Insulin resistance in cirrhosis: prolonged reduction of hyperinsulinemia normalizes insulin sensitivity

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.

Glucose turnover at whole-body and skeletal muscle level in response to parenteral nutrition in male patients with alcoholic liver cirrhosis

BACKGROUND & AIMS

Cirrhosis is associated with insulin resistance and impaired glucose tolerance, which may be caused by impairments at different tissue levels (liver, skeletal muscle, and/or beta cell).

METHODS

Here, glucose kinetics at whole-body and skeletal muscle level in patients with cirrhosis (Child-Pugh A and B) were studied during parenteral nutrition using the isotope dilution technique and arteriovenous balance approach across the leg. As opposed to the euglycemic hyperinsulinemic clamp or glucose tolerance tests applied in previous studies, this approach provides a nutrient composition more similar to a normal meal while circumventing any possible portal-systemic shunting, impaired hepatic uptake and incretin effect.

RESULTS

We confirmed the presence of hepatic and peripheral insulin resistance in our patient population. Endogenous glucose production was less suppressed in response to parenteral nutrition. However, glucose uptake in skeletal muscle was increased.

CONCLUSION

Our results suggests that in our study participants with cirrhosis, the hepatic and peripheral insulin resistance is compensated for by increased insulin secretion and thus, increased glucose uptake in muscle. Hereby, glucose homeostasis is maintained.

Subclinical diabetes confirmed by 75-g OGTT influence on the prognosis of decompensated cirrhosis

BACKGROUND AND AIM

Disorders of glucose metabolism, such as impaired glucose tolerance (IGT) and diabetes mellitus (DM), frequently occur in cirrhosis. We aimed to evaluate who needs to be undertaken a 75-g oral glucose tolerance test (OGTT) to find underlying subclinical diabetes.

METHODS

This prospective study included 713 patients with either compensated (Child-Turcotte-Pugh [CTP] class A) or decompensated cirrhosis (CTP class B/C) without previous DM history. All patients underwent a 75-g OGTT. The patients were divided into three groups: normal glucose tolerance (NGT), IGT, and newly diagnosed DM (subclinical DM).

RESULTS

Among 713 patients, NGT was diagnosed in 139 (19.5%), IGT in 252 (35.3%), and subclinical DM in 322 (45.2%) patients, respectively. During a median follow-up period of 42.0 months, the cumulative survival rates of patients were as follows: NGT, 75.6%; IGT, 57.6%; and subclinical DM, 54.8%. Overall, IGT (adjusted hazard ratio [aHR], 1.605; 95% confidence interval [CI] = 1.009-2.553; P = 0.046) and subclinical DM (aHR, 1.840; 95% CI = 1.183-2.861; P = 0.001) were identified as independent predictors of mortality. In patients with compensated cirrhosis (n = 415), neither IGT nor subclinical DM conferred a higher mortality risk. However, among patients with decompensated cirrhosis (n = 298), those with IGT (aHR, 2.394; P = 0.015) and subclinical DM (aHR, 2.211; P = 0.022) showed a survival rate worse than those with NGT. In addition, subclinical DM was identified as an independent risk factor for infection (aHR, 2.508; P = 0.007).

CONCLUSIONS

IGT and subclinical diabetes by OGTT are associated with an unfavorable prognosis in cirrhosis, and the effect is pronounced in the decompensated state.

CLINICALTRIALS

gov, Number NCT04828512 (https://clinicaltrials.gov/ct2/show/NCT04828512).

Skeletal muscle protein turnover responses to parenteral nutrition in patients with alcoholic liver cirrhosis and sarcopenia

Alcoholic liver cirrhosis (ALC) is accompanied by sarcopenia. The aim of this study was to investigate the acute effects of balanced parenteral nutrition (PN) on skeletal muscle protein turnover in ALC. Eight male patients with ALC and seven age- and sex-matched healthy controls were studied for 3 h of fasting followed by 3 h of intravenous PN (SmofKabiven 1,206 mL: amino acid = 38 g, carbohydrates = 85 g, and fat = 34 g) 4 mL/kg/h. We measured leg blood flow and sampled paired femoral arteriovenous concentrations and quadriceps muscle biopsies while providing a primed continuous infusion of [ring-2d5]-phenylalanine to quantify muscle protein synthesis and breakdown. Patients with ALC exhibited shorter 6-min walking distance (ALC: 487 ± 38 vs. controls: 722 ± 14 m, P < 0.05), lower hand-grip strength (ALC: 34 ± 2 vs. controls: 52 ± 2 kg, P < 0.05), and computed tomography (CT)-verified leg muscle loss (ALC: 5,922 ± 246 vs. controls: 8,110 ± 345 mm2, P < 0.05). Net leg muscle phenylalanine uptake changed from negative (muscle loss) during fasting to positive (muscle gain) in response to PN (ALC: -0.18 ± +0.01 vs. 0.24 ± 0.03 µmol/kg muscle·min-1; P < 0.001 and controls: -0.15 ± 0.01 vs. 0.09 ± 0.01 µmol/kg muscle·min-1; P < 0.001) but with higher net muscle phenylalanine uptake in ALC than controls (P < 0.001). Insulin concentrations were substantially higher in patients with ALC during PN. Our results suggest a higher net muscle phenylalanine uptake during a single infusion of PN in stable patients with ALC with sarcopenia compared with healthy controls.NEW & NOTEWORTHY Muscle protein turnover responses to parenteral nutritional (PN) supplementation have not previously been studied in stable alcoholic liver cirrhosis (ALC). We applied stable isotope tracers of amino acids to directly quantify net muscle protein turnover responses to PN in sarcopenic males with ALC and healthy controls. We found a higher net muscle protein gain in ALC during PN, thereby providing the physiological rationale for future clinical trials of PN as a potential countermeasure to sarcopenia.

Domestic Dogs and Horses as Sentinels of Per- and Polyfluoroalkyl Substance Exposure and Associated Health Biomarkers in Gray's Creek North Carolina

Central North Carolina (NC) is highly contaminated with per- and polyfluoroalkyl substances (PFAS), in part due to local fluorochemical production. Little is known about the exposure profiles and long-term health impacts for humans and animals that live in nearby communities. In this study, serum PFAS concentrations were determined using liquid chromatography high-resolution mass spectrometry and diagnostic clinical chemistry endpoints were assessed for 31 dogs and 32 horses that reside in Gray's Creek NC at households with documented PFAS contamination in their drinking water. PFAS were detected in every sample, with 12 of the 20 PFAS detected in ≥50% of samples from each species. The average total PFAS concentrations in horses were lower compared to dogs who had higher concentrations of PFOS (dogs 2.9 ng/mL; horses 1.8 ng/mL), PFHxS (dogs 1.43 ng/mL, horses < LOD), and PFOA (dogs 0.37 ng/mL; horses 0.10 ng/mL). Regression analysis highlighted alkaline phosphatase, glucose, and globulin proteins in dogs and gamma glutamyl transferase in horses as potential biomarkers associated with PFAS exposure. Overall, the results of this study support the utility of companion animal and livestock species as sentinels of PFAS exposure differences inside and outside of the home. As in humans, renal and hepatic health in domestic animals may be sensitive to long-term PFAS exposures.

Modeling the progression of Type 2 diabetes with underlying obesity

Environmentally induced or epigenetic-related beta-cell dysfunction and insulin resistance play a critical role in the progression to diabetes. We developed a mathematical modeling framework capable of studying the progression to diabetes incorporating various diabetogenic factors. Considering the heightened risk of beta-cell defects induced by obesity, we focused on the obesity-diabetes model to further investigate the influence of obesity on beta-cell function and glucose regulation. The model characterizes individualized glucose and insulin dynamics over the span of a lifetime. We then fit the model to the longitudinal data of the Pima Indian population, which captures both the fluctuations and long-term trends of glucose levels. As predicted, controlling or eradicating the obesity-related factor can alleviate, postpone, or even reverse diabetes. Furthermore, our results reveal that distinct abnormalities of beta-cell function and levels of insulin resistance among individuals contribute to different risks of diabetes. This study may encourage precise interventions to prevent diabetes and facilitate individualized patient treatment.

