AIM: To review the effectiveness of exercise as a therapy for nonalcoholic fatty liver disease(NAFLD) and potential benefits in treating insulin resistance and atherosclerosis.METHODS: Medline(EBSCOhost) and Pub Med w...AIM: To review the effectiveness of exercise as a therapy for nonalcoholic fatty liver disease(NAFLD) and potential benefits in treating insulin resistance and atherosclerosis.METHODS: Medline(EBSCOhost) and Pub Med were searched for English-language randomized controlled trials and prospective cohort studies in human adults aged ≥ 18 which investigated the various effects of exercise alone, a combination of exercise and diet, or exercise and diet coupled with behavioral modification on NAFLD from 2010 to Feburary 2015.RESULTS: Eighteen of 2298 available studies were chosen for critical review, which included 6925 patients. Nine(50%) studies were randomized controlled trials. Five(27.8%) studies utilized biopsy to examine the effects of physical activity on hepatic histology. The most commonly employed imaging modality to determine change in hepatic steatosis was hydrogen-magnetic resonance spectroscopy. Only two studies examined the effects of low impact physical activity for patients with significant mobility limitations and one compared the efficacy of aerobic and resistance exercise. No studies examined the exact duration of exercise required for hepatic and metabolic improvement in NAFLD.CONCLUSION: While exercise improved hepatic steatosis and underlying metabolic abnormalities in NAFLD, more studies are needed to define the most beneficial form and duration of exercise treatment.展开更多
Nonalcoholic fatty liver disease(NAFLD) has become the dominant form of chronic liver disease in children and adolescents with the increasing prevalence of obesity worldwide. NAFLD represents a wide spectrum of condit...Nonalcoholic fatty liver disease(NAFLD) has become the dominant form of chronic liver disease in children and adolescents with the increasing prevalence of obesity worldwide. NAFLD represents a wide spectrum of conditions, ranging from fatty liver-which generally follows a benign, non-progressive clinical course-to non-alcoholic steatohepatitis, a subset of NAFLD that may progress to cirrhosis and end-stage liver disease or liver carcinoma. The underlying pathophysiological mechanism of "pediatric" NAFLD remains unclear, although it is strongly associated with obesity and insulin resistance. In this review we provide a general overview on the current understanding of NAFLD in children and adolescents, which underpins practice, enabling early diagnosis and appropriate therapeutic intervention for this life-threatening liver disease.展开更多
Nonalcoholic fatty liver disease(NAFLD) is defined as the presence of hepatic fat accumulation after the exclusion of other causes of hepatic steatosis, including other causes of liver disease, excessive alcohol consu...Nonalcoholic fatty liver disease(NAFLD) is defined as the presence of hepatic fat accumulation after the exclusion of other causes of hepatic steatosis, including other causes of liver disease, excessive alcohol consumption, and other conditions that may lead to hepatic steatosis. NAFLD encompasses a broad clinical spectrum ranging from nonalcoholic fatty liver to nonalcoholic steatohepatitis(NASH), advanced fibrosis, cirrhosis, and finally hepatocellular carcinoma(HCC). NAFLD is the most common liver disease in the world and NASH may soon become the most common indication for liver transplantation. Ongoing persistence of obesity with increasing rate of diabetes will increase the prevalence of NAFLD, and as this population ages, many will develop cirrhosis and end-stage liver disease. There has been a general increase in the prevalence of NAFLD, with Asia leading the rise, yet the United States is following closely behind with a rising prevalence from 15% in 2005 to 25% within 5 years. NAFLD is commonly associated with metabolic comorbidities, including obesity, type Ⅱ diabetes, dyslipidemia, and metabolic syndrome. Our understanding of the pathophysiology of NAFLD is constantly evolving. Based on NAFLD subtypes, it has the potential to progress into advanced fibrosis, end-stage liver disease and HCC. The increasing prevalence of NAFLD with advanced fibrosis, is concerning because patients appear toexperience higher liver-related and non-liver-related mortality than the general population. The increased morbidity and mortality, healthcare costs and declining health related quality of life associated with NAFLD makes it a formidable disease, and one that requires more in-depth analysis.展开更多
