Cirrhosis and insulin resistance: current knowledge, pathophysiological mechanisms, complications and potential treatments

Unlocking liver health: Can tackling myosteatosis spark remission in metabolic dysfunction-associated steatotic liver disease?

Myosteatosis is highly prevalent in metabolic dysfunction-associated steatotic liver disease (MASLD) and could reciprocally impact liver function. Decreasing muscle fat could be indirectly hepatoprotective in MASLD. We conducted a review to identify interventions reducing myosteatosis and their impact on liver function. Non-pharmacological interventions included diet (caloric restriction or lipid enrichment), bariatric surgery and physical activity. Caloric restriction in humans achieving a mean weight loss of 3% only reduces muscle fat. Lipid-enriched diet increases liver fat in human with no impact on muscle fat, except sphingomyelin-enriched diet which reduces both lipid contents exclusively in pre-clinical studies. Bariatric surgery, hybrid training (resistance exercise and electric stimulation) or whole-body vibration in human decrease both liver and muscle fat. Physical activity impacts both phenotypes by reducing local and systemic inflammation, enhancing insulin sensitivity and modulating the expression of key mediators of the muscle-liver-adipose tissue axis. The combination of diet and physical activity acts synergistically in liver, muscle and white adipose tissue, and further decrease muscle and liver fat. Several pharmacological interventions (patchouli alcohol, KBP-089, 2,4-dinitrophenol methyl ether, adipoRon and atglistatin) and food supplementation (vitamin D or resveratrol) improve liver and muscle phenotypes in pre-clinical studies by increasing fatty acid oxidation and anti-inflammatory properties. These interventions are effective in reducing myosteatosis in MASLD while addressing the liver disease itself. This review supports that disturbances in inter-organ crosstalk are key pathophysiological mechanisms involved in MASLD and myosteatosis pathogenesis. Focusing on the skeletal muscle might offer new therapeutic strategies to treat MASLD by modulating the interactions between liver and muscles.

Severe insulin resistance in a patient with diabetes after treatment with brentuximab vedotin

A man in his late 60s with a history of well-controlled type 2 diabetes and hepatic cirrhosis presented to the emergency department due to uncontrollable hyperglycaemia following the initial brentuximab vedotin (BV) infusion. BV was initiated as a treatment for mycosis fungoides, a form of cutaneous T-cell lymphoma. The patient was diagnosed with severe hyperglycaemia with ketosis. Empiric treatment with amoxicillin-clavulanic acid, hydration and intravenous insulin infusion was initiated. Hyperglycaemia persisted despite receiving massive amounts of insulin and was corrected only after treatment with high-dose methylprednisolone for suspected type B insulin resistance. Extremely high and difficult-to-treat hyperglycaemia is a rare side effect of BV. Unfortunately, the patient died of upper gastrointestinal bleeding 22 days after discharge. In patients with obesity and/or diabetes mellitus, the blood glucose levels should be carefully monitored when treated with BV.

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

BACKGROUND & AIMS

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

METHODS

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

RESULTS

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

CONCLUSION

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

Life-course adiposity and severe liver disease: a Mendelian randomization analysis

OBJECTIVE

There is little evidence on the genetic associations between life-course adiposity (including birth weight, childhood BMI, and adulthood BMI) and severe liver disease (SLD; including cirrhosis and liver cancer). The current study aimed to examine and contrast these associations.

METHODS

Genetic variants were obtained from genome-wide association studies. Two-sample Mendelian randomization (MR) analyses were performed to assess the genetic associations of life-course adiposity with SLD and liver biomarkers. Cox regression was used to estimate adjusted hazard ratios for SLD associated with genetic risk scores of life-course adiposity and adulthood weight change in the China Kadoorie Biobank.

RESULTS

In observational analyses, genetic predispositions to childhood adiposity and adulthood adiposity were each associated with SLD. There was a U-shaped association between adulthood weight change and risk of SLD. In meta-analyses of MR results, genetically predicted 1-standard deviation increase in birth weight was inversely associated with SLD at a marginal significance (odds ratio: 0.81 [95% CI: 0.65-1.00]), whereas genetically predicted 1-standard deviation higher childhood BMI and adulthood BMI were positively associated with SLD (odds ratio: 1.27 [95% CI: 1.05-1.55] and 1.79 [95% CI: 1.59-2.01], respectively). The results of liver biomarkers mirrored those of SLD.

