Non-alcoholic fatty liver disease in obese adults: clinical aspects and current management strategies

Small molecule-driven LKB1 deacetylation is responsible for the inhibition of hepatic lipid response in NAFLD

Nonalcoholic fatty liver disease (NAFLD) is a progressive condition characterized by ectopic fat accumulation in the liver, for which no FAD-approved drugs currently exist. Emerging evidence highlights the role of liver kinase B1 (LKB1), a key metabolic regulator, has been proposed in NAFLD, particularly in response to excessive nutrient levels. However, few agents have been identified that can prevent the progression of nonalcoholic steatohepatitis (NASH) by targeting LKB1 deacetylation. Through comprehensive screening of our in-house chemical library, we identified tranilast, a small molecule with remarkable inhibitory efficacy against lipid deposition induced by palmitic acid/oleic acid (PO). In this study, we investigated the novel biological function and mechanism of tranilast in regulating hepatic lipid response in NAFLD, focusing on its role in LKB1 deacetylation within hepatocytes. Our findings demonstrate that tranilast effectively reduced hepatic steatosis, inflammation, and fibrosis in NASH models induced by high-fat and high-cholesterol (HFHC) and methionine choline-deficient (MCD) diets. Mechanistic analysis using RNA sequencing revealed that tranilast mitigated hepatic lipid response by promoting LKB1 deacetylation and activating AMPK. Notably, in vivo experiments showed that the beneficial effects of tranilast in MCD diet-induced NASH model were reversed by the compound C (C-C), a known AMPK inhibitor, confirming that tranilast's effects on hepatic lipid response are mediated through the AMPK pathway. In summary, tranilast inhibits hepatic lipid response in NAFLD through LKB1 deacetylation, providing robust experimental evidence for the role of LKB1 in NAFLD. These findings position tranilast as a promising therapeutic candidate for the pharmacological management of metabolic diseases.

The Role of Dietary Ingredients and Herbs in the Prevention of Non-Communicable Chronic Liver Disease

BACKGROUND

Liver diseases are among the most commonly diagnosed conditions, with the main risk factors being inappropriate lifestyles, including poor diet, excessive alcohol consumption, low physical activity and smoking, including electronic cigarettes. Non-communicable chronic liver diseases also often develop as a result of accompanying overweight and obesity, as well as type 2 diabetes.

METHODS

The literature on risk factors for non-communicable chronic liver diseases, which show a high strong influence on their occurrence, was analysed.

RESULTS

Measures to prevent non-communicable chronic liver disease include the selection of suitable food ingredients that have proven protective effects on the liver. Such ingredients include dietary fibre, probiotics, herbs, various types of polyphenols and fatty acids (omega-3).

CONCLUSIONS

Because of their liver-protective effects, nutritionists recommend consuming vegetables, fruits, herbs and spices that provide valuable ingredients with anti-inflammatory and anti-cancer effects. These components should be provided with food and, in the case of probiotics, supplementation appears to be important. As a preventive measure, a diet rich in these nutrients is therefore recommended, as well as one that prevents overweight and other diseases that can result in liver disease.

Biochemical and nutritional determinants of non-alcoholic fatty liver disease in Omani adult patients: a case-control study

Background: Non-Alcoholic Fatty Liver Disease (NAFLD) is a risk factor for atherosclerosis, diabetes, kidney disease, and liver cirrhosis. Limited research exists on the biochemical and nutritional elements influencing NAFLD among adult patients in Oman. Objective: This study aimed to characterize the biochemical parameters and nutritional factors of Omani adults diagnosed with NAFLD at the Diwan Polyclinic in Muscat, Oman. Methods: This retrospective case–control study included 104 participants (52 cases and 52 controls) who have 2 or more risk factors for NAFLD and were referred to the Radiology department from January 2021 to January 2022 for abdominal ultrasound after Internal Medicine consultations. A validated scale, incorporating a semi-quantitative food frequency questionnaire, was employed. Results: The study revealed a significantly higher risk of NAFLD among men (69%) compared to women (31%). A common characteristic among participants was a prior diabetes diagnosis, 61.5% of the case group and 65% of the control group. While average liver enzyme levels were within the normal range for both groups, alanine transaminase levels were notably elevated in the case group. The case group exhibited a significantly higher average caloric intake than the control group. Conclusion: NAFLD is significantly more common among men. Alanine transaminase is significantly high in NAFLD group, which might be considered as a biochemical marker for NAFLD, but further investigations are needed. Moreover, high daily caloric intake is directly related to NAFLD.

