Lifestyle and Dietary Interventions in the Management of Nonalcoholic Fatty Liver Disease

Vertical Sleeve Gastrectomy Attenuates the Progression of Non-Alcoholic Steatohepatitis in Mice on a High-Fat High-Cholesterol Diet

OBJECTIVE

To determine whether vertical sleeve gastrectomy (VSG) attenuates fibrosis in mice on a high-fat high-cholesterol (HFHC) diet.

BACKGROUND

Bariatric surgery mitigates non-alcoholic steatohepatitis in 85-90% of obese patients. While animal models demonstrate similar results on a high-fat diet, none have observed the effects of bariatric surgery on a combined HFHC diet.

METHODS

Mice on a HFHC diet were used to confirm the development of hepatic fibrosis at 8 (n = 15) and 24 (n = 15) weeks. A separate cohort of mice on a HFHC diet for 12 weeks was subjected to either VSG (n = 18) or sham (n = 12) operations and remained on a HFHC diet for an additional 20 weeks. Changes in weight, dyslipidemia, and the development of steatosis and fibrosis were documented. Serum was obtained for bile acid analysis by liquid chromatography and mass spectrometry, while hepatic gene expression by RT-PCR was performed to evaluate intrahepatic lipid metabolism.

RESULTS

Hepatic steatosis and fibrosis developed after 8 weeks on the HFHC diet. After VSG, mice demonstrated a sustained decrease in weight with a significant decrease in fibrosis compared to sham mice. Serum total cholesterol, HDL, and LDL were significantly reduced following surgery, while serum bile acids were significantly elevated. Intra-hepatic cholesterol excretion was not upregulated based on hepatic gene expression of CYP7A1 and ABCG5/8.

CONCLUSIONS

VSG attenuates the development of hepatic fibrosis in diet-induced obese mice, presumably through enhancement of cholesterol elimination at the intestinal level.

Short-term Dietary Interventions for the Management of Nonalcoholic Fatty Liver

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) affects millions of individuals on a global scale and currently no gold standard treatment exists. The risk of developing NAFLD is considerably higher with increasing body mass index. Consequently, weight loss should be recommended to all overweight patients with fatty liver. However, lifestyle interventions, irrespective of weight status, may also influence the condition. The aim herein is to present examples of short-term interventions which assess direct effects of dietary-related components on hepatic steatosis.

METHODS

This review includes studies with short-term dietary-related interventions of up to 16 weeks that evaluate their efficacy in reducing intrahepatic lipid contents (hepatic steatosis). This review primarily focuses on the three main macronutrients: dietary carbohydrates, fats and proteins.

RESULTS

High saturated fat intake and high consumption of carbohydrates, particularly from simple sugars such as fructose are reported as risk factors for hepatic steatosis. Overall, shortterm hypocaloric diets have shown beneficial effects in reducing intrahepatic lipid contents. Macronutrient manipulations such as carbohydrate restriction as well as the consumption of unsaturated fatty acids are also reported to have efficacious effects.

CONCLUSION

This review highlights the different dietary interventions that can influence hepatic steatosis in the short term, illustrating both pro and anti-steatotic effects.

Lifestyle interventions for non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is a multi-factorial disease and the most common of chronic liver diseases worldwide. The four clinical-pathological entities which are usually followed by NAFLD course include non-alcoholic steatosis, non-alcoholic steatohepatitis, advanced fibrosis/cirrhosis, and hepatocellular carcinoma. The cornerstones of NAFLD management and treatment, however, are healthy lifestyles such as dietary modifications, regular physical activity, and gradual weight loss. At present, no drugs or pharmacological agents have been approved for long-term treatment of NAFLD. Therefore, lifestyle modification is considered the main clinical recommendation and an initial step for the management of NAFLD.

Mitochondrial Dysfunction in the Transition from NASH to HCC

The liver constantly adapts to meet energy requirements of the whole body. Despite its remarkable adaptative capacity, prolonged exposure of liver cells to harmful environmental cues (such as diets rich in fat, sugar, and cholesterol) results in the development of chronic liver diseases (including non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH)) that can progress to hepatocellular carcinoma (HCC). The pathogenesis of these diseases is extremely complex, multifactorial, and poorly understood. Emerging evidence suggests that mitochondrial dysfunction or maladaptation contributes to detrimental effects on hepatocyte bioenergetics, reactive oxygen species (ROS) homeostasis, endoplasmic reticulum (ER) stress, inflammation, and cell death leading to NASH and HCC. The present review highlights the potential contribution of altered mitochondria function to NASH-related HCC and discusses how agents targeting this organelle could provide interesting treatment strategies for these diseases.

