Decreased expression of insulin and increased expression of pancreatic transcription factor PDX-1 in islets in patients with liver cirrhosis: a comparative investigation using human autopsy specimens

Unraveling the mechanisms of hepatogenous diabetes and its therapeutic perspectives

The review focused mainly on the pathogenesis of hepatogenous diabetes (HD) in liver cirrhosis (LC). This review reveals parallels between the mechanisms of metabolic dysfunction observed in LC and type II diabetes (T2DM), suggesting a shared pathway leading to HD. It underscores the role of insulin in HD pathogenesis, highlighting key factors such as insulin signaling, glucose metabolism, insulin resistance (IR), and the influence of adipocytes. Furthermore, the impact of adipose tissue accumulation, fatty acid metabolism, and pro-inflammatory cytokines like Tumor necrosis factor-α (TNF-α) on IR are discussed in the context of HD. Altered signaling pathways, disruptions in the endocrine system, liver inflammation, changes in muscle mass and composition, and modifications to the gut microbiota collectively contribute to the complex interplay linking cirrhosis and HD. This study highlights how important it is to identify and treat this complex condition in cirrhotic patients by thoroughly analyzing the link between cirrhosis, IR, and HD. It also emphasizes the vitality of targeted interventions. Cellular and molecular investigations into IR have revealed potential therapeutic targets for managing and preventing HD.

Effects of Liver Fibrosis on Islet Function in Patients with Chronic Hepatitis B Complicated with Impaired Fasting Glucose

Background

Patients with chronic hepatitis B (CHB) and cirrhosis often have impaired fasting glucose (IFG). This study sought to investigate the impact of liver fibrosis on islet function in individuals diagnosed with CHB and IFG.

Material and Methods

Patients with chronic hepatitis B (CHB) and impaired fasting glucose (IFG) were selected for this study. They were divided into low-risk (L-R), intermediate-risk (M-R), and high-risk (H-R) liver fibrosis groups based on the FIB-4 score. The study compared islet function among different risk groups of liver fibrosis and analyze the correlation between liver fibrosis and islet function. Additionally, the patients were divided into a diabetes mellitus (DM) group and a non-DM (NDM) group based on the development of DM. The cumulative risk of progression to DM in patients with L-R, M-R, and H-R liver fibrosis was analyzed using the Kaplan-Meier method. Hazard ratios (HRs) and confidence intervals (CIs) were calculated for DM development through Cox regression analysis.

Results

In this study of 228 individuals, higher FIB-4 scores were observed in the DM group compared to the NDM group. Patients with H-R liver fibrosis displayed lower islet function and had a significantly higher risk of developing DM. The FIB-4 score and fasting plasma glucose (FPG) were identified as independent risk factors for DM progression in CHB patients with IFG.

Conclusion

Among patients with CHB and IFG, the severity of liver fibrosis is associated with islet function, and the FIB-4 score is a significant risk factor for DM development.

Hepatogenous diabetes: Knowledge, evidence, and skepticism

The diabetogenic potential of liver cirrhosis (LC) has been known for a long time, and the name "hepatogenous diabetes" (HD) was coined in 1906 to define the condition. Diabetes mellitus (DM) that develops as a consequence of LC is referred to as HD. In patients with LC, the prevalence rates of HD have been reported to vary from 21% to 57%. The pathophysiological basis of HD seems to involve insulin resistance (IR) and pancreatic β-cell dysfunction. The neurohormonal changes, endotoxemia, and chronic inflammation of LC initially create IR; however, the toxic effects eventually lead to β-cell dysfunction, which marks the transition from impaired glucose tolerance to HD. In addition, a number of factors, including sarcopenia, sarcopenic obesity, gut dysbiosis, and hyperammonemia, have recently been linked to impaired glucose metabolism in LC. DM is associated with complications and poor outcomes in patients with LC, although the individual impact of each type 2 DM and HD is unknown due to a lack of categorization of diabetes in most published research. In fact, there is much skepticism within scientific organizations over the recognition of HD as a separate disease and a consequence of LC. Currently, T2DM and HD are being treated in a similar manner although no standardized guidelines are available. The different pathophysiological basis of HD may have an impact on treatment options. This review article discusses the existence of HD as a distinct entity with high prevalence rates, a strong pathophysiological basis, clinical and therapeutic implications, as well as widespread skepticism and knowledge gaps.