CONCLUSIONS

The current study provided genetic evidence on the associations between life-course adiposity and SLD.

Insulin Resistance: An Unresolved Riddle

Insulin resistance (IR) is a rather common condition that is often diagnosed on the basis of an arbitrary "increased insulin value" or the presence of symptoms indicative of the Metabolic Syndrome [...].

The Intestinal Microbiome and the Metabolic Syndrome-How Its Manipulation May Affect Metabolic-Associated Fatty Liver Disease (MAFLD)

Metabolic-associated fatty liver disease (MAFLD) is now the predominant liver disease worldwide consequent to the epidemic of obesity. The intestinal microbiome (IM), consisting of the bacteria, fungi, archaea, and viruses residing in the gastrointestinal tract, plays an important role in human metabolism and preserving the epithelial barrier function. Disturbances in the IM have been shown to influence the development and progression of MAFLD and play a role in the development of metabolic syndrome (MS). The main treatment for MAFLD involves lifestyle changes, which also influence the IM. Manipulation of the IM by fecal microbial transplantation (FMT) has been approved for the treatment of recurrent Closteroides difficile infection. This may be administered by endoscopic administration from the lower or upper GI tract. Other methods of administration include nasogastric tube, enema, and oral capsules of stool from healthy donors. In this narrative review, we elaborate on the role of the IM in developing MS and MAFLD and on the current experience with IM modulation by FMT on MAFLD.

Evaluation and Management of Nutritional Consequences of Chronic Liver Diseases

Liver diseases are the major predisposing conditions for the development of malnutrition, sarcopenia, and frailty. Recently, the mechanism of the onset of these complications has been better established. Regardless of the etiology of the underlying liver disease, the clinical manifestations are common. The main consequences are impaired dietary intake, altered macro- and micronutrient metabolism, energy metabolism disturbances, an increase in energy expenditure, nutrient malabsorption, sarcopenia, frailty, and osteopathy. These complications have direct effects on clinical outcomes, survival, and quality of life. The nutritional status should be assessed systematically and periodically during follow-up in these patients. Maintaining and preserving an adequate nutritional status is crucial and should be a mainstay of treatment. Although general nutritional interventions have been established, special considerations are needed in specific settings such as decompensated cirrhosis, alcohol-related liver disease, and metabolic-dysfunction-associated fatty liver disease. In this review, we summarize the physiopathology and factors that impact the nutritional status of liver disease. We review how to assess malnutrition and sarcopenia and how to prevent and manage these complications in this setting.

The crucial role and mechanism of insulin resistance in metabolic disease

Insulin resistance (IR) plays a crucial role in the development and progression of metabolism-related diseases such as diabetes, hypertension, tumors, and nonalcoholic fatty liver disease, and provides the basis for a common understanding of these chronic diseases. In this study, we provide a systematic review of the causes, mechanisms, and treatments of IR. The pathogenesis of IR depends on genetics, obesity, age, disease, and drug effects. Mechanistically, any factor leading to abnormalities in the insulin signaling pathway leads to the development of IR in the host, including insulin receptor abnormalities, disturbances in the internal environment (regarding inflammation, hypoxia, lipotoxicity, and immunity), metabolic function of the liver and organelles, and other abnormalities. The available therapeutic strategies for IR are mainly exercise and dietary habit improvement, and chemotherapy based on biguanides and glucagon-like peptide-1, and traditional Chinese medicine treatments (e.g., herbs and acupuncture) can also be helpful. Based on the current understanding of IR mechanisms, there are still some vacancies to follow up and consider, and there is also a need to define more precise biomarkers for different chronic diseases and lifestyle interventions, and to explore natural or synthetic drugs targeting IR treatment. This could enable the treatment of patients with multiple combined metabolic diseases, with the aim of treating the disease holistically to reduce healthcare expenditures and to improve the quality of life of patients to some extent.

Improving the prognosis before and after liver transplantation: Is muscle a game changer?

