Circulating adiponectin reflects severity of liver disease but not insulin sensitivity in liver cirrhosis

Plasma Adiponectin Levels in Relation to Chronic Hepatitis B Infection Progression to Liver Cancer Milestones: A Prospective Study

Introduction

Our previous nested-case-control study demonstrated elevated adiponectin increased liver cirrhosis and HCC risk in HBV carriers. We extended the analysis to the whole REVEAL-HBV cohort to prospectively evaluate whether adiponectin directly affected end-stage liver diseases, or through affecting HBV progression.

Methods

Baseline plasma adiponectin was determined to investigate the association between adiponectin and subsequent HBeAg, HBsAg, and HBV DNA seroclearance, and the development of cirrhosis, HCC and liver-related death. Whether HBV characteristics modify the adiponectin-milestones associations was also examined.

Results

Among 3,931 HBsAg(+)/anti-HCV(-) REVEAL-HBV participants, 3,684 had sufficient biosamples left for adiponectin assay. Elevated adiponectin was associated with a higher chance of HBeAg-seropositive, high HBV viral load (≥2 × 105 IU/mL) and high HBsAg titers (≥1,000 IU/mL) in a dose-response manner (OR = 2.25, 95% CI: 1.55-3.28; OR = 2.11, 95% CI: 1.47-3.04; and OR = 1.92, 95% CI: 1.47-2.52 for Q5 vs. Q1, respectively). Those with the highest quintile had a lower chance of achieving HBeAg (HR = 0.48, 95% CI: 0.27-0.85), HBsAg (HR = 0.69, 95% CI: 0.49-0.97), and HBV DNA seroclearance (HR = 0.63, 95% CI: 0.43-0.90) and a higher chance of developing liver cirrhosis (HR = 2.88, 95% CI: 1.98-4.20, HCC (HR = 2.38, 95% CI: 1.52-3.73), and died from liver-related causes (HR = 2.32, 95% CI: 1.51-3.54). HBV genotype significantly modified the adiponectin-HCC (Pinteraction = 0.005) and adiponectin-liver death associations (Pinteraction = 0.0157), with higher risk among genotype C.

Conclusion

Elevated adiponectin is consistently associated with all important chronic HBV infection milestones toward progression to liver cancer. The exact mechanism of how adiponectin mediates HBV infection toward carcinogenesis remains unclear and warrants further investigation. Disentangling this may help us in finding new HBV treatment target, biomarker in HBV surveillance to identify high-risk patients, or even cancer prevention.

Adiponectin as a biomarker in liver cirrhosis-A systematic review and meta-analysis

INTRODUCTION

Adiponectin, a key adipokine, shows promise as a non-invasive biomarker for liver cirrhosis by reflecting inflammation and metabolic changes, but conflicting findings highlight the need for a systematic review and meta-analysis to clarify its role. Our study aimed to evaluate adiponectin levels across various stages of liver cirrhosis, compare them with other chronic liver diseases (CLD) and hepatocellular carcinoma (HCC), and assess its potential as a diagnostic and prognostic biomarker.

METHODS

Our systematic search was conducted on September 2023 using PubMed, EMBASE and Scopus, searching for observational studies evaluating serum and plasma adiponectin levels in liver cirrhosis. Inclusion and exclusion criteria were applied, and study quality was assessed using the Newcastle-Ottawa Scale. To evaluate the overall effect size, we utilized a random-effects model along with a mean difference (MD) analysis. The principal summary outcome was the MD in adiponectin levels.

RESULTS

We included 16 articles involving 2617 subjects in our qualitative and quantitative synthesis. We found significantly higher adiponectin levels in liver cirrhosis patients (8.181 [95% CI 3.676, 12.686]), especially in Child-Pugh B individuals (13.294 [95% CI 4.955, 21.634]), compared to controls. Child-Pugh A patients did not show significant differences compared to controls. In addition, adiponectin levels were significantly elevated in primary biliary cholangitis (PBC) patients compared to controls (8.669 [95% CI .291, 17.047]), as well as in liver cirrhosis compared to other CLD patients (4.805 [95% CI 1.247, 8.363]), including non-alcoholic fatty liver disease (NAFLD) (8.532 [95% CI 3.422, 13.641]), but not viral hepatitis. No significant MD was observed between liver cirrhosis and HCC patients.

CONCLUSION

Adiponectin levels are significantly elevated in liver cirrhosis, especially in advanced stages, potentially serving as a biomarker for advanced cirrhosis. Adiponectin also differentiates cirrhosis from other CLD, including NAFLD. However, its role in distinguishing cirrhosis from viral hepatitis and HCC is limited.

Serum Adiponectin Is Elevated in Critically Ill Patients with Liver Disease and Associated with Decreased Overall Survival

BACKGROUND

Adiponectin, an adipokine with anti-inflammatory properties, has been implicated in various liver diseases. This study aimed to elucidate the prognostic value of serum adiponectin levels in critically ill patients with liver disease.

METHODS

This observational study included 161 critically ill patients admitted to the medical ICU of RWTH Aachen University Hospital due to acute liver failure or decompensated advanced chronic liver disease. Serum adiponectin levels were measured at ICU admission and after 48 h. Clinical parameters and outcomes, including transplant-free survival, were analyzed.

RESULTS

Serum adiponectin concentrations were significantly elevated compared to healthy controls (p < 0.001). Levels were particularly high in patients with sepsis compared to those with gastrointestinal bleeding as the precipitating factor of acute decompensation (p = 0.045) and were higher in female patients (p = 0.023). Adiponectin concentrations correlated with the Model of End-Stage Liver Disease (MELD) score and Child-Pugh score. Multivariate analysis confirmed a significant correlation with total bilirubin (r = 0.292, p < 0.001) and serum sodium (r = -0.265, p = 0.028). Higher adiponectin concentrations were associated with a trend towards poorer 30- and 180-day survival. Cox regression analysis identified a significant association between increased adiponectin concentration and reduced transplant-free survival (p = 0.037), supported by a Kaplan-Meier analysis using a cutoff of 119 ng/mL (log-rank 5.145, p = 0.023).

CONCLUSIONS

Elevated serum adiponectin concentrations are associated with liver dysfunction and poor outcomes in critically ill patients. Higher adiponectin levels at ICU admission may predict poorer transplant-free survival. Further research in larger, multicenter cohorts is warranted to validate these findings and explore the underlying mechanisms.

Innate Immunity and MASLD

Metabolic dysfunction-associated steatotic liver disease (MASLD) has emerged as the most common liver disease worldwide in recent years. MASLD commonly presents as simple hepatic steatosis, but ~25% of patients develop liver inflammation, progressive fibrosis, liver cirrhosis and related hepatocellular carcinoma. Liver inflammation and the degree of fibrosis are key determinants of the prognosis. The pathophysiology of liver inflammation is incompletely understood and involves diverse factors and specifically innate and adaptive immune responses. More specifically, diverse mediators of innate immunity such as proinflammatory cytokines, adipokines, inflammasomes and various cell types like mononuclear cells, macrophages and natural killer cells are involved in directing the inflammatory process in MASLD. The activation of innate immunity is driven by various factors including excess lipids and lipotoxicity, insulin resistance and molecular patterns derived from gut commensals. Targeting pathways of innate immunity might therefore appear as an attractive therapeutic strategy in the future management of MASLD and possibly its complications.

Maternal Adverse Outcomes in Hypertensive Disorders of Pregnancy and Their Association with Serum Adiponectin and Redox Markers

Background: Premature termination of pregnancy because of unmanageable maternal complications in hypertensive disorders of pregnancy (HDP) results in adverse neonatal outcome. Identification of biochemical derangements associated with maternal complications may help in the better medical management of the mother resulting in better neonatal outcomes. Method: Healthy pregnant women (C); pregnant women with gestational hypertension (GH), and preeclampsia (late [LP] and early [EP] onset) were studied. Maternal serum redox markers and adipokines were evaluated for their association with maternal complications. Results: Adiponectin levels were significantly raised in preeclampsia groups when compared with control and GH groups. Univariate and multivariate analysis confirmed that malondialdehyde (MDA) and total antioxidant status (TAS) were associated with eclampsia; adiponectin and TAS with HELLP syndrome; adiponectin, MDA and TAS with severe preeclampsia; and adiponectin with impaired renal function. Conclusion: We identified that increased serum adiponectin, MDA, and TAS were associated with adverse maternal outcomes.