Oral Health and "Modern" Digestive Diseases: Pathophysiologic and Etiologic Factors

In the contemporary era of medicine, exploring the complexity of the human body and its intricate interactions has become a central concern for health researchers. The main purpose of this article is to summarize the current understanding of relevant pathophysiological factors such as chronic inflammation, dysbiosis (microbial imbalance), and metabolic disorders, as well as etiological factors including dietary habits, lifestyle choices, obesity, metabolic syndrome, and genetic predispositions, as well as to emphasize potential avenues for upcoming studies and their medical significance. Additionally, this article aims to assess the potential impact of integrated treatment approaches on patient outcomes, emphasizing the need for interdisciplinary collaboration between gastroenterologists, dentists, and other healthcare professionals to develop comprehensive care plans that address both oral and digestive health issues simultaneously. Among the branches with a significant impact on general well-being are oral cavity health and digestive diseases, which have been the subject of intensive research in recent decades. In this context, analysis of the current state of knowledge on oral cavity disorders in relation to "modern" digestive diseases such as non-alcoholic fatty liver disease (NAFLD), small intestinal bacterial overgrowth (SIBO), inflammatory bowel disease (IBD), and irritable bowel syndrome (IBS) becomes essential for a deeper understanding of the interconnections between oral and digestive health. The temporal overlap or succession, whether preceding or following, of oral manifestations and digestive disorders should be taken seriously by both gastroenterologists and dentists to facilitate early diagnosis and explain to patients the correlation between these two body systems. In summary, this article underscores the importance of understanding the intricate relationship between oral and digestive health, advocating for interdisciplinary approaches to improve patient outcomes and guide future research.

Nutrition in Liver Disease - A Review

PURPOSE OF REVIEW : Nutrition is commonly overlooked in chronic liver disease. Both obesity and malnutrition are independent risk factors of poor prognosis in cirrhosis. This review aims to summarize the current literature regarding how nutrition contributes to liver disease, how to screen patients, and what nutritional and activity recommendations can help prevent adverse outcomes. RECENT FINDINGS: Screening for malnutrition, obesity, and sarcopenia through ambulatory bedside methods is recommended every 8-12 weeks in high risk patients. A Mediterranean diet with emphasis on high protein intake of 1.2-1.5 g/kg/day, and increasing physical activity can help to improve nutritional status. It remains critical to screen and identify patients with liver disease for malnutrition, obesity, and sarcopenia. Identifying an individualized action plan through a multidisciplinary approach can be helpful. Dietary recommendations to improve outcomes should be based on well-studied approaches. These can include the use of the Mediterranean diet in those with metabolic dysfunction-associated steatotic liver disease (MASLD) and a high protein diet in those with cirrhosis and sarcopenia. Routine assessment of improvement or decline should continue throughout a patient's clinical course.

Role of Oxidative Stress and Carcinoembryonic Antigen-Related Cell Adhesion Molecule 1 in Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) has become a widely studied subject due to its increasing prevalence and links to diseases such as type 2 diabetes and obesity. It has severe complications, including nonalcoholic steatohepatitis, cirrhosis, hepatocellular carcinoma, and portal hypertension that can lead to liver transplantation in some cases. To better prevent and treat this pathology, it is important to understand its underlying physiology. Here, we identify two main factors that play a crucial role in the pathophysiology of NAFLD: oxidative stress and the key role of carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1). We discuss the pathophysiology linking these factors to NAFLD pathophysiology.

Adipokine gremlin-1 promotes hepatic steatosis via upregulation of ER stress by suppressing autophagy-mediated signaling

Gremlin-1 (GR1) is a novel adipokine that is highly expressed in human adipocytes and has been shown to inhibit the BMP2/4-TGFb signaling pathway. It has an effect on insulin sensitivity. Elevated levels of Gremlin have been shown to lead to insulin resistance in skeletal muscle, adipocytes, and hepatocytes. In this study, we investigated the effect of GR1 on hepatic lipid metabolism under hyperlipidemic conditions and explored the molecular mechanisms associated with GR1 by in vitro and in vivo studies. We found that palmitate increased GR1 expression in visceral adipocytes. Recombinant GR1 increased lipid accumulation, lipogenesis, and ER stress markers in cultured primary hepatocytes. Treatment with GR1 increased EGFR expression and mTOR phosphorylation and reduced autophagy markers. EGFR or rapamycin siRNA reduced the effects of GR1 on lipogenic lipid deposition and ER stress in cultured hepatocytes. Administration of GR1 via the tail vein induced lipogenic proteins and ER stress while suppressing autophagy in the livers of experimental mice. Suppression of GR1 by in vivo transfection reduced the effects of a high-fat diet on hepatic lipid metabolism, ER stress, and autophagy in mice. These results suggest that the adipokine GR1 promotes hepatic ER stress due to the impairment of autophagy, ultimately causing hepatic steatosis in the obese state. The current study demonstrated that targeting GR1 may be a potential therapeutic approach for treating metabolic diseases, including metabolic-associated fatty liver disease (MAFLD).

Fatty Liver Disease-Alcoholic and Non-Alcoholic: Similar but Different

In alcohol-induced liver disease (ALD) and in non-alcoholic fatty liver disease (NAFLD), there are abnormal accumulations of fat in the liver. This phenomenon may be related to excessive alcohol consumption, as well as the combination of alcohol consumption and medications. There is an evolution from simple steatosis to steatohepatitis, fibrosis and cirrhosis leading to hepatocellular carcinoma (HCC). Hepatic pathology is very similar regarding non-alcoholic fatty liver disease (NAFLD) and ALD. Initially, there is lipid accumulation in parenchyma and progression to lobular inflammation. The morphological changes in the liver mitochondria, perivenular and perisinusoidal fibrosis, and hepatocellular ballooning, apoptosis and necrosis and accumulation of fibrosis may lead to the development of cirrhosis and HCC. Medical history of ethanol consumption, laboratory markers of chronic ethanol intake, AST/ALT ratio on the one hand and features of the metabolic syndrome on the other hand, may help in estimating the contribution of alcohol intake and the metabolic syndrome, respectively, to liver steatosis.