Emerging data have shown a close association between compositional changes in gut microbiota and the development of nonalcoholic fatty liver disease(NAFLD).The change in gut microbiota may alter nutritional absorption...Emerging data have shown a close association between compositional changes in gut microbiota and the development of nonalcoholic fatty liver disease(NAFLD).The change in gut microbiota may alter nutritional absorption and storage.In addition,gut microbiota are a source of Toll-like receptor(TLR)ligands,and their compositional change can also increase the amount of TLR ligands delivered to the liver.TLR ligands can stimulate liver cells to produce proinflammatory cytokines.Therefore,the gut-liver axis has attracted much interest,particularly regarding the pathogenesis of NAFLD.The abundance of the major gut microbiota,including Firmicutes and Bacteroidetes,has been considered a potential underlying mechanism of obesity and NAFLD,but the role of these microbiota in NAFLD remains unknown.Several reports have demonstrated that certain gut microbiota are associated with the development of obesity and NAFLD.For instance,a decrease in Akkermansia muciniphila causes a thinner intestinal mucus layer and promotes gut permeability,which allows the leakage of bacterial components.Interventions to increase Akkermansia muciniphila improve the metabolic parameters in obesity and NAFLD.In children,the levels of Escherichia were significantly increased in nonalcoholic steatohepatitis(NASH)compared with those in obese control.Escherichia can produce ethanol,which promotes gut permeability.Thus,normalization of gut microbiota using probiotics or prebiotics is a promising treatment option for NAFLD.In addition,TLR signaling in the liver is activated,and its downstream molecules,such as proinflammatory cytokines,are increased in NAFLD.To data,TLR2,TLR4,TLR5,and TLR9 have been shown to be associated with the pathogenesis of NAFLD.Therefore,gut microbiota and TLRs are targets for NAFLD treatment.展开更多
Nonalcoholic fatty liver disease(NAFLD) is a condition in which excess fat accumulates in the liver of a patient without a history of alcohol abuse.Nonalcoholic steatohepatitis(NASH),a severe form of NAFLD,can progres...Nonalcoholic fatty liver disease(NAFLD) is a condition in which excess fat accumulates in the liver of a patient without a history of alcohol abuse.Nonalcoholic steatohepatitis(NASH),a severe form of NAFLD,can progress to liver cirrhosis and hepatocellular carcinoma.NAFLD is regarded as a hepatic manifestation of metabolic syndrome and incidence has been increasing worldwide in line with the increased prevalence of obesity,type 2 diabetes,and hyperlipemia.Animal models of NAFLD/NASH give crucial information,not only in elucidating pathogenesis of NAFLD/NASH but also in examining therapeutic effects of various agents.An ideal model of NAFLD/NASH should correctly reflect both hepatic histopathology and pathophysiology of human NAFLD/NASH.Animal models of NAFLD/NASH are divided into genetic,dietary,and combination models.In this paper,we review commonly used animal models of NAFLD/NASH referring to their advantages and disadvantages.展开更多
Sedentary lifestyle and poor dietary choices are leading to a weight gain epidemic in westernized countries, subsequently increasing the risk for developing the metabolic syndrome and nonalcoholic fatty liver disease ...Sedentary lifestyle and poor dietary choices are leading to a weight gain epidemic in westernized countries, subsequently increasing the risk for developing the metabolic syndrome and nonalcoholic fatty liver disease (NAFLD). NAFLD is estimated to affect approximate 30% of the general US population and is considered the hepatic manifestation of the metabolic syndrome. Recent findings linking the components of the metabolic syndrome with NAFLD and the progression to nonalcoholic steatohepatitis (NASH) will be reviewed; in particular, the role of visceral adipose tissue, insulin resistance, and adipocytokines in the exacerbation of these conditions. While no therapy has been proven effective for treating NAFLD/NASH, common recommendations will be discussed.展开更多
Nonalcoholic fatty liver disease （NAFLD） is an increasingly recognized cause of liver-related morbidity and mortality. It can develop secondary to numerous causes but a great majority of NAFLD cases occur in patient...Nonalcoholic fatty liver disease （NAFLD） is an increasingly recognized cause of liver-related morbidity and mortality. It can develop secondary to numerous causes but a great majority of NAFLD cases occur in patients who are obese or present with other components of metabolic syndrome （hypertension, dyslipidemia, diabetes）. This is called primary NAFLD and insulin resistance plays a key role in its pathogenesis. Obesity is characterized by expanded adipose tissue, which is under a state of chronic inflammation. This disturbs the normal storage and endocrine functions of adipose tissue. In obesity, the secretome （adipokines, oytokines, free fatty acids and other lipid moieties） of fatty tissue is amplified, which through its autocrine, paracrine actions in fat tissue and systemic effects especially in the liver leads to an altered metabolic state with insulin resistance （IR）. IR leads to hyperglycemia and reactive hyperinsulinemia, which stimulates lipid-accumulating processes and impairs hepatic lipid metabolism. IR enhances free fatty acid delivery to liver from the adipose tissue storage due to uninhibited lipolysis. These changes result in hepatic abnormal fat accumulation, which may initiate the hepatic IR and further aggravate the altered metabolic state of whole body. Hepatic steatosis can also be explained by the fact that there is enhanced dietary fat delivery and physical inactivity. IR and NAFLD are also seen in various lipodystrophic states in contrary to popular belief that these problems only occur due to excessive adiposity in obesity. Hence, altered physiology of adipose tissue is central to development of IR, metabolic syndrome and NAFLD.展开更多