Potential Effect of DPP-4 Inhibitors Towards Hepatic Diseases and Associated Glucose Intolerance

Dipeptidyl-peptidase-4 (DPP-4) is an enzyme having various properties and physiological roles in lipid accumulation, resistance to anticancer agents, and immune stimulation. DPP-4 includes membrane-bound peptidases and is a kind of enzyme that cleaves alanine or proline-containing peptides such as incretins, chemokines, and appetite-suppressing hormones (neuropeptide) at their N-terminal dipeptides. DPP-4 plays a role in the final breakdown of peptides produced by other endo and exo-peptidases from nutritious proteins and their absorption in these tissues. DPP-4 enzyme activity has different modes of action on glucose metabolism, hunger regulation, gastrointestinal motility, immune system function, inflammation, and pain regulation. According to the literature survey, as DPP-4 levels increase in individuals with liver conditions, up-regulation of hepatic DPP-4 expression is likely to be the cause of glucose intolerance or insulin resistance. This review majorly focuses on the cleavage of alanine or proline-containing peptides such as incretins by the DPP-4 and its resulting conditions like glucose intolerance and cause of DPP-4 level elevation due to some liver conditions. Thus, we have discussed the various effects of DPP-4 on the liver diseases like hepatitis C, non-alcoholic fatty liver, hepatic regeneration and stem cell, hepatocellular carcinoma, and the impact of elevated DPP-4 levels in association with liver diseases as a cause of glucose intolerance and their treatment drug of choices. In addition, the effect of DPP-4 inhibitors on obesity and their negative aspects are also discussed in brief.

Short-Term SGLT2 Inhibitor Administration Does Not Alter Systemic Insulin Clearance in Type 2 Diabetes

Background: Decreased insulin clearance could be a relatively upstream abnormality in obesity, metabolic syndrome, and nonalcoholic fatty liver disease. Previous studies have shown that sodium-glucose cotransporter 2 inhibitor (SGLT2i) increases insulin–C-peptide ratio, a marker of insulin clearance, and improves metabolic parameters. We evaluated the effects of the SGLT2i tofogliflozin on metabolic clearance rate of insulin (MCRI) with a hyperinsulinemic euglycemic clamp study, the gold standard for measuring systemic insulin clearance. Methods: Study participants were 12 Japanese men with type 2 diabetes. We evaluated MCRI and tissue-specific insulin sensitivity with a hyperinsulinemic euglycemic clamp (insulin infusion rate, 40 mU/m²·min) before and immediately after a single dose (n = 12) and 8 weeks (n = 9) of tofogliflozin. We also measured ectopic fat in muscle and liver and the abdominal fat area using ¹H-magnetic resonance spectroscopy and magnetic resonance imaging, respectively, before and after 8 weeks of tofogliflozin. Results: MCRI did not change after a single dose of tofogliflozin (594.7 ± 67.7 mL/min·m² and 608.3 ± 90.9 mL/min·m², p = 0.61) or after 8 weeks (582.5 ± 67.3 mL/min·m² and 602.3 ± 67.0 mL/min·m², p = 0.41). The 8-week treatment significantly improved glycated hemoglobin and decreased body weight (1.7%) and the subcutaneous fat area (6.4%), whereas insulin sensitivity and ectopic fat in muscle and liver did not change significantly. Conclusions: MCRI did not change after a single dose or 8 weeks of tofogliflozin. Increased MCRI does not precede a decrease in body fat or improved glycemic control.

Pancreas stiffness in liver cirrhosis is an indicator of insulin secretion caused by portal hypertension and pancreatic congestion

AIM

Portal hypertension induces pancreatic congestion and impaired insulin secretion in patients with liver cirrhosis (LC). However, its mechanism is unclear, with no established noninvasive imaging method for the evaluation of its pathogeneses. The present study focused on pancreas stiffness, as assessed by shear wave elastography (SWE), and examined its association with portal hypertension and insulin secretion.

METHODS

Shear wave elastography and contrast-enhanced ultrasonography were utilized to evaluate pancreas stiffness and congestion, respectively. A glucagon challenge test was used for insulin secretion assessment. Furthermore, rat models of carbon tetrachloride (CCl₄ )-induced LC and portal hypertension were used to identify the direct effects of pancreatic congestion. Immunohistochemistry staining of the pancreas was carried out on human autopsy samples.

RESULTS

Pancreas stiffness measured by SWE was higher in patients with LC than in controls and showed significant correlation with pancreatic congestion. The glucagon challenge test indicated a lower value for the change in C-peptide immunoreactivity in the LC group, which was inversely correlated with pancreas stiffness and congestion. Additionally, portal hypertension and insulin secretion dysfunction were confirmed in CCl₄ rat models. Autopsy of human samples revealed congestive and fibrotic changes in the pancreas and the relationship between insulin secretion and their factors in patients with LC.