Unexpected Rapid Increase in the Burden of NAFLD in China From 2008 to 2018: A Systematic Review and Meta-Analysis

With rapid lifestyle transitions, the increasing burden of nonalcoholic fatty liver disease (NAFLD) in China has emerged as a major public health issue. To obtain a comprehensive overview of the status of NAFLD over the past decade, we evaluated the epidemiology, risk factors, complications, and management of NAFLD in China through a systematic review and meta-analysis. Five English literature databases and three Chinese databases were searched for relevant topics from 2008 to 2018. A total of 392 studies with a population of 2,054,554 were included. National prevalence of NAFLD was 29.2%, with a heavier disease burden among the middle-aged, males, those in northwest China and Taiwan, regions with a gross domestic product per capita greater than 100,000 yuan, and Uygur and Hui ethnic groups. Currently, original studies on natural history and complications of NAFLD in China are scarce. Several studies revealed that NAFLD is positively correlated with the incidence of extrahepatic tumors, diabetes, cardiovascular disease and metabolic syndrome. The Chinese population may have a higher hereditary risk of NAFLD due to more frequent nonsynonymous mutations in genes regulating lipid metabolism. Ultrasonography is the primary imaging tool in the detection of NAFLD in China. Serum tests and risk stratification algorithms for staging NAFLD remain under investigation. Specific pharmaceutical treatments for NAFLD are still undergoing clinical trials. It is noteworthy that the Chinese are underrepresented compared with their proportion of the NAFLD population in such trials. Conclusion: China experienced an unexpected rapid increase in the burden of NAFLD over a short period. Rising awareness and urgent actions need to be taken in order to control the NAFLD pandemic in China.

Effects of aerobic exercise training on the arterial stiffness and intramyocellular or extramyocellular lipid in overweight and obese men

Intramyocellular lipid (IMCL) and extramyocellular lipid (EMCL) of ectopic fat in muscles are associated with arterial stiffness in normal-weight individuals. Furthermore, aerobic exercise training-induced changes in IMCL or EMCL content are related to a decrease in arterial stiffness in elderly people. Though arterial stiffness is strongly related with obesity, but the effects of aerobic exercise training on IMCL or EMCL content, with a particular focus on arterial stiffness, in obese individuals remains unclear. Here, we investigated the effects of aerobic exercise training on IMCL or EMCL content and arterial stiffness in obese individuals. First, in a cross-sectional study, we examined the relationship between arterial stiffness and IMCL or EMCL content in 24 overweight and obese men. Secondly, we investigated the effects of aerobic exercise intervention on arterial stiffness and IMCL or EMCL content in 21 overweight and obese men. In the cross-sectional study, EMCL content was positively correlated with baPWV and β-stiffness index, whereas IMCL content was negatively correlated with baPWV. In the intervention study, there were no significant changes in baPWV, β-stiffness index, and IMCL and EMCL contents after aerobic exercise training. However, exercise-induced change in baPWV and β-stiffness index were positively correlated with changes in EMCL content. Moreover, the group of improvements in baPWV was only correlated significantly with reduced EMCL content. These results suggest that IMCL and EMCL contents may affect arterial stiffness in overweight and obese men.

Web-Based Exercise as an Effective Complementary Treatment for Patients With Nonalcoholic Fatty Liver Disease: Intervention Study

Background

Physical inactivity is a major risk factor for nonalcoholic fatty liver disease (NAFLD). Exercise-based prevention interventions for improving cardiorespiratory fitness are a recommended complementary treatment for NAFLD. Achievement of minimally effective physical activity to improve cardiorespiratory fitness among patients typically involves high personal and financial expenses in face-to-face settings. We designed an eHealth approach for patients with NAFLD to improve the cardiorespiratory fitness and report the first results of the HELP (Hepatic Inflammation and Physical Performance in Patients With NASH [nonalcoholic steatohepatitis]) study.

Objective

We aimed to assess the effectiveness of an 8-week, tailored, Web-based exercise intervention for cardiorespiratory fitness improvement, expressed as peak oxygen uptake (peak volume of oxygen [VO_2peak]), in patients with histologically confirmed NAFLD.

Methods

In a 24-month period, 44 patients were enrolled into an 8-week, prospective, single-arm study with 12 weeks of follow-up. After a medical examination and performance diagnostics, a sports therapist introduced the patients to a Web-based platform for individualized training support. Regular individual patient feedback was provided to systematically adapt the weekly exercise schedule, which allowed us to monitor and ensure patient adherence to strength and endurance training and optimize the step-wise progressive exercise load. Exercise progression was based on an a priori algorithm that considered the subjective rate for both perceived exhaustion and general physical discomfort. The VO_2peak was assessed at baseline and at the end of the study by spiroergometry.

Results

A total of 43 patients completed the intervention with no adverse events. The VO_2peak increased significantly by 2.4 mL/kg/min (8.8%; 95% confidence interval [CI]: 1.48-3.27; P<.001) accompanied by a reduction of 1.0 kg in a body weight (95% CI: 0.33-1.58; P=.004) and 1.3 kg in body fat mass (95% CI: 0.27-2.27; P=.01). In an exploratory analysis, step-wise logistic regression analysis revealed low body fat and VO_2peak at baseline and the total minutes of endurance training during the intervention as main contributors to a positive change in VO_2peak. Our predictive model indicated that the average patient with NAFLD needed 223 min for stabilization of VO_2peak and 628 min for average improvement in VO_2peak. However, in patients with a VO_2peak approximately 20% higher than the average VO_2peak, 628 min were only sufficient to stabilize the VO_2peak and >40% reduction in the average fat mass would be required to achieve an average outcome.