Insights Into the Controversial Aspects of Adiponectin in Cardiometabolic Disorders

In 2016, the World Health Organization estimated that more than 1.9 billion adults were overweight or obese. This impressive number shows that weight excess is pandemic. Overweight and obesity are closely associated with a high risk of comorbidities, such as insulin resistance and its most important outcomes, including metabolic syndrome, type 2 diabetes mellitus, and cardiovascular disease. Adiponectin has emerged as a salutary adipocytokine, with insulin-sensitizing, anti-inflammatory, and cardiovascular protective properties. However, under metabolically unfavorable conditions, visceral adipose tissue-derived inflammatory cytokines might reduce the transcription of the adiponectin gene and consequently its circulating levels. Low circulating levels of adiponectin are negatively associated with various conditions, such as insulin resistance, type 2 diabetes mellitus, metabolic syndrome, and cardiovascular disease. In contrast, several recent clinical trials and meta-analyses have reported high circulating adiponectin levels positively associated with cardiovascular mortality and all-cause mortality. These results are biologically intriguing and counterintuitive, and came to be termed "the adiponectin paradox". Adiponectin paradox is frequently associated with adiponectin resistance, a concept related with the downregulation of adiponectin receptors in insulin-resistant states. We review this contradiction between the apparent role of adiponectin as a health promoter and the recent evidence from Mendelian randomization studies indicating that circulating adiponectin levels are an unexpected predictor of increased morbidity and mortality rates in several clinical conditions. We also critically review the therapeutic perspective of synthetic peptide adiponectin receptors agonist that has been postulated as a promising alternative for the treatment of metabolic syndrome and type 2 diabetes mellitus.

Data on Adiponectin from 2010 to 2020: Therapeutic Target and Prognostic Factor for Liver Diseases?

The review describes the role of adiponectin in liver diseases in the presence and absence of surgery reported in the literature in the last ten years. The most updated therapeutic strategies based on the regulation of adiponectin including pharmacological and surgical interventions and adiponectin knockout rodents, as well as some of the scientific controversies in this field, are described. Whether adiponectin could be a potential therapeutic target for the treatment of liver diseases and patients submitted to hepatic resection or liver transplantation are discussed. Furthermore, preclinical and clinical data on the mechanism of action of adiponectin in different liver diseases (nonalcoholic fatty disease, alcoholic liver disease, nonalcoholic steatohepatitis, liver cirrhosis and hepatocellular carcinoma) in the absence or presence of surgery are evaluated in order to establish potential targets that might be useful for the treatment of liver disease as well as in the practice of liver surgery associated with the hepatic resections of tumors and liver transplantation.

Glutathione S-transferase T1 and M1 null genotype distribution among non-alcoholic fatty liver disease patients and its association with cytokine and adipokine profiles

AIM OF THE STUDY

Among the key genes involved in the development of non-alcoholic fatty liver disease (NAFLD) are genes encoding the synthesis of glutathione S-transferase (GST).

MATERIAL AND METHODS

Deletion polymorphism of GSTT1 and GSTM1 genes was investigated in 104 NAFLD patients and 45 healthy individuals. Biochemical blood analysis, tumor necrosis factor-α (TNF-α), interleukin-10, leptin and adiponectin plasma levels were studied.

RESULTS

The distribution of deletion vs. non-deletion genotypes of the GSTT1 gene in NAFLD patients was 18 (17.3%) vs. 86 (82.7%) patients and in healthy people it was 6 (13.3%) vs. 39 (86.7%) individuals. The genotype distribution of the GSTM1 gene was as follows: 52 (50.0%) NAFLD patients had null genotype vs. 52 patients (50.0%) with non-deletion genotype; in the control group - 23 (51.1%) vs. 22 (48.9%) individuals. Deletion of the GSTT1 gene in NAFLD patients was associated with twice as high (p = 0.01) TNF-α level in the blood as compared to patients with normal genotype. Higher concentration of leptin in blood by 37.1% (p = 0.04) was observed in patients with null genotype of the GSTM1 gene, as compared to those with normal genotype.

CONCLUSIONS

Deletion polymorphism of GSTT1 and GSTM1 genes distribution among NAFLD patients did not differ as compared to healthy individuals. Null-genotype GSTT1 gene carriers were characterized by higher TNF-α concentration and null-genotype GSTM1 gene carriers were characterized by elevated leptin level as compared to normal genotype carriers.

The Possible Role of Adipokines in HCV Associated Hepatocellular Carcinoma

Background:

Adipokines play an important role in the regulation of inflammation and tumor progression.

Aim:

Assessment of the possible role of adiponectin, leptin and visfatin in HCV associated hepatocellular carcinoma (HCC).

Methods:

patients were classified into 85 patients with HCV associated HCC, 100 patients with chronic hepatitis C viral (HCV) infection compared to 50 normal control (NC) subjects. All subjects included in the study were assessed for HCV infection by seropositive HCV antibodies, as well as HCV RNA by RT-PCR. Serum levels of adiponectin, leptin and visfatin were assessed using enzyme linked immunosorbent assay (ELISA). The data were correlated to the relevant clinic-pathological features of the patients, and the overall survival (OS) rate.

Results:

There was a significant difference in the serum levels of adiponectin and visfatin among HCC, HCV and NC groups (P<0.001). The serum levels of leptin and alpha fetoprotein (AFP) were significantly higher in HCC group (P<0.001). There was a significant association between the serum level of adiponectin and advanced Child class liver cirrhosis (P=0.03), as well as with poor performance status (ECOG, P=0.02). Serum leptin associated significantly with the number of lesions in the liver (P=0.006), visfatin associated with increased mortality rate (P<0.001). Adiponectin, leptin and visfatin associated significantly with liver cirrhosis in HCV patients (P<0.01). Leptin achieved the highest sensitivity (98.8%). visfatin achieved the highest specificity (100%) and PPV (100%) for detection of HCC. The combination of serum leptin and visfatin for the diagnosis of HCV associated HCC showed sensitivity, specificity, PPV, NPV and accuracy (100%, 96.6%, 93.4%, 100% and 97.4%; respectively).

Conclusion:

Adiponectin, leptin and visfatin have an important role(s) in the pathogenesis of HCV associated HCC.

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.

Ethnopharmacological Applications Targeting Alcohol Abuse: Overview and Outlook

Excessive alcohol consumption is the cause of several diseases and thus is of a major concern for society. Worldwide alcohol consumption has increased by many folds over the past decades. This urgently calls for intervention and relapse counteract measures. Modern pharmacological solutions induce complete alcohol self-restraint and prevent relapse, but they have many side effects. Natural products are most promising as they cause fewer adverse effects. Here we discuss in detail the medicinal plants used in various traditional/folklore medicine systems for targeting alcohol abuse. We also comprehensively describe preclinical and clinical studies done on some of these plants along with the possible mechanisms of action.

Organokines in disease

Studies have linked obesity, metabolic syndrome, type 2 diabetes, cardiovascular disease (CVD), nonalcoholic fatty liver disease (NAFLD) and dementia. Their relationship to the incidence and progression of these disease states suggests an interconnected pathogenesis involving chronic low-grade inflammation and oxidative stress. Metabolic syndrome represents comorbidities of central obesity, insulin resistance, dyslipidemia, hypertension and hyperglycemia associated with increased risk of type 2 diabetes, NAFLD, atherosclerotic CVD and neurodegenerative disease. As the socioeconomic burden for these diseases has grown signficantly with an increasing elderly population, new and alternative pharmacologic solutions for these cardiometabolic diseases are required. Adipose tissue, skeletal muscle and liver are central endocrine organs that regulate inflammation, energy and metabolic homeostasis, and the neuroendocrine axis through synthesis and secretion of adipokines, myokines, and hepatokines, respectively. These organokines affect each other and communicate through various endocrine, paracrine and autocrine pathways. The ultimate goal of this review is to provide a comprehensive understanding of organ crosstalk. This will include the roles of novel organokines in normal physiologic regulation and their pathophysiological effect in obesity, metabolic syndrome, type 2 diabetes, CVD, NAFLD and neurodegenerative disorders.

Obesity in acute alcoholic hepatitis increases morbidity and mortality

BACKGROUND

Alcohol and obesity synergise to increase the risk of liver-related mortality. We examined the influence of adiposity on clinical outcomes in alcoholic hepatitis (AH) and the underlying inflammatory crosstalk between adipose tissue (AT) and the liver.