AIM:To clarify whether nonalcoholic fatty liver disease(NAFLD)increases the risk of cardiovascular disease.METHODS:We carried out a prospective observational study with a total of 1637 apparently healthy Japanese men ...AIM:To clarify whether nonalcoholic fatty liver disease(NAFLD)increases the risk of cardiovascular disease.METHODS:We carried out a prospective observational study with a total of 1637 apparently healthy Japanese men and women who were recruited from a health check-up program.NAFLD was diagnosed by abdominal ultrasonography.The metabolic syndrome(MS)was defined according to the modified National Cholesterol Education Program(NCEP)ATP Ⅲ criteria.Five years after the baseline evaluations,the incidence of cardiovascular disease was assessed by a self-administered questionnaire.RESULTS:Among 1221 participants available for outcome analyses,the incidence of cardiovascular disease was higher in 231 subjects with NAFLD at baseline(5 coronary heart disease,6 ischemic stroke,and 1 cerebral hemorrhage)than 990 subjects without NAFLD(3 coronary heart disease,6 ischemic stroke,and 1 cerebral hemorrhage).Multivariate analyses indicated that NAFLD was a predictor of cardiovascular disease independent of conventional risk factors(odds ratio 4.12,95% CI,1.58 to 10.75,P = 0.004).MS was alsoindependently associated with cardiovascular events.But simultaneous inclusion of NAFLD and MS in a multivariate model revealed that NAFLD but not MS retained a statistically significant correlation with cardiovascular disease.CONCLUSION:Although both of them were predictors of cardiovascular disease,NAFLD but not MS retained a statistically significant correlation with cardiovascular disease in a multivariate model.NAFLD is a strong predictor of cardiovascular disease and may play a central role in the cardiovascular risk of MS.展开更多
Nonalcoholic fatty liver disease(NAFLD) is today considered the most common form of chronic liver disease, affecting a high proportion of the population worldwide. NAFLD encompasses a large spectrum of liver damage, r...Nonalcoholic fatty liver disease(NAFLD) is today considered the most common form of chronic liver disease, affecting a high proportion of the population worldwide. NAFLD encompasses a large spectrum of liver damage, ranging from simple steatosis to steatohepatitis, advanced fibrosis and cirrhosis. Obesity, hyperglycemia, type 2 diabetes and hypertriglyceridemia are the most important risk factors. The pathogenesis of NAFLD and its progression to fibrosis and chronic liver disease is still unknown. Accumulating evidence indicates that mitochondrial dysfunction plays a key role in the physiopathology of NAFLD, although the mechanisms underlying this dysfunction are still unclear. Oxidative stress is considered an important factor in producing lethal hepatocyte injury associated with NAFLD. Mitochondrial respiratory chain is the main subcellular source of reactive oxygen species(ROS), which may damage mitochondrial proteins, lipids and mitochondrial DNA. Cardiolipin, a phospholipid located at the level of the inner mitochondrial membrane, plays an important role in several reactions and processes involved in mitochondrial bioenergetics as well as in mitochondrial dependent steps of apoptosis. This phospholipid is particularly susceptible to ROS attack. Cardiolipin peroxidation has been associated with mitochondrial dysfunction in multiple tissues in several physiopathological conditions, including NAFLD. In this review, we focus on the potential roles played by oxidative stress and cardiolipin alterations in mitochondrial dysfunction associated with NAFLD.展开更多
With the increasing number of individuals with diabetes and obesity,nonalcoholic fatty liver disease(NAFLD) is becoming increasingly prevalent,affecting one-quarter of adults worldwide. The spectrum of NAFLD ranges fr...With the increasing number of individuals with diabetes and obesity,nonalcoholic fatty liver disease(NAFLD) is becoming increasingly prevalent,affecting one-quarter of adults worldwide. The spectrum of NAFLD ranges from simple steatosis or nonalcoholic fatty liver(NAFL) to nonalcoholic steatohepatitis(NASH). NAFLD, especially NASH, may progress to fibrosis, leading to cirrhosis and hepatocellular carcinoma. NAFLD can impose a severe economic burden,and patients with NAFLD-related terminal or deteriorative liver diseases have become one of the main groups receiving liver transplantation. The increasing prevalence of NAFLD and the severe outcomes of NASH make it necessary to use effective methods to identify NAFLD. Although recognized as the gold standard, biopsy is limited by its sampling bias, poor acceptability, and severe complications, such as mortality, bleeding, and pain. Therefore, noninvasive methods are urgently needed to avoid biopsy for diagnosing NAFLD. This review discusses the current noninvasive methods for assessing NAFLD,including steatosis, NASH, and NAFLD-related fibrosis, and explores the advantages and disadvantages of measurement tools. In addition, we analyze potential noninvasive biomarkers for tracking disease processes and monitoring treatment effects, and explore effective algorithms consisting of imaging and nonimaging biomarkers for diagnosing advanced fibrosis and reducing unnecessary biopsies in clinical practice.展开更多
