Serum levels of soluble dipeptidyl peptidase-4 in type 2 diabetes are associated with severity of liver fibrosis evaluated by transient elastography (FibroScan) and the FAST (FibroScan-AST) score, a novel index of non-alcoholic steatohepatitis with significant fibrosis

The interplay between diabetes and non-alcoholic fatty liver disease: a cross-sectional study from Pakistan

Background and objectives

Non-alcoholic fatty liver disease (NAFLD) is characterized by ectopic deposition of fat in the liver, in the absence of other secondary causes of fat buildup. The relationship between NAFLD, including alanine aminotransferase (ALT), and glycated haemoglobin (HbA1c), is important for predicting the severity of disease and prognosis. This study aims to investigate the association of HbA1c in type 2 diabetes mellitus (T2DM) patients with NAFLD via measuring the ALT levels.

Materials and methods

This retrospective cross-sectional study enroled 130 patients with T2DM and NAFLD. The association between levels of HbA1c and ALT in patients of NAFLD with controlled and uncontrolled T2DM, respectively, was investigated. Stratification was done based on gender and diabetic control, using HbA1c levels as a marker of glycemic control. Serum ALT levels were also compared in both groups.

Results

The mean age of the participants was 50.2±5.7 years. The total participants were 130, of which 77 (59.3%) were females and 53 (40.7%) were males. The numbers of patients having uncontrolled T2DM (HbA1c>7%), and controlled T2DM (HbA1c <7%) were 78 (60%) and 52 (40%), respectively. Moreover, 46 (35.3%) females and 32 (24.7%) males had uncontrolled T2DM, and 31 (23.8%) females and 21 (16.2%) males had controlled T2DM. The mean ALT level for uncontrolled and controlled T2DM in female patients was found to be 24.6±3.4 and 13.5±2.4, respectively, (P <0.05). For male patients, it was found to be 54.0±4.9 and 29.1±5.4, respectively (P=0.008).

Conclusion

There is a positive association between elevated HbA1c and ALT levels in T2DM patients with NAFLD.

Inter-organ crosstalk during development and progression of type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) is characterized by tissue-specific insulin resistance and pancreatic β-cell dysfunction, which result from the interplay of local abnormalities within different tissues and systemic dysregulation of tissue crosstalk. The main local mechanisms comprise metabolic (lipid) signalling, altered mitochondrial metabolism with oxidative stress, endoplasmic reticulum stress and local inflammation. While the role of endocrine dysregulation in T2DM pathogenesis is well established, other forms of inter-organ crosstalk deserve closer investigation to better understand the multifactorial transition from normoglycaemia to hyperglycaemia. This narrative Review addresses the impact of certain tissue-specific messenger systems, such as metabolites, peptides and proteins and microRNAs, their secretion patterns and possible alternative transport mechanisms, such as extracellular vesicles (exosomes). The focus is on the effects of these messengers on distant organs during the development of T2DM and progression to its complications. Starting from the adipose tissue as a major organ relevant to T2DM pathophysiology, the discussion is expanded to other key tissues, such as skeletal muscle, liver, the endocrine pancreas and the intestine. Subsequently, this Review also sheds light on the potential of multimarker panels derived from these biomarkers and related multi-omics for the prediction of risk and progression of T2DM, novel diabetes mellitus subtypes and/or endotypes and T2DM-related complications.

Association Between DPP4 Inhibitor Use and the Incidence of Cirrhosis, ESRD, and Some Cancers in Patients With Diabetes

CONTEXT

There are relatively few data on noncardiovascular (non-CV) long-term clinical outcomes of dipeptidyl peptidase 4 inhibitor (DPP4i) treatment.

OBJECTIVE

We aimed to evaluate some non-CV effects of DPP4is in patients with diabetes.

METHODS

Based on data from the National Health Insurance Service database in Korea (2007-2018), we conducted 3 pairwise comparisons of metformin-combined antidiabetic therapies in adult patients with diabetes: DPP4is vs (1) all other oral antidiabetic agents, (2) sulfonylureas/glinides, and (3) thiazolidinediones (TZDs). Major outcomes were liver cirrhosis, end-stage renal disease (ESRD), and cancers in the liver, kidney, and pancreas. Adjusted hazard ratios (HRs) and 95% CIs for the outcomes were estimated using an adjusted Cox model.

RESULTS

Of the 747 124 patients included, 628 217 had received DPP4i therapy for a mean duration of 33.8 ± 25.0 months. Compared with TZD therapy, DPP4i therapy was associated with higher adjusted HRs [95% CIs] for liver cirrhosis (1.267 [1.108-1.449]), ESRD (1.596 [1.139-2.236]), liver cancer (1.117 [1.011-1.235]), and pancreatic cancer (1.158 [1.040-1.290]). Furthermore, apart from liver cirrhosis, a higher risk of each of these outcomes was associated with DPP4i use than with non-DPP4i use. The higher adjusted HRs associated with DPP4i use further increased when patients with long-term exposure to DPP4is were analyzed.