METHODS

A cohort of 233 patients with AH from the UK and USA provided data to analyse the effects of obesity in AH. Body mass index was corrected for the severity of ascites, termed cBMI. Inflammatory and metabolic profiling was undertaken by proteome analysis of human serum samples. The effect of alcohol on adipose tissue and CXCL11 expression was studied in 3 T3-derived adipocytes and in mice using the high-fat diet-plus-binge ethanol model.

FINDINGS

Obesity was common amongst patients with AH, seen in 19% of individuals. Obesity (HR 2.22, 95%CI 1.1-4.3, p = .022) and underweight (HR 2.38, 1.00-5.6, p = .049) were independently associated with mortality at 3 months. Proteome analysis demonstrated multiple metabolic and inflammatory factors differentially expressed in obese AH verse lean AH, with CXCL11 being the most elevated factor in obese AH. In vitro analysis of cultured adipocytes and in vivo analysis of mouse models showed that alcohol induced CXCL11 expression in AT, but not in liver.

INTERPRETATION

Obesity is common in AH and associated with a greater than two-fold increase in short-term mortality. Obese AH is associated with a different inflammatory phenotype, with the greatest elevation in CXCL11. These data confirm that adiposity is clinically important in acute alcohol-related liver disease and illustrate the adipose-liver inflammatory axis in AH. FUND: This work was supported in part by an EASL Sheila Sherlock Physician Scientist Fellowship. The funder played no role in gathering or analysing data or writing the manuscript. This paper presents independent research supported by the NIHR Birmingham Biomedical Research Centre at the University Hospitals Birmingham NHS Foundation Trust and the University of Birmingham. The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR or the Department of Health and Social Care.

Treatment of Type-1 Hepatorenal Syndrome with Pentoxifylline: A Randomized Placebo Controlled Clinical Trial

INTRODUCTION

Type-1 hepatorenal syndrome (HRS-1) portends a poor prognosis in patients with cirrhosis. Currently available medical therapies are largely ineffective, save for liver transplantation. We aimed to determine if pentoxifylline (PTX) therapy in addition to the standard of care of volume expansion with albumin and vasoconstriction with midodrine and octreotide (AMO) is safe and efficacious compared to AMO in HRS-1 treatment.

MATERIAL AND METHODS

Hospitalized subjects with decompensated cirrhosis and HRS-1 were enrolled. PTX or placebo was administered with AMO therapy for up to 14 days. The primary endpoint was HRS-1 resolution (serum creatinine ≤ 1.5 g/dL for &gt; 24 h). Secondary endpoints were change in creatinine and MELD score, partial treatment response, 30-and 180-day overall and transplant free survival.

RESULTS

Twelve subjects with mean age 58.9 ± 6.2 years were enrolled and randomized. Mean MELD score was 26.5 ± 7.4 and 58.3% were male. Overall cohort 30- and 180-day survival was 58.3% and 33.3% respectively. Two subjects underwent liver transplantation. HRS-1 resolution (16.7% vs. 16.7%, p = 1.000), partial treatment response (33.3% vs. 16.7%, p = 0.505), change in creatinine (+0.48 g/dL, 95% CI -0.49-1.46 vs. +0.03 g/dL, 95% CI -0.64- 0.70, p = 0.427), 30-day survival (66.6% vs. 50.0%, p = 0.558) and 180-day survival (50.0% vs. 16.7%, p = 0.221) were similar between the two groups. Serious adverse events necessitating treatment discontinuation were rare (n = 1, PTX).

DISCUSSION

The addition of PTX to AMO in the treatment of HRS-1 is safe when compared to the current standard of care. Future large-scale prospective study to validate the efficacy of this treatment seems warranted.

Alcohol, adipose tissue and liver disease: mechanistic links and clinical considerations

Adipose tissue represents a large volume of biologically active tissue that exerts substantial systemic effects in health and disease. Alcohol consumption can profoundly disturb the normal functions of adipose tissue by inducing adipocyte death and altering secretion of adipokines, pro-inflammatory mediators and free fatty acids from adipose tissue, which have important direct and indirect effects on the pathogenesis of alcoholic liver disease (ALD). Cessation of alcohol intake quickly reverses inflammatory changes in adipose tissue, and pharmacological treatment that normalizes adipose tissue function improves experimental ALD. Obesity exacerbates liver injury induced by chronic or binge alcohol consumption, and obesity and alcohol can synergize to increase risk of ALD and progression. Physicians who care for individuals with ALD should be aware of the effects of adipose tissue dysfunction on liver function, and consider strategies to manage obesity and insulin resistance. This Review examines the effect of alcohol on adiposity and adipose tissue and the relationship between alcohol, adipose tissue and the liver.

Adipokines and Non-Alcoholic Fatty Liver Disease: Multiple Interactions

Accumulating evidence links obesity with low-grade inflammation which may originate from adipose tissue that secretes a plethora of pro- and anti-inflammatory cytokines termed adipokines. Adiponectin and leptin have evolved as crucial signals in many obesity-related pathologies including non-alcoholic fatty liver disease (NAFLD). Whereas adiponectin deficiency might be critically involved in the pro-inflammatory state associated with obesity and related disorders, overproduction of leptin, a rather pro-inflammatory mediator, is considered of equal relevance. An imbalanced adipokine profile in obesity consecutively contributes to metabolic inflammation in NAFLD, which is associated with a substantial risk for developing hepatocellular carcinoma (HCC) also in the non-cirrhotic stage of disease. Both adiponectin and leptin have been related to liver tumorigenesis especially in preclinical models. This review covers recent advances in our understanding of some adipokines in NAFLD and associated HCC.

Adipokines in Liver Cirrhosis

Liver fibrosis can progress to cirrhosis, which is considered a serious disease. The Child-Pugh score and the model of end-stage liver disease score have been established to assess residual liver function in patients with liver cirrhosis. The development of portal hypertension contributes to ascites, variceal bleeding and further complications in these patients. A transjugular intrahepatic portosystemic shunt (TIPS) is used to lower portal pressure, which represents a major improvement in the treatment of patients. Adipokines are proteins released from adipose tissue and modulate hepatic fibrogenesis. These proteins affect various biological processes that are involved in liver function, including angiogenesis, vasodilation, inflammation and deposition of extracellular matrix proteins. The best studied adipokines are adiponectin and leptin. Adiponectin protects against hepatic inflammation and fibrogenesis, and leptin functions as a profibrogenic factor. These and other adipokines are supposed to modulate disease severity in patients with liver cirrhosis. Consequently, circulating levels of these proteins have been analyzed to identify associations with parameters of hepatic function, portal hypertension and its associated complications in patients with liver cirrhosis. This review article briefly addresses the role of adipokines in hepatitis and liver fibrosis. Here, studies having analyzed these proteins in systemic blood in cirrhotic patients are listed to identify adipokines that are comparably changed in the different cohorts of patients with liver cirrhosis. Some studies measured these proteins in systemic, hepatic and portal vein blood or after TIPS to specify the tissues contributing to circulating levels of these proteins and the effect of portal hypertension, respectively.

Plasma Adiponectin and Hepatocellular Carcinoma Survival Among Patients Without Liver Transplantation

AIM

To investigate the levels of leptin and adiponectin in prediction of hepatocellular carcinoma (HCC) survival among patients without liver transplantation.

MATERIALS AND METHODS

We measured pretreatment plasma leptin and adiponectin in 172 HCC cases who were prospectively followed-up over 7 years.

RESULTS

Gender, hepatitis B virus (HBV) and hepatitis C virus (HCV) infection, high body mass index (BMI), diabetes mellitus (DM) history and Child-Pugh (CP) class were associated with leptin and adiponectin levels, while α-fetoprotein (AFP) and presence of metastasis, being outside the Milan criteria and Barcelona clinic liver cancer (BCLC) stage, were significantly associated with liver transplantation and HCC survival. No significant association was observed for leptin or adiponectin and HCC survival in the overall group. In subgroup analyses among those without liver transplantation, we found significant associations between metastasis, Milan criteria, BCLC stage, hepatitis B surface antigen (HBsAg) and HCC survival. When separately determining the Cox proportional hazard models and Kaplan-Meier survival curves by liver transplantation status, higher adiponectin was significantly associated with an increased hazard ratio (HR) of death of 1.72 (95% confidence interval (CI)=1.12-2.64), i.e. poor survival among patients without liver transplantation. A multivariate Cox proportional hazard model, including adiponectin, CP class, presence of metastasis, tumor outside of Milan criteria, AFP and BCLC stage B/C parameters, also showed significant association with poor HCC survival (likelihood ratio test p<0.0001). No significant impact was observed for leptin on HCC survival regardless of liver transplantation status.