It is estimated that 30% of the adult population in Japan is affected by nonalcoholic fatty liver disease (NAFLD). Fatty changes of the liver are generally diagnosed using imaging methods such as abdominal ultrasonogr...It is estimated that 30% of the adult population in Japan is affected by nonalcoholic fatty liver disease (NAFLD). Fatty changes of the liver are generally diagnosed using imaging methods such as abdominal ultrasonography (US) and computed tomography (CT), but the sensitivity of these imaging techniques is low in cases of mild steatosis. Alanine aminotransferase levels may be normal in some of these patients, warranting the necessity to establish a set of parameters useful for detecting NAFLD, and the more severe form of the disease, nonalcoholic steatohepatitis (NASH). Although liver biopsy is currently the gold standard for diagnosing progressive NASH, it has many drawbacks, such as sampling error, cost, and risk of complications. Furthermore, it is not realistic to perform liver biopsies on all NAFLD patients. Diagnosis of NASH using various biomarkers, scoring systems and imaging methods, such as elastography, has recently been attempted. The NAFIC score, calculated from the levels of ferritin, fasting insulin, and type IV collagen 7S, is useful for the diagnosis of NASH, while the NAFLD fibrosis score and the FIB-4 index are useful for excluding NASH in cases of advanced fibrosis. This article reviews the limitations and merits of liver biopsy and noninvasive diagnostic tests in the diagnosis of NAFLD/NASH.展开更多
Nonalcoholic fatty liver disease(NAFLD)is a frequent cause of chronic liver diseases,ranging from simple steatosis to nonalcoholic steatohepatitis(NASH)-related liver cirrhosis.Although liver biopsy is still the gold ...Nonalcoholic fatty liver disease(NAFLD)is a frequent cause of chronic liver diseases,ranging from simple steatosis to nonalcoholic steatohepatitis(NASH)-related liver cirrhosis.Although liver biopsy is still the gold standard for the diagnosis of NAFLD,especially for the diagnosis of NASH,imaging methods have been increasingly accepted as noninvasive alternatives to liver biopsy.Ultrasonography is a well-established and costeffective imaging technique for the diagnosis of hepatic steatosis,especially for screening a large population at risk of NAFLD.Ultrasonography has a reasonable accuracy in detecting moderate-to-severe hepatic steatosis although it is less accurate for detecting mild hepatic steatosis,operator-dependent,and rather qualitative.Computed tomography is not appropriate for general population assessment of hepatic steatosis given its inaccuracy in detecting mild hepatic steatosis and potential radiation hazard.However,computed tomography may be effective in specific clinical situations,such as evaluation of donor candidates for hepatic transplantation.Magnetic resonance spectroscopy and magnetic resonance imaging are now regarded as the most accurate practical methods of measuring liver fat in clinical practice,especially for longitudinal followup of patients with NAFLD.Ultrasound elastography and magnetic resonance elastography are increasingly used to evaluate the degree of liver fibrosis in patients with NAFLD and to differentiate NASH from simple steatosis.This article will review current imaging methods used to evaluate hepatic steatosis,including the diagnostic accuracy,limitations,and practical applicability of each method.It will also briefly describe the potential role of elastography techniques in the evaluation of patients with NAFLD.展开更多
Nonalcoholic fatty liver disease (NAFLD) is a condition in which excess fat accumulates in the liver of a patient with no history of alcohol abuse or other causes for secondary hepatic steatosis. The pathogenesis of N...Nonalcoholic fatty liver disease (NAFLD) is a condition in which excess fat accumulates in the liver of a patient with no history of alcohol abuse or other causes for secondary hepatic steatosis. The pathogenesis of NAFLD and nonalcoholic steatohepatitis (NASH) has not been fully elucidated. The “two-hit“ hypothesis is probably a too simplified model to elaborate complex pathogenetic events occurring in patients with NASH. It should be better regarded as a multiple step process, with accumulation of liver fat being the first step, followed by the development of necroinflammation and fibrosis. Adipose tissue, which has emerged as an endocrine organ with a key role in energy homeostasis, is responsive to both central and peripheral metabolic signals and is itself capable of secreting a number of proteins. These adipocyte-specific or enriched proteins, termed adipokines, have been shown to have a variety of local, peripheral, and central effects. In the current review, we explore the role of adipocytokines and proinflammatory cytokines in the pathogenesis of NAFLD. We particularly focus on adiponectin, leptin and ghrelin, with a brief mention of resistin, visfatin and retinol-binding protein 4 among adipokines, and tumor necrosis factor-α, interleukin (IL)-6, IL-1, and briefly IL-18 among proinflammatory cytokines. We update their role in NAFLD, as elucidated in experimental models and clinical practice.展开更多