Liver transplantation (LT) is currently the only curative treatment option for selected patients with end stage liver disease or hepatocellular carcinoma. Improving waiting list-mortality, post-transplant morbidity and mortality and refining the selection of the patients remain our current central objectives. In this field, different concepts dealing with nutrition and the muscle such as sarcopenia, malnutrition, frailty or myosteatosis have emerged as possible game changers. For more than a decade, many prospective studies have demonstrated that sarcopenia and frailty are major predictive factors of mortality in the waiting list but also after LT. Malnutrition is also a well-known risk factor for morbidity and mor-tality. Muscle composition is a newer concept giving insight on muscle quality which has also been shown to be linked to poorer outcomes. Each of these terms has a precise definition as well as pathophysiological mechanisms. The bi-directional liver-muscle axis makes sense in this situation. Defining the best, easy to use in clinical practice tools to assess muscle quality, quantity, and function in this specific population and developing quality prospective studies to identify interventional strategies that could improve these parameters as well as evaluate the effect on mortality are among the important challenges of today.

Liver Fetuin-A at Initiation of Insulin Resistance

Hepatokines (liver secreted proteins with possible distant action) are emerging potential players in insulin resistance in type 2 diabetic patients. Here, we explored the effect of a high-fat diet on the expression of fetuin-A, one of those candidate liver proteins, and its relationship with liver macrophage activation. Mice were fed a normal diet or a high-fat diet for 3 days, known to initiate steatosis and liver insulin resistance. A preventive liver macrophage depletion was obtained by intravenous injection of clodronate-loaded liposomes. The mRNA and protein expression of fetuin-A was evaluated by qPCR, Western blot and immunofluorescence on different insulin-sensitive tissues (liver, adipose tissue, and muscle). Short-term high-fat diet-induced steatosis, liver macrophage activation, and hepatic insulin resistance together with a significantly increased expression of liver AHSG (α2-HS glycoprotein/fetuin-A) mRNA and serum fetuin-A concentration. On immunofluorescence, fetuin-A was mostly expressed in centrilobular hepatocytes. This increase in fetuin-A under high-fat diet was not evidenced in other peripheral insulin-sensitive tissues (skeletal muscle and adipose tissue). The mRNA expression of α2-HS glycoprotein was 800 times higher within the liver compared with the adipose tissue or the muscle. Liver macrophage depletion that significantly ameliorated insulin sensitivity was associated with a significant decrease in α2-HS glycoprotein mRNA expression. In conclusion, this study demonstrated liver fetuin-A overexpression at the initiation of high-fat diet feeding, concurrent with hepatic steatosis and insulin resistance. Targeting liver macrophages in this setting reduced liver α2-HS glycoprotein expression suggesting that fetuin-A acts as an hepatokine with proinsulin resistance effects.

Targeting the Gut Microbiome to Treat Metabolic Dysfunction-Associated Fatty Liver Disease: Ready for Prime Time?

Numerous studies show a modification of the gut microbiota in patients with obesity or diabetes. Animal studies have also shown a causal role of gut microbiota in liver metabolic disorders including steatosis whereas the human situation is less clear. Patients with metabolic dysfunction associated fatty liver disease (MAFLD) also have a modification in their gut microbiota composition but the changes are not fully characterized. The absence of consensus on a precise signature is probably due to disease heterogeneity, possible concomitant medications and different selection or evaluation criteria. The most consistent changes were increased relative abundance of Proteobacteria, Enterobacteriaceae and Escherichia species and decreased abundance of Coprococcus and Eubacterium. Possible mechanisms linking the microbiota and MAFLD are increased intestinal permeability with translocation of microbial products into the portal circulation, but also changes in the bile acids and production of microbial metabolites such as ethanol, short chain fatty acids and amino acid derivatives able to modulate liver metabolism and inflammation. Several interventional studies exist that attempt to modulate liver disease by administering antibiotics, probiotics, prebiotics, synbiotics, postbiotics or fecal transplantation. In conclusion, there are both gaps and hopes concerning the interest of gut microbiome evaluation for diagnosis purposes of MAFLD and for new therapeutic developments that are often tested on small size cohorts.