CONCLUSION

Higher levels of plasma adiponectin may predict poor HCC survival among patients without liver transplantation.

Elevated serum α-fetoprotein levels in patients with chronic hepatitis C virus genotype 4: not the end of the story

BACKGROUND AND AIM

Elevated serum α-fetoprotein (AFP) is not uncommonly seen among patients with chronic hepatitis C. This study aimed to identify clinical characteristics, histological characteristics, and biochemical markers associated with increased serum AFP levels in hepatitis C virus genotype 4-infected patients with no evidence of hepatocellular carcinoma and to determine the effect of lifestyle modification on these parameters.

METHODS

The study included 447 chronic hepatitis C patients with no evidence of hepatocellular carcinoma and 100 healthy controls. They underwent liver biopsies, homeostasis model assessment-insulin resistance (HOMA-IR), measurement of serum insulin, leptin, adiponectin, tumor necrosis factor-α, and interleukin-6 levels by an enzyme-linked immunosorbent assay, and assessment of AFP levels. Eighty patients with HOMA-IR greater than 3 received prospective longitudinal lifestyle intervention.

RESULTS

In a multivariate analysis, platelet count less than 140×10/cm, a mean platelet volume of at least 9.5 fl, a neutrophil-lymphocyte ratio (NLR) of at least 2, an aspartate transaminase level of at least 55 IU/l, a γ-glutamyl transpeptidase level of at least 40 IU/l, an albumin level of up to 3.8 g/dl, HOMA-IR greater than 3, a leptin level of at least 10 pg/ml, an iron level of at least 165 μg/dl, a ferritin level of at level 175 ng/ml, and hepatic fibrosis F3-F4 were found to be independently associated with elevated AFP levels. The lifestyle intervention significantly improved BMI, platelet indices, NLR, γ-glutamyl transpeptidase, leptin, leptin/adiponectin ratio, tumor necrosis factor-α, interleukin-6, HOMA-IR, and AFP levels.

CONCLUSION

Elevated insulin resistance, leptin, serum iron, ferritin, mean platelet volume, NLR, and advanced fibrosis, as well as decreased platelet count and serum albumin, are independently associated with an elevated AFP level. Lifestyle modification can improve (reduce) insulin resistance, leptin, leptin/adiponectin ratio, platelet count and their indices, NLR, and AFP level.

Adipokines levels are associated with the severity of liver disease in patients with alcoholic cirrhosis

AIM: To investigate the adipokine levels of leptin, adiponectin, resistin, visfatin, retinol-binding protein 4 (RBP4), apelin in alcoholic liver cirrhosis (ALC).

METHODS: Forty non-diabetic ALC patients [median age: 59 years, males: 35 (87.5%), Child-Pugh (CP) score: median 7 (5-12), CP A/B/C: 18/10/12, Model for End-stage Liver Disease (MELD): median 10 (6-25), follow-up: median 32.5 mo (10-43)] were prospectively included. The serum adipokine levels were estimated in duplicate by ELISA. Somatometric characteristics were assessed with tetrapolar bioelectrical impedance analysis. Pearson’s rank correlation coefficient was used to assess possible associations with adipokine levels. Univariate and multivariate Cox regression analysis was used to determine independent predictors for overall survival.

RESULTS: Body mass index: median 25.9 (range: 20.1-39.3), fat: 23.4% (7.6-42.1), fat mass: 17.8 (5.49-45.4), free fat mass: 56.1 (39.6-74.4), total body water (TBW): 40.6 (29.8-58.8). Leptin and visfatin levels were positively associated with fat mass (P < 0.001/P = 0.027, respectively) and RBP4 with TBW (P = 0.025). Median adiponectin levels were significantly higher in CPC compared to CPA (CPA: 7.99 ± 14.07, CPB: 7.66 ± 3.48, CPC: 25.73 ± 26.8, P = 0.04), whereas median RBP4 and apelin levels decreased across the spectrum of disease severity (P = 0.006/P = 0.034, respectively). Following adjustment for fat mass, visfatin and adiponectin levels were significantly increased from CPA to CPC (both P < 0.001), whereas an inverse correlation was observed for both RBP4 and apelin (both P < 0.001). In the multivariate Cox regression analysis, only MELD had an independent association with overall survival (HR = 1.53, 95%CI: 1.05-2.32; P = 0.029).

CONCLUSION: Adipokines are associated with deteriorating liver function in a complex manner in patients with alcoholic liver cirrhosis.

Correlates of adiponectin in hepatitis C-infected children: the importance of body mass index

OBJECTIVES

Adiponectin is a regulator of cytokines that, in turn, play a vital role in inflammatory and immune responses. Adiponectin is therefore likely to have a contributory role in hepatitis C virus (HCV) infection. We sought to characterize adiponectin levels and examine correlates in a pediatric HCV-infected cohort.

METHODS

We performed a cross-sectional study in children (5-17 years of age, n = 86) in the Pediatric Study of Hepatitis C (PEDS-C) trial. Adiponectin levels were univariately correlated with patient demographics, anthropometrics, and viral and histological measures. Multivariate regression models were used to identify the unique (ie, nonconfounded) associations with adiponectin concentrations.

RESULTS

Body mass index (BMI) had the highest univariate inverse correlation with log(e) adiponectin (r = -0.5, P < 0.0001). In multivariate analysis, BMI remained inversely correlated with log(e) adiponectin after accounting for age and route of HCV transmission (r = -0.38, P = 0.0003). Steatosis and fibrosis were inversely related to log(e) adiponectin in univariate analysis, but these associations were not statistically significant after multivariate adjustments (P ≥ 0.1827).

CONCLUSIONS

High BMI among HCV-infected children is associated with lower adiponectin levels. Practitioners should be cognizant of the possible risks of low adiponectin when managing HCV-infected children who are overweight. Further studies are indicated to determine the impact of having low adiponectin on HCV infection in youth.

The multifaceted and controversial immunometabolic actions of adiponectin

Adiponectin, one of the most abundant adipose-derived hormones, has variable actions in many tissues and organs. Although principally known for its insulin-sensitizing activity, recent data also highlight its homeostatic function, which is mediated both by direct actions on metabolic cells and indirectly through immunomodulatory effects on immune cells. Here we review the multifaceted immunometabolic actions of adiponectin and attempt to unify some of the contradictory reports on adiponectin function in inflammatory processes. We propose that a holistic understanding of adiponectin function can be garnered only from understanding its actions both on the immune system and on metabolism.

Mechanisms behind the link between obesity and gastrointestinal cancers

Obesity and obesity-related disorders such as non-alcoholic fatty liver disease (NAFLD), metabolic syndrome and type 2 diabetes exhibit an increased risk of developing various gastrointestinal cancers. These malignancies include mainly esophageal, gastric, colorectal, pancreatic and hepatocellular carcinoma. Whereas underlying pathomechanisms remain unclear, chronic inflammation accompanying obesity has evolved in the last years as a crucial contributing factor. Obesity is also commonly characterized by inflammation in the organ where those cancers appear. Various pathways might participate involving rather diverse components such as innate immunity, (adipo)-cytokines such as adiponectin or leptin, insulin, insulin-like growth factors, the gut's microbiota and others. An imbalance in these systems could substantially contribute to chronic inflammation and subsequent cancer development. Future studies have to elucidate in more detail underlying mechanisms in the development of obesity-related carcinogensis and potential therapeutic strategies besides weight loss.

Clinical implication of changes in serum adiponectin in patients with hepatogenic diabetes

Adiponectin is a protein hormone that modulates glucose metabolism and fatty acid oxidation. We explored the clinical implication of serum adiponectin in hepatogenic diabetes. Serum adiponectin levels were determined using enzyme-linked immunochemistry assay in 78 individuals including 19 hepatogenic diabetes, 20 type 2 diabetes (T2D), 20 chronic liver disease and 19 healthy controls. Cases and controls were matched by gender and body mass index (BMI). There is no difference in serum adiponectin levels among hepatogenic diabetic, T2D and healthy control groups. The levels of adiponectin are highest in chronic liver disease and lowest in T2D. Insulin levels are highest in hepatic diabetics and lowest in T2D. Hepatic diabetics have the lowest insulin sensitivity index (ISI). Serum adiponectin levels were negatively correlated with triglycerides and total cholesterol in T2D. Serum adiponectin is significantly increased in chronic liver disease, but lacks association with hepatogenic diabetes.

