Association of diabetes and hepatitis C infection: epidemiologic evidence and pathophysiologic insights

Surgical management of the diabetic foot: The current evidence

The prevalence of diabetes mellitus and its associated complications, particularly diabetic foot pathologies, poses significant healthcare challenges and economic burdens globally. This review synthesises current evidence on the surgical management of the diabetic foot, focusing on the interplay between neuropathy, ischemia, and infection that commonly culminates in ulcers, infections, and, in severe cases, amputations. The escalating incidence of diabetes mellitus underscores the urgency for effective management strategies, as diabetic foot complications are a leading cause of hospital admissions among diabetic patients, significantly impacting morbidity and mortality rates. This review explores the pathophysiological mechanisms underlying diabetic foot complications and further examines diabetic foot ulcers, infections, and skeletal pathologies such as Charcot arthropathy, emphasising the critical role of early diagnosis, comprehensive management strategies, and interdisciplinary care in mitigating adverse outcomes. In addressing surgical interventions, this review evaluates conservative surgeries, amputations, and reconstructive procedures, highlighting the importance of tailored approaches based on individual patient profiles and the specific characteristics of foot pathologies. The integration of advanced diagnostic tools, novel surgical techniques, and postoperative care, including offloading and infection control, are discussed in the context of optimising healing and preserving limb function.

Diabetic patients with chronic hepatitis C virus response compared to non diabetics when treated with directly acting antiviral therapy

BACKGROUND AND STUDY AIMS

Hepatitis C virus (HCV) impairs glucose homoestasis, thus influences its clinical picture and prognosis. This study aimed at evaluating Diabetes mellitus (DM) on Egyptian patients with chronic hepatitis C (CHC), and its impact on their virologic response when treated with directly acting antiviral (DAA) medications.

PATIENTS AND METHODS

Adult patients with CHC were divided into 2 groups; Diabetic patients, and Non diabetic patients serving as control group. All patients were subjected to thorough clinical evaluation, basic biochemical laboratory tests including fasting blood glucose/glycosylated haemoglobin (HbA1C), and virologic assay. They were treated with various combined DAAs, and were monitored during, at and after end of treatment.

RESULTS

Diabetic patients constituted 9.85 % of CHC, and had generally worse laboratory tests (significantly higher transaminases, platelet count, Fib4 and hepatic steatosis) than non diabetic patients, and a less sustained virologic response (SVR) (significantly in Sofosbuvir (SOF) + pegylated interferon (PegIFN) + ribavirin (RBV), SOF + RBV, SOF + daclatasvir (DAC)). Although DM did not play a significant influence on SVR, yet Fib4 and SOF + RBV + PEG-IFN were significant factors affecting SVR among diabetics, while female gender and viraemia were significant factors affecting SVR among non diabetics. Hepatic fibrosis and SOF/RBV significantly influenced SVR in both groups.

CONCLUSIONS

Diabetic patients with CHC have worse liver biochemical profile, yet DM per se did not influence the virologic response to DAAs, however, some factors played roles in affecting SVR among them.

Spatial epidemiology of diabetes: Methods and insights

Diabetes mellitus (DM) is a growing epidemic with global proportions. It is estimated that in 2019, 463 million adults aged 20-79 years were living with DM. The latest evidence shows that DM continues to be a significant global health challenge and is likely to continue to grow substantially in the next decades, which would have major implications for healthcare expenditures, particularly in developing countries. Hence, new conceptual and methodological approaches to tackle the epidemic are long overdue. Spatial epidemiology has been a successful approach to control infectious disease epidemics like malaria and human immunodeficiency virus. The implementation of this approach has been expanded to include the study of non-communicable diseases like cancer and cardiovascular diseases. In this review, we discussed the implementation and use of spatial epidemiology and Geographic Information Systems to the study of DM. We reviewed several spatial methods used to understand the spatial structure of the disease and identify the potential geographical drivers of the spatial distribution of DM. Finally, we discussed the use of spatial epidemiology on the design and implementation of geographically targeted prevention and treatment interventions against DM.

Association between hepatitis C antiviral treatment and diabetes mellitus: A case series

The hepatitis C virus (HCV) infects 185 million people worldwide, and diabetes mellitus (DM) affects 415 million. There has long been a possible association between DM and liver outcomes for patients with HCV infection. We present two cases of worsening glucose resistance and one case of emergent type 1 DM after completion of HCV. The complex interactions between HCV infection and both type 1 and type 2 DM have not yet been elucidated. In addition, consequences and side effects of treatment options for HCV have not been fully studied in the diabetic population. Our case series illustrates a potential complication of HCV treatment, which may warrant additional consideration prior to initiation of therapy as well as monitoring and surveillance post-cure.

Liraglutide Inhibits Hepatitis C Virus Replication Through an AMP Activated Protein Kinase Dependent Mechanism

Insulin resistance and diabetes are both associated with chronic hepatitis C virus (HCV) infection, and the glucagon-like peptide-1(GLP-1) receptor agonist, liraglutide, is a common therapy for diabetes. Our aim was to investigate whether liraglutide treatment can inhibit HCV replication. A cell culture-produced HCV infectious system was generated by transfection of in vitro-transcribed genomic JFH-1 ribonucleic acid (RNA) into Huh-7.5 cells. Total RNA samples were extracted to determine the efficiency of HCV replication. The Ava5 cells were treated with liraglutide and cell viability was calculated. A Western blot analysis of the protein expression was performed. The immunoreactive blot signals were also detected. Liraglutide activated GLP-1 receptors in the HCV infectious system, and inhibited subgenomic HCV RNA replication in the HuH-7.5 cells. The Western blot analysis revealed both HCV protein and replicon RNA were reduced after treatment with liraglutide in a dose-dependent manner. Liraglutide decreased the cell viability of HCV RNA at an optimum concentration of 120 μg/mL, activated the 5′ adenosine monophosphate-activated protein kinase (AMPK) and the phosphorylated- transducer of regulated cyclic adenosine monophosphate (CAMP) response element-binding protein 2 (TORC2), thereby decreasing the cell viability of phosphoenolpyruvate carboxykinase (PEPCK) and G6pase RNA Therefore, we conclude that liraglutide can inhibit HCV replication via an AMPK/TORC2-dependent pathway.

Benefits of hepatitis C cure with antivirals: why test and treat?

Chronic hepatitis C virus (HCV) infection is one of the major causes of death worldwide due to infectious agents. The advent of direct-acting antivirals has dramatically improved the chance of HCV elimination, even for patients with decompensated cirrhosis. Along with HCV cure, benefits are recognized in terms of regression of liver fibrosis and risk of hepatocellular carcinoma. Furthermore, beyond hepatic outcomes, several extrahepatic benefits may result from sustained HCV eradication, including improvements in the neurocognitive function and reduced cardiovascular disease risk. Finally, there is no doubt that the individual success of direct-acting antivirals is largely contributing to halt HCV transmission globally, in the absence of an effective HCV prophylactic vaccine.

Systemic manifestations of hepatitis C infection

Chronic hepatitis C (HCV) is a common infection affecting 185 million people worldwide. The most common manifestation of chronic HCV is progressive liver fibrosis, cirrhosis, liver failure and hepatocellular carcinoma. However, several systemic manifestations of HCV have been recognized and reported in the literature. The purpose of this review is to assimilate published literature based on evidence to categorize these extrahepatic manifestations with the likelihood of a causal association with HCV. Exciting recent developments have resulted in simple all oral interferon-free highly effective therapy for HCV. However, this treatment is also expensive and less accessible to most affected individuals as treatment recommendations are based on stage of liver fibrosis. Expanding the scope of HCV therapy to those with extrahepatic manifestations beyond what is currently recommended will significantly reduce the morbidity and mortality in this aging population.