Rare leptin in non-alcoholic fatty liver cirrhosis: A case report

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD)-related cirrhosis is mainly caused by NAFLD by causing inflammation which leads to fibrosis. The role of leptin in NAFLD-related cirrhosis has been rarely reported.

CASE SUMMARY

This study presents the case of a 65-year-old male patient who was referred to The First Affiliated Hospital of Guangxi University of Chinese Medicine, Guangxi, China, for diagnosis and treatment for liver cirrhosis. Initially, the cause of liver cirrhosis was unknown. After radiology, laboratory examination, pathological results and analysis of the patient’s signs and symptoms, the case was finally diagnosed with final NAFLD-related cirrhosis. Although this study reports a single case, the findings might expand the understanding of leptin’s role in NAFLD-related cirrhosis and might provide a basis for the clinical diagnostic criteria, pathological features and treatment of NAFLD-related cirrhosis.

CONCLUSION

Although the occurrence of marasmus NAFLD-related cirrhosis is rare, it needs to be distinguished from other liver diseases, including viral hepatitis, drug-induced liver disease, Wilson's disease and autoimmune liver disease. Aggressive treatment is needed to prevent the progression of NAFLD-related cirrhosis.

Non-Alcoholic Fatty Liver Disease and Extrahepatic Cancers: A Wolf in Sheep’s Clothing?

Non-alcoholic fatty liver disease (NAFLD) is now considered the main driver and leading cause of chronic liver disease globally. The umbrella term NAFLD describes a range of liver conditions closely related to insulin resistance, metabolic syndrome, diabetes mellitus, obesity, and dyslipidemia. At the same time, several malignancies, including hepatocellular carcinoma and colorectal cancer, are considered to be common causes of death among patients with NAFLD. At first, our review herein aims to investigate the role of NAFLD in developing colorectal neoplasms and adenomatous polyps based on the current literature. We will also explore the connection and the missing links between NAFLD and extrahepatic cancers. Interestingly, any relationship between NAFLD and extrahepatic malignancies could be attributable to several shared metabolic risk factors. Overall, obesity, insulin resistance, metabolic syndrome, and related disorders may increase the risk of developing cancer. Therefore, early diagnosis of NAFLD is essential for preventing the progression of the disease and avoiding its severe complications. In addition, cancer screening and early detection in these patients may improve survival and reduce any delays in treatment.

Acetate-mediated-obestatin modulation attenuates adipose-hepatic dysmetabolism in high fat diet-induced obese rat model

PURPOSE

Approximately 650 million of world adult population is affected by obesity, which is characterized by adipose and hepatic metabolic dysfunction. Short chain fatty acids (SCFAs) have been linked to improved metabolic profile. However, the effect of SCFAs, particularly acetate on adipose-hepatic dysfunction is unclear. Therefore, the present study investigated the role of acetate on adipose-hepatic metabolic dysfunction and the possible involvement of obestatin in high fat diet-induced obese Wistar rats.

METHODS

Adult male Wistar rats (160-190 g) were allotted into groups (n = 6/group): Control, acetate-treated, obese and obese + acetate-treated groups received vehicle (distilled water), sodium acetate (200 mg/kg), 40% HFD and 40% HFD plus sodium acetate respectively. The administration lasted for 12 weeks.

RESULTS

HFD caused increased body weight gain and visceral adiposity, insulin resistance, hyperinsulinemia and increased pancreatic-β cell function and plasma/hepatic triglyceride and total cholesterol as well as decreased adipose triglyceride and total cholesterol, increased plasma, adipose, and hepatic malondialdehyde, TNF-α, uric acid, lactate production and plasma/adipose but not gamma-glutamyl transferase and decreased plasma, adipose, and hepatic nitric oxide, glucose-6-phosphate dehydrogenase (G6PD), glutathione (GSH) and obestatin concentration compared to the control group. Notwithstanding, treatment with acetate attenuated the alterations.

CONCLUSIONS

The results demonstrate that high fat diet-induced obesity is characterized with adipose and hepatic lipid dysmetabolism, which is associated with obestatin suppression. Findings also suggest that acetate provide protection against adipose and hepatic metabolic perturbations by restoring obestatin as well as G6PD/GSH-dependent antioxidant system.

Hesperidin attenuates hepatic lipid accumulation in mice fed high-fat diet and oleic acid induced HepG2 via AMPK activation

AIMS

In recent years, more and more people are suffering from lifestyle-related disease such as nonalcoholic fatty liver disease (NAFLD) because of unhealthy diet and lack of physical exercise. Hesperidin (HDN) is a flavonoid found in high concentrations in citrus fruits. In this study, we investigated the effect of HDN on NAFLD, providing information to develop dietary supplements for NAFLD treatment and prevention.