Sarcopenia in Patients with Cirrhosis after Transjugular Intrahepatic Portosystemic Shunt Placement

Background Sarcopenia is frequently found in patients with cirrhosis and is associated with liver dysfunction, cirrhosis-related complications, and poorer quality of life. Purpose To evaluate changes in skeletal muscle and fat mass at CT and to evaluate the relationship of sarcopenia to mortality in patients with cirrhosis after transjugular intrahepatic portosystemic shunt (TIPS) placement. Materials and Methods Patients who underwent TIPS between August 2016 and May 2020 were included in this retrospective study. Skeletal muscle and fat mass were evaluated at CT at the L3 vertebra at baseline and at 2 months, 5 months, and 1 year after TIPS. Sarcopenia was defined as L3 skeletal muscle index (SMI) less than 50 cm²/m² for men and less than 39 cm²/m² for women. The primary end point was change in skeletal muscle and fat mass, and secondary end points included survival and the predictive factors for survival. Changes in skeletal muscle and fat mass over time were analyzed by generalized estimating equations. Results A total of 224 patients (159 men [113 with and 46 without sarcopenia] and 65 women [32 with and 33 without sarcopenia]) were included. In male patients with sarcopenia, the mean L3 SMI increased from 41.8 cm²/m² (baseline) to 49.1 cm²/m² (at 5-month follow-up; P < .001) and 49.6 cm²/m² (at 1-year follow-up; P < .001) after TIPS. In female patients with sarcopenia, SMI increased from 33.7 cm²/m² (at baseline) to 40.6 cm²/m² (at 5-month follow-up; P < .001) and 42.0 cm²/m² (at 1-year follow-up; P < .001) after TIPS. Sarcopenia (hazard ratio, 3.0; 95% CI: 1.2, 7.8) was identified as an independent risk factor for mortality after TIPS, and the patients who converted from sarcopenic to nonsarcopenic had higher cumulative survival rate than those who did not (96.4% vs 82.1%; log-rank P = .04). Conclusion In patients with sarcopenia, both skeletal muscle and fat mass increased after transjugular intrahepatic portosystemic shunt placement. The reversal of sarcopenia could reduce the risk of death. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Lee in this issue.

Cirrhosis-associated immune dysfunction

The term cirrhosis-associated immune dysfunction (CAID) comprises the distinctive spectrum of immune alterations associated with the course of end-stage liver disease. Systemic inflammation and immune deficiency are the key components of CAID. Their severity is highly dynamic and progressive, paralleling cirrhosis stage. CAID involves two different immune phenotypes: the low-grade systemic inflammatory phenotype and the high-grade systemic inflammatory phenotype. The low-grade systemic inflammatory phenotype can be found in patients with compensated disease or clinical decompensation with no organ failure. In this phenotype, there is an exaggerated immune activation but the effector response is not markedly compromised. The high-grade systemic inflammatory phenotype is present in patients with acute-on-chronic liver failure, a clinical situation characterized by decompensation, organ failure and high short-term mortality. Along with high-grade inflammation, this CAID phenotype includes intense immune paralysis that critically increases the risk of infections and worsens prognosis. The intensity of CAID has important consequences on cirrhosis progression and correlates with the severity of liver insufficiency, bacterial translocation and organ failure. Therapies targeting the modulation of the dysfunctional immune response are currently being evaluated in preclinical and clinical studies.

Association Between Metabolic Dysfunction-Associated Fatty Liver Disease and the Risk of Cirrhosis in Patients with Chronic Hepatitis B-A Retrospective Cohort Study

BACKGROUND

Metabolic dysfunction-associated fatty liver disease (MAFLD) is a novel proposed concept that is being recognized worldwide. Both chronic hepatitis B (CHB) and MAFLD have been independently attributed to an increased risk of disease development to cirrhosis. However, it is still unclear whether MAFLD is associated with an increased risk of cirrhosis in CHB patients.

AIM

This study aimed to analyze the impact of MAFLD on the risk of cirrhosis in CHB patients.

METHODS

In this retrospective cohort study, consecutive CHB patients with or without MAFLD were enrolled from January 1st, 2007, to May 1st, 2020, in Guangdong Provincial Hospital of Chinese Medicine. Inverse probability treatment weighting (IPTW) was performed to balance the covariates across groups. The weighted Kaplan-Meier analysis and Cox regression analysis were used to compare both groups for the risk of cirrhosis.

RESULTS

A total of 1223 CHB patients were included in this study during the median follow-up of 5.25 years; of these patients, 355 were CHB-MAFLD patients. After IPTW, the weighted Kaplan-Meier analysis showed that the weighted cumulative incidence of cirrhosis was significantly higher in patients with MAFLD than that in patients without MAFLD (12.6% versus 7.1%, P=0.015). In the weighted multivariate Cox analysis, coexisting MAFLD was related to an increased risk of cirrhosis [adjusted weighted hazard ratio (HR) 1.790; P =0.020]. Age (>40 years, adjusted weighted HR, 1.950; P=0.015), diabetes mellitus (adjusted weighted HR, 1.883; P=0.041), non-antiviral treatment (adjusted weighted HR, 2.037; P=0.013), and baseline serum HBV DNA levels (>2.4 log¹⁰ IU/mL, adjusted weighted HR, 1.756; P=0.045) were significant risk factors for cirrhosis.