Conclusions

This is the first study to show that patients with NAFLD can be effectively supported by a Web-based approach, which can increase the VO_2peak to a similar extent as face-to-face interventions. Patients with low body fat and low VO_2peak benefited the most from our intervention. In terms of future treatment strategies, NAFLD patients with high body fat may particularly benefit from body-fat reduction through a strict nutritional intervention, subsequently enabling a more effective exercise intervention.

Trial Registration

ClinicalTrials.gov NCT02526732; https://clinicaltrials.gov/ct2/show/NCT02526732 (Archived by WebCite at http://www.webcitation.org/74pXhXXfq)

International Registered Report Identifier (IRRID)

RR2-10.2196/resprot.8607

Plant-derived oleanolic acid ameliorates markers associated with non-alcoholic fatty liver disease in a diet-induced pre-diabetes rat model

BACKGROUND

The increased prevalence of non-alcoholic fatty liver disease (NAFLD) in type 2 diabetes mellitus (T2DM) patients is becoming a worldwide health burden. Studies have indicated, however, that the onset of NAFLD occurs during pre-diabetes, a condition that often precedes the onset of T2DM. Oleanolic acid has been reported to improve glucose homeostasis in diet-induced pre-diabetes; however, the effects of this triterpene on liver function have not been evaluated.

PURPOSE

This study was aimed at evaluating the therapeutic effects of oleanolic acid (OA) on selected markers of NAFLD in a pre-diabetes rat model.

METHODS AND MATERIALS

Pre-diabetes was induced by exposing Sprague Dawley rats to a high-fat high-carbohydrate diet for 20 weeks. The pre-diabetic rats were then treated with OA (80 mg/kg) or metformin (500 mg/kg) in the presence and absence of dietary interventions for a period of 12 weeks. The effects of OA were evaluated on parameters including plasma triglycerides (TGs), very low-density lipoprotein (VLDL) particles, bilirubin, AST, ALT, SREBP and antioxidant profile while the livers were collected for histological analysis.

RESULTS

The findings of this study showed that the administration of OA to pre-diabetic rats ameliorated body/liver weights ratio and significantly decreased plasma triglycerides (TGs) and VLDL. Furthermore, OA also ameliorated hepatic oxidative stress, lowered the SREBP expression and intrahepatic TGs. In addition, OA administration decreased plasma concentrations of bilirubin and liver damage enzyme biomarkers.

CONCLUSION

The findings of the study suggest that OA ameliorates the risk of developing pre-diabetes-related NAFLD through the prevention of intrahepatic fat accumulation while also lowering hepatic inflammation.

Bergamot Polyphenols Boost Therapeutic Effects of the Diet on Non-Alcoholic Steatohepatitis (NASH) Induced by "Junk Food": Evidence for Anti-Inflammatory Activity

Wrong alimentary behaviors and so-called “junk food” are a driving force for the rising incidence of non-alcoholic fatty liver disease (NAFLD) among children and adults. The “junk food” toxicity can be studied in “cafeteria” (CAF) diet animal model. Young rats exposed to CAF diet become obese and rapidly develop NAFLD. We have previously showed that bergamot (Citrus bergamia Risso et Poiteau) flavonoids, in the form of bergamot polyphenol fraction (BPF), effectively prevent CAF diet-induced NAFLD in rats. Here, we addressed if BPF can accelerate therapeutic effects of weight loss induced by a normocaloric standard chow (SC) diet. 21 rats fed with CAF diet for 16 weeks to induce NAFLD with inflammatory features (NASH) were divided into three groups. Two groups were switched to SC diet supplemented or not with BPF (CAF/SC±BPF), while one group continued with CAF diet (CAF/CAF) for 10 weeks. BPF had no effect on SC diet-induced weight loss, but it accelerated hepatic lipid droplets clearance and reduced blood triglycerides. Accordingly, BPF improved insulin sensitivity, but had little effect on leptin levels. Interestingly, the inflammatory parameters were still elevated in CAF/SC livers compared to CAF/CAF group after 10 weeks of dietary intervention, despite over 90% hepatic fat reduction. In contrast, BPF supplementation decreased hepatic inflammation by reducing interleukin 6 (Il6) mRNA expression and increasing anti-inflammatory Il10, which correlated with fewer Kupffer cells and lower inflammatory foci score in CAF/SC+BPF livers compared to CAF/SC group. These data indicate that BPF mediates a specific anti-inflammatory activity in livers recovering from NASH, while it boosts lipid-lowering and anti-diabetic effects of the dietary intervention.

Future of Treatment for Nonalcoholic Steatohepatitis: Can the Use of Safe, Evidence-Based, Clinically Proven Supplements Provide the Answer to the Unmet Need?

The epidemic of nonalcoholic fatty liver disease (NAFLD) has created a real and unmet therapeutic need. The long regulatory pathway and the focus on selected subsets of patients with established and advanced disease are some of the current obstacles to providing effective treatment for the majority of NAFLD patients. The complexity of the disease pathogenesis, which involves multiple mechanisms, requires targeting of more than one pathway or a combination-based therapy. Although the drugs being developed may prevent progression to cirrhosis or may decrease negative liver outcomes, their effects on cardiometabolic health and cancer prevention remain unknown. Providing expensive compounds to a large proportion of the population for long-term use would place an economic burden on health care providers. Thus, there is a missed opportunity for early intervention in the course of the disease, by providing agents that improve cardiometabolic status and the progression of fatty liver toward steatohepatitis. Several natural supplements have the potential to meet these needs. This review discusses some of the major obstacles to drug development for NASH treatment. Milestones in bringing evidenced-based, scientifically proven, patent-protected, clinically tested, safe compounds to patients with NAFLD or NASH within a relatively short period of time are presented. The regulatory, intellectual property, manufacturing, and clinical development steps, along with applicable timelines, are discussed. These compounds may provide a possible solution to the challenges associated with the treatment of the majority of patients.