CONCLUSIONS

In patients with LC, pancreas stiffness measured by SWE could be a potential noninvasive test for evaluating pancreatic congestion and fibrosis due to portal hypertension. Moreover, it was associated with impaired insulin secretion, and could aid in guiding the treatment for hepatogenous diabetes.

Salvianolate Reduces Glucose Metabolism Disorders in Dimethylnitrosamine-Induced Cirrhotic Rats

OBJECTIVE

To evaluate the preventive effect of salvianolate (Sal B) on glucose metabolism disorders of dimethylnitrosamine (DMN)-induced cirrhotic rats.

METHODS

Fifty-five Wistar rats were randomly divided into a control group (n=10) and a cirrhotic group (n=45) according to a random number table. Liver cirrhosis was induced by intraperitoneal administration of DMN. The cirrhotic rats were divided into model, Sal B and metformin groups (n=15), respectively. Rats in the model group were given saline, two treatment groups were given Sal B (50 mg/kg), metformin (150 mg/kg) respectively for 28 consecutive days, while rats in the control group were injected 0.9% saline with same volume of vehicle. Body weight was measured everyday. Insulin sensitivity was determined by euglycemic hyperinsulinemic clamp. Organ index, glucose tolerance test (OGTT), and fasting plasma glucose (FPG), fasting insulin (FINS), hepatic glycogen, hydroxyproline (HYP) and liver function were detected at the end of the treatment. Area under the curve (AUC) for OGTT was calculated. Liver and pancreas histology were determined by histopathological examination with hematoxylin and eosin staining (HE), Sirius Red staining and Masson's trichrome staining, respectively. Hepatic expression of α-smooth muscle actin (α-SMA) and collagen (Col I) were evaluated by immunohistochemical staining.

RESULTS

Compared with the model group, Sal B significantly increased body and liver weight, liver-body ratio, glucose infusion rate (GIR), FPG, FINS levels and hepatic glycogen at the end of administration (P<0.05 or P<0.01). Meanwhile, Sal B significantly decreased AUC for OGTT, spleen weight, spleen-body ratio, aminotransferase and HYP level (P<0.05 or P<0.01). Sal B was also effective in alleviating necrosis of liver tissue, suppressing fibrosis progression and inhibiting the expression of α-SMA and Col I in liver. Compared with the metformin group, Sal B had advantages in ameliorating FPG, hepatic glycogen, spleen weight, organ index, liver function and cirrhosis (P<0.05). Metformin increased insulin sensitivity more potently than Sal B (P<0.05).

CONCLUSIONS

Sal B could improve glucose metabolism in cirrhotic rats by protecting hepatic glycogen reserve, increasing insulin sensitivity, and alleviating pancreatic morphology abnormalities. Sal B was clinically potential in preventing glucose metabolism anomalies accompanied with cirrhosis.

Pancreatic congestion in liver cirrhosis correlates with impaired insulin secretion

BACKGROUND

Although impaired glucose tolerance is common in cirrhosis, this condition's pathogenesis remains undefined. This study aimed to clarify pathogenesis related to the pancreas in cirrhotic patients, and to evaluate associations between insulin secretion and pancreatic congestion due to portal hypertension.

METHODS

Pancreatic perfusion parameters were analyzed by dynamic contrast-enhanced ultrasound (CE-US) in 41 patients (20 cirrhotic, 21 non-cirrhotic; age, 67.9 ± 13.3; female, 19), and prospectively compared to delta C-peptide immunoreactivity (ΔCPR). In a separate study, a retrospective chart review with human autopsy specimens was conducted, and vessels and islets of the pancreas were analyzed in 43 patients (20 cirrhotic, 23 controls; age, 71.5 ± 11.6; female, 15).

RESULTS

In the CE-US study, the clinical characteristics indicative of portal hypertension (e.g., ascites and varices) had significantly higher incidences in the cirrhotic group than in the control group. Pancreatic drainage times were greater in the cirrhotic group (p < 0.0001), and had a significant negative correlation with ΔCPR (R = 0.42, p = 0.0069). In the histopathological study, the islets were enlarged in the cirrhotic group (p < 0.0001). However, the percentage of insulin-positive area per islet was decreased in the cirrhotic group (p < 0.0001), and had a significant negative correlation with the wall thickness of the pancreatic vein (R = 0.63, p < 0.0001).

CONCLUSIONS

Pancreatic congestion was present in cirrhotic patients. Moreover, pancreatic congestion and insulin secretion were significantly correlated. This pathogenesis could be a key factor underlying the development of hepatogenous diabetes in cirrhotic patients.