Objective： To investigate the relationship between alanine aminotransferase （ALT） levels and metabolic syndrome （MS） in nonalcoholic fatty liver disease （NAFLD）. Methods： A total of 26527 subjects who received...Objective： To investigate the relationship between alanine aminotransferase （ALT） levels and metabolic syndrome （MS） in nonalcoholic fatty liver disease （NAFLD）. Methods： A total of 26527 subjects who received medical health checkup in our hospital from January 2005 to July 2007 were enrolled in the study. The diagnosis of fatty liver was based on ultrasound imaging. MS was defined according to the criteria of the Adult Treatment Panel III. ALT, triglyceride （TG）, high density lipoprotein cholesterol （HDL-c）, fasting plasma glucose （FPG）, height, weight, waist circumference （WC）, systolic blood pressure （SBP） and diastolic blood pressure （DBP） were measured in each subject to analyze the relationship between MS and ALT activity Results： （1） The prevalence of NAFLD in men （30.94%） was significantly higher than that in women （15.65%）; （2） The incidence of MS in NAFLD （33.83%） was significantly greater than that in non-NAFLD （10.62%）; （3） Of the 6470 subjects with NAFLD, in the age-adjusted partial correlation analysis, there were statistically significant correlations between the ALT levels and most metabolic risk factors in each sex （P〈0.01）, except that ALT levels multiple stepwise regression analysis, SBP lost its significance, and had no correlation with HDL-c in women. Moreover, in the WC, body mass index （BMI）, age, DBP, TG and FPG were independently associated with ALT levels in both sexes （P〈0.05）. HDL-c remained significant and was independently related to ALT levels in men; （4） ALT levels were significantly higher in subjects with MS compared to those without MS （P〈0.001）. Mean ALT levels increased with the number of MS components in each sex （P〈0.05 for trend）. Conclusion： We found a strong relationship between ALT levels and MS in NAFLD and revealed that the cluster of MS components might be the predictor for ALT elevations.展开更多
Nonalcoholic fatty liver disease(NAFLD)/nonalcoholic steatohepatitis(NASH) is considered to be a hepatic manifestation of metabolic syndrome, and its incidence is rapidly increasing worldwide. It is currently the most...Nonalcoholic fatty liver disease(NAFLD)/nonalcoholic steatohepatitis(NASH) is considered to be a hepatic manifestation of metabolic syndrome, and its incidence is rapidly increasing worldwide. It is currently the most common chronic liver disease. NASH can progress to liver cirrhosis and hepatocellular carcinoma, and may result in liver-related death. Currently, the principal treatment for NAFLD/NASH is lifestyle modification by diet and exercise. However, pharmacological therapy is indispensable because obese patients with NAFLD often have difficulty maintaining improved lifestyles. The pathogenesis of NAFLD/NASH has not been completely elucidated. However, insulin resistance, inflammatory cytokines, and oxidative stress are thought to be important in the development and/or progression of the disease. Currently, insulin sensitizers(thiazolidinediones) and antioxidants(vitamin E) seem to be the most promising therapeutic agents for NAFLD/NASH, and lipid-lowering drugs, pentoxifylline, angiotensin receptor blockers, and n-3 polyunsaturated fatty acids also have promise. However, there is a lack of consensus regarding the most effective and appropriate pharmacotherapy for NAFLD/NASH. Animal experiments suggest that herbal medicines and natural products may be promising therapeutic agents for NAFLD/NASH, but their efficacy and safety are yet to be investigated in human studies. In this paper, we review the existing and potential pharmacological therapies for NAFLD/NASH.展开更多
Nonalcoholic fatty liver disease(NAFLD)has emerged as a common public health problem in recent decades.However,the underlying mechanisms leading to the development of NAFLD are not fully understood.The endoplasmic ret...Nonalcoholic fatty liver disease(NAFLD)has emerged as a common public health problem in recent decades.However,the underlying mechanisms leading to the development of NAFLD are not fully understood.The endoplasmic reticulum(ER)stress response has recently been proposed to play a crucial role in both the development of steatosis and progression to nonalcoholic steatohepatitis.ER stress is activated to regulate protein synthesis and restore homeostatic equilibrium when the cell is stressed due to the accumulation of unfolded or misfolded proteins.However,delayed or insufficient responses to ER stress may turn physiological mechanisms into pathological consequences,including fat accumulation,insulin resistance,inflammation,and apoptosis,all of which play important roles in the pathogenesis of NAFLD.Therefore,understanding the role of ER stress in the pathogenesis of NAFLD has become a topic of intense investigation.This review highlights the recent findings linking ER stress signaling pathways to the pathogenesis of NAFLD.展开更多