Current and future therapeutic regimens for nonalcoholic fatty liver disease and nonalcoholic steatohepatitis

Nonalcoholic fatty liver disease (NAFLD) and its progressive form non-alcoholic steatohepatitis (NASH), are rapidly becoming among the top causes of cirrhosis, hepatocellular carcinoma, and indications for liver transplantation. Other than lifestyle modification through diet and exercise, there are currently no other approved treatments for NASH/NAFLD. Although weight loss can be effective, it is difficult to achieve and sustain. In contrast, bariatric surgery can improve metabolic conditions associated with NAFLD, and has been shown to improve liver histology. To have approved regimens for the treatment of NASH/NAFLD, several issues must be addressed. First, all stakeholders must agree on the most appropriate clinical trial endpoints for NASH. Currently, resolution of NASH (without worsening fibrosis) or reduction of fibrosis stage (without worsening NASH) are the accepted endpoints by the regulatory authorities. It is important to recognize the prognostic implication of histologic features of NASH. In this context, although histologic NASH has been associated with advanced fibrosis, it is not an independent predictor of long-term mortality. In contrast, there are significant data to suggest that fibrosis stage is the only robust and independent predictor of liver-related mortality. In addition to the primary endpoints, several important secondary endpoints, including noninvasive biomarkers, long-term outcomes, and patient-reported outcomes must be considered. In 2018, a few phase 3 clinical trials for the treatment of NASH have been initiated. Additionally, a number of phase 2a and 2b clinical trials targeting different pathogenic pathways in NASH are in the pipeline of emerging therapies.

CONCLUSION

Over the next 5 years, some of these regimens are expected to provide potential new treatment options for patients with NASH/NAFLD. (Hepatology 2018;68:361-371).

Evidence-Based Exercise Recommendations to Reduce Hepatic Fat Content in Youth- a Systematic Review and Meta-Analysis

The main purposes of this study were to elucidate the effects of supervised-exercise training (ET) interventions on hepatic fat content and on non-alcoholic fatty liver disease (NAFLD) prevalence in children and adolescents and to provide information about the optimal ET prescription (type, intensity, volume, and frequency) needed to reduce hepatic fat content in youths. Supervised-ET interventions performed in children and adolescents (6-19 years) that provided results of exercise effects on hepatic fat content or NAFLD prevalence were included. Supervised-exercise significantly reduced hepatic fat content compared to the control groups. Lifestyle interventions that included supervised-ET significantly reduced the prevalence of NAFLD. This systematic review and meta-analysis shows that supervised-ET could be an effective strategy in the management and prevention of NAFLD in children and adolescents. Both aerobic and resistance ET, at vigorous or moderate-to-vigorous intensities, with a volume ≥60 min/session and a frequency ≥3 sessions/week, aiming to improve cardiorespiratory fitness and muscular strength, had benefits on hepatic fat content reduction in youth. These data concur with the international recommendations of physical activity for health promotion in youth and may be useful when designing ET programs to improve and prevent hepatic steatosis in the pediatric population.

The effect of low volume sprint interval training in patients with non-alcoholic fatty liver disease

OBJECTIVES

Exercise is an important part of disease management in patients with non-alcoholic fatty liver disease (NAFLD), but adherence to current exercise recommendations is poor. Novel low-volume sprint interval training (SIT) protocols with total training time commitments of ≤30 min per week have been shown to improve cardiometabolic risk and functional capacity in healthy sedentary participants, but the efficacy of such protocols in the management of NAFLD remains unknown. The aim of the present study was to examine whether a low-volume SIT protocol can be used to improve liver function, insulin resistance, body composition, physical fitness, cognitive function and general well-being in patients with NAFLD.

METHODS

In the present study, 7 men and 2 women with NAFLD (age: 45 ± 8 y, BMI: 28.7 ± 4.1 kg·m^-2) completed a 6-week control period followed by 6 weeks of twice-weekly SIT sessions (5-10 × 6-s 'all-out' cycle sprints). Body composition, blood pressure, liver function, metabolic function, functional capacity, cognitive function and quality of life were assessed at baseline, following the control period, and following the SIT intervention.

RESULTS

Walking speed during the walk test (+12%), estimated V̇O₂max (+8%), verbal fluency (+44%), and blood platelet count (+12%; all p < 0.05) significantly increased during the control period. These measures remained significantly raised compared to baseline following the SIT intervention, but did not significantly change any further compared to the post-control time-point. Diastolic blood pressure decreased from 87 ± 10 to 77 ± 8 mm Hg from the end of the control period to the end of the SIT intervention (p < 0.05).