Plasma adipokines and risk of hepatocellular carcinoma in chronic hepatitis B virus-infected carriers: a prospective study in taiwan

BACKGROUND

Obesity is considered a risk factor for hepatocellular carcinoma (HCC). The relationship between adipocytokine and HCC in hepatitis B virus (HBV) carriers remains unclear. We prospectively investigated the association of adiponectin, leptin, and visfatin levels with HCC.

METHODS

We conducted a nested case-control study in a community-based cohort with 187 incident HCC and 374 HCC-free HBV carriers. Unconditional logistic regression was conducted to estimate the ORs and 95% confidence intervals (CI).

RESULTS

Adiponectin, but not leptin and visfatin, levels were associated with an increased risk of HCC after adjustment for other metabolic factors and HBV-related factors. The risk was increased [OR = 0.51; 95% CI, 0.12-2.11; OR = 4.88 (1.46-16.3); OR = 3.79 (1.10-13.0); OR = 4.13 (1.13-15.1) with each additional quintiles, respectively] with a significant dose-response trend (P(trend) = 0.003). HCC risk associated with higher adiponectin level was higher in HBV carriers with ultrasonographic fatty liver, genotype C infection, higher viral load, and with elevated alanine aminotransferase. Longitudinally, participants with higher adiponectin were less likely to achieve surface antigen of hepatitis B virus (HBsAg) seroclearance and more likely to have persistently higher HBV DNA. Eventually, they were more likely to develop liver cirrhosis [OR = 1.65 (0.62-4.39); OR = 3.85 (1.47-10.1); OR = 2.56 (0.96-6.84); OR = 3.76 (1.33-10.7) for the second, third, fourth, and fifth quintiles, respectively; P(trend) = 0.017] before HCC.

CONCLUSIONS

Elevated adiponectin levels were independently associated with an increased risk of HCC.

IMPACT

Adiponectin may play different roles in the virus-induced and metabolic-related liver diseases, but the underlying mechanism remains unknown.

Plasma levels of adiponectin and primary liver cancer risk in middle-aged Japanese adults with hepatitis virus infection: a nested case-control study

BACKGROUND

Excess body weight is an independent risk factor for primary liver cancer, and the role of adiponectin in the pathogenesis of obesity-related malignancies is a focus of research interest. Few prospective studies have examined the association between circulating adiponectin and liver cancer risk, so we investigated this association in a nested case-control study of a population-based prospective cohort in Japan.

METHODS

From 18,628 target participants of ages 40 to 69 years who returned the baseline questionnaire and provided blood samples, we selected those with either hepatitis B or C virus infection at baseline (n = 1,544). Among these, 90 were newly diagnosed with primary liver cancer from 1993 through 2006, and matched to 177 controls. The ORs of liver cancer development based on plasma levels of adiponectin were estimated with a conditional logistic regression model.

RESULTS

Median values of total and high-molecular-weight (HMW) adiponectin tended to be higher in the patients with liver cancer, and plasma levels of adiponectin were positively associated with liver cancer risk. Body mass index- and diabetes-adjusted ORs for the highest tertile of total and HMW adiponectin levels versus the lowest were 3.30 [95% confidence interval (CI), 1.45-7.53; Ptrend < 0.01] and 3.41 (95% CI, 1.50-7.73; Ptrend < 0.01), respectively. There was no effect modification by body mass index and diabetes.

CONCLUSIONS

Higher plasma adiponectin levels were associated with an increased risk of primary liver cancer in middle-aged Japanese adults with hepatitis virus infection.

IMPACT

Circulating adiponectin levels may be a risk marker for primary liver cancer.

Obesity, adipokines and hepatocellular carcinoma

Obesity is rapidly becoming pandemic and is associated with increased carcinogenesis, especially hepatocellular carcinoma (HCC). Adipose tissue is considered as an endocrine organ because of its capacity to secrete a variety of adipokines, such as leptin, adiponectin and resistin. Recently, adipokines have been demonstrated to be associated with kinds of chronic liver diseases including fibrosis, cirrhosis and carcinogenesis. Direct evidence is accumulating rapidly supporting the inhibitory and/or activating role of adipokines in the process of carcinogenesis and progression of human HCC. This review aims to provide important insight into the potential mechanisms of adipokines in the development of HCC.

Serum adiponectin levels are associated with hepatitis B viral load in overweight to obese hepatitis B virus carriers

OBJECTIVE

This study aimed to investigate the association between serum adiponectin and chronic hepatitis B virus (HBV) infection.

DESIGN AND METHODS

We conducted a campus-based cross-sectional study in Northern Taiwan, an HBV-endemic country. A total of 506 participants, including 147 chronic HBV-infected individuals and 359 healthy controls, were assessed for anthropometric indices, serum adiponectin levels, serum HBV viral load and markers, serum alanine aminotransferase levels and metabolic factors.

RESULTS

Older age, male gender, higher alanine aminotransferase, higher body mass index, greater waist circumference, lower fasting glucose, higher triglycerides, and higher adiponectin were associated with chronic HBV infection in univariate analyses. In multivariate analysis, the presence of chronic HBV infection was positively associated with serum adiponectin levels (P < 0.0001) and high adiponectin levels over the 75th percentile (odds ratio, 4.25; 95% confidence interval, 2.36-7.66; P < 0.0001) after adjusting for age, gender, body mass index, and insulin resistance index. Furthermore, serum adiponectin levels were positively associated with HBV viral load in overweight to obese HBV-infected subjects (P = 0.018).

CONCLUSION

Although chronic HBV-infected individuals were heavier than healthy controls, they had significantly higher serum adiponectin levels than healthy counterparts. Additionally, adiponectin levels were positively associated with HBV viral load in overweight to obese HBV-infected subjects. Future research should focus on elucidating adiponectin pathways, which may contribute to the development of adjuvant treatments for chronic HBV infection.

Adiponectin: a key playmaker adipocytokine in non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is the hepatic manifestation of metabolic syndrome and can progress to cirrhosis, liver failure, and hepatocellular carcinoma. In the last two decades, the prevalence of NAFLD has been growing in most developed countries, mainly as a consequence of its close association with obesity and diabetes mellitus. The exact pathogenesis of NAFLD and especially the mechanisms leading to disease progression have not been completely understood. Adipocytes produce and secrete several bioactive substances known as adipocytokines which are implicated in the pathogenesis of the disease. Among them, adiponectin is an insulin-sensitizing adipocytokine possessing multiple beneficial effects on obesity-related medical complication. This review focuses on the role of adiponectin in NAFLD pathogenesis and its potential use as a diagnostic tool but also as therapeutic target for NAFLD management.

Whole-body insulin resistance is associated with elevated serum α-fetoprotein levels in patients with chronic hepatitis C

OBJECTIVE

Little is known about the relationship between elevated serum α-fetoprotein (AFP) levels and insulin resistance, which adversely influence the clinical course of chronic hepatitis C (CHC). Therefore, we investigated the association between serum AFP and insulin resistance in patients with CHC.

METHODS

We retrospectively investigated 300 patients with CHC without hepatoma who underwent liver biopsies and oral glucose tolerance tests. Patients taking antidiabetic drugs were excluded. We analyzed factors associated with elevated AFP levels (≥ 10.0 ng/mL) in 265 eligible patients. Twenty patients with a homeostasis model assessment for insulin resistance value of ≥ 2.0 and a whole-body insulin sensitivity index of <5.0 received prospective lifestyle intervention.

RESULTS

A univariate analysis showed that the body mass index, platelet count, levels of albumin, aspartate aminotransferase, alanine aminotransferase and γ-glutamyl transpeptidase, glucose metabolism, hepatic inflammation, fibrosis and steatosis were associated with elevated AFP levels. In a multivariate analysis, a platelet count of < 15 × 10(4) /μL, aspartate aminotransferase level of ≥ 50 IU/L, γ-glutamyl transpeptidase level of ≥ 35 IU/L, whole-body insulin sensitivity index of <5.0 and stage 3-4 fibrosis were independently associated with an elevated AFP level. A Bayesian Network analysis showed that the aspartate aminotransferase level, whole-body insulin sensitivity index and hepatic fibrosis were directly associated with an elevated AFP level. The lifestyle intervention significantly improved the serum AFP level, homeostasis model assessment for insulin resistance and whole-body insulin sensitivity index.