Extrahepatic manifestations of hepatitis C infection: navigating CHASM

This article describes the importance of extrahepatic systemic manifestations of chronic hepatitis C virus (HCV) infection. While most HCV literature focuses on liver injury and fibrosis progression, a spectrum of systemic disease processes, collectively called C hepatitis-associated systemic manifestations (CHASMs), are present in a high proportion of infected persons. These include thyroid disease (Hashimoto's thyroiditis, Graves disease, and thyroid cancer), cardiovascular disease (atherosclerosis, carotid artery disease, and coronary artery disease), renal disease (MPGN and glomerulosclerosis), eye disease (Mooren's ulcers and sicca syndrome), skin disease (PCT, vasculitis, and lichen planus), lymphomas (NHL and splenic T-cell), and diabetes. Mechanistic understanding of how HCV leads to CHASM processes could lead to development of new interventions. The role of early HCV treatment and cure may result in preventive strategies for a variety of complex disease states. Key Points • Systemic extrahepatic complications of HCV comprise a spectrum of disease states in many organs and systems.• Effective treatment of HCV may reduce or eliminate some but not all of these systemic complications.• Further research into early treatment intervention as a prevention strategy for systemic disease is warranted.

Significance of Hepatic Insulin Clearance in Patients with Chronic Hepatitis C and Non-alcoholic Fatty Liver Disease

Objective Hyperinsulinemia plays an important role in the pathophysiological processes of chronic hepatitis C (CHC) and non-alcoholic fatty liver disease (NAFLD). However, there are few reports on hepatic insulin clearance in patients with these diseases. Methods A total of 74 CHC patients and 37 NAFLD patients were enrolled in this study. We evaluated their hepatic insulin clearance, insulin sensitivity and β-cell function with an oral glucose tolerance test. Results Hepatic insulin clearance in the patients with CHC was significantly correlated with platelets (r=0.271, p=0.020) and liver fibrosis (r=-0.234, p=0.045) and was significantly affected by both steatosis (mild: 0.157±0.078, severe: 0.114±0.053, p=0.024) and fibrosis (mild: 0.167±0.0857, severe: 0.125±0.052, p=0.010). There were no significant differences in (homeostasis model assessment) HOMA-β among steatosis and fibrosis stages. In the NAFLD patients, those with severe fibrosis had significantly reduced hepatic insulin clearance (mild: 0.135±0.045, severe: 0.098±0.031, p=0.013) and significantly increased HOMA-β (mild: 115.6±67.1, severe: 172.8±65.7, p=0.018) compared with the patients with mild fibrosis. Conclusion Liver fibrosis development is associated with hepatic insulin clearance in both the CHC and NAFLD patients.

Association between HCV infection and diabetes type 2 in Egypt: is it time to split up?

PURPOSE

There is a conflicting evidence about the association between hepatitis C virus (HCV) infection and diabetes mellitus. The objective of this study was to assess this association in Egypt, the country with the highest HCV prevalence in the world.

METHODS

The source of data was from the Egypt Demographic and Health Survey conducted in 2008. Using multivariable logistic regression analyses to account for known confounders, the association was investigated at two levels']: (1) HCV exposure (HCV antibody status) and diabetes mellitus and (2) diabetes mellitus and chronic HCV infection (HCV RNA status) among HCV-exposed individuals.

RESULTS

We found no evidence for an association between HCV antibody status and diabetes (adjusted odds ratio [OR] = 0.87; 95% confidence interval [CI], 0.63-1.19). However, among HCV-exposed individuals, we found an evidence for an association between diabetes and active HCV infection (adjusted OR = 2.44, 95% CI, 1.30-4.57).

CONCLUSIONS

Although it does not appear that HCV exposure and diabetes are linked, there might be an association between diabetes and chronic HCV infection. The HCV-diabetes relationship may be more complex than previously anticipated. Therefore, a call for an "amicable divorce" to the HCV-diabetes relationship could be premature.

Variability in Zucker diabetic fatty rats: differences in disease progression in hyperglycemic and normoglycemic animals

Both obesity and chronic inflammation are often associated with insulin resistance and type 2 diabetes. The Zucker diabetic fatty (ZDF) rat (fa/fa) is an obese animal model frequently used in type 2 diabetes research. The current study determines whether chronic administration (from 5 weeks of age through 24 weeks of age) of salsalate, a salicylate with anti-inflammatory properties, would be effective in mitigating diabetes disease progression in ZDF rats. Although a trend existed for lower blood glucose in the salsalate-treated group, significant differences were obscured by high animal-level variability. However, even in the non-drug-treated group, not all ZDF rats became diabetic as expected. Therefore, animals were parsed into two groups, regardless of drug treatment: normoglycemic ZDF rats, which maintained blood glucose profiles identical to nondiabetic Zucker lean rats (ZLRs), and hyperglycemic ZDF rats, which exhibited progressive elevation in blood glucose. To ascertain the differences between ZDF rats that became hyperglycemic and those that did not, relevant physiological indices and expression levels of adiponectin, tumor necrosis factor-α, interleukin-6, and glucocorticoid-induced leucine zipper messenger RNAs in adipose tissue were measured at sacrifice. Plasma C-reactive protein concentrations and expression levels of cytokine and glucocorticoid-induced leucine zipper messenger RNAs suggested more prevalent chronic inflammation in hyperglycemic animals. Early elevation of the insulin-sensitizing adipokine, adiponectin, was present in both ZDF groups, with the rate of its age-related decline faster in hyperglycemic animals. The most marked difference between the two groups of ZDF animals was in insulin output. Although the two ZDF populations had very similar elevated plasma insulin concentrations for the first 10 weeks, after that time, plasma insulin decreased markedly in the animals that became hyperglycemic, whereas it remained high in the normoglycemic ZDF rats. Thus, hyperglycemic ZDF animals exhibit both insulin resistance and progressive beta cell failure, whereas normoglycemic ZDF rats exhibit a lesser degree of insulin resistance that does not progress to beta cell failure. In these respects, the normoglycemic ZDF rats appear to revert back to a phenotype that strongly resembles that of nondiabetic Zucker fatty rats from which they were derived.

Steroid-induced diabetes: a clinical and molecular approach to understanding and treatment

Since the advent of glucocorticoid therapy for autoimmune disease in the 1940s, their widespread application has led to the concurrent therapy-limiting discovery of many adverse metabolic side effects. Unanticipated hyperglycemia associated with the initiation of glucocorticoids often leads to preventable hospital admissions, prolonged hospital stays, increased risks for infection and reduced graft function in solid organ transplant recipients. Challenges in managing steroid-induced diabetes stem from wide fluctuations in post-prandial hyperglycemia and the lack of clearly defined treatment protocols. The mainstay of treatment is insulin therapy coincident with meals. This article aims to review the pathogenesis, risk factors, diagnosis and treatment principles unique to steroid-induced diabetes.