MATERIALS AND METHODS

Testing kits, hematoxylin-eosin staining, oil red O staining, western blot, immunofluorescence, cck-8 assay, and blood biochemical analysis were carried out during the experiments in vivo and in vitro.

KEY FINDINGS

The current study revealed that HDN significantly reduced liver index and serum lipid levels, and protected against liver steatosis and injury induced by HFD. In addition, HDN suppressed oil acid induced intracellular lipid accumulation in HepG2 cells. Moreover, HDN increased the expression level of pAMPK and downregulated SREBP-1C, ACC and FAS expression in vivo and in vitro.

SIGNIFICANCE

In summary, HDN attenuates lipid accumulation in vivo and in vitro via AMPK activation, suggesting that HDN may serve as a potential therapeutic agent for treating NAFLD.

Non-alcoholic fatty liver disease in irritable bowel syndrome: More than a coincidence?

Irritable bowel syndrome (IBS) and non-alcoholic fatty liver disease (NAFLD) are amongst the most common gastrointestinal and liver conditions encountered in primary and secondary care. Recently, there has been interest in the apparent co-incidence of NAFLD in patients with IBS mainly driven by improved understanding of their shared risk factors and pathophysiology. In this paper we summarize the shared risk factors which include; overlapping nutritional and dietary factors as well as shared putative mechanisms of pathophysiology. These include changes in the gut microbiome, gut permeability, immunity, small bowel bacterial overgrowth and bile acid metabolism. This paper describes how these shared risk factors and etiological factors may have practical clinical implications for these highly prevalent conditions. It also highlights some of the limitations of current epidemiological data relating to estimates of the overlapping prevalence of the two conditions which have resulted in inconsistent results and, therefore the need for further research. Early recognition and management of the overlap could potentially have impacts on treatment outcomes, compliance and morbidity of both conditions. Patients with known IBS who have abnormal liver function tests or significant risk factors for NAFLD should be investigated appropriately for this possibility. Similarly, IBS should be considered in patients with NAFLD and symptoms of abdominal pain associated with defecation, an altered bowel habit and bloating.

Bariatric surgery: blessing or sometimes curse for the liver?

INTRODUCTION

Nowadays morbid obesity has become a worldwide health issue and the use of bariatric surgery undoubtedly results not only in weight reduction but also in the improvement of comorbidities. Although bariatric surgery is the optimal choice for metabolic syndrome resolution and hepatic function improvement, there is evidence that in rare cases it may lead to aggressive steatohepatitis, acute liver failure, fibrosis, and deterioration of the overall prognosis, without having fully understood the underlying pathophysiological mechanisms.

CASE REPORT

In this case report we present a 45-year-old female patient with morbid obesity, body mass index 80, who underwent long-limb Roux en Y gastric bypass (LL-RYGB) and was admitted to the emergency department with jaundice and impaired liver function laboratory tests on postoperative day 90. The examinations revealed elevated bilirubin and transaminases, with prolonged prothrombin time and low albumin levels. A liver biopsy was performed and showed active steatohepatitis. The hepatic values were gradually further impaired and the decision for surgery, in order to reverse the hepatic dysfunction, was taken. A gastrostomy in the bypassed stomach was performed and the activation of the closed biliopancreatic loop led to clinical improvement and amelioration of the prognosis.

CONCLUSIONS

Patients at high risk for hepatic failure after bariatric surgery should be better evaluated preoperatively and a tailor-made approach should be applied in order to avoid such a disastrous complication.

Physalin B ameliorates nonalcoholic steatohepatitis by stimulating autophagy and NRF2 activation mediated improvement in oxidative stress

Non-alcoholic steatohepatitis (NASH) is the progressive stage of non-alcoholic fatty liver disease that may ultimately lead to cirrhosis and liver cancer, and there are few therapeutic options for its treatment. Physalin B (PB), a withanolide isolated from Physalis species (Solanaceae), exhibits a broad spectrum of biological activities, however, the potential role of PB in NASH has not been evaluated. The present study investigated the protective effects of PB against NASH and further elucidated the mechanisms of PB in hepatic autophagy and oxidative stress in vitro and in vivo. We conducted a series of experiments using methionine-choline deficient (MCD) diet induced NASH mice and cultured L02 cells. Serum markers of liver injury, morphology, and the histology of liver tissues were investigated. Western blot assays and quantitative real-time PCR were used to investigate the hepatoprotective effect of PB. PB significantly ameliorated hepatic injury, including hepatic index, transaminase activities, histology, and inflammation in MCD-induced mice. Moreover, PB markedly increased the expression of P62 and the ratio of LC3Ⅱ/Ⅰ in vitro and in vivo. Furthermore, PB promoted the interaction between endogenous KEAP1 and P62, reduced the interaction between KEAP1 and NRF2, activated the nuclear translocation of NRF2 and NRF2 target gene expression, and ultimately attenuated oxidative stress. In addition, knockdown of P62 blocked PB-mediated activation of NRF2 in L02 cells. These results clearly indicated that PB ameliorated NASH by stimulating autophagy and P62-KEAP1-NRF2 antioxidative signaling, suggesting that PB is expected to become a novel therapeutic drug for NASH.