CONCLUSION

We found that MAFLD was associated with a higher risk of cirrhosis in CHB patients.

Glycoursodeoxycholic acid ameliorates diet-induced metabolic disorders with inhibiting endoplasmic reticulum stress

Recent studies reveal that bile acid metabolite composition and its metabolism are changed in metabolic disorders, such as obesity, type 2 diabetes and metabolic associated fatty liver disease (MAFLD), yet its role and the mechanism remain largely unknown. In the present study, metabolomic analysis of 163 serum and stool samples of our metabolic disease cohort was performed, and we identified glycoursodeoxycholic acid (GUDCA), glycine-conjugated bile acid produced from intestinal bacteria, was decreased in both serum and stool samples from patients with hyperglycemia. RNA-sequencing and quantitative PCR results indicated that GUDCA alleviated endoplasmic reticulum (ER) stress in livers of high fat diet (HFD)-fed mice without alteration of liver metabolism. In vitro, GUDCA reduced palmitic acid induced-ER stress and -apoptosis, as well as stabilized calcium homeostasis. In vivo, GUDCA exerted effects on amelioration of HFD-induced insulin resistance and hepatic steatosis. In parallel, ER stress and apoptosis were decreased in GUDCA-treated mice as compared with vehicle-treated mice in liver. These findings demonstrate that reduced GUDCA is an indicator of hyperglycemia. Supplementation of GUDCA could be an option for the treatment of diet-induced metabolic disorders, including insulin resistance and hepatic steatosis, with inhibiting ER stress.

Muscle mass depletion in chronic liver diseases: An accelerated model of aging or a distinct entity?

Sarcopenia was initially defined as loss of muscle mass, strength and function related to aging. This phenomenon is a multifactorial process. The evaluation of the geriatric population in which sarcopenia has extensively been studied opens the field for other chronic diseases. Cirrhosis is one of them and the term "sarcopenia" is now also used in this pathological situation. It must be emphasized that the pathophysiology of sarcopenia in cirrhosis is likely different from the pathogenesis in geriatric patients. Furthermore, cirrhosis has heterogeneous causes. Therefore, we need a better understanding of the changes in muscle physiology specifically in chronic liver diseases as well as easy, accurate, reproducible and validated tools, taking into consideration etiology specific aspects to identify sarcopenia in every cirrhotic patient.

Risk of hepatocellular carcinoma and fibrosis evolution in hepatitis C patients with severe fibrosis or cirrhosis treated with direct acting antiviral agents

Background and study aims

Cirrhosis associated to chronic hepatitis C virus (HCV) is one of the leading cause of hepatocellular carcinoma (HCC). The goal of our study was to evaluate first the risk and determinants of HCC and second the evolution of fibrosis in patients treated for HCV with advanced fibrosis stages who achieved sustained virological response (SVR) after direct-acting antivirals (DAA) treatment.

Patients and methods

We conducted a prospective study on HCV patients with F3 or F4 Metavir fibrosis scores treated with DAA between October 2014 and February 2017. The annual incidence rate for HCC was calculated. We used Cox regression model in order to identify factors associated with HCC. Transient elastography (TE) was performed 12 and 24 months after the end of DAA treatment and non-invasive liver fibrosis biomarkers were performed twice a year during follow-up.

Results

143 patients with severe fibrosis or cirrhosis were enrolled in the study. 6 patients developed HCC. The annual incidence rate of HCC in our cohort was 2.7 per 100 patients. Risk factors associated with HCC after DAA were genotype 2 and steatosis. Overall TE values significantly decreased after DAA treatment with a median value prior to treatment of 16.9 kPa to a median of 10.8 kPa 24 months after the end of the treatment. Biological fibrosis scores also significantly decreased following viral eradication.

Conclusions

DAA treatment does not seem to be associated with HCC promotion after HCV eradication in patients with severe fibrosis stages. DAA-induced SVR is associated with a reduced estimation of fibrosis.