HIV infection and glycemic response to newly initiated diabetic medical therapy

OBJECTIVES

Type 2 diabetes (DM2) is increasingly common in HIV-infected individuals. Antiretroviral agents and chronic inflammation may adversely affect glycemic control. However, little is known about the effectiveness of diabetic medical therapy in HIV-infected patients. The objective of this study was to compare the effectiveness of initial diabetic medical therapy in patients with and without HIV infection.

DESIGN

A retrospective cohort study was conducted among adults with DM2 initiating diabetic medications within the Centers for AIDS Research Network of Integrated Clinical Systems cohort.

METHODS

Generalized estimating equations were used to compare changes in hemoglobin A1c (HbA1c) through the year after initiation of therapy, controlling for baseline HbA1c and demographic and clinical covariates.

RESULTS

Two hundred and eighty-six HIV-infected patients and 858 age and sex-matched HIV-uninfected patients initiated diabetic medications during the study period. Overall, patients had an adjusted absolute mean reduction in HbA1c of 1.04% [95% confidence interval (CI) -0.87 to -1.22] during the first year of therapy. HIV-infected patients achieved significantly smaller reductions in HbA1c, with an absolute mean difference of -0.17% (95% CI -0.28 to -0.06; P = 0.003). On subanalyses, HIV-infected patients on a protease inhibitor-based regimen had significantly smaller reductions in HbA1c compared to HIV-uninfected patients (adjusted absolute difference -0.21%, 95% CI -0.35 to -0.08; P = 0.002).

CONCLUSION

Patients with HIV infection who initiate diabetic medical therapy achieve smaller reductions in HbA1c than patients without HIV infection in the course of routine clinical care. This less robust response may in part be related to use of antiretrovirals that exacerbate insulin resistance, specifically protease inhibitors.

Relation of serum insulin-like growth factor-1 (IGF-1) levels with hepatitis C virus infection and insulin resistance

The prospect of the growing worldwide epidemic of hepatitis C virus (HCV) infection and type 2 diabetes mellitus certainly merits attention toward their controversial relationship. Insulin-like growth factor-1 (IGF-1) plays an important role in glucose homeostasis. This study is a cross-sectional study considered as an initial investigation aimed to evaluate the effect of HCV infection on serum IGF-1, as well as to find out whether IGF-1 has a role in development of insulin resistance (IR) in HCV infection. A total of 45 subjects divided into 3 groups were included in the study: chronic HCV-infected patients (15 patients), chronic HCV-infected diabetic patients (15 patients), and diabetic patients without HCV infection (15 patients), along with 15 healthy controls. HCV RNA was quantified using real-time polymerase chain reaction (PCR). Serum IGF-1 levels were measured by enzyme-linked immunosorbent assay (ELISA). Homeostasis model assessment of insulin resistance [HOMA-IR], insulin sensitivity [HOMA-S], and β-cell function [HOMA-β] were determined by previously validated mathematic indexes. Fasting blood glucose, insulin levels, and liver parameters including alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were determined. IGF-1 levels were significantly lower in the 3 patient groups compared with controls (P = 0.001). The HCV group demonstrated high HOMA-IR and HOMA-β with a positive correlation between HOMA-IR and either HOMA-β or fasting insulin (P < 0.001). In addition, a negative correlation was found between IGF-1 levels and both AST and ALT, and HOMA-IR was correlated positively with AST activity (P < 0.05). In HCV patients with detectable viremia, IGF-1 levels were correlated negatively with HOMA-β (P < 0.01) and with HOMA-IR. However, this correlation did not reach statistical significance (P = 0.074). No significant correlation was found between HCV viral load and the studied parameters. In conclusion, low IGF-I levels might have a role in IR among HCV viremic patients.

Inflammatory mechanisms in obesity

The modern rise in obesity and its strong association with insulin resistance and type 2 diabetes have elicited interest in the underlying mechanisms of these pathologies. The discovery that obesity itself results in an inflammatory state in metabolic tissues ushered in a research field that examines the inflammatory mechanisms in obesity. Here, we summarize the unique features of this metabolic inflammatory state, termed metaflammation and defined as low-grade, chronic inflammation orchestrated by metabolic cells in response to excess nutrients and energy. We explore the effects of such inflammation in metabolic tissues including adipose, liver, muscle, pancreas, and brain and its contribution to insulin resistance and metabolic dysfunction. Another area in which many unknowns still exist is the origin or mechanism of initiation of inflammatory signaling in obesity. We discuss signals or triggers to the inflammatory response, including the possibility of endoplasmic reticulum stress as an important contributor to metaflammation. Finally, we examine anti-inflammatory therapies for their potential in the treatment of obesity-related insulin resistance and glucose intolerance.

Adipose tissue deficiency and chronic inflammation in diabetic Goto-Kakizaki rats

Type 2 diabetes (T2DM) is a heterogeneous group of diseases that is progressive and involves multiple tissues. Goto-Kakizaki (GK) rats are a polygenic model with elevated blood glucose, peripheral insulin resistance, a non-obese phenotype, and exhibit many degenerative changes observed in human T2DM. As part of a systems analysis of disease progression in this animal model, this study characterized the contribution of adipose tissue to pathophysiology of the disease. We sacrificed subgroups of GK rats and appropriate controls at 4, 8, 12, 16 and 20 weeks of age and carried out a gene array analysis of white adipose tissue. We expanded our physiological analysis of the animals that accompanied our initial gene array study on the livers from these animals. The expanded analysis included adipose tissue weights, HbA1c, additional hormonal profiles, lipid profiles, differential blood cell counts, and food consumption. HbA1c progressively increased in the GK animals. Altered corticosterone, leptin, and adiponectin profiles were also documented in GK animals. Gene array analysis identified 412 genes that were differentially expressed in adipose tissue of GKs relative to controls. The GK animals exhibited an age-specific failure to accumulate body fat despite their relatively higher calorie consumption which was well supported by the altered expression of genes involved in adipogenesis and lipogenesis in the white adipose tissue of these animals, including Fasn, Acly, Kklf9, and Stat3. Systemic inflammation was reflected by chronically elevated white blood cell counts. Furthermore, chronic inflammation in adipose tissue was evident from the differential expression of genes involved in inflammatory responses and activation of natural immunity, including two interferon regulated genes, Ifit and Iipg, as well as MHC class II genes. This study demonstrates an age specific failure to accumulate adipose tissue in the GK rat and the presence of chronic inflammation in adipose tissue from these animals.

New treatments for chronic hepatitis C

Treatments for chronic hepatitis C has evolved significantly in the past 15 years. The standard of care (SOC) is peginterferon alfa-2a/-2b with ribavirin for 48 weeks or 24 weeks in patients infected with HCV genotype 1 or 2/3, respectively. The treatment duration can be individualized based on the baseline viral load and the speed of the virologic response during treatment. However, current therapies are associated with side effects, complications, and poor patient tolerability. Therefore, there is an urgent need to identify better strategies for treating this disease. An improved sustained virologic response (SVR) can be achieved with new HCV-specific inhibitors against NS3/4A and NS5B polymerases. Recent trials have found SVR rates in patients with HCV genotype 1 infection of 61~68% and 67~75% for combining the SOC with the protease inhibitors telaprevir and boceprevir, respectively. Several new HCV-specific inhibitors such as protease inhibitors and nucleoside and non-nucleoside polymerase inhibitors as well as non-HCV-specific compounds with anti-HCV activity are currently in clinical evaluation. In this review we discuss these new treatments for chronic hepatitis C.