CONCLUSION

Whole-body insulin resistance is associated with an elevated serum AFP level in patients with CHC. Lifestyle interventions targeting insulin resistance can reduce the serum AFP level and may ameliorate the clinical course of CHC.

Adipocytokines and hepatocellular carcinoma

Adipocytokines are primarily adipocyte-derived products, although certain members are also synthesized by other cell types. These adipocytokines, similarly to classical cytokines, are characterized by very pleiotropic functions affecting biological processes throughout the body. An increasing number of adipocytokines has recently been recognized, such as adiponectin, leptin, pre-B cell colony-enhancing factor/Nampt/visfatin, resistin, progranulin, and others. Adiponectin has emerged as the most abundant circulating adipocytokine, is produced almost exclusively by adipocytes, and has mainly anti-inflammatory and anti-diabetic functions. In contrast, leptin is produced by many cell types beyond adipocytes, regulates immunity and T cell functions, and acts in a more pro-inflammatory fashion. Adipocytokines play a fundamental role in adipose tissue homeostasis (i.e. health) and disease, especially in obesity-related disorders such as non-alcoholic fatty liver diseases (NAFLD) and their complications, including hepatocellular carcinoma (HCC). Lack of adiponectin as observed in NAFLD drives steatosis and inflammation in the liver, and evidence is increasing that this adipocytokine has many anti-tumor properties and might play a rather protective role in HCC. The role of leptin in NAFLD is still unclear and this adipocytokine seems to have opposite effects in HCC, acting more as a tumor promoter. Evidence is increasing that HCC tissue produces various adipocytokines, and adiponectin expression in HCC seems to be decreased whereas leptin expression is rather increased. In conclusion, adipocytokines are increasingly recognized as pleiotropic molecules involved in the pathophysiology of HCC, which might lead to therapeutic approaches targeting these mediators.

Changes in adipokines after transjugular intrahepatic porto-systemic shunt indicate an anabolic shift in metabolism

BACKGROUND & AIMS

Decompressing the portal hypertension by inserting a transjugular intrahepatic porto-systemic shunt (TIPS) in undernourished liver cirrhosis patients results in gains in body weight. It is important to understand whether this reflects an advantageous or unfavourable shift in nutrition status. This to some extent can be judged from the changes in the patients' adipokine patterns. We, therefore, examined the circulating levels of the most important adipokines before and after the TIPS procedure.

METHODS

Twenty-five liver cirrhosis patients were examined before TIPS insertion and followed for six months after the procedure. Their body composition was determined by the bioimpedance technique. The serum concentrations of adiponectin, retinol binding protein 4 (RBP4), and leptin were measured.

RESULTS

The TIPS procedure induced a 12% increase in body cell mass (P = 0.03) but did not change the body fat mass. At six months, serum adiponectin was increased by 60% (mean ± SD, 10.7 ± 6.1 vs. 16.9 ± 8.9 mg/L; P = 0.001), serum RBP4 was decreased by 45% (28.6 ± 20.0 vs. 16.3 ± 9.6 mg/L; P = 0.01), and the leptin levels remained unchanged.

CONCLUSIONS

The TIPS-related tissue build up was accompanied by increased adiponectin and decreased RBP4. Such changes are associated with an anabolic condition where the adipose tissue possesses residual capacity for energy storage. TIPS, therefore, can be considered to be nutritionally beneficial to cirrhosis patients.

The promoting effect of adiponectin in hepatocellular carcinoma

BACKGROUND AND OBJECTIVES

Adipokines may explain the newly established association of obesity with hepatocellular carcinoma (HCC). This study investigated if adiponectin levels in HCC patients differed from healthy controls and their potential effect in the development of HCC.

METHODS

Radioimmunoassay was used to determine serum adiponectin levels of 65 HCC patients and 165 healthy controls. The expressions of adiponectin protein in the tumor and adjacent non-tumor parts were examined by the immunoblotting method. Cell proliferation assays were used to assess the bioeffects of adiponectin in two human liver cancer cell lines.

RESULTS

Serum adiponectin levels were significantly higher in the HCC patients than the controls. Significant correlations of serum adiponectin levels with serum triglyceride levels and insulin resistance were found in the controls, but not in the HCC patients. In contrast, serum adiponectin levels significantly correlated with serum albumin and alkaline phosphatase levels in the HCC patients, but this trend was not observed in the controls. The expression pattern of adiponectin protein between the paired tumor and adjacent non-tumor tissues significantly correlated with tumor size. In vitro, adiponectin increased cell proliferation in a dose-dependent manner.

CONCLUSIONS

Increased adiponectin expressions were found in HCC and this increase might contribute to tumor growth.

Total and high molecular weight adiponectin and hepatocellular carcinoma with HCV infection

Background

Adiponectin is shown to be inversely associated with development and progression of various cancers. We evaluated whether adiponectin level was associated with the prevalence and histological grade of hepatocellular carcinoma (HCC), and liver fibrosis in patients with hepatitis C virus (HCV) infection.

Methods

A case-control study was conducted on 97 HCC patients (cases) and 97 patients (controls) matched for sex, Child-Pugh grade and platelet count in patients with HCV infection. The serum total and high molecular weight (HMW) adiponectin levels were measured by enzyme-linked immunosorbent assays and examined in their association with the prevalence of HCC. In addition, the relationship between these adiponectin levels and body mass index (BMI), progression of liver fibrosis, and histological grade of HCC was also evaluated. Liver fibrosis was assessed using the aspartate aminotransferase to platelet ratio index (APRI).

Results

There were no significant differences in the serum total and HMW adiponectin levels between cases and controls. Moreover, there were no inverse associations between serum total and HMW adiponectin levels and BMI in both cases and controls. On the other hand, serum total and HMW adiponectin levels are positively correlated with APRI in both cases (r = 0.491, P<0.001 and r = 0.485, P<0.001, respectively) and controls (r = 0.482, P<0.001 and r = 0.476, P<0.001, respectively). Interestingly, lower serum total (OR 11.76, 95% CI: 2.97–46.66 [P<0.001]) and HMW (OR 10.24, CI: 2.80–37.40 [P<0.001] adiponectin levels were independent risk factors of worse histological grade of HCC.

Conclusions

Our results suggested that serum total and HMW adiponectin levels were predictors of liver fibrosis, but not prevalence of HCC in patients with HCV infection. Moreover, low these adiponectin levels were significantly associated with worse histological grades.

Serum adiponectin upon admission to the intensive care unit may predict mortality in critically ill patients

PURPOSE

Adiponectin has been proposed as an important regulator of glucose metabolism influencing obesity and insulin resistance, which are important risk factors for the outcome of critically ill patients. Moreover, experimental models of inflammation suggest protective anti-inflammatory properties of adiponectin. We therefore investigated the potential pathogenic role and prognostic value of circulating adiponectin levels in critical illness.

MATERIALS AND METHODS

One hundred seventy critically ill patients (122 with sepsis and 48 without sepsis) were prospectively studied at admission to the medical intensive care unit (ICU) and compared with 60 healthy controls. Patients' survival was followed for approximately 3 years.

RESULTS

Adiponectin serum concentrations did not differ between healthy controls and critically ill patients, neither in patients with nor in patients without sepsis. However, patients with decompensated liver cirrhosis had significantly elevated serum adiponectin levels. Likewise to non-critically ill subjects, ICU patients with preexisting diabetes or obesity displayed significantly reduced circulating adiponectin. Inflammatory cytokines did not correlate with serum adiponectin. Interestingly, low adiponectin levels at ICU admission were an independent positive predictor of short-term and overall survival.

CONCLUSIONS

Although serum concentrations did not differ in critically ill patients from controls, low adiponectin levels at admission to ICU have been identified as an independent predictor of survival.

Fibrosis is associated with adiponectin resistance in chronic hepatitis C virus infection

BACKGROUND

Chronic hepatitis C virus (HCV) infection is frequently associated with insulin resistance which has been suggested to promote fibrotic progression. Adiponectin, an adipocyte-derived insulin-sensitizing hormone, might play a protective role against hepatic fibrosis.

MATERIALS AND METHODS

This observational case-control study investigated the adiponectin status in insulin resistant, nondiabetic, chronic HCV-infected patients (n=54; 13 women, 41 men) compared with age-, sex- and BMI-matched healthy controls. Liver biopsies from patients with chronic HCV hepatitis were analysed for the adiponectin and adiponectin receptors (ADIPOR) 1 and 2 mRNA and protein expressions.