Dietary anthocyanins as potential natural modulators for the prevention and treatment of non-alcoholic fatty liver disease: A comprehensive review

Nonalcoholic fatty liver disease (NAFLD) refers to a metabolic syndrome linked with type 2 diabetes mellitus, obesity, and cardiovascular diseases. It is characterized by the accumulation of triglycerides in the hepatocytes in the absence of alcohol consumption. The prevalence of NAFLD has abruptly increased worldwide, with no effective treatment yet available. Anthocyanins (ACNs) belong to the flavonoid subclass of polyphenols, are commonly present in various edible plants, and possess a broad array of health-promoting properties. ACNs have been shown to have strong potential to combat NAFLD. We critically assessed the literature regarding the pharmacological mechanisms and biopharmaceutical features of the action of ACNs on NAFLD in humans and animal models. We found that ACNs ameliorate NAFLD by improving lipid and glucose metabolism, increasing antioxidant and anti-inflammatory activities, and regulating gut microbiota dysbiosis. In conclusion, ACNs have potential to attenuate NAFLD. However, further mechanistic studies are required to confirm these beneficial impacts of ACNs on NAFLD.

Naringenin attenuates non-alcoholic fatty liver disease by down-regulating the NLRP3/NF-κB pathway in mice

BACKGROUND AND PURPOSE

Naringenin, a flavonoid compound with strong anti-inflammatory activity, attenuated non-alcoholic fatty liver disease (NAFLD) induced by a methionine-choline deficient (MCD) diet in mice. However, the mechanisms underlying this suppression of inflammation and NAFLD remain unknown.

EXPERIMENTAL APPROACH

WT and NLRP3-/- mice were fed with MCD diet for 7 days to induce NAFLD and were given naringenin by gavage at the same time. in vitro experiments used HepG2 cells, primary hepatocytes, and Kupffer cells (KCs) stimulated by LPS or LPS plus oleic acid (OA).

KEY RESULTS

Treating WT mice with naringenin (100 mg·kg-1 ·day-1 ) attenuated hepatic lipid accumulation and inflammation in the livers of mice given the MCD diet. NLRP3-/- mice showed less hepatic lipid accumulation than WT mice, but naringenin did not ameliorate hepatic lipid accumulation further in NLRP3-/- mice. Treating the HepG2 cells with naringenin or NLRP3 inhibitor MCC950 reduced lipid accumulation. Naringenin inhibited activation of the NLRP3/NF-κB pathway stimulated by OA together with LPS. In KCs isolated from WT mice, naringenin inhibited NLRP3 expression. Naringenin also inhibited lipid deposition, NLRP3 and IL-1β expression in WT hepatocytes but was not effective in NLRP3-/- hepatocytes. After re-expressing NLRP3 in NLRP3-/- hepatocytes by adenovirus, the anti-lipid deposition effect of naringenin was restored.

CONCLUSION AND IMPLICATIONS

Naringenin prevented NAFLD via down-regulating the NLRP3/NF-κB signalling pathway both in KCs and in hepatocytes, thus attenuating inflammation in the mice livers.

Gender differences in diet-induced steatotic disease in Cyp2b-null mice

Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease; however, progression to nonalcoholic steatohepatitis (NASH) is associated with most adverse outcomes. CYP2B metabolizes multiple xeno- and endobiotics, and male Cyp2b-null mice are diet-induced obese (DIO) with increased NAFLD. However, the DIO study was not performed long enough to assess progression to NASH. Therefore, to assess the role of Cyp2b in fatty liver disease progression from NAFLD to NASH, we treated wildtype (WT) and Cyp2b-null mice with a normal diet (ND) or choline-deficient, L-amino acid-defined high fat diet (CDAHFD) for 8 weeks and determined metabolic and molecular changes. CDAHFD-fed WT female mice gained more weight and had greater liver and white adipose tissue mass than their Cyp2b-null counterparts; males experienced diet-induced weight loss regardless of genotype. Serum biomarkers of liver injury increased in both CDAHFD-fed female and male mice; however CDAHFD-fed Cyp2b-null females exhibited significantly lower serum ALT, AST, and ASP concentrations compared to WT mice, indicating Cyp2b-null females were protected from liver injury. In both genders, hierarchical clustering of RNA-seq data demonstrates several gene ontologies responded differently in CDAHFD-fed Cyp2b-null mice compared to WT mice (lipid metabolism > fibrosis > inflammation). Oil Red O staining and direct triglycerides measurements confirmed that CDAHFD-fed Cyp2b-null females were protected from NAFLD. CDAHFD-fed Cyp2b-null mice showed equivocal changes in fibrosis with transcriptomic and serum markers suggesting less inflammation due to glucocorticoid-mediated repression of immune responses. In contrast to females, CDAHFD-fed Cyp2b-null males had higher triglyceride levels. Results indicate that female Cyp2b-null mice are protected from NAFLD while male Cyp2b-null mice are more susceptible to NAFLD, with few significant changes in NASH development. This study confirms that increased NAFLD development does not necessarily lead to progressive NASH. Furthermore, it indicates a role for Cyp2b in fatty liver disease that differs based on gender.