Double-stranded RNA-dependent protein kinase links pathogen sensing with stress and metabolic homeostasis

As chronic inflammation is a hallmark of obesity, pathways that integrate nutrient- and pathogen sensing pathways are of great interest in understanding the mechanisms of insulin resistance, type 2 diabetes, and other chronic metabolic pathologies. Here, we provide evidence that double-stranded RNA-dependent protein kinase (PKR) can respond to nutrient signals as well as endoplasmic reticulum (ER) stress and coordinate the activity of other critical inflammatory kinases such as the c-Jun N-terminal kinase (JNK) to regulate insulin action and metabolism. PKR also directly targets and modifies insulin receptor substrate and hence integrates nutrients and insulin action with a defined pathogen response system. Dietary and genetic obesity features marked activation of PKR in adipose and liver tissues and absence of PKR alleviates metabolic deterioration due to nutrient or energy excess in mice. These findings demonstrate PKR as a critical component of an inflammatory complex that responds to nutrients and organelle dysfunction.

Targeting host factors: a novel rationale for the management of hepatitis C virus

Hepatitis C is recognized as a major threat to global public health. The current treatment of patients with chronic hepatitis C is the addition of ribavirin to interferon-based therapy which has limited efficacy, poor tolerability, and significant expense. New treatment options that are more potent and less toxic are much needed. Moreover, more effective treatment is an urgent priority for those who relapse or do not respond to current regimens. A major obstacle in combating hepatitis C virus (HCV) infection is that the fidelity of the viral replication machinery is notoriously low, thus enabling the virus to quickly develop mutations that resist compounds targeting viral enzymes. Therefore, an approach targeting the host cofactors, which are indispensable for the propagation of viruses, may be an ideal target for the development of antiviral agents because they have a lower rate of mutation than that of the viral genome, as long as they have no side effects to patients. Drugs targeting, for example, receptors of viral entry, host metabolism or nuclear receptors, which are factors required to complete the HCV life cycle, may be more effective in combating the viral infection. Targeting host cofactors of the HCV life cycle is an attractive concept because it imposes a higher genetic barrier for resistance than direct antiviral compounds. However the principle drawback of this strategy is the greater potential for cellular toxicity.

Clearance of HCV by Combination Therapy of Pegylated Interferon alpha-2a and Ribavirin Improves Insulin Resistance

BACKGROUND/AIMS

Chronic hepatitis C virus (HCV) infection is associated with a higher risk of the development of insulin resistance. If HCV is a causal factor for insulin resistance, then clearance of HCV might decrease insulin resistance. The aim of this study was to elucidate the effects of clearance of HCV on insulin resistance.

METHODS

We analyzed 28 patients with HCV infection who received combination treatment of 180 microg of pegylated interferon alpha-2a and ribavirin at our institution from May 2004 to November 2006. Insulin resistance was calculated according to the homeostasis model assessment of insulin resistance (HOMA-IR) method.

RESULTS

Twenty-two patients (78.6%) achieved sustained virologic response (SVR), where the fasting plasma glucose level significantly decreased after antiviral treatment. Fasting serum insulin and HOMA-IR also significantly decreased after antiviral treatment, whereas the BMI value was not significantly affected. For the nonresponders (n=6), no significant changes were evident in BMI, fasting plasma glucose, fasting serum insulin, and HOMA-IR at 6 months after the end of antiviral treatment. Logistic regression analysis indicated that the only independent factor contributing to the reduction of insulin resistance was the complete disappearance of HCV RNA at 6 months after the end of antiviral treatment (SVR).

CONCLUSIONS

The clearance of HCV by the combination therapy of pegylated interferon alpha-2a and ribavirin improves insulin resistance by reducing fasting serum insulin and glucose levels.

Peroxisome proliferator-activated receptors and hepatitis C virus-induced insulin resistance

Insulin resistance and type 2 diabetes are associated with hepatitis C virus infection. A wealth of clinical and experimental data suggests that the virus is directly interfering with the insulin signalling in hepatocytes. In the case of at least one viral genotype (the type 3a), insulin resistance seems to be directly mediated by the downregulation of the peroxisome proliferator-activated receptor gamma. Whether and how this interaction may be manipulated pharmacologically, in order to improve the responsiveness to antivirals of insulin resistant chronic hepatitis C, patients remain to be fully explored.

Prevalence of hepatitis C infection and risk factors in hospitalized diabetic patients: results of a cross-sectional study

OBJECTIVES

Although there may exist a nosocomial risk of hepatitis C virus (HCV) infection in patients with type 1 or type 2 diabetes, this risk has not been fully investigated thus far and its magnitude is unknown. The aim of this multicenter cross-sectional study was to evaluate the prevalence of, and risk factors for, hepatitis C infection in consecutive hospitalized patients with diabetes and to assess the nosocomial risk and magnitude of HCV infection in these patients.

PATIENTS AND METHODS

Consecutive hospitalized patients with diabetes seen in 11 French hepatogastroenterology and diabetology departments were studied. The prevalence of anti-HCV antibodies was compared with that observed in healthy blood donors and individuals seen during routine medical checkup. Diabetic patients with anti-HCV antibodies were compared with patients without anti-HCV antibodies for assessment of risk factors.

RESULTS

In total 1561 patients were studied. Independent risk factors for HCV infection were assessed through multivariate analysis. Thirty-three patients (2.11%) had anti-HCV antibodies and 21 (63.70%) had HCV identified risk factors. The prevalence of HCV infection was higher in patients with diabetes than in blood donors (0.08%) or healthy controls (0.20%) (P<0.001). Multivariate analysis identified four independent risk factors for HCV infection: blood transfusion before 1991 [odds ratio (OR)=2.88, P=0.033], intravenous drug use (OR=21.37, P=0.012), treatment in a hepatogastroenterology center (OR=4.17, P=0.002) and a high number (>2) of previous admissions since the onset of diabetes (OR=2.52, P=0.039).

CONCLUSION

A nosocomial source of HCV infection in hospitalized diabetic patients is suggested by the increased risk of HCV infection associated with the number of hospitalizations. This may account for at least 36% of cases of HCV infection.

Uncovering glucose abnormalities in people with hepatitis C infection: should oral glucose tolerance test become a standard of care?

Hepatitis C and type 2 diabetes mellitus (DM) are two rising epidemics with significant impact on each other. Hepatitis C-infected patients have a higher incidence of type 2 diabetes, and diabetic patients have a high prevalence of hepatitis C. There is mounting evidence that glucose abnormalities have a negative impact on the disease progression as well as antiviral therapy outcomes. Utilization of oral glucose tolerance testing has the potential to uncover previously undetected DM as well as impaired glucose tolerance or prediabetes in patients with chronic hepatitis C (CHC). Early detection of diabetes and prediabetes with oral glucose tolerance testing in CHC patients can lead to interventions, with significant positive impact on disease progression and antiviral therapy outcomes.