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.

Hepatic fibrosis of any origin in a large population of type 2 diabetes patients

BACKGROUND AND AIMS

Excess morbidity and mortality from chronic liver disease in type 2 diabetes (T2DM) is recognized; however, the clinical features associated with liver fibrosis (LF) of any origin are poorly known. Metabolic status and/or coexisting complications over time may play a role.

METHODS AND RESULTS

We interrogated the database of the diabetes unit network of Piedmont (Italy) (71,285 T2DM patients) and calculated a fibrosis-4 score (FIB-4) from data recorded between 2006 and 2019. Comorbidities were obtained by linkage with hospital data. The study population was subdivided by aetiology of LF (alcoholic, viral, metabolic). Associations between upper level of FIB-4 and demographic and clinical variables were evaluated separately for each group using robust Poisson models and presented as prevalence ratios. Nearly one-quarter (24%) of T2DM patients had some form of LF: viral (0.44%) and alcoholic (0.53%) forms were far less frequent than metabolic ones (22.7%). Only 1 out of 5 of these patients had a history of known cirrhosis. Age, male sex, duration of diabetes, coronary disease, hyperuricemia, renal failure, and features of liver failure (e.g., lower body-mass index, lipid and HbA1c levels) were positively associated with metabolic LF. More intensive treatments with insulin and segretagogue emerged as a significant predictive indicators of LF of metabolic origin.

CONCLUSION

A sizeable proportion of T2DM patients has some degree of LF, mainly of metabolic origin and often undiagnosed. There is a need to clarify whether the link between insulin therapy and advanced LF is causal or not.

Hepatogenous Diabetes: A Primer

As liver is one of the primary organs involved in glucose homeostasis, it is not surprising that patients with liver dysfunction in chronic liver disease usually develop impaired glucose tolerance and subsequently overt diabetes later in their natural course. Diabetes that develops after the onset of cirrhosis of liver is usually referred to as hepatogenous diabetes (HD). It is an underrecognized and a hallmark endocrinological event in chronic liver disease. HD is associated with a higher risk of developing hepatic decompensations, such as ascites, variceal bleeding, hepatic encephalopathy, renal dysfunction, refractory ascites, and hepatocellular carcinoma along with reduced survival rates than normoglycemic patients with cirrhosis of liver. It is quite different from type 2 diabetes mellitus with the absence of classical risk factors, dissimilar laboratory profiles, and decreased incidence of microvascular complications. Furthermore, the management of patients with HD is challenging because of altered pharmacokinetics of most antidiabetic drugs and increased risk of hypoglycemia and other adverse effects. Hence, a clear understanding of the epidemiology, pathophysiology, clinical implications, laboratory diagnosis, and management of HD is essential for both hepatologists as well as endocrinologists, which is narrated briefly in this review.

Hepatocrinology

Hepatocrinology is defined as a bidirectional, complex relationship between hepatic physiology and endocrine function, hepatic disease and endocrine dysfunction, hepatotropic drugs and endocrine function, and endocrine drugs and hepatic health. The scope of hepatocrinology includes conditions of varied etiology (metabolic, infectious, autoimmune, and invasive) that we term as hepato-endocrine syndromes. This perspective shares the definition, concept, and scope of hepatocrinology and shares insight related to this aspect of medicine. It is hoped that this communication will encourage further attention and research in this critical field.

Impact of Liver Cirrhosis on Incidence of Dialysis Among Patients with Type 2 Diabetes

INTRODUCTION

Renal injury is a common complication of liver cirrhosis and type 2 diabetes mellitus (T2DM). The aim of this study was to analyze the association between cirrhosis and dialysis in patients with T2DM.

METHODS

This was a retrospective study of specific patient populations using data collected from the National Health Insurance Research Database, National Health Research Institutes, Taiwan on patients treated between 1999 and 2007. The study population comprised 1271,759 patients with T2DM without cirrhosis, 38,860 patients with cirrhosis without T2DM, 11,487 patients with T2DM and cirrhosis, and 579,173 patients without T2DM and cirrhosis (non-cirrhotic control group).

RESULTS

The average incidence of dialysis in patients with T2DM and liver cirrhosis (2.466%) was 10.6-, 2.3-, and 102.7-fold higher than that in patients with T2DM without cirrhosis (0.232%), with cirrhosis without T2DM (1.071%), and patients without both T2DM and cirrhosis (0.024%), respectively. Adjusted odds ratio (OR) for dialysis risk was 3.19 in patients with T2DM and cirrhosis, 2.16 in patients with T2DM without cirrhosis, and 1.98 in patients with cirrhosis without T2DM, compared to that in patients without T2DM and cirrhosis. Male sex (adjusted hazard ratio [HR] 1.15), age (45-49 vs. 20-34 years [reference]; adjusted HR 1.34), low-income households (adjusted HR 1.46), cirrhosis (adjusted HR 3.42), and diabetic complications severity index (adjusted HR 1.71) were predictors of dialysis in T2DM patients. In addition, those with T2DM participating in the pay-for-performance (P4P) program had a significantly lower relative risk for requiring dialysis (HR 0.64).

CONCLUSION

Liver cirrhosis is an independent risk factor for dialysis in patients with T2DM. Participating in the P4P program for diabetes care may reduce the risk of requiring dialysis in patients with T2DM.

Post-transplant diabetes mellitus and preexisting liver disease - a bidirectional relationship affecting treatment and management

Liver cirrhosis and diabetes mellitus (DM) are both common conditions with significant socioeconomic burden and impact on morbidity and mortality. A bidirectional relationship exists between DM and liver cirrhosis regarding both etiology and disease-related complications. Type 2 DM (T2DM) is a well-recognized risk factor for chronic liver disease and vice-versa, DM may develop as a complication of cirrhosis, irrespective of its etiology. Liver transplantation (LT) represents an important treatment option for patients with end-stage liver disease due to non-alcoholic fatty liver disease (NAFLD), which represents a hepatic manifestation of metabolic syndrome and a common complication of T2DM. The metabolic risk factors including immunosuppressive drugs, can contribute to persistent or de novo development of DM and NAFLD after LT. T2DM, obesity, cardiovascular morbidities and renal impairment, frequently associated with metabolic syndrome and NAFLD, may have negative impact on short and long-term outcomes following LT. The treatment of DM in the context of chronic liver disease and post-transplant is challenging, but new emerging therapies such as glucagon-like peptide-1 receptor agonists (GLP-1RAs) and sodium–glucose cotransporter 2 inhibitors (SGLT2i) targeting multiple mechanisms in the shared pathophysiology of disorders such as oxidative stress and chronic inflammation are a promising tool in future patient management.