CONCLUSION

DPP4i therapy in patients with diabetes was associated with a higher risk of liver cirrhosis and cancer, ESRD, and pancreatic cancer than TZD therapy and, except for liver cirrhosis, the risk of these outcomes was greater with DPP4i treatment than with non-DPP4i treatment.

Regulatory Networks, Management Approaches, and Emerging Treatments of Nonalcoholic Fatty Liver Disease

The pathogenesis of NAFLD is complex and diverse, involving multiple signaling pathways and cytokines from various organs. Hepatokines, stellakines, adipokines, and myokines secreted by hepatocytes, hepatic stellate cells, adipose tissue, and myocytes play an important role in the occurrence and development of nonalcoholic fatty liver disease (NAFLD). The nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) contributes to the progression of NAFLD by mediating liver inflammation, immune response, hepatocyte death, and later compensatory proliferation. In this review, we first discuss the crosstalk and interaction between hepatokines, stellakines, adipokines, and myokines and NF-κB in NAFLD. The characterization of the crosstalk of NF-κB with these factors will provide a better understanding of the molecular mechanisms involved in the progression of NAFLD. In addition, we examine new expert management opinions for NAFLD and explore the therapeutic potential of silymarin in NAFLD/NASH.

Ultrasound-Based Hepatic Elastography in Non-Alcoholic Fatty Liver Disease: Focus on Patients with Type 2 Diabetes

Non-alcoholic fatty liver disease (NAFLD) is the most prevalent liver disease and is the hepatic expression of metabolic syndrome. The development of non-invasive methods for the diagnosis of hepatic steatosis and advanced fibrosis in high-risk patients, especially those with type 2 diabetes mellitus, is highly needed to replace the invasive method of liver biopsy. Elastographic methods can bring significant added value to screening and diagnostic procedures for NAFLD in patients with diabetes, thus contributing to improved NAFLD management. Pharmacological development and forthcoming therapeutic measures that address NAFLD should also be based on new, non-invasive, and reliable tools that assess NAFLD in at-risk patients and be able to properly guide treatment in individuals with both diabetes and NAFLD. This is the first review aiming to outline and discuss recent studies on ultrasound-based hepatic elastography, focusing on NAFLD assessment in patients with diabetes.

Dipeptidyl Peptidase 4 (DPP4) as A Novel Adipokine: Role in Metabolism and Fat Homeostasis

Dipeptidyl peptidase 4 (DPP4) is a molecule implicated in the regulation of metabolic homeostasis and inflammatory processes, and it exerts its main action through its enzymatic activity. DPP4 represents the enzyme most involved in the catabolism of incretin hormones; thus, its activity impacts appetite, energy balance, and the fine regulation of glucose homeostasis. Indeed, DPP4 inhibitors represent a class of antidiabetic agents widely used for the treatment of Type 2 diabetes mellitus (T2DM). DPP4 also acts as an adipokine and is mainly secreted by the adipose tissue, mostly from mature adipocytes of the visceral compartment, where it exerts autocrine and paracrine activities. DPP4 can disrupt insulin signaling within the adipocyte and in other target cells and tissues, where it also favors the development of a proinflammatory environment. This is likely at the basis of the presence of elevated circulating DPP4 levels in several metabolic diseases. In this review, we summarize the most recent evidence of the role of the DPP4 as an adipokine-regulating glucose/insulin metabolism and fat homeostasis, with a particular focus on clinical outcomes associated with its increased secretion in the presence of adipose tissue accumulation and dysfunction.

Therapeutic targets, novel drugs, and delivery systems for diabetes associated NAFLD and liver fibrosis

Type 2 diabetes mellitus (T2DM) associated non-alcoholic fatty liver disease (NAFLD) is the fourth-leading cause of death. Hyperglycemia induces various complications, including nephropathy, cirrhosis and eventually hepatocellular carcinoma (HCC). There are several etiological factors leading to liver disease development, which involve insulin resistance and oxidative stress. Free fatty acid (FFA) accumulation in the liver exerts oxidative and endoplasmic reticulum (ER) stresses. Hepatocyte injury induces release of inflammatory cytokines from Kupffer cells (KCs), which are responsible for activating hepatic stellate cells (HSCs). In this review, we will discuss various molecular targets for treating chronic liver diseases, including homeostasis of FFA, lipid metabolism, and decrease in hepatocyte apoptosis, role of growth factors, and regulation of epithelial-to-mesenchymal transition (EMT) and HSC activation. This review will also critically assess different strategies to enhance drug delivery to different cell types. Targeting nanocarriers to specific liver cell types have the potential to increase efficacy and suppress off-target effects.