Arterial calcification: a tumor necrosis factor-alpha mediated vascular Wnt-opathy

Arterial calcification is common in patients with type 2 diabetes mellitus (DM), chronic kidney disease (CKD), and other chronic inflammatory disorders. Arterial calcification is associated with significant morbidity and increased early mortality. The molecular signature of vascular calcification in diabetes is strikingly similar to that of CKD. Low-grade arterial inflammation is common to both conditions, and increased levels of tumor necrosis factor-alpha (TNF-alpha) have been reported in both DM and CKD. Recently, we described a novel TNF-alpha regulated Msx2-Wnt osteogenic program that regulates arterial calcification in an animal model of type 2 DM. TNF-alpha induces the osteogenic bone morphogenetic protein-2 (BMP-2), Msx2, Wnt3a, and Wnt7a mRNAs and leads to increased aortic calcium accumulation. Treatment with the TNF-alpha neutralizing antibody infliximab abrogates aortic BMP-2-Msx2-Wnt3a and Wnt7a signaling and attenuates aortic calcium accumulation significantly. Mice with vascular TNF-alpha augmented by the SM22-TNF-alpha transgene upregulate the aortic Msx2-Wnt3a/Wnt7a axis. Furthermore, SM22-TNF-alphaTg;TOPGAL mice exhibit greater beta-galactosidase reporter staining versus TOPGAL siblings in the aorta and coronaries, which indicates enhanced mural Wnt signaling in response to TNF-alpha. Thus, inflammatory TNF-alpha signals promote aortic osteogenic Msx2-Wnt programs in type 2 DM, and arterial calcification in this model is a TNF-alpha-driven Wnt-opathy. Having established the role of TNF-alpha in diabetic vascular calcification, an unmet need exists to evaluate the role of TNF-alpha and Msx2-Wnt signals in CKD-related calcification models. If validated in these models, then these findings will have significant therapeutic applications.

Review article: nonalcoholic fatty liver disease and hepatitis C virus--partners in crime

BACKGROUND

Both nonalcoholic fatty liver disease (NAFLD) and chronic hepatitis C (CHC) are frequent causes of chronic liver disease. In recent years, there have been significant revelations as regards the relationship between NAFLD and CHC.

AIM

To conduct a systematic, evidence-based review of the epidemiology, pathophysiology and potential treatments of coexistent NAFLD and CHC.

METHODS

The terms such as hepatitis C, fatty liver, NAFLD, nonalcoholic steatohepatitis and steatosis were searched on PubMed up to January 2008. References from selected articles and pertinent abstracts were also included.

RESULTS

Hepatic steatosis affects up to 80% of patients with CHC and is dependent on both viral and host factors. While insulin resistance (IR) is associated with hepatic steatosis and hepatitis C virus, genotype-specific pathogenic mechanisms have been identified and are currently the focus of intense investigation in the literature. Clinical implications of concurrent NAFLD, CHC and IR include increased disease progression, elevated risk of hepatocellular carcinoma, and decreased response to antiviral therapy.

CONCLUSIONS

NAFLD and IR are common in patients with CHC virus infection. IR is a driving force in the development of hepatic steatosis. Because of the clinical implications of hepatic steatosis and IR in the setting of CHC, further studies evaluating treatments, which may increase response to antiviral therapy, are needed.

Prevalence of hepatitis C in Swedish diabetics is low and comparable to that in health care workers

OBJECTIVES

An association between hepatitis C virus (HCV) infection and diabetes has been reported, in particular from countries with a high prevalence of HCV. To assess if this association could be found in a region with low prevalence of HCV (0.33%), we determined the prevalence of anti-HCV in a large cohort of patients with diabetes.

METHODS

The prevalence of anti-HCV was determined with an enzyme-linked immunosorbent assay in 874 patients with diabetes representing 72.5% of a total research cohort of 1205 patients who were invited to participate. The results were confirmed with immunoblot. Samples from confirmed patients were tested for HCV RNA and genotyped.

RESULTS

In 499 patients with type 1 diabetes and 375 patients with type 2 diabetes six patients were anti-HCV positive (four with type 1 diabetes and two with type 2 diabetes corresponding to a prevalence of 0.80 and 0.53%, respectively, in accordance with the prevalence among health care workers in Sweden; 0.68%). Liver biopsies in three of the patients showed only mild inflammation without fibrosis and in two of the other three the albumin and/or PT-INR level was normal contradicting any substantial impairment of the liver function.

CONCLUSIONS

The low anti-HCV prevalence that we found contradicts an etiologic role of HCV in the development of diabetes in Sweden. The risk of being infected with HCV when attending the health care system seems to be rather small in a low-prevalence area.

Reduced incidence of new-onset posttransplantation diabetes mellitus during the last decade

BACKGROUND

A previous study (1995-1996) of 173 nondiabetic renal transplant recipients (historical cohort; HC) revealed a 20% incidence of new-onset posttransplantation diabetes mellitus (PTDM) and 32% with impaired glucose tolerance (IGT) or impaired fasting glucose (IFG). We examined whether glucose tolerance has improved after recent changes in our immunosuppressive protocol and a switch from deferred to preemptive cytomegalovirus (CMV) therapy.

METHODS

A total of 321 consecutive, nondiabetic patients (new cohort; NC) were examined 10 weeks after kidney transplantation with an oral glucose tolerance test (n=301) between January 2004 and December 2005.

RESULTS

Although recipients in the NC were on average 3 years older [mean (SD): 50.3 (14.6) vs. 47.4 (16.0), P=0.038] and had a higher mean body mass index [24.5 (3.6) vs. 23.5 (3.8) kg/m(2), P=0.003], a significantly lower incidence of both PTDM (13%) and IGT/IFG (18%) was observed in the NC (P<0.001) as compared to the HC. The patients in the NC received a significantly lower mean daily oral prednisolone dose [13.2 (4.7) vs. 15.3 (6.6) mg/day, P<0.001], and had lower frequencies of rejections (36% vs. 57%, P<0.001) and CMV infection (54% vs. 63%, P=0.071). Patients in the NC had significantly lower odds of developing PTDM, even after adjustment for age, prednisolone dose, HLA-B27 status and CMV infection (odds ratio: 0.42, 95% CI: 0.23-0.77, P=0.005).

CONCLUSIONS

The odds of developing PTDM are more than halved over the last decade. Possible explanations are changes in immunosuppressive therapy, fewer rejections, and lower doses of steroids.

Inflammatory biomarkers associated with obesity and insulin resistance: a focus on lipocalin-2 and adipocyte fatty acid-binding protein

Obesity is an important risk factor for a cluster of metabolic and cardiovascular diseases, including insulin resistance, Type 2 diabetes, nonalcoholic fatty liver disease and atherosclerosis. Systemic low-grade inflammation, characterized by elevated circulating concentrations of proinflammatory factors, has recently been proposed to be a key mediator that links obesity with its medical complications. Adipose tissue is now recognized as the major contributor to systemic inflammation associated with obesity. As obesity develops, adipose tissue is infiltrated with activated macrophages. The 'inflamed' adipose tissue secretes a large number of proinflammatory adipokines and/or cytokines, which can act either in an autocrine manner to perpetuate local inflammation or in an endocrine manner to induce insulin resistance and endothelial dysfunction. In this review, we summarize recent advances in several newly identified adipose tissue-derived inflammatory factors, with the focus on lipocalin-2 and adipocyte fatty acid-binding protein (A-FABP). Both lipocalin-2 and A-FABP possess lipid-binding properties and are important integrators of metabolic and inflammatory pathways. A growing body of evidence from experimental, epidemiological and genetic studies suggests that both lipocalin-2 and A-FABP represent a novel class of serum biomarkers for risk prediction and therapeutic intervention of obesity-related medical complications.

Increased prevalence of infectious endocarditis in patients with type II diabetes mellitus

BACKGROUND

Patients with diabetes mellitus (DM) are at increased risk of infection. However, there are controversial reports about DM association with infectious endocarditis (IE). We evaluated the occurrence of IE in DM patients compared to a matched control.