Leptin as a Key Player in Insulin Resistance of Liver Cirrhosis? A Cross-Sectional Study in Liver Transplant Candidates

Insulin resistance is associated with increased risk of death and liver transplantation in the cirrhotic population, independent of disease aetiology. However, factors accounting for insulin resistance in the context of cirrhosis are incompletely understood. This study aimed to investigate the association between adiponectin and leptin with insulin resistance in cirrhotic patients and to assess the influence of disease severity on insulin resistance and metabolic status. This cross-sectional study included 126 non-diabetic cirrhotic transplant candidates. The homeostasis model assessment 2 model was used to determine the insulin resistance index, and fasting adiponectin, leptin, insulin, c-peptide, glucose, HbA1c, and lipid profiles were analysed. Insulin resistance was detected in 83% of subjects and associated with increased leptin, fasting plasma glucose and body mass index, and lower triglyceride levels. Logistic regression analysis identified leptin and triglycerides as independent predictors of insulin resistance (OR 1.247, 95% CI 1.076-1.447, p = 0.003; OR 0.357, 95% CI 0.137-0.917, p = 0.032.). Leptin levels remained unchanged, whereas adiponectin levels increased (p < 0.001) with disease progression, and inversely correlated with HbA1c (ρ = -0.349, p < 0.001). Our results indicate that leptin resistance, as indicated by elevated leptin levels, can be regarded as a contributing factor to insulin resistance in cirrhotic patients, whereas triglycerides elicited a weak protective effect. Progressively increasing adiponectin levels elicited a positive effect on glucose homeostasis, but not insulin sensitivity across disease stages.

Hepatogenous Diabetes: An Underestimated Problem of Liver Cirrhosis

The prevalence of diabetes mellitus in cirrhotic patients is much higher than that in the general population. Two types of diabetes are usually seen in patients with cirrhosis: type 2 diabetes mellitus and hepatogenous diabetes (HD). The HD is an acquired condition which is believed to be caused by impaired insulin clearance and pancreatic β-cell dysfunction in cirrhotic patients. Increased levels of advanced glycation end products and hypoxia-inducible factors have been implicated in the pathogenesis of HD. Patients with HD typically present with normal fasting glucose, but abnormal response to an oral glucose tolerance test, which is required for the diagnosis. Because the level of glycated hemoglobin is often falsely low in patients with cirrhosis, it does not help in the early diagnosis of HD. HD is associated with an increased rate of complications of cirrhosis, decreased 5-year survival rate, and increased risk of hepatocellular carcinoma. The major complications of cirrhosis associated with HD include hepatic encephalopathy (HE), spontaneous bacterial peritonitis, sepsis, variceal hemorrhage, and renal dysfunction. Treatment of HD may be difficult as many antihyperglycemic therapies are associated with increased risk of complications in cirrhosis, particularly hypoglycemia. Biguanides, alpha-glucosidase inhibitors, and new medications such as dipeptidyl peptidase-4 inhibitors and sodium-glucose co-transporter 2 inhibitors appear to be safe in patients with cirrhosis. Though insulin therapy is currently advocated, requirement of insulin is variable and is difficult to predict. The liver transplantation usually results in reversal of HD. This review article provides an overview of magnitude, patients' characteristics, clinical implications, pathophysiological mechanisms, diagnosis, and management of HD.

Challenges in diagnosing and monitoring diabetes in patients with chronic liver diseases

The prevalence and mortality of diabetes mellitus and liver disease have risen in recent years. The liver plays an important role in glucose homeostasis, and various chronic liver diseases have a negative effect on glucose metabolism with the consequent emergence of diabetes. Some aspects related to chronic liver disease can affect diagnostic tools and the monitoring of diabetes and other glucose metabolism disorders, and clinicians must be aware of these limitations in their daily practice. In cirrhotic patients, fasting glucose may be normal in up until 23% of diabetes cases, and glycated hemoglobin provides falsely low results, especially in advanced cirrhosis. Similarly, the performance of alternative glucose monitoring tests, such as fructosamine, glycated albumin and 1,5-anhydroglucitol, also appears to be suboptimal in chronic liver disease. This review will examine the association between changes in glucose metabolism and various liver diseases as well as the particularities associated with the diagnosis and monitoring of diabetes in liver disease patients. Alternatives to routinely recommended tests will be discussed.

NAFLD/NASH in patients with type 2 diabetes and related treatment options

Type 2 diabetes may reduce life expectancy and patients' quality of life due to its micro- and macro-vascular complications and to the higher risk of several types of cancer. An emerging important factor is represented by the hepatic involvement; it is recognized that excessive hepatic fat accumulation represents a typical feature of diabetic patients and that it also plays an important pathogenic role. It is now evident that non-alcoholic fatty liver disease (NAFLD), generally perceived as a benign condition, may have on the contrary an important deleterious impact for diabetic patients increasing the risk to develop cardiovascular complications but also serious hepatic diseases, in particular non-alcoholic steatohepatitis (NASH), cirrhosis and hepatocellular carcinoma. Lifestyle intervention, bariatric surgery and several drug therapies have now accumulated evidence of efficacy in treating NASH. On the other hand, their durability and safety in the long-term is yet to be proven and their use may be sometimes associated with side effects or higher risk of adverse events limiting the regular administration or contraindicating it. Professional health care providers, building awareness about the importance of these hepatic complications, should put more efforts in primary prevention using a behavioral therapy needing a multidisciplinary approach, in secondary prevention applying on a regular basis in the clinical setting available predictive algorithms to identify the patients at higher cardiovascular and hepatologic risk, and in tertiary prevention treating, when not contraindicated, the diabetic patients preferentially with drugs with proven benefit on NAFLD/NASH.

Cirrhosis of Liver and Diabetes Mellitus: The Diabolic Duo?

Introduction

Cirrhosis of the liver and diabetes mellitus are two chronic illnesses with significant impact on the quality of life. Studies from different part of the world have shown the combination to be associated with higher incidence of complications of cirrhosis and reduced survival. However, data on the impact of pre-cirrhotic and post-cirrhotic diabetes on cirrhosis is minimal.

Aim

The aim of the study was to determine the complications of cirrhosis patients with and without co-existent DM and to compare the relation between cirrhosis patients with antecedent DM and hepatogenous DM.

Materials and Methods

The present prospective study was conducted at a tertiary care hospital in Kerala, India, over a period of three years. Cirrhosis patients with and without diabetes, along with subcategorization as antecedent and hepatogenous diabetes, were studied for various complications and outcome including death. Chi-square and Mann-whitney tests were used for comparing data.

Results

Patients with cirrhosis and diabetes had higher incidence of gall stones (27.6% versus 13.2%; p=0.008) and urinary infection (29.3% versus 7.5%; p=<0.001). Incidence of hepatocellular carcinoma and mortality were similar between the groups. Patients with antecedent diabetes and hepatogenous diabetes were similar with respect to complications and mortality. Child-Turcotte-Pugh (CTP) score, Model for End stage Liver Disease (MELD) score, urinary tract and respiratory infections and duration of cirrhosis were independent predictors of mortality in patients with cirrhosis.

Conclusion

Coexistent diabetes mellitus increases the incidence of complications and hospitalizations in cirrhosis patients but without impact on mortality rates. There is no significant morbidity or mortality difference between cirrhotics with antecedent diabetes and hepatogenous diabetes.

Hepatogenous diabetes: Is it time to separate it from type 2 diabetes?

By definition, hepatogenous diabetes is directly caused by loss of liver function, implying that it develops after cirrhosis onset. Therefore, it should be distinguished from type 2 diabetes developing before cirrhosis onset, in which specific causes of liver disease play a major role, in addition to traditional risk factors. Currently, although hepatogenous diabetes shows distinct pathophysiological and clinical features, it is not considered as an autonomous entity. Recent evidence suggests that the failing liver exerts an independent "toxic" effect on pancreatic islets resulting in β-cell dysfunction. Moreover, patients with hepatogenous diabetes usually present with normal fasting glucose and haemoglobin A_1c levels and abnormal response to an oral glucose tolerance test, which is therefore required for diagnosis. This article discusses the need to separate hepatogenous diabetes from type 2 diabetes occurring in subjects with chronic liver disease and to identify individuals suffering from this condition for prognostic and therapeutic purposes.