Nonalcoholic fatty liver disease(NAFLD)is quickly becoming one of the most prominent causes of liver disease worldwide.The increasing incidence of NAFLD is tied to the obesity epidemic and the subsequent metabolic der...Nonalcoholic fatty liver disease(NAFLD)is quickly becoming one of the most prominent causes of liver disease worldwide.The increasing incidence of NAFLD is tied to the obesity epidemic and the subsequent metabolic derangements brought along with it.Current efforts to elucidate the mechanism and causes of the disease have answered some questions,but much remains unknown about NAFLD.The aim of this article is to discuss the current knowledge regarding the pathogenesis of the disease,as well as the current and future diagnostic,preventative,and therapeutic options available to clinicians for the management of NAFLD.展开更多
基金Supported by The American Association for the Study of Liver Disease(AASLD) Foundation to Dr.VanWagner LB
文摘AIM: To review the effectiveness of exercise as a therapy for nonalcoholic fatty liver disease(NAFLD) and potential benefits in treating insulin resistance and atherosclerosis.METHODS: Medline(EBSCOhost) and Pub Med were searched for English-language randomized controlled trials and prospective cohort studies in human adults aged ≥ 18 which investigated the various effects of exercise alone, a combination of exercise and diet, or exercise and diet coupled with behavioral modification on NAFLD from 2010 to Feburary 2015.RESULTS: Eighteen of 2298 available studies were chosen for critical review, which included 6925 patients. Nine(50%) studies were randomized controlled trials. Five(27.8%) studies utilized biopsy to examine the effects of physical activity on hepatic histology. The most commonly employed imaging modality to determine change in hepatic steatosis was hydrogen-magnetic resonance spectroscopy. Only two studies examined the effects of low impact physical activity for patients with significant mobility limitations and one compared the efficacy of aerobic and resistance exercise. No studies examined the exact duration of exercise required for hepatic and metabolic improvement in NAFLD.CONCLUSION: While exercise improved hepatic steatosis and underlying metabolic abnormalities in NAFLD, more studies are needed to define the most beneficial form and duration of exercise treatment.
基金Supported by The National Key Research and Development Program of China,No.2016YFC1305301
文摘Nonalcoholic fatty liver disease(NAFLD) has become the dominant form of chronic liver disease in children and adolescents with the increasing prevalence of obesity worldwide. NAFLD represents a wide spectrum of conditions, ranging from fatty liver-which generally follows a benign, non-progressive clinical course-to non-alcoholic steatohepatitis, a subset of NAFLD that may progress to cirrhosis and end-stage liver disease or liver carcinoma. The underlying pathophysiological mechanism of "pediatric" NAFLD remains unclear, although it is strongly associated with obesity and insulin resistance. In this review we provide a general overview on the current understanding of NAFLD in children and adolescents, which underpins practice, enabling early diagnosis and appropriate therapeutic intervention for this life-threatening liver disease.
文摘Nonalcoholic fatty liver disease(NAFLD) is defined as the presence of hepatic fat accumulation after the exclusion of other causes of hepatic steatosis, including other causes of liver disease, excessive alcohol consumption, and other conditions that may lead to hepatic steatosis. NAFLD encompasses a broad clinical spectrum ranging from nonalcoholic fatty liver to nonalcoholic steatohepatitis(NASH), advanced fibrosis, cirrhosis, and finally hepatocellular carcinoma(HCC). NAFLD is the most common liver disease in the world and NASH may soon become the most common indication for liver transplantation. Ongoing persistence of obesity with increasing rate of diabetes will increase the prevalence of NAFLD, and as this population ages, many will develop cirrhosis and end-stage liver disease. There has been a general increase in the prevalence of NAFLD, with Asia leading the rise, yet the United States is following closely behind with a rising prevalence from 15% in 2005 to 25% within 5 years. NAFLD is commonly associated with metabolic comorbidities, including obesity, type Ⅱ diabetes, dyslipidemia, and metabolic syndrome. Our understanding of the pathophysiology of NAFLD is constantly evolving. Based on NAFLD subtypes, it has the potential to progress into advanced fibrosis, end-stage liver disease and HCC. The increasing prevalence of NAFLD with advanced fibrosis, is concerning because patients appear toexperience higher liver-related and non-liver-related mortality than the general population. The increased morbidity and mortality, healthcare costs and declining health related quality of life associated with NAFLD makes it a formidable disease, and one that requires more in-depth analysis.