METHOD

Treatment files of inpatients' admission that contained discharge diagnosis (ICD-9 codes) from Veterans Health Administration hospitals were used for this study. ICD-9 codes for DM (n=293,124) and a control group with ICD-9 codes for hypertension without DM (n=552,623) were utilized for comparison. The prevalence of IE was studied using ICD-9 codes for IE. Multivariate analysis was performed adjusting for chronic and acute renal failure and aortic and mitral valve disease. Continuous variables were analyzed by unpaired t tests. Binary variables were analyzed using the chi-square test and Fisher's Exact Tests.

RESULTS

IE was present in 1340 (0.5%) DM patients versus 1412 (0.3%) patients from the control group (relative increase of 40%). Using multivariate analysis adjusting for renal failure and valvular abnormalities, DM remained independently associated with IE (odds ratio=1.9; 95% confidence interval=1.8-2.1; P<.0001).

CONCLUSION

Patients with type II DM have significantly higher prevalence of IE independent of renal failure or valvular abnormalities consistent with increased vulnerability of DM patients for infections.

Association between chronic hepatitis B virus infection and diabetes among Asian Americans and Pacific Islanders

BACKGROUND

Asians have a higher prevalence of both diabetes (diabetes mellitus) and chronic hepatitis B virus infection compared to Caucasians. The aim of this study was to investigate whether hepatitis B virus infection was associated with diabetes mellitus among Asian Americans and Pacific Islanders.

METHODS

We reviewed the electronic medical records of 411 Asian and 424 Pacific Islanders seen at our medical centre over a 5-year period. Diabetes mellitus was defined by the presence of two or more random blood glucose levels > or =200mg/dL, an ICD-9 diagnostic code of diabetes mellitus, or use of medications for diabetes mellitus. Hepatitis B virus infection was defined by a positive HBsAg test.

RESULTS

Diabetes mellitus was diagnosed in 223 of the 835 subjects (26.7%), whereas hepatitis B virus infection was diagnosed in 56 (13.8%) of the 407 subjects tested for HBsAg. Overall, the prevalence of diabetes mellitus was significantly higher in patients with hepatitis B virus than in those without hepatitis B virus (58.9% vs. 33.3%, P<0.001), and this remained significant after adjustment for potential confounding variables (OR=3.17; 95% CI, 1.58-6.35). When Asians and Pacific Islanders were analysed separately, the prevalence of diabetes mellitus in patients with hepatitis B virus was significantly higher than in those without hepatitis B virus among Asians (65.0% vs. 27.5%, P<0.001) but not in Pacific Islanders (43.8% vs. 37.1%, P=0.60). Among the 390 subjects who were tested for both hepatitis B virus and hepatitis C virus, the prevalence of diabetes mellitus was 29.4% in uninfected subjects, 44.4% in patients with hepatitis B virus monoinfection, 47.2% in patients with hepatitis C virus monoinfection and 85.0% in patients with hepatitis B virus and hepatitis C virus coinfection (P<0.001).

CONCLUSIONS

Hepatitis B virus infection is strongly associated with diabetes mellitus among Asian Americans, but not in Pacific Islanders, whereas hepatitis C virus infection was associated with diabetes mellitus in both ethnic groups.

Clearance of HCV improves insulin resistance, beta-cell function, and hepatic expression of insulin receptor substrate 1 and 2

OBJECTIVES

Hepatitis C virus (HCV) infection is linked to greater insulin resistance. Although HCV itself is a candidate for the development of insulin resistance, the effects of antiviral treatment on impaired glucose metabolism remain unclear. The aim of this study is to examine the effects of clearance of HCV on insulin resistance, beta-cell function, and hepatic expression of insulin receptor substrate (IRS)1/2, central molecules for insulin signaling.

METHODS

We analyzed 89 biopsy-proven patients with chronic HCV infection. Patients received interferon-alpha or interferon-alpha plus ribavirin for 6 months and were classified into three groups at 6 months after the conclusion of antiviral therapy according to their response to antiviral therapy: sustained responders (N = 29), relapsers (N = 12), and nonresponders (N = 48). Insulin resistance and beta-cell function were assessed by the homeostasis model assessment method (HOMA-IR and HOMA-%B, respectively). Hepatic expression of IRS1/2 was evaluated by immunoblotting and immunostaining in 14 sustained responders.

RESULTS

In nonresponders and relapsers, there were no significant changes in HOMA-IR and HOMA-%B values after antiviral therapy. On the other hand, in sustained responders, HOMA-IR values significantly decreased to 1.7 +/- 0.8 from 3.1 +/- 1.1 (P < 0.05) after antiviral therapy. Similarly, HOMA-%B values significantly decreased to 90.6 +/- 10.0 from 113.7 +/- 15.3 (P < 0.05). Immunoblotting showed a threefold increase in IRS1/2 expression after clearance of HCV. Immunostaining revealed that greater IRS1/2 expression was seen in hepatocytes.

CONCLUSIONS

We showed that clearance of HCV improves insulin resistance, beta-cell function, and hepatic IRS1/2 expression.

Association between liver fibrosis and insulin sensitivity in chronic hepatitis C patients

BACKGROUND

Several clinical studies have suggested a possible link between chronic hepatitis caused by hepatitis C virus (HCV) and the development of diabetes mellitus. We investigated the association between liver fibrosis and glucose intolerance in HCV-infected patients by measuring insulin sensitivity and beta-cell function.

METHOD

A total of 83 chronic HCV-infected patients were recruited into this study. We evaluated insulin sensitivity and beta-cell function of all patients in a fasting state (homeostasis model assessment of insulin resistance [HOMA-R] and homeostasis model assessment of beta-cell function [HOMA-beta]) and after an oral load of 75 g glucose (whole-body insulin sensitivity index [WBISI] and Delta-insulin/Delta-glucose 30).

RESULTS

In a multivariate analysis, severe fibrosis was the only independent factor associated with insulin resistance. There were significant differences in both HOMA-R (P= 0.0063) and WBISI (P= 0.0159) between patients with mild fibrosis (N = 34) and those with severe fibrosis (N = 49). Although HOMA-beta was increased significantly in the subjects with severe fibrosis compared with those with mild fibrosis (P= 0.0169), Delta-insulin/Delta-glucose 30 showed no significant difference in stage of liver fibrosis, suggesting an uncertain association between liver fibrosis and beta-cell function.

CONCLUSION

Our findings suggest that the development of liver fibrosis is associated with insulin resistance in HCV-infected patients.

The evolving role of leptin and adiponectin in chronic liver diseases

Leptin and adiponectin, the main metabolic products of adipose tissue, have been implicated in a wide spectrum of human diseases. Given the frequent presence of hepatic steatosis in several chronic liver diseases, there is currently increasing interest in the role of these adipokines in the development of hepatic steatosis and also in necroinflammation and fibrosis, mostly in patients with nonalcoholic fatty liver disease or chronic hepatitis C. According to experimental data, reduced adiponectin levels and increased leptin levels associated with leptin resistance, which are usually observed in obese patients with or without metabolic syndrome, may result in fat accumulation in the liver and in the enhancement of liver inflammation and mostly fibrogenesis. Increased leptin and decreased adiponectin serum levels have been detected initially in patients with nonalcoholic steatohepatitis and more recently in patients with chronic hepatitis C compared to healthy controls in most but not all studies, while the data on the associations between these adipokine levels and the severity of hepatic steatosis or fibrosis are still rather conflicting. However, several potential confounding parameters were not evaluated in all studies. Therefore, the associations between adipokines and liver histological lesions and their effects on liver cells should be evaluated further in prospective, carefully designed studies, including larger cohorts of patients with detailed assessment of metabolic and other potential confounding factors.