RESULTS

Serum adiponectin levels were higher in patients with chronic HCV hepatitis than in healthy controls (12·1±4·7 vs. 9·5±4·4 mg L(-1) in men, P = 0·01; 18·2±4·4 vs. 13·6±5·3mgL(-1) in women, P=0·02). BMI, HDL cholesterol and triglycerides levels correlated with adiponectin levels both in patients and in controls, while no correlation with glucose, insulin and HOMA-IR values could be detected. Nonetheless, insulin resistance was predictive of steatosis and fibrosis in chronic HCV-infected patients. Interestingly, patients with none or mild fibrosis showed serum adiponectin levels similar to those in healthy controls, while hyperadiponectinemia was associated with moderate to severe stages of fibrosis. Hyperadiponectinemia was unlikely sustained by liver production as hepatocytes did not express the protein. ADIPOR1 mRNA, but not ADIPOR2 levels, was reduced in chronic HCV hepatitis. The reduced ADIPOR1 expression was confirmed by immunohistochemistry.

CONCLUSIONS

In patients with chronic HCV hepatitis, fibrosis was associated with hyperadiponectinemia. Chronic HCV-infected hepatocytes showed reduced ADIPOR1 expression, suggesting a pattern of adiponectin resistance.

The association between adiponectin (+45T/G) and adiponectin receptor-2 (+795G/A) single nucleotide polymorphisms with cirrhosis in Iranian population

Adiponectin which possesses anti-inflammatory and insulin-sensitizing properties is elevated in blood circulation of liver cirrhosis patients. The genetic variations in the adiponectin gene can affect the circulating adiponectin level and stimulation of adiponectin receptor that may affect the activity of adiponectin. We investigated the effect of adiponectin single nucleotide polymorphisms (SNP) 45 T/G and adiponectin receptor-2 gene SNP 795G/A in cirrhotic Iranian population. A total of 97 cirrhotic patients and 128 healthy controls from Iranian population were genotyped for the adiponectin and adiponectin receptor 2 gene (+45T>G and 795G/A) by polymerase chain reaction-restriction fragment length polymorphism. G frequency was 21.1% versus 12.89% (P = 0.001) for SNP45, and G frequency was 75.8% versus 76.2% (P = 0.526) for SNP795G/A in the patients and control group, respectively. Based on our findings, the expression of the G allele at SNP45 is higher in the patient group compared with healthy subjects, suggesting that it may affect liver injury through changes in the plasma adiponectin level.

Interleukin-32: a new proinflammatory cytokine involved in hepatitis C virus-related liver inflammation and fibrosis

Interleukin 32 (IL-32) is a recently described proinflammatory cytokine that activates p38 mitogen-activated protein kinase (MAPK) and nuclear factor kappa B (NF-κB), thereby inducing proinflammatory cytokines such as IL-1β and tumor necrosis factor alpha (TNF-α). We investigated the role of IL-32 in patients with chronic hepatitis C virus (HCV) infection. Steady-state hepatic messenger RNA (mRNA) levels of IL-32 were determined in a cohort of 90 subjects; anti-IL-32 staining was used in a second cohort of 132 consecutive untreated chronic HCV patients. Correlations with histological features of steatosis, inflammation, and fibrosis were made. In vitro, endogenous IL-32 in monocytes and in the human hepatoma cell line Huh-7.5 were examined. The effects of IL-32-overexpression and IL-32-silencing on HCV replication were studied using HCV luciferase reporter viruses. There were highly significant positive associations between hepatic IL-32 mRNA expression and liver steatosis, inflammation, fibrosis, smooth muscle actin (SMA) area, and serum alanine aminotransferase (ALT) levels. IL-32 protein expression was positively associated with portal inflammation, SMA area, and ALT. In vitro, IL-1β and TNF-α significantly induced IL-32 expression in human Huh-7.5 cells. Alone, stimulation with interferon alpha (IFN-α) did not induce IL-32 expression in Huh-7.5. However, IFN-α exerted a significant additive effect on TNF-α-induced but not IL-1β-induced IL-32 expression, particularly in CD14+ monocytes. This effect was dependent both on NF-κB and Jak/STAT signaling. Viral infection of Huh-7.5 cells resulted in a significant (11-fold) induction of IL-32 mRNA expression. However, modulation of IL-32 in Huh-7.5 cells by overexpression or silencing did not influence HCV virus replication as determined by luciferase assays.

CONCLUSION

IL-32 is a novel proinflammatory cytokine involved in HCV-associated liver inflammation/fibrosis. IL-32 is expressed by human hepatocytes and hepatoma cells and its expression is regulated by proinflammatory stimuli.

Adiponectin down-regulates COL-I expression in human hepatic stellate cells

AIM: To observe the effect of transfection of full-length adiponectin cDNA on the expression of collagen I (COL-I) in human hepatic stellate cells (LX-2) and to explore possible mechanisms involved.

METHODS: LX-2 cells were transfected with the empty plasmid (P7) or the recombinant plasmid carrying the full-length adiponectin cDNA. Forty-eight hours later, the expression of COL-I mRNA and protein was detected by real-time PCR and ELISA; cell survival was detected by MTT assay; apoptosis was detected by annexin V-FITC staining; and the changes in caspase-3 protein expression were detected by Western blot.

RESULTS: Compared to cells transfected with the empty plasmid and untransfected cells, the expression of COL-I mRNA and protein (179.00 ng/L ± 16.83 ng/L vs 532.30 ng/L ± 27.52 ng/L, 570.00 ng/L ± 16.12 ng/L, both P < 0.01) were significantly down-regulated, cell viability decreased (65.70% ± 1.56% vs 93.15% ± 1.90%, 95.82% ± 2.52%, both P < 0.01), apoptosis rate increased (14.70% ± 2.34% vs 1.60% ± 0.23%, 1.80% ± 0.15%, both P < 0.01), and the expression of caspase-3 was up-regulated (0.62 ± 0.09 vs 0.21 ± 0.04, 0.22 ± 0.07, both P < 0.01) in cells transfected with the recombinant plasmid.

CONCLUSION: Adiponectin can down-regulate COL-I expression, inhibit cell proliferation, induce caspase-3-mediated apoptosis, and thus restrain liver fibrosis.

Serum adiponectin and transient elastography as non-invasive markers for postoperative biliary atresia

Background

Biliary atresia (BA) is a progressive inflammatory disorder of the extrahepatic bile ducts leading to the obliteration of bile flow. The purpose of this study was to determine serum adiponectin in BA patients and to investigate the relationship of adiponectin with clinical parameters and liver stiffness scores.

Methods

Sixty BA patients post Kasai operation and 20 controls were enrolled. The mean age of BA patients and controls was 9.6 ± 0.7 and 10.1 ± 0.7 years, respectively. BA patients were classified into two groups according to their serum total bilirubin (TB) levels (non-jaundice, TB < 2 mg/dl vs. jaundice, TB ≥ 2 mg/dl) and liver stiffness (insignificant fibrosis, liver stiffness < 7 kPa vs. significant fibrosis, liver stiffness ≥ 7 kPa). Serum adiponectin levels were analyzed by enzyme-linked immunosorbent assay. Liver stiffness scores were examined by transient elastography (FibroScan).

Results

BA patients had markedly higher serum adiponectin levels (15.5 ± 1.1 vs. 11.1 ± 1.1 μg/ml, P = 0.03) and liver stiffness than controls (30.1 ± 3.0 vs. 5.1 ± 0.5 kPa, P < 0.001). Serum adiponectin levels were significantly elevated in BA patients with jaundice compared with those without jaundice (24.4 ± 1.4 vs. 11.0 ± 0.7 μg/ml, P < 0.001). In addition, BA patients with significant liver fibrosis had remarkably greater serum adiponectin than insignificant fibrosis counterparts (17.7 ± 1.2 vs. 9.4 ± 1.1 μg/ml, P < 0.001). Subsequent analysis revealed that serum adiponectin was positively correlated with total bilirubin, hyaluronic acid, and liver stiffness (r = 0.58, r = 0.46, and r = 0.60, P < 0.001, respectively).

Conclusions

Serum adiponectin and liver stiffness values were higher in BA patients compared with normal participants. The elevated serum adiponectin levels also positively correlated with the degree of hepatic dysfunction and liver fibrosis. Accordingly, serum adiponectin and transient elastography could serve as the useful non-invasive biomarkers for monitoring the severity and progression in postoperative BA.