CONCLUSION

This study does not support the use of 6 weeks of a low volume SIT protocol involving twice-weekly sessions with 5-10 × 6-s 'all-out' cycle sprints as an intervention for NAFLD disease management.

Current Treatment of Nonalcoholic Fatty Liver Disease/Nonalcoholic Steatohepatitis

Treatment of nonalcoholic fatty liver disease (NAFLD)/nonalcoholic steatohepatitis (NASH) is focused on patients with NASH because they are at highest risk for progressive liver disease. Current first-line treatment consists of lifestyle modifications. Patients should lose at least 7% to 10% of body weight via a combination of physical exercise and calorie restriction dieting. Surgical or endoscopic surgery for weight loss can be considered in obese patients, depending on degree of excess body weight and comorbidities. There is no currently approved pharmacotherapy for NASH. Vitamin E and pioglitazone have the most evidence of therapeutic efficacy but have limitations. The treatment modality chosen should be individualized.

NAFLD Related-HCC: The Relationship with Metabolic Disorders

Obesity increases death rates of all cancers including non-alcoholic fatty liver disease (NAFLD)-related hepatocellular carcinoma (NAFLD-HCC). NAFLD is considered as hepatic manifestation of metabolic syndrome and is a multi-system disease. Recent prevalence studies have intensively reported the association of obesity, metabolic risk factors and HCC incidence and mortality. Mechanistic studies suggested that immune response, PI3K/AKT/mTOR/PTEN pathway, mitochondrial dysfunction and genetic alterations are important mediators in the progression of NAFLD-HCC from metabolic disorder. In this book chapter, we attempt to collate current research on NAFLD-HCC that lead to our understandings on how metabolic disorders may intersect with cancer development. We also discussed the prevention options of NAFLD-HCC in view of obesity and metabolic disorder. These studies have extended our knowledge on the complicated mechanism of NAFLD and HCC, and provided the prevention options of NAFLD-HCC in patients with obesity and metabolic diseases.

Disturbed Vitamin A Metabolism in Non-Alcoholic Fatty Liver Disease (NAFLD)

Vitamin A is required for important physiological processes, including embryogenesis, vision, cell proliferation and differentiation, immune regulation, and glucose and lipid metabolism. Many of vitamin A’s functions are executed through retinoic acids that activate transcriptional networks controlled by retinoic acid receptors (RARs) and retinoid X receptors (RXRs).The liver plays a central role in vitamin A metabolism: (1) it produces bile supporting efficient intestinal absorption of fat-soluble nutrients like vitamin A; (2) it produces retinol binding protein 4 (RBP4) that distributes vitamin A, as retinol, to peripheral tissues; and (3) it harbors the largest body supply of vitamin A, mostly as retinyl esters, in hepatic stellate cells (HSCs). In times of inadequate dietary intake, the liver maintains stable circulating retinol levels of approximately 2 μmol/L, sufficient to provide the body with this vitamin for months. Liver diseases, in particular those leading to fibrosis and cirrhosis, are associated with impaired vitamin A homeostasis and may lead to vitamin A deficiency. Liver injury triggers HSCs to transdifferentiate to myofibroblasts that produce excessive amounts of extracellular matrix, leading to fibrosis. HSCs lose the retinyl ester stores in this process, ultimately leading to vitamin A deficiency. Non-alcoholic fatty liver disease (NAFLD) is the hepatic manifestation of metabolic syndrome and is a spectrum of conditions ranging from benign hepatic steatosis to non-alcoholic steatohepatitis (NASH); it may progress to cirrhosis and liver cancer. NASH is projected to be the main cause of liver failure in the near future. Retinoic acids are key regulators of glucose and lipid metabolism in the liver and adipose tissue, but it is unknown whether impaired vitamin A homeostasis contributes to or suppresses the development of NAFLD. A genetic variant of patatin-like phospholipase domain-containing 3 (PNPLA3-I148M) is the most prominent heritable factor associated with NAFLD. Interestingly, PNPLA3 harbors retinyl ester hydrolase activity and PNPLA3-I148M is associated with low serum retinol level, but enhanced retinyl esters in the liver of NAFLD patients. Low circulating retinol in NAFLD may therefore not reflect true “vitamin A deficiency”, but rather disturbed vitamin A metabolism. Here, we summarize current knowledge about vitamin A metabolism in NAFLD and its putative role in the progression of liver disease, as well as the therapeutic potential of vitamin A metabolites.

Managing the Burden of Non-NASH NAFLD

Purpose of Review

The purpose of this review article is to raise awareness of the significance of steatosis that exist within the spectrum of nonalcoholic fatty liver disease (NAFLD). While the impact of nonalcoholic steatohepatitis (NASH), and its potential for histologic progression to cirrhosis and hepatocellular carcinoma is widely appreciated, the impact of non-NASH NAFLD (steatosis) on morbidity and mortality is less well recognized.

Recent Findings

NAFLD is a spectrum of hepatic pathology with a rising prevalence worldwide. Steatosis without fibrosis carries a low risk of progression to cirrhosis but likely confers an increased risk of diabetes mellitus and cardiovascular disease.