5-Lipooxygenase Derivatives as Serum Biomarkers of a Successful Dietary Intervention in Patients with NonAlcoholic Fatty Liver Disease

Background: It was previously shown that a bodyweight reduction among patients with nonalcoholic fatty liver (NAFLD) was connected to the lower concentration of arachidonic and linoleic acid derivatives in their blood. We hypothesized that the concentration of these lipids was correlated with the extent of their body mass reduction and, thus, liver steatosis. Methods: We analyzed 68 individuals who completed the dietary intervention. Patients were divided into two groups depending on their body mass reduction (more or less than 7%). Before and after the dietary intervention, all patients had the following measurements recorded: body mass, waist circumference, stage of steatosis, fatty liver index, liver enzymes, lipid parameters, insulin and glucose. Concentrations of lipoxins A4 (LTX A4), hydroxyeicosatetraenoic fatty acids (5(S)-HETE, 12(S)-HETE and 16(S)-HETE), hydroxyoctadecaenoic acids (9(S)-HODE and 13(S)-HODE) and 5-oxo-eicosatetraenoic acid (5-oxo-ETE) were measured in serum samples collected before and after the dietetic intervention using high-performance liquid chromatography (HPLC). Results: Patients who reduced their body mass by more than 7% revealed a significant improvement in their steatosis stage, waist circumference, fatty liver index, triglycerides and cholesterol. Conclusion: A reduction in body mass by more than 7% but not by less than 7% revealed a significant improvement in steatosis stage; waist circumference; fatty liver index; and levels of triglycerides, cholesterol, 5-oxo-ETE and LTXA-4.

Comparative Study on Beneficial Effects of Hydroxytyrosol- and Oleuropein-Rich Olive Leaf Extracts on High-Fat Diet-Induced Lipid Metabolism Disturbance and Liver Injury in Rats

Oleuropein and hydroxytyrosol, as major compounds of olive leaves, have been reported to exert numerous pharmacological properties, including anticancer, antidiabetic, and anti-inflammatory activities. The purpose of this study is to evaluate and compare the protective effect of oleuropein- and hydroxytyrosol-rich extracts, derived from olive leaves, on high-fat diet-induced lipid metabolism disturbance and liver injury in rats. In this respect, four groups of male rats (8 per group) were used: control group (Control), group treated with high-fat diet (HFD), group treated with HFD and oleuropein (HFD + OLE), and group treated with HFD and hydroxytyrosol (HFD + HYD). The current research showed that the treatment with the HFD increased the body weight and adipose tissue mass in male rats. Moreover, the plasma levels of triglycerides, total cholesterol, LDL-cholesterol, AST, ALT, LDH, and TNF-α were also raised. The hepatic immunohistochemical analysis revealed a significant increase in the expression of inflammatory genes (COX-2, NF-κB, and TNF-α). Equally, it showed a rise of the apoptotic markers (a decrease in the expression of the Bcl-2 and an increase of the P53). In addition, the oral administration of oleuropein- and hydroxytyrosol-rich olive leaf extracts at 16 mg/kg similarly reduced the body weight and adipose tissue mass and improved the lipid profile. Moreover, these extracts, mainly the hydroxytyrosol-rich extract, reduced the elevated liver enzymes, enhanced the antioxidant status, and attenuated the liver inflammation and apoptosis. These findings suggest that the oleuropein- and hydroxytyrosol-rich olive leaf extracts possessed hypolipidemic and hepatoprotective effects against the HFD-induced metabolic disorders by enhancing the antioxidative defense system and blocking the expression of the proteins involved in inflammation and liver damage.

NAFLD as a continuum: from obesity to metabolic syndrome and diabetes

BACKGROUND

The prevalence of non-alcoholic fatty liver disease (NAFLD) has been increasing rapidly. It is nowadays recognized as the most frequent liver disease, affecting a quarter of global population and regularly coexisting with metabolic disorders such as type 2 diabetes, hypertension, obesity, and cardiovascular disease. In a more simplistic view, NAFLD could be defined as an increase in liver fat content, in the absence of secondary cause of steatosis. In fact, the clinical onset of the disease is a much more complex process, closely related to insulin resistance, limited expandability and dysfunctionality of adipose tissue. A fatty liver is a main driver for a new recognized liver-pancreatic α-cell axis and increased glucagon, contributing to diabetes pathophysiology.

MAIN TEXT

This review will focus on the clinical and pathophysiological connections between NAFLD, insulin resistance and type 2 diabetes. We reviewed non-invasive methods and several scoring systems for estimative of steatosis and fibrosis, proposing a multistep process for NAFLD evaluation. We will also discuss treatment options with a more comprehensive view, focusing on the current available therapies for obesity and/or type 2 diabetes that impact each stage of NAFLD.

CONCLUSION

The proper understanding of NAFLD spectrum-as a continuum from obesity to metabolic syndrome and diabetes-may contribute to the early identification and for establishment of targeted treatment.

Dietary Patterns and Components in Nonalcoholic Fatty Liver Disease (NAFLD): What Key Messages Can Health Care Providers Offer?