Re-evaluation of glycated hemoglobin and glycated albumin with continuous glucose monitoring system as markers of glycemia in patients with liver cirrhosis

Liver cirrhosis (LC) is frequently accompanied by glucose intolerance. The present study was designed to determine whether glycated hemoglobin A1c (HbA1c) and glycated albumin (GA) were predictive markers of glycemia, as determined by a continuous glucose monitoring system (CGMS), in patients with LC. A total of 30 patients with LC, including 3, 19, 5, 2 and 1 with LC due to hepatitis B virus, hepatitis C virus, non-alcoholic steatohepatitis, alcohol and unknown causes, respectively, were assessed by CGMS. The average, maximum and minimum blood glucose (BG) levels were measured by CGMS, and correlated with HbA1c and GA. The average, maximum and minimum BG in these individuals were 142±38.7, 209.3±65.7 and 85.1±25.4 mg/dl, respectively. HbA1c was significantly correlated with average BG (r=0.447, P=0.015) and maximum BG (r=0.523, P=0.004). In addition, GA was significantly correlated with average BG (r=0.687, P<0.001) and maximum BG (r=0.648, P<0.001). Neither HbA1c nor GA was significantly correlated with minimum BG. Correlation analysis yielded formulas by which HbA1c and GA were predictive of average BG in individuals with LC: Average BG=19.2 × HbA1c (%) + 36.5 and average BG=6.6 × GA (%) + 13.0, respectively. In conclusion, HbA1c and GA showed significant correlations with average and maximum BG, as determined by CGMS. The derived formulas allow for estimates of average BG based on HbA1c and GA, and may contribute to the control of glycemia in patients with LC.

Diabetes Mellitus Heightens the Risk of Hepatocellular Carcinoma Except in Patients With Hepatitis C Cirrhosis

OBJECTIVES

As most hepatocellular carcinoma (HCC) patients have cirrhosis, the association between diabetes and HCC may be confounded by the fact that diabetes is common in patients with cirrhosis. The aim of this study is to investigate whether diabetes increases the risk of HCC in patients with cirrhosis and whether the etiology of liver disease modifies the association between diabetes and HCC.

METHODS

All liver cirrhosis patients who had repeated radiographic evaluation of the liver (that is, ultrasound, computed tomography, or magnetic resonance image) at Mayo Clinic Rochester between January 2006 and December 2011 were included. The Cox proportional hazard regression analysis was used to investigate the effect of diabetes on the risk of HCC.

RESULTS

A total of 739 patients met the eligibility criteria, of whom 253 (34%) had diabetes. After a median follow-up of 38 months, 69 (9%) patients developed HCC. In patients without hepatitis C virus (HCV) infection, diabetes was significantly associated with the risk of developing HCC (hazard ratio (HR)=2.1, 95% confidence interval (CI)=1.1-4.1), whereas in patients with HCV, there was no association (HR=0.8, 95% CI=0.4-1.8). When adjusted for covariates, the interaction between HCV and diabetes remained significant (HR for non-HCV=1.9, 95% CI=0.9-3.7; HR for HCV=0.6, 95% CI=0.2-1.3). Lack of association between diabetes and HCC was externally validated in 410 patients with HCV cirrhosis enrolled in the HALT-C trial.

CONCLUSIONS

Diabetes increases the risk of HCC in patients with non-HCV cirrhosis. In HCV cirrhosis patients who already have very high risk, diabetes may not increase the risk any further.

Hepatogenous diabetes: Is it a neglected condition in chronic liver disease?

Diabetes mellitus (DM) that occurs because of chronic liver disease (CLD) is known as hepatogenous diabetes (HD). Although the association of diabetes and liver cirrhosis was described forty years ago, it was scarcely studied for long time. Patients suffering from this condition have low frequency of risk factors of type 2 DM. Its incidence is higher in CLD of viral, alcoholic and cryptogenic etiology. Its pathophysiology relates to liver damage, pancreatic dysfunction, interactions between hepatitis C virus (HCV) and glucose metabolism mechanisms and genetic susceptibility. It associates with increased rate of liver complications and hepatocellular carcinoma, and decreased 5-year survival rate. It reduces sustained virological response in HCV infected patients. In spite of these evidences, the American Diabetes Association does not recognize HD. In addition, the impact of glucose control on clinical outcomes of patients has not been evaluated. Treatment of diabetes may be difficult due to liver insufficiency and hepatotoxicity of antidiabetic drugs. Notwithstanding, no therapeutic guidelines have been implemented up to date. In this editorial, authors discuss the reasons why they think that HD may be a neglected pathological condition and call attention to the necessity for more clinical research on different fields of this disease.

Lispro insulin in people with non-alcoholic liver cirrhosis and type 2 diabetes mellitus

AIMS

To compare metabolic control under lispro and recombinant regular human insulin (RHI) in people with diet-unresponsive type 2 diabetes mellitus (T2DM) and compensated non-alcoholic liver disease (CLD).

METHODS

108 people with T2DM and CLD were randomly allocated to RHI or lispro according to a 12+12 week cross-over protocol. A 1-week continuous glucose monitoring (CGM) session was performed at the end of each treatment period followed by a standard meal test with a 12IU lispro or RHI shot ahead.

RESULTS

CGM showed higher glycemic excursions under RHI than under lispro (p<0.01) with lower glucose levels in the late post-absorption phase (p<0.05) and even more during the night (p<0.01). Post-challenge incremental areas under the curve (ΔAUC) were undistinguishable for insulin but lower for glucose, while insulin peaked higher and earlier and glycemic excursions were lower with lispro than with RHI (0.05<p<0.001).

CONCLUSIONS

Lispro granted lower early postprandial glucose levels and late postprandial hypoglycemic rates and therefore might represent the treatment of choice for people with T2DM and compensated CLD. This might depend on its faster/shorter-living effects, as well as, on the lower liver glucose output expected from its earlier hepatic distribution.

Current Concepts in Diabetes Mellitus and Chronic Liver Disease: Clinical Outcomes, Hepatitis C Virus Association, and Therapy

Hereditary type 2 diabetes mellitus is a risk factor for chronic liver disease, and ~30 % of patients with liver cirrhosis develop diabetes. Diabetes mellitus has been associated with cirrhotic and non-cirrhotic hepatitis C virus liver infection, can aggravate the course the liver infection, and can induce a lower sustained response to antiviral treatment. Evidences that HCV may induce metabolic and autoimmune disturbances leading to hypobetalipoproteinemia, steatosis, insulin resistance, impaired glucose tolerance, thyroid disease, and gonadal dysfunction have been found. Prospective studies have demonstrated that diabetes increases the risk of liver complications and death in patients with cirrhosis. However, treatment of diabetes in these patients is complex, as antidiabetic drugs can promote hypoglycemia and lactic acidosis. There have been few therapeutic studies evaluating antidiabetic treatments in patients with liver cirrhosis published to date; thus, the optimal treatment for diabetes and the impact of treatment on morbidity and mortality are not clearly known. As numbers of patients with chronic liver disease and diabetes mellitus are increasing, largely because of the global epidemics of obesity and nonalcoholic fatty liver disease, evaluation of treatment options is becoming more important. This review discusses new concepts on hepatogenous diabetes, the diabetes mellitus–hepatitis C virus association, and clinical implications of diabetes mellitus in patients with chronic liver disease. In addition, the effectiveness and safety of old and new antidiabetic drugs, including incretin-based therapies, will be described.

Plasma betatrophin levels in patients with liver cirrhosis

AIM: To investigate the plasma levels of betatrophin in patients with cirrhosis.