Summary

About a quarter of the world population is affected by NAFLD. NAFLD represents a burden to affected individuals, economics of the health care system and contributes significantly to morbidity and mortality worldwide. An increased level of awareness and knowledge about risk factors and diagnostic strategies is needed to identify patients affected with disease.

Treatment options for alcoholic and non-alcoholic fatty liver disease: A review

Alcoholic liver disease (ALD) and non-alcoholic fatty liver disease (NAFLD) are serious health problems worldwide. These two diseases have similar pathological spectra, ranging from simple steatosis to hepatitis to cirrhosis and hepatocellular carcinoma. Although most people with excessive alcohol or calorie intake display abnormal fat accumulation in the liver (simple steatosis), a small percentage develops progressive liver disease. Despite extensive research on understanding the pathophysiology of both these diseases there are still no targeted therapies available. The treatment for ALD remains as it was 50 years ago: abstinence, nutritional support and corticosteroids (or pentoxifylline as an alternative if steroids are contraindicated). As for NAFLD, the treatment modality is mainly directed toward weight loss and co-morbidity management. Therefore, new pathophysiology directed therapies are urgently needed. However, the involvement of several inter-related pathways in the pathogenesis of these diseases suggests that a single therapeutic agent is unlikely to be an effective treatment strategy. Hence, a combination therapy towards multiple targets would eventually be required. In this review, we delineate the treatment options in ALD and NAFLD, including various new targeted therapies that are currently under investigation. We hope that soon we will be having an effective multi-therapeutic regimen for each disease.

Non-alcoholic fatty liver disease: A poorly known pandemic

Non-alcoholic fatty liver disease (NAFLD) consists of an excessive depositing of fat in the liver, which can end up by causing inflammation, fibrosis and also cirrhosis with the corresponding complications including liver cancer. NAFLD has become the most common liver disease worldwide. The incidence has increased in parallel with the obesity, diabetes and metabolic syndrome epidemic, thus resulting in becoming one of the main indications for liver transplant. The diagnosis has principally been through histology but with the development of non-invasive methods, these have helped in simplifying the management of these patients in clinical practice. The only therapeutic strategies currently available are focused on weight loss (lifestyle changes or bariatric surgery). There is still no approved pharmacological option for the treatment of NAFLD, however there are a number of molecular studies in advanced stages of development.

Independent and joint effects of moderate alcohol consumption and smoking on the risks of non-alcoholic fatty liver disease in elderly Chinese men

Background

Whether cigarette smoking and moderate drinking are associated with non-alcoholic fatty liver disease (NAFLD)has not been fully described. This study investigated the separate and joint effects of smoking and moderate drinking on Chinese men with NAFLD.

Methods

Across-sectional assay from DFTJ Cohort study was performed with a size of 9432 elderly Chinese men excluding excessive alcohol consumption (<210g/week). Fatty liver was diagnosed by standardized ultrasonographic inspection. The odds ratio (OR) of alcohol consumption and smoking for the prevalence of NAFLD were analyzed using multiple logistic regression with multiple adjustments.

Results

The prevalence of NAFLD in current smokers (pack-year≥40) and drinkers (80~210g/week or drinking duration≥35years) was significantly higher than that in non-smokers and non-drinkers, respectively. The combination of current smoking (pack-year≥40) and drinking (80~210g/week) was associated with the highest risk of NAFLD (OR 1.85; 95% confidence interval [CI] 1.28–2.68;P<0.01). The similar combined effect was found in participants with pack-year≥40 and drinking duration≥35 years (OR 1.72; 95% CI 1.26–2.34;P<0.01). Moreover, an interaction was observed between current smoking and moderate drinking in NAFLD.

Conclusions

In elderly Chinese men, cigarette smoking and moderate alcohol consumption exerts an evident joint effect and interaction on the prevalence of NAFLD, although both are significantly and independently associated with NAFLD prevalence. Such findings highlight particular significance of avoidance of cigarette and alcohol on NAFLD prevention.

Mitochondrial Adaptation in Nonalcoholic Fatty Liver Disease: Novel Mechanisms and Treatment Strategies

Nonalcoholic fatty liver disease (NAFLD) is prevalent in patients with obesity or type 2 diabetes. Nonalcoholic steatohepatitis (NASH), encompassing steatosis with inflammation, hepatocyte injury, and fibrosis, predisposes to cirrhosis, hepatocellular carcinoma, and even cardiovascular disease. In rodent models and humans with NAFLD/NASH, maladaptation of mitochondrial oxidative flux is a central feature of simple steatosis to NASH transition. Induction of hepatic tricarboxylic acid cycle closely mirrors the severity of oxidative stress and inflammation in NASH. Reactive oxygen species generation and inflammation are driven by upregulated, but inefficient oxidative flux and accumulating lipotoxic intermediates. Successful therapies for NASH (weight loss alone or with incretin therapy, or pioglitazone) likely attenuate mitochondrial oxidative flux and halt hepatocellular injury. Agents targeting mitochondrial dysfunction may provide a novel treatment strategy for NAFLD.