Nonalcoholic fatty liver disease (NAFLD) is a rising epidemic worldwide and will be the leading cause of cirrhosis, hepatocellular carcinoma, and liver transplant within the next decade. NAFLD is considered as the hepatic manifestation of metabolic syndrome. Behaviors, such as a sedentary lifestyle and consuming a Western diet, have led to substantial challenges in managing NAFLD patients. With no curative pharmaceutical therapies, lifestyle modifications, including dietary changes and exercise, that ultimately lead to weight loss remain the only effective therapy for NAFLD. Multiple diets, including low-carbohydrate, low-fat, Dietary Approaches to Stop Hypertension (DASH), and Mediterranean (MD) diets, have been evaluated. NAFLD patients have shown better outcomes with a modified diet, such as the MD diet, where patients are encouraged to increase the consumption of fruits and vegetables, whole grains, and olive oil. It is increasingly clear that a personalized approach to managing NAFLD patients, based on their preferences and needs, should be implemented. In our review, we cover NAFLD management, with a specific focus on dietary patterns and their components. We emphasize the successful approaches highlighted in recent studies to provide recommendations that health care providers could apply in managing their NAFLD patients.

Clinical and metabolic characterization of obese subjects without non-alcoholic fatty liver: A targeted metabolomics approach

INTRODUCTION

As a small proportion of obese individuals do not develop metabolic complications and non-alcoholic fatty liver disease (NAFLD), this study aimed to provide a comprehensive clinical, metabolic and genetic description of obese subjects with healthy livers.

METHODS

A total of 183 subjects were stratified, according to BMI, presence of metabolic syndrome, biochemical liver tests and hepatic steatosis on ultrasound, into: (i) lean controls (n = 69); (ii) obese healthy (n = 50); and (iii)obese NAFLD (n = 62) groups. Detailed clinical, genetic and metabolic evaluations were then performed.

RESULTS

Obese healthy subjects did not differ in glucose parameters from lean controls, and had a lower rate of minor TM6SF2 gene variants compared with obese NAFLD (2/49 vs. 11/60, respectively; P = 0.035) and lean controls (13/64; P = 0.035), but significantly higher leptin concentrations than lean controls (P < 0.001); they also higher adiponectin concentrations (P < 0.001), and lower TNF-α and IL-6 concentrations (P = 0.01 and P < 0.001, respectively), than obese NAFLD subjects. Also, metabolomic studies identified ether- and ester-containing phospholipids [PC ae C44:6, PC ae C42:5, PC aa C40:4; P < 0.001, corrected by the false discovery rate (FDR) method] and found that the amino-acids lysine, glycine and isoleucine (FDR < 0.001) differed between the two obese groups, but not between lean controls and obese healthy subjects.

CONCLUSION

Obese people with healthy livers are characterized by intact glucose homoeostasis, lower pro-inflammatory cytokine levels, and higher adiponectin and leptin concentrations compared with obese people with NAFLD. In addition, the major allele of TM6SF2, a set of phosphatidylcholines and several amino acids are associated with healthy livers in obesity.

Diabetes Intervention Accentuating Diet and Enhancing Metabolism (DIADEM-I): a randomised controlled trial to examine the impact of an intensive lifestyle intervention consisting of a low-energy diet and physical activity on body weight and metabolism in early type 2 diabetes mellitus: study protocol for a randomized controlled trial

Background

Type 2 diabetes mellitus (T2DM) and obesity are syndemic and will have a significant impact on affected individuals and healthcare services worldwide. Evidence shows that T2DM remission can be achieved with significant weight loss in those who are younger with early diabetes and requiring fewer medications for glycaemic control. DIADEM-I aims to examine the impact of an intensive lifestyle intervention (ILI) using a low-energy diet (LED) meal replacement approach combined with physical activity in younger individuals with early T2DM.

Methods

The planned study is an ongoing, non-blinded, pragmatic, randomised controlled, parallel-group trial examining the impact of an LED-based ILI on body weight and diabetes remission in younger (18–50 years) T2DM individuals with early diabetes (≤ 3-year duration). The ILI will be compared to usual medical care (UMC). The primary outcome will be weight loss at 12 months. Other key outcomes of interest include diabetes remission, glycaemic control, diabetes complications, cardiovascular health, physical activity, mental health, and quality of life. It is planned for the study to include 138 subjects for assessment of the primary outcome. Safety will be assessed throughout.

Discussion

If DIADEM-I demonstrates a clinically significant effect for younger individuals with early T2DM, it will inform clinical guidelines and services of the future for management of T2DM.

Trial registration

ISRCTN: ISRCTN20754766 (date assigned: 7 June 2017); ClinicalTrials.gov, ID: NCT03225339 Registered on 26 June 2017.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-2660-1) contains supplementary material, which is available to authorized users.

Association of calf circumference with insulin resistance and non-alcohol fatty liver disease: the REACTION study

BACKGROUND

The feature of nonalcoholic fatty liver disease (NAFLD) is pathological excessive liver lipid accumulation of subjects who without history of alcohol abuse. Calf circumference is a proxy for lower-body fat and screening method for the identification of subjects with acatastatic lipid accumulation. The objective of this study was to examine the association between calf circumference and NAFLD.

METHODS

The study was a cross-sectional analysis including 8850 middle-aged and elderly individuals. NAFLD was examined by hepatic ultrasound and without alcohol abuse and other liver diseases. Calf circumference was measured on the lower right leg at the point of maximal circumference.