METHODS: Forty patients diagnosed at the clinic with liver cirrhosis according to biological, ultrasonographic, or histological criteria were included. The severity of cirrhosis was classified according to Pugh’s modification of Child’s classification and MELD score. Insulin resistance (IR) was assessed by the Homeostasis Model Assessment. A total of 20 patients showed a MELD score higher than 14. The control group consisted in 15 sex-and aged-matched subjects. Fasting blood samples were obtained for subsequent analysis. Serum insulin was determined by Liaison automated immune chemiluminiscence assay (DiaSorin S.p.A.) using a sandwich assay. The sensitivity of the assay was 0.2 μU/mL. The intra and interassay variation coefficients were < 4% and < 10%, respectively. The normal values were between 2 and 17 μU/mL. Human active betatrophin was analyzed by specific quantitative sandwich ELISA (Aviscera Bioscience^®). The sensitivity of the assay was 0.4 ng/mL, and the intra and interassay reproducibility were < 6% and < 10%, respectively.

RESULTS: Plasma betatrophin levels were significantly increased in patients with cirrhosis compared with those in healthy subjects (P = 0.0001). Betatrophin levels were also associated with disease severity, being higher in Child-Pugh C patients compared to Child-Pugh B (P < 0.0005) and in patients who displayed a MELD score higher than 14 points compared to patients with lower punctuation (P = 0.01). In addition, we found a positive correlation between plasma betatrophin levels and the severity of cirrhosis according to Child-Pugh classification (r = 0.53; P < 0.01) or MELD score (r = 0.45; P < 0.01). In the overall cohort, a moderate correlation between serum betatrophin and plasmatic bilirrubin (r = 0.39; P < 0.01) has been observed, as well as an inverse correlation between betatrophin and albumin (r = -0.41; P < 0.01) or prothrombin time (r = -0.44; P <0.01). Moreover, insulin resistance was observed in 82.5% of the cirrhotic patients. In this group of patients, betatrophin levels were significantly higher than those in the group of patients without IR (P < 0.05).

CONCLUSION: Plasma betatrophin is increased in patients with cirrhosis. This increase is related to the severity of cirrhosis, as well as with the emergence of insulin resistance.

Subclinical abnormal glucose tolerance is a predictor of death in liver cirrhosis

AIM: To determine if subclinical abnormal glucose tolerance (SAGT) has influence on survival of non-diabetic patients with liver cirrhosis.

METHODS: In total, 100 patients with compensated liver cirrhosis and normal fasting plasma glucose were included. Fasting plasma insulin (FPI) levels were measured, and oral glucose tolerance test (OGTT) was performed. According to OGTT results two groups of patients were formed: those with normal glucose tolerance (NGT) and those with SAGT. Patients were followed every three months. The mean follow-up was 932 d (range of 180-1925). Survival was analyzed by the Kaplan-Meyer method, and predictive factors of death were analyzed using the Cox proportional hazard regression model.

RESULTS: Of the included patients, 30 showed NGT and 70 SAGT. Groups were significantly different only in age, INR, FPI and HOMA2-IR. Patients with SAGT showed lower 5-year cumulated survival than NGT patients (31.7% vs 71.6%, P = 0.02). Differences in survival were significant only after 3 years of follow-up. SAGT, Child-Pugh B, and high Child-Pugh and Model for End-Stage Liver Disease (MELD) scores were independent predictors of death. The causes of death in 90.3% of cases were due to complications related to liver disease.

CONCLUSION: SAGT was associated with lower survival. SAGT, Child-Pugh B, and high Child-Pugh and MELD scores were independent negative predictors of survival.

Diagnostic sensitivity of carbohydrate deficient transferrin in heavy drinkers

Background and Aim

Carbohydrate deficient transferrin (CDT) is the most specific serum biomarker of heavy alcohol consumption, defined as ≥ 350–420 g alcohol/week. Despite introduction of a standardized reference measurement technique, widespread use of CDT remains limited due to low sensitivity. The aim of this study was to determine the factors that affect diagnostic sensitivity in patients with sustained heavy alcohol intake.

Methods

Patients with a self-reported history of sustained heavy alcohol consumption were recruited from the hepatology outpatient department or medical wards. Each patient was interviewed with a validated structured questionnaire of alcohol consumption and CDT analysis using the standardized reference measurement technique with high performance liquid chromatography was performed on serum collected at time of interview.

Results

52 patients were recruited: 19 from the hepatology outpatient department and 33 from general medical wards. Median alcohol intake was 1013 (range 366–5880) g/week over the preceding two week period. 26 patients had a diagnostic CDT based on a threshold value of %CDT > 1.7 indicating heavy alcohol consumption, yielding a sensitivity of 50%. Overweight/obesity (defined as body mass index (BMI) ≥ 25 kg/m² in Caucasians and ≥ 23.0 kg/m² in Asians), female gender and presence of cirrhosis were independently associated with non-diagnostic %CDT (≤ 1.7).

Conclusions

CDT has limited sensitivity as a biomarker of heavy alcohol consumption. Caution should be applied when ordering and interpreting %CDT results, particularly in women, patients with cirrhosis and those with an elevated BMI.

[Diabetes in liver cirrhosis]

The prevalence of overt diabetes mellitus (DM) in liver cirrhosis is about 30%. However, DM or impaired glucose tolerance can be observed in 90% after an oral glucose tolerance test in patients with normal fasting plasma glucose. Type 2 DM may produce cirrhosis, whereas DM may be a complication of cirrhosis. The latter is known as «hepatogenous diabetes». Overt and subclinical DM is associated with liver complications and death in cirrhotic patients. Treating diabetes is difficult in cirrhotic patients because of the metabolic impairments due to liver disease and because the most appropriate pharmacologic treatment has not been defined. It is also unknown if glycemic control with hypoglycemic agents has any impact on the course of the liver disease.

Impact of obesity and insulin-resistance on cirrhosis and portal hypertension

Obesity is sharply rising worldwide and is increasingly recognized in patients with cirrhosis. This review summarizes the available data documenting a detrimental role of obesity and insulin-resistance on the risk of appearance of clinical events in patients with cirrhosis. Molecular pathways explaining the harmful effect of obesity and insulin resistance in the natural history of cirrhosis are largely unknown. Increasing knowledge of mechanisms leading to white adipose tissue dysfunction on one side, and to portal hypertension on the other side, allow hypothesizing that a link between the pathophysiology of obesity, insulin resistance and portal hypertension in cirrhosis exists. Mechanisms likely involved in this interplay are discussed in this article.

Evaluation of a novel non-invasive (13) C-glucose breath test for the identification of diabetes mellitus in cirrhotic patients

AIM

  Diabetes mellitus (DM) has been reported to worsen the long-term prognosis of cirrhotic patients, and many studies have reported that DM is an independent risk factor for hepatocellular carcinoma. However, an accurate diagnosis of DM is sometimes difficult in cirrhotic patients. Recently, a novel non-invasive (13) C-glucose breath test has been reported to be useful for diagnosing insulin resistance in non-cirrhotic patients. The aim of this study was to evaluate the efficacy of this tool for the identification of DM in cirrhotic patients.

METHODS

  Thirty eight cirrhotic patients with normal fasting serum glucose and hemoglobin A1c levels underwent the (13) C-glucose breath test and the oral glucose tolerance test. Blood and breath samples were collected at baseline and at 30, 60 and 120 min after ingestion of 100 mg (13) C-labeled glucose and 75 g glucose.

RESULTS

  There was a strong correlation between the change in the concentrations at 2 h for the measured (13) C-glucose breath test (2h-BT) and the 2 h plasma glucose level (r = -0.60, P < 0.0001). In a receiver-operator curve analysis using the 2h-BT, the area under the curve was determined to be 0.88, with a sensitivity and specificity (cut-off value of 3.5‰) of 82% and 85%, respectively, for the detection of DM. Multivariate analysis showed the 2h-BT to be an independent parameter to identify DM.