Management of Nonalcoholic Fatty Liver Disease in Patients With Type 2 Diabetes: A Call to Action

Traditionally a disease of hepatologists, nonalcoholic fatty liver disease (NAFLD) has recently become a major concern for a broad spectrum of health care providers. Endocrinologists and those caring for patients with type 2 diabetes mellitus (T2DM) are at center stage, as T2DM appears to worsen the course of NAFLD and the liver disease makes diabetes management more challenging. However, the nature of this relationship remains incompletely understood. Although the increasing prevalence of NAFLD is frequently attributed to the epidemic of obesity and is often oversimplified as the "hepatic manifestation of the metabolic syndrome," it is a much more complex disease process that may also be observed in nonobese individuals and in patients without clinical manifestations of the metabolic syndrome. It carries both metabolic and liver-specific complications that make its approach unique among medical conditions. Diabetes appears to promote the development of nonalcoholic steatohepatitis (NASH), the more severe form of the disease, and increases the risk of cirrhosis and hepatocellular carcinoma. Patients and physicians face many uncertainties, including fragmented information on the natural history of the disease, challenges in the diagnosis of NASH, and few pharmacological agents with proven efficacy. However, recent advances in diagnosis and treatment, combined with the risk of serious consequences from inaction, call for health care providers to be more proactive in the management of patients with T2DM and NASH.

Non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease has emerged a major challenge because of it prevalence, difficulties in diagnosis, complex pathogenesis, and lack of approved therapies. As the burden of hepatitis C abates over the next decade, non-alcoholic fatty liver disease will become the major form of chronic liver disease in adults and children and could become the leading indication for liver transplantation. This overview briefly summarizes the most recent data on the pathophysiology, diagnosis, and treatment of non-alcoholic fatty liver disease. Ongoing clinical trials are focused on an array of disease mechanisms and reviewed here are how these treatments fit into the current paradigm of substrate overload lipotoxic liver injury. Many of the approaches are directed at downstream events such as inflammation, injury and fibrogenesis. Addressing more proximal processes such as dysfunctional satiety mechanisms and inappropriately parsimonious energy dissipation are potential therapeutic opportunities that if successfully understood and exploited would not only address fatty liver disease but also the other components of the metabolic syndrome such as obesity, diabetes and dyslipidemia.

Non-pharmacological interventions in non-alcoholic fatty liver disease patients

Patients with non-alcoholic fatty liver disease have unhealthy diets, sedentary behaviour and not enough physical activity. This lifestyle triggers liver disease and probably favours its progression. It also has significant deleterious effects on health and longevity and should therefore be corrected by first-line therapy at all stages of the disease. However, important questions remain: is weight loss alone beneficial or do particular diets have beneficial effects beyond weight loss? Which specific micro- or macronutrients are clearly harmful? Does exercise without weight loss improve hepatic histology and what type of exercise is optimal? Does moderate or only vigorous exercise have metabolic and hepatic benefits? What is the efficacy of lifestyle measures outside of clinical trials? And most importantly, what is the turning point in the natural history of liver disease when non-pharmacological measures should be combined with drug therapy?

Aerobic vs. resistance exercise in non-alcoholic fatty liver disease: A systematic review

BACKGROUND & AIMS

Exercise is a first-line therapy for patients with non-alcoholic fatty liver disease (NAFLD). We sought to: 1) summarize effective aerobic and resistance exercise protocols for NAFLD; and 2) compare the effects and energy consumption of aerobic and resistance exercises.

METHODS

A literature search was performed using PubMed, Web of Science, and Scopas to January 28, 2016. From a total of 95 articles, 23 studies including 24 aerobic and 7 resistance exercise protocols were selected for the summary of exercise protocols. Twelve articles including 13 aerobic and 4 resistance exercise protocols were selected for the comparative analysis.

RESULTS

For aerobic exercise, the median effective protocol was 4.8 metabolic equivalents (METs) for 40min/session, 3times/week for 12weeks. For resistance exercise, the median effective protocol was 3.5 METs for 45min/session, 3times/week for 12weeks. Aerobic and resistance exercise improved hepatic steatosis. No significant difference was seen in the duration, frequency, or period of exercise between the two exercise groups; however, %VO₂max and energy consumption were significantly lower in the resistance than in the aerobic group (50% [45-98] vs. 28% [28-28], p=0.0034; 11,064 [6394-21,087] vs. 6470 [4104-12,310] kcal/total period, p=0.0475).

CONCLUSIONS

Resistance exercise improves NAFLD with less energy consumption. Thus, resistance exercise may be more feasible than aerobic exercise for NAFLD patients with poor cardiorespiratory fitness or for those who cannot tolerate or participate in aerobic exercise. These data may indicate a possible link between resistance exercise and lipid metabolism in the liver.

LAY SUMMARY

Both aerobic and resistance exercise reduce hepatic steatosis in non-alcoholic fatty liver disease (NAFLD) with similar frequency, duration, and period of exercise (40-45min/session 3times/week for 12weeks); however, the two forms of exercise have different characteristics. Intensity and energy consumption were significantly lower for resistance than for aerobic exercise. Resistance exercise may be more feasible than aerobic exercise for NAFLD patients with poor cardiorespiratory fitness or for those who cannot tolerate or participate in aerobic exercise.