RESULTS

The mean of calf circumference were 35.7 cm for male and 34.6 cm for female (P < 0.001), respectively. Compared with the lowest calf circumference quartile, the odds ratio for NAFLD in the highest quartile was 2.73 (95% CI 2.34-3.19, P _trend <0.001) after adjusted for potential cofounders. There were also significant positive correlation between calf circumference and HOMA-IR, liver enzyme levels and triglycerides. In addition, we found significant positive correlation of calf circumference with the HOMA-IR and fasting insulin level in overweight and obese subjects (BMI ≥ 24 kg/m2) but not in lean subjects (test for interaction: P both less than 0.001 for insulin and HOMA-IR).

CONCLUSION

High calf circumference is significantly associated with elevated prevalence of NAFLD and increasing insulin resistance.

Protective effect of Hua Tan Qu Shi decoction against liver injury in rats with nonalcoholic fatty liver disease

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD), is currently a worldwide health problem. None of the existing treatment medications had got a satisfactory effect. Hua Tan Qu Shi (HTQS) decoction is a Chinese herbal formula, which has been used clinically to treat NAFLD for years. However, the underlying mechanisms are still unclear.

METHODS

High-fat diet (HFD) induced non-alcoholic fatty liver disease rats treated with or without HTQS decoction by gavage for 10 weeks and examined by serology, 24-h albuminuria, histology, immunohistochemistry, and molecular analyses.

Clinical and Metabolic Characterization of Lean Caucasian Subjects With Non-alcoholic Fatty Liver

OBJECTIVES

Non-alcoholic fatty liver disease (NAFLD) is closely linked to obesity; however, 5-8% of lean subjects also have evidence of NAFLD. We aimed to investigate clinical, genetic, metabolic and lifestyle characteristics in lean Caucasian subjects with NAFLD.

METHODS

Data from 187 subjects allocated to one of the three groups according to body mass index (BMI) and hepatic steatosis on ultrasound were obtained: lean healthy (BMI≤25 kg/m², no steatosis, N=71), lean NAFLD (BMI≤25 kg/m², steatosis, N=55), obese NAFLD (BMI≥30 kg/m², steatosis; N=61). All subjects received a detailed clinical and laboratory examination including oral glucose tolerance test. The serum metabolome was assessed using the Metabolomics AbsoluteIDQ p180 kit (BIOCRATES Life Sciences). Genotyping for single-nucleotide polymorphisms (SNPs) associated with NAFLD was performed.

RESULTS

Lean NAFLD subjects had fasting insulin concentrations similar to lean healthy subjects but had markedly impaired glucose tolerance. Lean NAFLD subjects had a higher rate of the mutant PNPLA3 CG/GG variant compared to lean controls (P=0.007). Serum adiponectin concentrations were decreased in both NAFLD groups compared to controls (P<0.001 for both groups) The metabolomics study revealed a potential role for various lysophosphatidylcholines (lyso-PC C18:0, lyso-PC C17:0) and phosphatidylcholines (PCaa C36:3; false discovery rate (FDR)-corrected P-value<0.001) as well as lysine, tyrosine, and valine (FDR<0.001).

CONCLUSIONS

Lean subjects with evidence of NAFLD have clinically relevant impaired glucose tolerance, low adiponectin concentrations and a distinct metabolite profile with an increased rate of PNPLA3 risk allele carriage.

Therapeutic effect of teduglutide on non-alcoholic fatty liver disease in rats

AIM: To assess the therapeutic effect of glucagon-like peptide (GLP-2) analogue teduglutide on non-alcoholic fatty liver disease (NAFLD) in rats.

METHODS: Thirty SD rats were randomized into a normal diet group and a high-fat diet group. After feeding for 12 weeks, six rats were respectively selected from the two groups to determine whether the NAFLD model was successfully established. From the 13^th week, the rest rats in the normal diet group served as controls (n = 6), and the rest rats of the high-fat diet group were randomized into a NAFLD group (n = 6) and a GLP-2 group (n = 6). The rats in the GLP-2 group were injected with teduglutide and the other two groups were injected with normal saline for 7 d. Then blood samples were collected from the ocular veniplex and rats were sacrificed. NAFLD related biochemical indicators were determined and pathological results were observed.

RESULTS: The NAFLD model was successfully established. Compared to the normal group, triglyceride (TG) and total cholesterol (TC) levels in liver homogenate and NAFLD activity score (NAS) were significantly higher in the high-fat diet group (P < 0.05). Moreover, duodenal mucosal epithelial cells were loosely arranged, and intercellular space and Claudin-2 protein expression were increased (P < 0.05). After treatment with GLP-2, TG and TC levels in liver homogenate and liver NAS were significantly lower than those of the NAFLD group (P < 0.05). Accordingly, the arrangement of intestinal epithelial cells was improved, and intercellular space and Claudin-2 protein expression were decreased (P < 0.05).

CONCLUSION: NAFLD can cause the loose of intestinal mucosal cells and the increase of Claudin-2 protein expression. Teduglutide might exert its therapeutic effect on NAFLD by decreasing the expression of Claudin-2 protein.