CONCLUSION

  The (13) C-glucose breath test is a useful tool and has the potential to become a routine outpatient examination for the screening of DM in cirrhotic patients.

Nutrition therapy for liver diseases based on the status of nutritional intake

The dietary intake of patients with nonalcoholic fatty liver disease (NAFLD) is generally characterized by high levels of carbohydrate, fat, and/or cholesterol, and these dietary patterns influence hepatic lipid metabolism in the patients. Therefore, careful investigation of dietary habits could lead to better nutrition therapy in NAFLD patients. The main treatment for chronic hepatitis C (CHC) is interferon-based antiviral therapy, which often causes a decrease in appetite and energy intake; hence, nutritional support is also required during therapy to prevent undernourishment, treatment interruption, and a reduction in quality of life. Moreover, addition of some nutrients that act to suppress viral proliferation is recommended. As a substitutive treatment, low-iron diet therapy, which is relatively safe and effective for preventing hepatocellular carcinoma, is also recommended for CHC patients. Some patients with liver cirrhosis (LC) have decreased dietary energy and protein intake, while the number of LC patients with overeating and obesity is increasing, indicating that the nutritional state of LC patients has a broad spectrum. Therefore, nutrition therapy for LC patients should be planned on an assessment of their complications, nutritional state, and dietary intake. Late evening snacks, branched-chain amino acids, zinc, and probiotics are considered for effective nutritional utilization.

Insulin resistance in patients with cirrhosis and portal hypertension

Insulin resistance (IR) is involved in the pathogenesis of endothelial dysfunction and is also present in patients with cirrhosis. Intrahepatic endothelial dysfunction plays a major role, increasing hepatic vascular resistance and promoting portal hypertension (PH). In addition, β-adrenergic agonists and insulin share several intracellular signaling pathways. Thus IR may influence the response to β-blockers. This study aimed at evaluating the relationship between IR and hepatic hemodynamics in patients with cirrhosis and with the portal pressure response to acute β-blockade. Forty-nine patients with cirrhosis and PH were included. Hepatic and systemic hemodynamics were measured, and IR was estimated by using the updated homeostasis model assessment (HOMA)-2 index. Patients with HOMA-2 > 2.4 were considered IR. In patients with hepatic venous pressure gradient (HVPG) ≥ 10 mmHg) [clinically significant PH (CSPH)], hemodynamic measurements were performed again 20 min after intravenous propranolol. Mean HOMA-2 index was 3 ± 1.4. Fifty-seven percent of patients had IR. A weak correlation between HOMA-2 index and HVPG was observed. Eighty-six percent of patients had CSPH. HOMA-2 index was an independent predictor of CSPH. However, in patients with CSPH, the correlation between HOMA-2 index and HVPG was lost. HVPG, but not IR, predicted the presence of esophageal varices. Response to propranolol was not different between patients with or without IR. In nondiabetic patients with cirrhosis, HOMA-2 index is directly associated with the presence of CSPH and indirectly with varices, but does not allow either grading HVPG or predicting its response to propranolol.

Effect of transjugular intrahepatic portosystemic shunt on glycometabolism in cirrhosis patients

OBJECTIVE

Patients with liver cirrhosis suffer from hyperinsulinemia, hyperglucagonemia and a certain degree of insulin resistance, and portosystemic shunts may be involved in the etiology. A transjugular intrahepatic portosystemic shunt (TIPS) as a treatment for the complications of portal hypertension leads to hemodynamic changes. The objective of the present study is to evaluate whether TIPS can also affect glycometabolism in cirrhosis patients.

METHODS

Forty-six liver cirrhosis patients (experimental group [EG]) without diabetes who underwent TIPS were evaluated. Portal venous pressure (PVP), cardiac output (CO) and blood flow in the shunt (BFS) were measured or calculated before TIPS, after 15 minutes and, finally, after 90 days. Twenty-five liver cirrhosis patients without diabetes and without TIPS were included as the control group (CG). Oral glucose tolerance tests (OGTTs) were carried out at 0, 1, 7, 30 and 90 days after TIPS or after inclusion in the study. Indices related to glycometabolism and liver function, which included biochemical values, were also investigated.

RESULTS

PVP changed immediately from 39.43 ± 1.29 cmH(2)O to 21.43 ± 1.42 cmH(2)O and remained stable thereafter. A pronounced increase in CO was observed after TIPS, while BFS did not change significantly. Also, glycosylated hemoglobin A(1c) (HbA(1c)), fasting plasma glucose (FPG), fasting plasma C-peptide (FPC), glucagon-like peptide-1 (GLP-1) and 2-h post-challenge plasma glucose (2 hPG) were non significantly increased after the shunt. Statistically significant hyperinsulinemia and hyperglucagonemia persisted for 90 days after TIPS. In addition, TIPS was followed by an increase in insulin resistance (IR) and β-cell function. Thirty-four patients in the EG and 15 in the CG were diagnosed with diabetes or prediabetes after 90 days. No significant differences in biochemical values were observed 90 days after the shunt.

CONCLUSION

In addition to causing hemodynamic changes, TIPS augments hyperglucagonemia because of increased secretion and decreased clearance of glucagon in the liver, whereas IR deteriorates after the procedure. However, glycemic control does not worsen after TIPS, and the procedure is not associated with a higher risk of diabetes largely because of the simultaneous increase in insulin.

Effects of GLUT4 expression on insulin resistance in patients with advanced liver cirrhosis

Decreased glucose tolerance and diabetes are frequently observed in advanced liver cirrhosis patients and may be related to insulin resistance. Glucose transporter-4 (GLUT4), one of the most important glucose transporters, plays a key role in the development of type 2 diabetes. In order to study the mechanism of insulin resistance in liver cirrhosis patients, we measured the insulin sensitivity index and determined the GLUT4 protein and mRNA contents of skeletal muscle by Western blotting and reverse transcription-polymerase chain reaction (RT-PCR), respectively, in normal people and liver cirrhosis patients. The results showed that the levels of glucose, insulin, and C-peptide in two liver cirrhosis groups were higher and the insulin sensitivity index lower than those of the normal control group. The sensitivity of insulin may decrease with the decline of liver function. However, the contents of GLUT4 protein and mRNA in patients with advanced liver cirrhosis were similar to those of normal controls. In conclusion, insulin resistance is observed in patients with advanced liver cirrhosis but may not be correlated with the skeletal contents of GLUT4 protein and mRNA.

Why does NAFLD predict type 2 diabetes?

Based on the "lipotoxic" hypothesis, the free fatty acid flux from the excessive amount of adipose tissue toward the peripheral tissues would induce the development of insulin resistance especially when the triglyceride storage or the concentration of intermediate fat metabolites (diacylglycerides, ceramides) within the cytoplasm of these cells become excessive. Nonalcoholic fatty liver disease (NAFLD) includes a wide spectrum of liver damage, ranging from simple steatosis to steatohepatitis and advanced fibrosis. NAFLD is associated with general and intra-abdominal obesity and with a reduced ability of insulin to stimulate metabolic pathways in the liver itself and in other tissues. There are animal models and models in human diseases sustaining the hypothesis that a primary hepatic disease may determine the development of type 2 diabetes (T2DM). Epidemiologic data generated on surrogate markers of NAFLD (transaminases and γ-glutamyltransferase), semiquantitative assessment of fatty liver (ultrasound), and surrogate algorithms of NAFLD also support a causative effect of NAFLD on the risk to develop T2DM. In spite of the presence of these indirect associations, a clear-cut link between NAFLD and abnormal β-cell function is yet to be reported. Therefore, more data are warranted to prove what is considered a likely causative relationship between NAFLD and T2DM.

