroup analysis showed that the degree of reduction in SBP was associated with the dose of liraglutide but that significance disappeared when the intervention lasted over 1 year. Liraglutide 3.0 mg/d significantly reduced DBP by 1.46 mmHg (95% CI -2.61, 0.32), P = 0.01, but liraglutide 1.8 mg/d slightly increased DBP by 0.47 mmHg (95% CI 0.11, 0.83), P = 0.01, compared with placebo.

CONCLUSIONS

This meta-analysis demonstrated that liraglutide significantly reduced SBP in individuals with or without pathoglycaemia compared with placebo, but the difference was no longer significant when the intervention lasted over 1 year. Moreover, the effect of liraglutide on blood pressure is associated with the dose. This finding may provide additional evidence for cardiovascular protection.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Anti-Diabetic Medications for the Pharmacologic Management of NAFLD

As a chronic disease encompassing a wide spectrum of liver-related histologic damage, nonalcoholic fatty liver disease (NAFLD) is becoming a global epidemic with significant impacts on all-cause morbidity and mortality. Insulin resistance and type 2 diabetes mellitus predispose individuals to NAFLD and related complications. Therefore, timely intervention with anti-diabetic medications may prevent and delay the development of NAFLD or have a therapeutic implication. The focus of this review is to evaluate the evidence supporting the efficacy of anti-diabetic medications in the treatment of NAFLD. While many of these anti-diabetic agents have shown to improve biochemical parameters, their effect on hepatic histology is limited. Among anti-diabetic medications, only thiazolidinediones and glucagon-like peptide-1 receptor agonists demonstrate significant improvement in hepatic histology.

Non-alcoholic Fatty Liver Disease: A Review of Anti-diabetic Pharmacologic Therapies

Non-alcoholic fatty liver disease (NAFLD), the most common cause of liver disease, affects approximately 75 to 100 million Americans. Patients with concurrent NAFLD and type 2 diabetes mellitus have a higher risk of progressing to advanced fibrosis and non-alcoholic steatohepatitis compared to non-diabetics. Lifestyle modifications, including weight loss, remain the mainstay of treatment for NAFLD, as there are no medications currently indicated for this disease state. Anti-diabetic pharmacologic therapies aimed at improving insulin sensitivity and decreasing insulin production have been studied to determine their potential role in slowing the progression of NAFLD. In this review, we focus on the evidence surrounding anti-diabetic medications and their ability to improve disease progression in patients with NAFLD.

The Effect of Sitagliptin on Lipid Metabolism of Fatty Liver Mice and Related Mechanisms

Background

In clinics, patients with type 2 diabetes complicated with non-alcoholic fatty liver disease (NAFLD) have been shown to receive significant improvements in blood glucose levels, lipid levels, and liver function after sitagliptin treatment, although the mechanism of drug action remains poorly understood. This study investigated the possible mechanism of sitagliptin on lipid metabolism of NAFLD mice.

Material/Methods

Male C57/BL6 mice were induced for NAFLD via 16 weeks of a high-fat diet, and were treated with 15 mg/kg/day sitagliptin for 16 consecutive weeks. Blood lipid levels were measured and samples were stained with hematoxylin and eosin (H&E) and oil red staining for liver pathology and lipid deposition. Serum levels of fibroblast growth factor (FGF)-9 and FGF-21 were quantified by enzyme-linked immunosorbent assay (ELISA). Peroxisome proliferator-activated receptor (PPAR)-α, and cAMP reactive element binding homolog (CREBH) were measured by Western blotting, while fatty acid synthase and carnitine palmitoyltransferase 1 (CPT1) mRNA levels were assayed by RT-PCR.

Results

Compared to the control group, the NAFLD model mice had liver fatty disease, lower serum FGF-21 and FGF-19 levels, elevated serum lipid levels, depressed PPAR-α, CREBH, and CPT1 expression, and enhanced FAS expression (p<0.05). Sitagliptin treatment depressed blood lipid levels, increased serum FGF-21 and FGF-19 levels, PPAR-α, CREBH, and CPT1 expression, and suppressed FAS expression (p<0.05).

Conclusions

Sitagliptin can protect liver tissue and modulate lipid metabolism in NAFLD mice via elevating FGF-21 and FGF-19, upregulating liver PPAR-α and CREBH levels, and mediating expression levels of key enzymes for lipid metabolism.