Insulin resistance, serum leptin, and adiponectin levels and outcomes of viral hepatitis C cirrhosis

BACKGROUND & AIMS

Mechanisms linking obesity and unfavourable outcomes in patients with viral hepatitis C (HCV) cirrhosis are not well understood. Obesity is associated with insulin resistance, increased leptin, and decreased adiponectin serum levels.

METHODS

We assessed the predictive value of those factors for the occurrence of hepatocellular carcinoma (HCC) and liver-related death or transplantation in a cohort of 248 patients (mean age 58 (12 years, BMI 25.4 ± 4.4 kg/m(2)) with compensated HCV cirrhosis and persistent infection prospectively followed and screened for HCC.

RESULTS

The mean baseline serum levels of adiponectin and leptin were 16.8 ± 15 mg/L and 16.8 ± 19 ng/ml, respectively. The mean homeostasis model assessment of insulin resistance (HOMA) index was 3.8 ± 3; median 2.9. After a median follow-up of 72 months, 61 patients developed HCC, 58 died of liver causes, and 17 were transplanted. The incidences (Kaplan Meier) of HCC were 7%, 18%, and 27% at 5 years (p=0.017) and of liver-related death or transplantation 15%, 15% and 29% (p=0.002) according to the lowest, middle and highest tertile of HOMA, respectively. In multivariate analysis, the HOMA index was associated with HCC occurrence (HR=1.10, [1.01-1.21] p=0.026) and was a strong predictor of liver-related death or transplantation (HR=1.13, [1.07-1.21] p<0.0001). Serum levels of adiponectin and leptin were not associated with the outcome.

CONCLUSIONS

In patients with compensated HCV cirrhosis, insulin resistance but not serum levels of adiponectin and leptin predicted the occurrence of HCC and of liver-related death or transplantation.

Study of adiponectin in chronic liver disease and cholestasis

PURPOSE

Adiponectin is an adipocytokine suggested to have a hepatoprotective effect. To date, little information is available in the literature regarding changes in serum adiponectin levels in cirrhosis and cholestasis and the associated metabolic disturbances. In order to elucidate the role of adiponectin in chronic liver disease our aim was to determine serum adiponectin in patients with different grades of cirrhosis and cholestasis and to correlate it with markers of liver injury, inflammation and cholestasis. We also aimed to correlate adiponectin with markers of metabolic syndrome such as body mass index and insulin resistance.

METHODS

Forty patients with cirrhosis; 30 patients with cirrhosis and cholestasis; and 20 matched controls were studied. They were subjected to clinical assessment, laboratory investigations: serum bilirubin, ALT, AST, alkaline phosphatase, GGT, albumin, C-reactive protein, prothrombin activity, fasting blood sugar, insulin. HOMA index was calculated. Abdominal ultrasonography and upper GI endoscopy were performed.

RESULTS

Adiponectin was elevated in patients with cirrhosis and cirrhosis/cholestasis and was significantly higher in Child A and B. Adiponectin showed correlation with liver cell injury, marker of inflammation, synthetic liver function and markers of cholestasis. Adiponectin did not correlate with complications of cirrhosis as ascites and esophageal varices nor did it correlate with BMI or HOMA.

CONCLUSIONS

Adiponectin is elevated in cirrhosis and shows correlation with degree of hepatocellular injury and cholestasis. Finally, adiponectin levels in cirrhosis do not correlate with parameters of body composition or metabolism but exclusively with reduced liver function.

Insulin resistance is associated with hepatocellular carcinoma in chronic hepatitis C infection

AIM: To elucidate the role of insulin resistance (IR) and serum adiponectin level in hepatocellular carcinoma (HCC) associated with chronic hepatitis C.

METHODS: Clinical and biochemical characteristics were collected from 165 consecutive patients with newly diagnosed HCC. Homeostasis model assessment of IR (HOMA-IR) and serum adiponectin level were investigated in 188 patients with different stages of hepatitis C virus (HCV) infection.

RESULTS: Among HCC patients, type 2 diabetics (DM) was more prevalent in HCV subjects (35.6%, n = 59) compared to hepatitis B virus (HBV; 12.7%, n = 63) or non-HBV, non-HCV cases (7.1%, n = 28). In patients with chronic hepatitis C, HCC subjects had higher blood sugar (P < 0.001), insulin level (P = 0.003) and HOMA-IR (P = 0.018) than those with chronic hepatitis and advanced fibrosis. Age, male sex and body mass index were significantly associated with serum adiponectin level, whereas HOMA-IR was not. Based on stepwise logistic regression analysis, age (OR: 1.124, P < 0.001), serum insulin level (OR: 1.585, P < 0.001), HOMA-IR (OR: 0.495, P = 0.001), DM (OR: 11.601, P = 0.002) and male sex (OR: 3.877, P = 0.016) were independently associated with HCC. This result was similar even if the diabetic subjects were excluded for analysis.

CONCLUSION: Insulin resistance measured by HOMA-IR, regardless of the presence of diabetes, is significantly associated with HCC development in patients with chronic HCV infection.

Reduction of insulin resistance with effective clearance of hepatitis C infection: results from the HALT-C trial

BACKGROUND & AIMS

Hepatitis C virus (HCV) infection is associated with an increased prevalence of diabetes and insulin resistance (IR); whether this is a causal relationship has not been established.

METHODS

We performed a longitudinal study within the lead-in phase of the Hepatitis C Antiviral Long-Term Treatment against Cirrhosis (HALT-C) Trial to evaluate whether suppression of hepatitis C is associated with improvement in IR. Participants had advanced hepatic fibrosis and carried non-3 HCV genotypes (n = 96). Patients underwent 24 weeks of pegylated interferon and ribavirin therapy and were categorized into HCV clearance groups at week 20 on the basis of HCV RNA levels; null responders had <1 log(10) decline (n = 38), partial responders had >or=1 log(10) decline (n = 37) but detectable HCV RNA, and complete responders had no detectable HCV RNA (n = 21). The primary outcome was change (week 20 minus week 0) in IR by using the homeostasis model assessment (HOMA2-IR).

RESULTS

Adjusting only for baseline HOMA2-IR, mean HOMA2-IR differences were -2.23 (complete responders), -0.90 (partial responders), and +0.18 (null responders) (P = .036). The observed differences in mean HOMA2-IR scores were ordered in a linear fashion across response groups (P = .01). The association between HCV clearance and improvement in HOMA2-IR could not be accounted for by adiponectin or tumor necrosis factor-alpha and was independent of potential confounders including age, gender, ethnicity, body mass index, duration of infection, medications used, and fibrosis.

CONCLUSIONS

HCV suppression correlates with improvement in IR. These data provide further support for a role of HCV in the development of insulin resistance.

The role of adiponectin in the pathogenesis and treatment of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is recognized as the most common type of chronic liver disease in Western countries and the leading cause of cryptogenic cirrhosis. Insulin resistance (IR) is a key factor in the pathogenesis of NAFLD, the latter being considered as the hepatic component of IR or metabolic syndrome (MetS). Although the pathogenesis of NAFLD is not fully elucidated, a complex interaction between adipokines and cytokines produced by adipocytes and/or inflammatory cells infiltrating adipose tissue appears to play a crucial role in MetS and NAFLD. Adiponectin is the most abundant and adipose-specific adipokine. In the liver, adiponectin acts through the activation of 5-AMP-activated protein kinase and peroxisome proliferator-activated receptor-alpha pathways and inhibition of toll-like receptor-4 mediated signalling. There is an evidence that adiponectin decreases hepatic and systematic IR and attenuates liver inflammation and fibrosis. Adiponectin generally predicts steatosis grade and severity of NAFLD, but it remains to be addressed to what extent this is a direct effect or related to the presence of more severe IR. Although there is no proven pharmacotherapy for the treatment of NAFLD, recent therapeutic strategies have focused on the indirect upregulation of adiponectin through the administration of various therapeutic agents and/or lifestyle modifications. Weight loss, through diet, lifestyle changes and/or medications including orlistat, sibutramine, rimonabant or bariatric surgery, increase adiponectin and may improve liver histology. Insulin sensitizers, including pioglitazone and rosiglitazone, and lipid-lowering agents, including statins and fibrates, also upregulate adiponectin and ameliorate liver histology. The wider use of new treatment approaches appears to signal the dawn of a new era in the management of NAFLD. In this adiponectin-focused review, the pathogenetic role and the potential therapeutic benefits of adiponectin in NAFLD are systematically analysed.