The morbidity and associated risk factors of cancer in chronic liver disease patients with diabetes mellitus: a multicenter field survey

BACKGROUND AND AIMS

Diabetes mellitus is associated with various cancers; however, little is known of the relationship between cancer and diabetes in chronic liver disease (CLD) patients. The aim of this study is to investigate the morbidity and associated factors of cancer, including the use of anti-diabetics, in CLD patients with diabetes.

PATIENTS AND METHODS

We performed a multicenter survey in 2012 and 478 CLD patients with diabetes were enrolled (age 64.3 ± 12.1 years, female/male 187/291). A frequency analysis of cancer and antidiabetic use was performed. Independent factors for cancer were analyzed using logistic regression and decision-tree analysis.

RESULTS

The morbidity of cancer was 33.3%. Hepatocellular carcinoma (HCC) and extra-hepatic cancer were diagnosed in 24.7 and 11.3% of enrolled patients, respectively. The frequency of antidiabetic use was 66.5%. Of prescribed antidiabetics, 39% were dipeptidyl-peptidase 4 inhibitors; however, their use was not significantly associated with cancer. In contrast, the use of exogenous insulin (OR 2.21; 95% CI 1.16-4.21, P = 0.0165) and sulfonylurea (OR 2.08; 95% CI 1.05-3.97, P = 0.0353) were independently associated with HCC and extra-hepatic cancer, respectively. In decision-tree analysis, exogenous insulin and sulfonylurea were also identified as a divergence factor for HCC and extra-hepatic cancer, respectively.

CONCLUSIONS

We found a high morbidity of not only HCC, but also extra-hepatic cancer in CLD patients with diabetes. We also showed a possible association between the use of antidiabetics and the morbidity of cancer. Thus, a large-scale cohort study is needed to establish a therapeutic strategy for diabetes to suppress carcinogenesis in CLD patients.

Independent factors associated with altered plasma active ghrelin levels in HCV-infected patients

BACKGROUND & AIMS

Metabolic disorders are frequently seen in hepatitis C virus (HCV)-infected patients. Ghrelin, a gut hormone, regulates hepatic metabolisms, and must be activated to exert its biological effects. The aims of this study were to investigate changes in plasma active ghrelin levels and identify independent factors associated with plasma active ghrelin levels in HCV-infected patients.

METHODS

We enrolled patients with HCV infection (n = 96), hepatitis B virus (HBV) infection (n = 49), non-alcoholic fatty liver disease (NAFLD; n = 20) and healthy subjects (CON; n = 16). Plasma active ghrelin levels were measured using ELISA. Factors associated with plasma active ghrelin levels were assessed by multivariate and Spearman's correlation analyses.

RESULTS

Plasma active ghrelin levels were significantly lower in relation to the severity of liver disease in both the HBV and HCV groups. Furthermore, HCV infection was identified as an independent factor associated with decreased plasma active ghrelin levels in the multivariate analysis (OR -3.05; 95% CI -0.93 to -19.51; P = 0.0192). Plasma active ghrelin levels were significantly correlated with serum albumin levels in the HCV group (ρ = 0.497, P < 0.0001).

CONCLUSIONS

We demonstrated that liver cirrhosis and HCV infection were independent factors associated plasma active ghrelin levels. Moreover, plasma active ghrelin levels were positively correlated with serum albumin levels among HCV-infected patients. Therefore, active ghrelin levels may be regulated by both progression of liver disease and HCV infection and could be involved in the regulation of serum albumin levels in HCV-infected patients.

Dipeptidyl peptidase-4: A key player in chronic liver disease

Dipeptidyl peptidase-4 (DPP-4) is a membrane-associated peptidase, also known as CD26. DPP-4 has widespread organ distribution throughout the body and exerts pleiotropic effects via its peptidase activity. A representative target peptide is glucagon-like peptide-1, and inactivation of glucagon-like peptide-1 results in the development of glucose intolerance/diabetes mellitus and hepatic steatosis. In addition to its peptidase activity, DPP-4 is known to be associated with immune stimulation, binding to and degradation of extracellular matrix, resistance to anti-cancer agents, and lipid accumulation. The liver expresses DPP-4 to a high degree, and recent accumulating data suggest that DPP-4 is involved in the development of various chronic liver diseases such as hepatitis C virus infection, non-alcoholic fatty liver disease, and hepatocellular carcinoma. Furthermore, DPP-4 occurs in hepatic stem cells and plays a crucial role in hepatic regeneration. In this review, we described the tissue distribution and various biological effects of DPP-4. Then, we discussed the impact of DPP-4 in chronic liver disease and the possible therapeutic effects of a DPP-4 inhibitor.