基金Supported by JSPS[Grant-in-Aid for Scientific Research(C)](to Miura K)
文摘Emerging data have shown a close association between compositional changes in gut microbiota and the development of nonalcoholic fatty liver disease(NAFLD).The change in gut microbiota may alter nutritional absorption and storage.In addition,gut microbiota are a source of Toll-like receptor(TLR)ligands,and their compositional change can also increase the amount of TLR ligands delivered to the liver.TLR ligands can stimulate liver cells to produce proinflammatory cytokines.Therefore,the gut-liver axis has attracted much interest,particularly regarding the pathogenesis of NAFLD.The abundance of the major gut microbiota,including Firmicutes and Bacteroidetes,has been considered a potential underlying mechanism of obesity and NAFLD,but the role of these microbiota in NAFLD remains unknown.Several reports have demonstrated that certain gut microbiota are associated with the development of obesity and NAFLD.For instance,a decrease in Akkermansia muciniphila causes a thinner intestinal mucus layer and promotes gut permeability,which allows the leakage of bacterial components.Interventions to increase Akkermansia muciniphila improve the metabolic parameters in obesity and NAFLD.In children,the levels of Escherichia were significantly increased in nonalcoholic steatohepatitis(NASH)compared with those in obese control.Escherichia can produce ethanol,which promotes gut permeability.Thus,normalization of gut microbiota using probiotics or prebiotics is a promising treatment option for NAFLD.In addition,TLR signaling in the liver is activated,and its downstream molecules,such as proinflammatory cytokines,are increased in NAFLD.To data,TLR2,TLR4,TLR5,and TLR9 have been shown to be associated with the pathogenesis of NAFLD.Therefore,gut microbiota and TLRs are targets for NAFLD treatment.
文摘Nonalcoholic fatty liver disease(NAFLD) is a condition in which excess fat accumulates in the liver of a patient without a history of alcohol abuse.Nonalcoholic steatohepatitis(NASH),a severe form of NAFLD,can progress to liver cirrhosis and hepatocellular carcinoma.NAFLD is regarded as a hepatic manifestation of metabolic syndrome and incidence has been increasing worldwide in line with the increased prevalence of obesity,type 2 diabetes,and hyperlipemia.Animal models of NAFLD/NASH give crucial information,not only in elucidating pathogenesis of NAFLD/NASH but also in examining therapeutic effects of various agents.An ideal model of NAFLD/NASH should correctly reflect both hepatic histopathology and pathophysiology of human NAFLD/NASH.Animal models of NAFLD/NASH are divided into genetic,dietary,and combination models.In this paper,we review commonly used animal models of NAFLD/NASH referring to their advantages and disadvantages.
文摘Sedentary lifestyle and poor dietary choices are leading to a weight gain epidemic in westernized countries, subsequently increasing the risk for developing the metabolic syndrome and nonalcoholic fatty liver disease (NAFLD). NAFLD is estimated to affect approximate 30% of the general US population and is considered the hepatic manifestation of the metabolic syndrome. Recent findings linking the components of the metabolic syndrome with NAFLD and the progression to nonalcoholic steatohepatitis (NASH) will be reviewed; in particular, the role of visceral adipose tissue, insulin resistance, and adipocytokines in the exacerbation of these conditions. While no therapy has been proven effective for treating NAFLD/NASH, common recommendations will be discussed.
基金Supported by The National Key Basic Research Project,No.2012CB517501Chinese Foundation for Hepatitis Prevention and Control–"WANG Bao-En"Liver Fibrosis Research Fund,No.XJS20120501+1 种基金Shanghai Science and Technology Committee,No.09140903500 and No.10411956300the 100-Talents Program of the Shanghai Municipal Health Bureau,No.XBR2011007
文摘AIM: To evaluate the performance of a novel non-invasive controlled attenuation parameter (CAP) to assess liver steatosis.
文摘Nonalcoholic fatty liver disease （NAFLD） is an increasingly recognized cause of liver-related morbidity and mortality. It can develop secondary to numerous causes but a great majority of NAFLD cases occur in patients who are obese or present with other components of metabolic syndrome （hypertension, dyslipidemia, diabetes）. This is called primary NAFLD and insulin resistance plays a key role in its pathogenesis. Obesity is characterized by expanded adipose tissue, which is under a state of chronic inflammation. This disturbs the normal storage and endocrine functions of adipose tissue. In obesity, the secretome （adipokines, oytokines, free fatty acids and other lipid moieties） of fatty tissue is amplified, which through its autocrine, paracrine actions in fat tissue and systemic effects especially in the liver leads to an altered metabolic state with insulin resistance （IR）. IR leads to hyperglycemia and reactive hyperinsulinemia, which stimulates lipid-accumulating processes and impairs hepatic lipid metabolism. IR enhances free fatty acid delivery to liver from the adipose tissue storage due to uninhibited lipolysis. These changes result in hepatic abnormal fat accumulation, which may initiate the hepatic IR and further aggravate the altered metabolic state of whole body. Hepatic steatosis can also be explained by the fact that there is enhanced dietary fat delivery and physical inactivity. IR and NAFLD are also seen in various lipodystrophic states in contrary to popular belief that these problems only occur due to excessive adiposity in obesity. Hence, altered physiology of adipose tissue is central to development of IR, metabolic syndrome and NAFLD.