Insulin resistance, chronic inflammatory state and the link with systemic lupus erythematosus-related coronary disease

The association of SLE with atherosclerosis suggests a common pathogenic mechanism. SLE and atherosclerosis are immune complex-mediated diseases. The integration of metabolism and immunity, which under normal conditions is beneficial for the maintenance of good health, can become deteriorative under conditions of metabolic challenge, as exemplified by the immunosuppression characteristic of malnourished or starving individuals. It is now apparent that obesity is associated with a state of chronic inflammation, particularly in white adipose tissue. However, in the absence of obesity, infusion of animals with inflammatory cytokines or lipids can cause insulin resistance. It is possible that the stresses of obesity are similar enough to the stresses of an infection and the body reacts to obesity as it would to an infection. Atherosclerosis can be considered to have a significant chronic inflammatory component. Inflammation also contributes to the typical dyslipidemia associated with SLE that is characterized by elevations of VLDL, LDL and triglycerides as well as reduced HDL. The link between insulin resistance and SLE can be explained by the chronic inflammatory state, and the consequent dyslipoproteinemia.

Distinctive characteristics of diabetes mellitus after hematopoietic cell transplantation during childhood

We report on six patients who developed diabetes mellitus after hematopoietic cell transplantation (HCT). The prevalence in our cohort of long-term survivors after HCT performed below 18 yr of age was 3%. The median age at onset of diabetes was 22.4 yr (range 11.3-34.4). The median period between HCT and diabetes was 10.1 yr (range 5.6-22.1). Five out of the six patients received total irradiation therapy and five had other endocrinological abnormalities. The onset of diabetes in all patients was insidious and none had diabetic ketoacidosis. Body mass indexes at diabetes onset were within normal levels. The clinical and laboratory features that characterized our patients with diabetes after HCT make it difficult to classify them as having type-1 or type-2 diabetes. The relatively high prevalence of diabetes and its insidious onset in this group of patients, advocate clinicians to evaluate carefully even slight variations in fasting blood glucose, usually included in the routine biochemistry follow-up. These data also suggest that HbA1c and oral glucose-tolerance test should be added to the follow-up program of late complications if fasting blood glucose levels are slightly increased.

Hepatitis C como factor de riesgo de diabetes mellitus tipo 2

INTRODUCTION

Hepatitis C virus (HCV) has been implicated as a risk factor for the development of diabetes mellitus, type 2 (DM2). Our aim is to check if HCV infection in our patients is a risk for the development of DM2. In that case, we study if the possible pathogenic mechanism could be related with an increase in iron deposits.

PATIENTS AND METHOD

A consecutive series of 305 patients that attended to our service for measurement of anti-HCV antibodies was collected. HCV-antibodies were identified by second generation ELISA and confirmed by immunoblot. We detected viral RNA in 56% of these patients by polymerase chain reaction. The control group was made up of 137 patients. In every case, we analyzed the plasma levels of glucose, ferritin and other biochemical parameters.

RESULTS

We found 13% of diabetics in the patient with viral RNA, 9.3% in the infected patients without RNA and 3.9% in the controls. The average of the ferritin level for the infected patients was 256 mg/l and for the controls was 151 mg/l (p = 0.01). The diabetic patients had ferritin levels of 346 mg/l and non-diabetic patients had 218 mg/l (p = 0.038). The presence of HCV-antibodies showed a 2.78 odds ratio for diabetes risk.

DISCUSSION

Our results showed a relationship between HCV infection and diabetes mellitus type 2, so that the percentage of diabetics increased parallelly with the degree of viral activity and the variable "presence of HCV-antibodies" was the one that most contributed to the risk. Although our results would support the role of the iron metabolism in the development of diabetes, follow-up studies of a cohort of patients infected by HCV would be necessary to contrast this statement.

Hepatitis C infection and diabetes

Since the discovery of the hepatitis C virus (HCV) in 1989, attention has been paid to the association of chronic HCV infection and the development of diabetes. The risk factors for diabetes include older age, HCV genotype 3, severe liver fibrosis, family history of diabetes, and liver/kidney transplantation. Emerging evidence in animals and humans has shown that HCV infection induces hepatic steatosis and increases tumor necrosis factor-alpha level, both resulting in the development of insulin resistance and subsequent type 2 diabetes. It is suggested that the presence of diabetes and hepatic steatosis may enhance fibrosis progression, hepatocellular carcinoma, and atherosclerosis. Interferon is reportedly associated with improved glucose tolerance. However, interferon might enhance underlying autoimmunity against beta cells, leading to overt type 1 diabetes that is genetically predisposed or give rise to hyperglycemia, resulting in the development of type 2 diabetes. In light of the national epidemic of type 2 diabetes, the link between HCV and diabetes would be a major public health problem. Further clinical researches are awaited in order to effectively detect, prevent, and treat HCV-associated type 2 diabetes, which would also slow the progression of hepatitis C itself.

Hepatitis C and steatosis: a reappraisal

The overall prevalence of steatosis in patients with Hepatitis C virus (HCV) chronic infection is 55.5% (range 34.8-81.2%). This is a two to threefold increase compared with the prevalence of steatosis in chronic hepatitides because of other aetiologies and of the figures expected on the grounds of a steatosis-HCV chance association. HCV genotype 3 (HCV-3) has specific epidemiological features; furthermore, as compared with HCV-non-3 genotypes, it is associated with a higher prevalence (74.1%vs 47.9%, P < 0.01) and with more severe grades of steatosis (prevalence of grade 3 steatosis 29.6 vs 5.5 P < 0.01). Host and viral factors play a role, although to a variable extent, in the pathogenesis of HCV-3 and non-3 steatosis. HCV load and body mass index are associated with steatosis in HCV-3 and in HCV-non-3 patients respectively. Serum cholesterol levels and liver steatosis at baseline follow an inverse relationship in HCV infection. As hypocholesterolaemia corrects only in those sustained responders to antiviral treatment both in genotype 3 and in non-3 genotypes, the occurrence of a virally induced, acquired and reversible hypobetalipoproteinaemia seems plausible. Steatosis affects the natural course of HCV infection: it is associated with fibrosis, a possible mediator of increased risk to develop type 2 diabetes, it impairs the response to antiviral treatment in HCV-3 patients and might constitute a risk factor for the development of hepatocellular carcinoma. These observations indicate the need to evaluate the efficacy of combined antiviral and 'metabolic' approaches vs standard antiviral regimes in patients with steatosis and HCV chronic infection.