Intensive insulin therapy improves insulin sensitivity and mitochondrial function in severely burned children

OBJECTIVE

To institute intensive insulin therapy protocol in an acute pediatric burn unit and study the mechanisms underlying its benefits.

DESIGN

Prospective, randomized study.

SETTING

An acute pediatric burn unit in a tertiary teaching hospital.

PATIENTS

Children, 4-18 yrs old, with total body surface area burned > or =40% and who arrived within 1 wk after injury were enrolled in the study.

INTERVENTIONS

Patients were randomized to one of two groups. Intensive insulin therapy maintained blood glucose levels between 80 and 110 mg/dL. Conventional insulin therapy maintained blood glucose < or =215 mg/dL.

MEASUREMENTS AND MAIN RESULTS

Twenty patients were included in the data analysis consisting of resting energy expenditure, whole body and liver insulin sensitivity, and skeletal muscle mitochondrial function. Studies were performed at 7 days postburn (pretreatment) and at 21 days postburn (posttreatment). Resting energy expenditure significantly increased posttreatment (1476 +/- 124 to 1925 +/- 291 kcal/m(2) x day; p = .02) in conventional insulin therapy as compared with a decline in intensive insulin therapy. Glucose infusion rate was identical between groups before treatment (6.0 +/- 0.8 conventional insulin therapy vs. 6.8 +/- 0.9 mg/kg x min intensive insulin therapy; p = .5). Intensive insulin therapy displayed a significantly higher glucose clamp infusion rate posttreatment (9.1 +/- 1.3 intensive insulin therapy versus 4.8 +/- 0.6 mg/kg x min conventional insulin therapy, p = .005). Suppression of hepatic glucose release was significantly greater in the intensive insulin therapy after treatment compared with conventional insulin therapy (5.0 +/- 0.9 vs. 2.5 +/- 0.6 mg/kg x min; intensive insulin therapy vs. conventional insulin therapy; p = .03). States 3 and 4 mitochondrial oxidation of palmitate significantly improved in intensive insulin therapy (0.9 +/- 0.1 to 1.7 +/- 0.1 microm O(2)/CS/mg protein/min for state 3, p = .004; and 0.7 +/- 0.1 to 1.3 +/- 0.1 microm O(2)/CS/mg protein/min for state 4, p < .002), whereas conventional insulin therapy remained at the same level of activity (0.9 +/- 0.1 to 0.8 +/- 0.1 microm O(2)/CS/mg protein/min for state 3, p = .4; 0.6 +/- 0.03 to 0.7 +/- 0.1 microm O(2)/CS/mg protein/min, p = .6).

CONCLUSION

Controlling blood glucose levels < or =120 mg/dL using an intensive insulin therapy protocol improves insulin sensitivity and mitochondrial oxidative capacity while decreasing resting energy expenditure in severely burned children.

Alcohol and breast cancer: the mechanisms explained

Breast cancer is a leading cause of death amongst women, several studies have shown significant association between alcohol consumption and breast cancer. The aim of this overview is to highlight some of the mechanisms by which alcohol consumption could increase the risk of developing breast cancer. Using online Medline search engine, article containing details about mechanisms which explain the link between alcohol and breast cancer were examined. A number of mechanisms were found by which alcohol could increase the risk of breast cancer, alcohol's interaction and effect on oestrogen secretion; number of oestrogen receptors; the generation of acetaldehyde and hydroxyl free radicals; cells migration and metastasis; secretion of IGF1 and interaction with HRT and folate metabolism. In conclusion, it is essential for clinicians to understand these mechanisms and inform patients of the link between alcohol and breast cancer.

Liver cirrhosis and diabetes: Risk factors, pathophysiology, clinical implications and management

About 30% of patients with cirrhosis have diabetes mellitus (DM). Nowadays, it is a matter for debate whether type 2 DM in the absence of obesity and hypertriglyceridemia may be a risk factor for chronic liver disease. DM, which develops as a complication of cirrhosis, is known as “hepatogenous diabetes”. Insulin resistance in muscular and adipose tissues and hyperinsulinemia seem to be the pathophysiologic bases of diabetes in liver disease. An impaired response of the islet β-cells of the pancreas and hepatic insulin resistance are also contributory factors. Non-alcoholic fatty liver disease, alcoholic cirrhosis, chronic hepatitis C (CHC) and hemochromatosis are more frequently associated with DM. Insulin resistance increases the failure of the response to treatment in patients with CHC and enhances progression of fibrosis. DM in cirrhotic patients may be subclinical. Hepatogenous diabetes is clinically different from that of type 2 DM, since it is less frequently associated with microangiopathy and patients more frequently suffer complications of cirrhosis. DM increases the mortality of cirrhotic patients. Treatment of the diabetes is complex due to liver damage and hepatotoxicity of oral hypoglycemic drugs. This manuscript will review evidence that exists in relation to: type 2 DM alone or as part of the metabolic syndrome in the development of liver disease; factors involved in the genesis of hepatogenous diabetes; the impact of DM on the clinical outcome of liver disease; the management of DM in cirrhotic patients and the role of DM as a risk factor for the occurrence and exacerbation of hepatocellular carcinoma.

Elevated plasma resistin concentrations in patients with liver cirrhosis

BACKGROUND

Resistin, an adipose-derived polypeptide hormone, has been proposed to be a candidate in insulin resistance, although its role in humans remains controversial. Liver cirrhosis (LC) is characterized by an elevated number of circulating proinflammatory cytokines, hyperinsulinemia and insulin resistance. The aim of this study was to determine the plasma resistin levels in patients with LC.

METHODS

Resistin levels were determined in 79 patients with LC and in 31 healthy controls. Patients included 34 with Child-Pugh grade A, 30 with Child's B and 15 with Child's C LC. Fasting plasma glucose, fasting plasma insulin, adiponectin, the homeostatic model assessment insulin resistance (HOMA-IR) index, quantitative insulin sensitivity check index (QUICKI) and biochemical parameters were also determined.

RESULTS

Plasma resistin levels were 7.61 +/- 6.70 ng/mL in the LC patients and 3.38 +/- 1.68 ng/mL in the controls, respectively. The plasma resistin levels were significantly elevated in patients with LC in comparison to the controls (P < 0.01). The plasma resistin levels increased in a stepwise fashion in line with a higher grade according to Child-Pugh classification. Fasting plasma insulin, adiponectin and HOMA-IR index were also significantly elevated in patients with LC in comparison to controls. Inversely, QUICKI significantly decreased in patients with LC. According to Spearman's rank correlation, log resistin showed significantly positive correlation with fasting plasma insulin, log adiponectin, HOMA-IR index, and a negative correlation with QUICKI (P < 0.01). The plasma resistin levels did not correlate with sex, body mass index and fasting plasma glucose levels.

CONCLUSION

The plasma resistin levels increased in patients with LC, thus showing a positive correlation with fasting plasma insulin, adiponectin, HOMA-IR index, and a negative correlation with QUICKI. Although a decreased extraction of resistin due to reduced liver function cannot be ruled out, resistin may contribute to insulin resistance in patients with LC. The pathophysiological roles of resistin in LC still require further investigation.

Nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) refers to the presence of hepatic steatosis not associated with a significant intake of ethanol. Insulin resistance is central to the pathogenesis of NAFLD; thus obesity, diabetes, and the metabolic syndrome are frequently associated with the disease. Consequently, as these metabolic conditions emerge as major health problems in Western society, it is now recognized that NAFLD is the most common chronic liver condition in the Western world. NAFLD is generally asymptomatic, although a minority of patients may present with evidence of progressive liver injury with complications of cirrhosis, liver failure, and hepatocellular carcinoma. Despite being common and potentially serious, relatively little is known about the natural history or prognostic significance of NAFLD. Although diabetes, obesity, and age are recognized risk factors for advanced liver disease, other significant factors leading to progressive liver injury remain to be identified. The treatment of NAFLD focuses upon modifying metabolic risk factors. Insulin-sensitizing and hepatoprotective drugs have been subjected to study trials, but as yet, no agent has conclusively been demonstrated to prevent disease progression. Management is further complicated by the inability to predict which patients will develop liver-related morbidity and thus benefit from treatment.

Muscle GLUT4 in cirrhosis

BACKGROUND/AIMS

The insulin-dependent glucose transporter GLUT4 mediates 50-80% of whole body glucose uptake, but its relation to the frequent glucose intolerance in patients with liver cirrhosis is unknown.

METHODS

Thirty patients and seven healthy controls underwent a 2-h oral glucose tolerance test and later a muscle biopsy. Levels of GLUT4 total protein and mRNA content were determined in muscle biopsies by polyclonal antibody labelling and RT-PCR, respectively.

RESULTS

GLUT4 protein content in the cirrhosis group was not different from that of the controls, but at variance with the control subjects it correlated closely with measures of glucose tolerance (R(2)=0.45; p=0.003). GLUT4 mRNA of the patients with cirrhosis was reduced to 56% of control value (95% ci: 27-86%; p=0.015) and was inversely related to the level of basal hyper-insulinemia (R(2)=0.39; p=0.004).

CONCLUSIONS

In cirrhosis GLUT4 protein content was quantitatively intact, while limiting glucose tolerance. This indicates loss of redundancy of the major glucose transport system, possibly related to the markedly decreased expression of its gene. Hyper-insulinemia may be a primary event. Our findings implicate the muscular GLUT4 system in the glucose intolerance of liver cirrhosis by a mechanism different from that in diabetes.

Role of meal carbohydrate content for the imbalance of plasma amino acids in patients with liver cirrhosis

BACKGROUND AND AIM

Imbalance of circulating branched chain amino acids (BCAA) versus aromatic amino acids (AAA) and hyperinsulinemia are common metabolic alterations in patients with liver cirrhosis. The aim of this study was to characterize the effect of the carbohydrate component of a protein-rich mixed meal on postprandial plasma concentrations of 21 amino acids, insulin and C-peptide in patients with compensated liver cirrhosis. Furthermore, the effect of a dietary intervention on the metabolic alterations in cirrhotic patients was examined.

METHODS

Eighteen patients with cirrhosis and 12 healthy volunteers received a protein-rich meal (pork filet 200 g) with or without carbohydrates (bread 50 g, glucose 20 g). A subgroup of four cirrhotic patients received an isoenergetic (117 kJ/kg bw) carbohydrate-enriched (60%) and -restricted (20%) diet for 7 days each.

RESULTS

In the cirrhotic patients, basal plasma insulin and C-peptide concentrations were significantly elevated. The ingestion of a protein-rich meal without additional carbohydrates led to a significantly greater increase of insulin and C-peptide in the cirrhotic patients compared to controls. Postprandial increases of leucine and isoleucine were reduced, whereas those of phenylalanine were higher in cirrhotic patients. The addition of carbohydrates led to higher insulin and C-peptide plasma concentrations in cirrhotic patients. Postprandial BCAA increases were more impaired in the cirrhotic group after additional carbohydrate ingestion (46%vs 82%). After the carbohydrate-restricted diet for 7 days BCAA plasma levels increased but the BCAA/AAA ratio remained unaltered.

CONCLUSIONS

The carbohydrate content of a meal enhances reduction of BCAA plasma concentrations in clinically stable cirrhotic patients. An imbalanced BCAA/AAA ratio cannot be avoided by a carbohydrate-reduced diet alone, supporting mandatory BCAA supplementation.

Hepatitis C and insulin resistance: mutual interactions. A review

Worldwide approximately 200 million people are chronically infected with hepatitis C virus (HCV). Chronic HCV infection represents the leading cause of liver cirrhosis and the main indication for liver transplantation in the western world. In addition, chronic HCV infection is associated with numerous clinical manifestations, including type 2 diabetes. An obvious and frequently suggested explanation for the connection between HCV infection and type 2 diabetes is that cirrhosis by itself causes insulin resistance. However, the prevalence of type 2 diabetes in HCV cirrhosis is higher than in HBV cirrhosis (23.6% vs 9.4%). This suggests that HCV infection by itself can lead to insulin resistance and predispose to the onset of type 2 diabetes. First, HCV core protein induces hepatic steatosis by inhibition of microsomal triglyceride transfer protein and hepatic steatosis causes insulin resistance. Secondly, HCV core protein inhibits, through elevation of TNF-alfa and other factors, the insulin-signalling pathways causing insulin resistance. Moreover, recent data strongly suggest that insulin resistance is an important predictor of poor response to antiviral therapy in chronic hepatitis patients treated with peginterferon plus ribavirin.

Impaired insulin action despite upregulation of proximal insulin signaling: novel insights into skeletal muscle insulin resistance in liver cirrhosis

BACKGROUND/AIMS

Disturbance in glucose metabolism is a common feature in liver diseases and this is associated with skeletal muscle insulin resistance. However, the underlying molecular mechanisms are unclear. To characterize skeletal muscle insulin resistance associated with liver disease, we examined muscles from animals after an acute, 5 weeks perturbation of the common bile duct. Clinical findings, elevated plasma levels of liver enzymes and histological examinations confirmed cirrhosis.

METHODS/RESULTS

: Cirrhotic animals were insulin resistant and this was associated with reduced glucose transport into muscles. Interestingly, activity in the proximal part of the insulin signaling cascade was not decreased, as evinced by increased activity of key enzymes in the signal to glucose transport. Expression of the glucose transporter, GLUT4, was normal. So together these results indicate that signaling downstream of PKB/Akt and/or the translocation of GLUT4 is impaired in skeletal muscle from cirrhotic animals.

CONCLUSIONS

In conclusion, in an animal model of liver cirrhosis whole body insulin resistance is associated with insulin resistance in skeletal muscles. Unlike other common forms of insulin resistance, muscles from cirrhotic animals have increased activity in the proximal insulin signaling cascade. This emphasizes the fact that skeletal muscle insulin resistance associated with liver cirrhosis is a unique entity.

Characterization of the molecular mechanisms involved in the increased insulin secretion in rats with acute liver failure

To investigate the mechanism of hyperinsulinaemia in rats with acute liver failure induced by the administration of d-galactosamine (GalN), we focused on the role of polyprimidine tract-binding protein (PTB) in islet insulin synthesis. Recent reports indicate that PTB binds and stabilizes mRNA encoding insulin and insulin secretory granule proteins, including islet cell autoantigen 512 (ICA512), prohormone convertase 1/3 (PC1/3), and PC2. In the present study, glucose-stimulated insulin secretion was significantly increased in GalN-treated rats compared to controls. Levels of mRNA encoding insulin 1, ICA512, and PC1/3 were increased in the pancreatic islets of GalN-treated rats. This mRNA level elevation was not prevented by pretreatment with actinomycin D. When the PTB-binding site in insulin 1 mRNA was incubated with the islet cytosolic fraction, the RNA-protein complex level was increased in the cytosolic fraction obtained from GalN-treated rats compared to the level in control rats. The cytosolic fraction obtained from pancreatic islets obtained from GalN-treated rats had an increased PTB level compared to the levels obtained from the pancreatic islets of control rats. These findings suggest that, in rats with acute liver failure, cytosolic PTB binds and stabilizes mRNA encoding insulin and its secretory granule proteins.