Identification of Metabolic risk phenotypes predisposing to Non-Alcoholic Fatty Liver Disease in a Pakistani Cohort

OBJECTIVES

Non-alcoholic fatty liver disease (NAFLD) has emerged in the last two decades with worldwide prevalence of 25.24%. Due to its increasing frequency in Pakistan, it was aimed to identify disease predisposing metabolic risks and their association with NAFLD.

METHODS

Anthropometric and biochemical investigations were collected from 1366 subjects with minor metabolic disturbances. Comparative analyses were performed to compute frequencies of common metabolic risk phenotypes while their associations with NAFLD were explored using regression analyses. The prevalence of NAFLD was also estimated in total, age, and gender-based population cohorts.

RESULTS

Among metabolic risk phenotypes obesity, hyperglycemia, hypertension, and dyslipidemia significantly associated (p<0.001) with NAFLD risk irrespective of age, gender, and BMI. Prevalence of NAFLD in total study cohort was 14.8%, 16.1% in males, 13.4% in females, 19.9% in ≥40 years and 8.7% in ≤40 years respectively.

CONCLUSION

General Pakistani populations experiencing common metabolic disturbances are at high risk of NAFLD development, especially male gender and advanced age. Based on these parameters the stratified NAFLD population could be treated accordingly.

Docosahexanoic Acid Plus Vitamin D Treatment Improves Features of NAFLD in Children with Serum Vitamin D Deficiency: Results from a Single Centre Trial

BACKGROUND

There are no licensed treatments for non alcoholic fatty liver disease (NAFLD) in adults or children. In NAFLD, several studies have shown a benefit of omega-3 fatty acid treatment on lipid profile, insulin-sensitivity and hepatic steatosis and it has also been suggested that Vitamin D treatment has potential antifibrotic properties in liver disease.

TRIAL DESIGN

To date, however, there are no studies that have tested the combination of Docosahexanoic acid (DHA) and vitamin D treatment which may benefit the whole spectrum of disease in NAFLD. Our aim therefore, was to test the effect of daily DHA (500 mg) plus vitamin D (800 IU) treatment, in obese children with biopsy-proven NAFLD and vitamin D deficiency, in a randomized, double-blind placebo-controlled trial.

METHODS

The 41/43 patients completed the study (18-treatment, 23-placebo). At 12 months: i) the main outcome was liver histology improvement, defined by NAS; ii) the secondary outcome was amelioration of metabolic parameters.

RESULTS

DHA plus vitamin D treatment reduced the NAFLD Activity Score (NAS), in the treatment group (5.4 v1.92; p<0.001 for baseline versus end of study). There was no change in fibrosis score, but a reduction of the activation of hepatic stellate cells (HSC) and fibrillar collagen content was noted (3.51±1.66 v. 1.59±1.37; p = 0.003) in treatment group. Moreover, the triglycerides (174.5 vs. 102.15 mg/dl), ALT (40.25 vs. 24.5 UI/l) and HOMA-IR (4.59 vs. 3.42) were all decreased with treatment.

CONCLUSION

DHA plus vitamin D treatment improved insulin-resistance, lipid profile, ALT and NAS. There was also decreased HSC activation and collagen content with treatment.

Neglected features of lifestyle: Their relevance in non-alcoholic fatty liver disease

AIM

To investigated in non-alcoholic-fatty-liver-disease (NAFLD), with ultrasound (US)-detected fatty liver, and in a group of non-alcoholic and otherwise healthy subjects, relationship of neglected features of lifestyle with NAFLD and obesity.

METHODS

Five hundred and thirty-two NAFLD and 667 non-NAFLD healthy subjects, age 21-60 years were studied. Severity of liver steatosis was assessed by US bright liver score. The adherence to mediterranean diet score (AMDS) was assessed on the basis of a 1-wk recall computerized questionnaire which included a detailed physical activity reports (Baecke questionnaire). The western dietary profile score, as a simplified paradigm of unhealthy diet, a questionnaire quantifying sun exposure score and a sleep habits questionnaires provided a further comprehensive lifestyle assessment.

RESULTS

Body mass index (BMI), insulin resistance (HOMA), and triglycerides, poorer adherence to a mediterranean diet profile, sedentary habits, minor sun exposure and use of “western diet” foods are greater in NAFLD. Multiple linear regression analysis, weighted by years of age, displays BMI, HOMA and AMDS as the most powerful independent predictors of fatty liver severity; however, also the physical activity score, the western diet habit and the sun exposure score are acting inside the model with significant independent effects.

CONCLUSION

Articulated clinical intervention, according to our results, are justified in NAFLD and can be pursued addressing by focused intervention nutritional profile, physical exercise mainly in open-air subsets for enhancing sun exposure and healthier sleep duration and rhythm.

Prevention of Hepatocellular Carcinoma

The epidemiology of hepatocellular carcinoma (HCC) has significantly changed throughout the past decade and will continue to do so in the future as a consequence of effective primary prevention and treatment of virus-related liver diseases. However, other risk factors for HCC are constantly on the rise, including alcoholic liver disease and nonalcoholic fatty liver disease. The knowledge on these and further risk factors associated with an increased risk of HCC provide the opportunity and chance for the development and implementation of successful preventive strategies to decrease the worldwide burden of HCC. This mini-review gives a short overview on current strategies in primary, secondary, and tertiary prevention of HCC.