Post-Transplant Diabetes Mellitus

New-onset diabetes mellitus in a previously non-diabetic transplant recipient is a serious adverse event that confers significant morbidity and mortality. The most significant consequences of post-transplant diabetes mellitus (PTDM) in solid organ transplant recipients include decreased patient and graft survival, an increased risk of infectious complications, and morbid cardiovascular events. The development of PTDM in the elderly is of particular concern because this group is already at increased risk of progression of cardiovascular disease. Because the elderly, especially those aged >65 years, are the fastest-growing segment of the renal transplant population, attention needs to be given to PTDM risk reduction and post-transplant management. PTDM develops as a consequence of both impaired insulin production and enhanced peripheral insulin resistance. A number of non-modifiable factors such as age, race, family history, hepatitis C, polycystic kidney disease and emerging genetic causes have been identified as risk factors for PTDM. However, a number of modifiable factors can be targets for intervention in high-risk patients, including bodyweight (through dietary restriction and exercise), hypertension, hyperlipidaemia and the effects of certain immunosuppressive agents. The two agents most responsible for PTDM are tacrolimus and corticosteroids, especially when used in combination. Attempts to modify doses and regimens designed to eliminate or avoid these drugs should be considered. Use of HMG-CoA reductase inhibitors ('statins') and ACE inhibitors is particularly helpful in controlling hypertension and hyperlipidaemia in the elderly because these agents confer protection against future adverse cardiovascular events. Bisphosphonates are also advantageous in controlling the progression of osteoporosis and possible increased risk of bone fractures. Future trials in the elderly should focus on such endpoints as PTDM, post-transplant neoplasia, cardiovascular events and bone fracture events in order to identify the safest regimens that provide the optimal control of rejection while limiting the morbidity from these secondary events.

Role of endoplasmic reticulum stress and c-Jun NH2-terminal kinase pathways in inflammation and origin of obesity and diabetes

Metabolic and immune systems are the most fundamental requirements for survival, and many metabolic and immune response pathways or nutrient- and pathogen-sensing systems have been evolutionarily highly conserved. Consequently, metabolic and immune pathways are also highly integrated and interdependent. In the past decade, it became apparent that this interface plays a critical role in the pathogenesis of chronic metabolic diseases, particularly obesity and type 2 diabetes. Importantly, the inflammatory component in obesity and diabetes is now firmly established with the discovery of causal links between inflammatory mediators, such as tumor necrosis factor (TNF)-alpha and insulin receptor signaling and the elucidation of the underlying molecular mechanisms, such as c-Jun NH2-terminal kinase (JNK)- and inhibitor of nuclear factor-kappaB kinase-mediated transcriptional and posttranslational modifications that inhibit insulin action. More recently, obesity-induced endoplasmic reticulum stress has been demonstrated to underlie the initiation of obesity-induced JNK activation, inflammatory responses, and generation of peripheral insulin resistance. This article will review the link between stress, inflammation, and metabolic disease, particularly type 2 diabetes, and discuss the mechanistic and therapeutic opportunities that emerge from this platform by focusing on JNK and endoplasmic reticulum stress responses.

Inflammation, stress, and diabetes

Over the last decade, an abundance of evidence has emerged demonstrating a close link between metabolism and immunity. It is now clear that obesity is associated with a state of chronic low-level inflammation. In this article, we discuss the molecular and cellular underpinnings of obesity-induced inflammation and the signaling pathways at the intersection of metabolism and inflammation that contribute to diabetes. We also consider mechanisms through which the inflammatory response may be initiated and discuss the reasons for the inflammatory response in obesity. We put forth for consideration some hypotheses regarding important unanswered questions in the field and suggest a model for the integration of inflammatory and metabolic pathways in metabolic disease.

Inflammation, stress, and diabetes

Over the last decade, an abundance of evidence has emerged demonstrating a close link between metabolism and immunity. It is now clear that obesity is associated with a state of chronic low-level inflammation. In this article, we discuss the molecular and cellular underpinnings of obesity-induced inflammation and the signaling pathways at the intersection of metabolism and inflammation that contribute to diabetes. We also consider mechanisms through which the inflammatory response may be initiated and discuss the reasons for the inflammatory response in obesity. We put forth for consideration some hypotheses regarding important unanswered questions in the field and suggest a model for the integration of inflammatory and metabolic pathways in metabolic disease.

Inflammation, stress, and diabetes

Over the last decade, an abundance of evidence has emerged demonstrating a close link between metabolism and immunity. It is now clear that obesity is associated with a state of chronic low-level inflammation. In this article, we discuss the molecular and cellular underpinnings of obesity-induced inflammation and the signaling pathways at the intersection of metabolism and inflammation that contribute to diabetes. We also consider mechanisms through which the inflammatory response may be initiated and discuss the reasons for the inflammatory response in obesity. We put forth for consideration some hypotheses regarding important unanswered questions in the field and suggest a model for the integration of inflammatory and metabolic pathways in metabolic disease.

Idiosyncratic liver injury: challenges and approaches

Clinical presentations of drug-induced liver injury (DILI) cover essentially the entire spectrum of known liver diseases. However, in the last 8 years the form of liver injury that has most frequently resulted in labeling restrictions is idiosyncratic hepatocellular injury leading to acute liver failure. This rare form of DILI has a characteristic clinical presentation that includes an acute onset after uneventful treatment with drug for weeks to months. Serum alanine aminotransferase rises to very high levels and the appearance of jaundice indicates a high mortality even if the therapy is discontinued. Drugs that can cause this type of injury almost always are associated with frequent (2-15% of all treated patients) and minor serum aminotransferase elevations. These elevations are believed to reflect true liver injury, but often reverse even if drug therapy is continued. The bases for this "adaptation" is not known, as is why some patients do not adapt and develop progressive liver injury. Understanding how drugs cause severe idiosyncratic hepatocellular toxicity has been frustrated by the lack of good preclinical models. Indeed, because these events occur so rarely, the vast majority of humans are not good models. Studies of genomic DNA from affected individuals should provide important insight but not the complete answer because environmental factors almost certainly contribute to individual susceptibility. The most fruitful approach may therefore lie in focused and well-controlled phenotype/genotype studies of the rare patients who have survived this type of injury. The National Institute of Diabetes and Digestive and Kidney Diseases of The National Institutes of Health has recently sponsored a cooperative agreement (UO1) to create a Drug Induced Liver Injury Network (DILIN). DILIN consists of University of Michigan, Indiana University, University of Connecticut, University of California, San Francisco, University of North Carolina, and Duke University. This network should provide heretofore missing resources required to address the problem.

Hepatitis C infection increases the risk of new-onset diabetes after transplantation in liver allograft recipients

BACKGROUND

Recent evidence suggests that new-onset diabetes after transplant (NODAT) adversely affects orthotopic liver transplant (OLTX) patient and graft survival. The objective of this study is to evaluate the effect of hepatitis C infection on the natural history of NODAT.

METHODS

A retrospective review of 492 OLTX recipients at a single center was conducted from January 1993 to January 2003. Patients were followed for a minimum of 12 months (range 12 months-10 years). The study population consisted of 444 OLTX recipients who were either HCV positive (n = 206) or HCV negative (n = 238). NODAT was defined by the need for antidiabetic medication for at least 7 days starting anytime after OLTX. Statistical analysis was performed by using the Student t test, Kaplan-Meier survival, and chi-square tests.

RESULTS

The overall incidence of NODAT was 33% (146/444). There was a significant difference in the development of NODAT between the HCV-positive group (82/206, 40%) and the HCV-negative group (64/238, 27%) (P < .001). Other independent risk factors for development of NODAT were male gender and age >50 years.

CONCLUSION

Hepatitis C infection contributes to the development of diabetes mellitus in OLTX recipients. The mechanisms behind HCV infection and associated NODAT in HCV-positive OLTX recipients warrant further investigation.