基金Supported by a grant from the Gifu Medical Association
文摘AIM:To clarify whether nonalcoholic fatty liver disease(NAFLD)increases the risk of cardiovascular disease.METHODS:We carried out a prospective observational study with a total of 1637 apparently healthy Japanese men and women who were recruited from a health check-up program.NAFLD was diagnosed by abdominal ultrasonography.The metabolic syndrome(MS)was defined according to the modified National Cholesterol Education Program(NCEP)ATP Ⅲ criteria.Five years after the baseline evaluations,the incidence of cardiovascular disease was assessed by a self-administered questionnaire.RESULTS:Among 1221 participants available for outcome analyses,the incidence of cardiovascular disease was higher in 231 subjects with NAFLD at baseline(5 coronary heart disease,6 ischemic stroke,and 1 cerebral hemorrhage)than 990 subjects without NAFLD(3 coronary heart disease,6 ischemic stroke,and 1 cerebral hemorrhage).Multivariate analyses indicated that NAFLD was a predictor of cardiovascular disease independent of conventional risk factors(odds ratio 4.12,95% CI,1.58 to 10.75,P = 0.004).MS was alsoindependently associated with cardiovascular events.But simultaneous inclusion of NAFLD and MS in a multivariate model revealed that NAFLD but not MS retained a statistically significant correlation with cardiovascular disease.CONCLUSION:Although both of them were predictors of cardiovascular disease,NAFLD but not MS retained a statistically significant correlation with cardiovascular disease in a multivariate model.NAFLD is a strong predictor of cardiovascular disease and may play a central role in the cardiovascular risk of MS.
文摘Nonalcoholic fatty liver disease(NAFLD) is today considered the most common form of chronic liver disease, affecting a high proportion of the population worldwide. NAFLD encompasses a large spectrum of liver damage, ranging from simple steatosis to steatohepatitis, advanced fibrosis and cirrhosis. Obesity, hyperglycemia, type 2 diabetes and hypertriglyceridemia are the most important risk factors. The pathogenesis of NAFLD and its progression to fibrosis and chronic liver disease is still unknown. Accumulating evidence indicates that mitochondrial dysfunction plays a key role in the physiopathology of NAFLD, although the mechanisms underlying this dysfunction are still unclear. Oxidative stress is considered an important factor in producing lethal hepatocyte injury associated with NAFLD. Mitochondrial respiratory chain is the main subcellular source of reactive oxygen species(ROS), which may damage mitochondrial proteins, lipids and mitochondrial DNA. Cardiolipin, a phospholipid located at the level of the inner mitochondrial membrane, plays an important role in several reactions and processes involved in mitochondrial bioenergetics as well as in mitochondrial dependent steps of apoptosis. This phospholipid is particularly susceptible to ROS attack. Cardiolipin peroxidation has been associated with mitochondrial dysfunction in multiple tissues in several physiopathological conditions, including NAFLD. In this review, we focus on the potential roles played by oxidative stress and cardiolipin alterations in mitochondrial dysfunction associated with NAFLD.
基金the Key Project of the National Natural Science Foundation(No.81630011,to H.L.)the National Science Fund for Distinguished Young Scholars(No.81425005,to H.L.)+2 种基金the Major Research Plan of the National Natural Science Foundation of China(No.91639304 and No.91729303,to H.L.)the Creative Group Project of Hubei Province(No.2016CFA010,to H.L.)the Hubei Science and Technology Support Project(No.2018BEC473,to H.L.)
文摘With the increasing number of individuals with diabetes and obesity,nonalcoholic fatty liver disease(NAFLD) is becoming increasingly prevalent,affecting one-quarter of adults worldwide. The spectrum of NAFLD ranges from simple steatosis or nonalcoholic fatty liver(NAFL) to nonalcoholic steatohepatitis(NASH). NAFLD, especially NASH, may progress to fibrosis, leading to cirrhosis and hepatocellular carcinoma. NAFLD can impose a severe economic burden,and patients with NAFLD-related terminal or deteriorative liver diseases have become one of the main groups receiving liver transplantation. The increasing prevalence of NAFLD and the severe outcomes of NASH make it necessary to use effective methods to identify NAFLD. Although recognized as the gold standard, biopsy is limited by its sampling bias, poor acceptability, and severe complications, such as mortality, bleeding, and pain. Therefore, noninvasive methods are urgently needed to avoid biopsy for diagnosing NAFLD. This review discusses the current noninvasive methods for assessing NAFLD,including steatosis, NASH, and NAFLD-related fibrosis, and explores the advantages and disadvantages of measurement tools. In addition, we analyze potential noninvasive biomarkers for tracking disease processes and monitoring treatment effects, and explore effective algorithms consisting of imaging and nonimaging biomarkers for diagnosing advanced fibrosis and reducing unnecessary biopsies in clinical practice.
基金Supported by Scholarship Funds from MSD Co.Ltd.(to Sumida Y)+3 种基金Scholarship Funds from MSD Co.Ltd.Dainippon Sumitomo Pharma Co.Ltd.(to Ioh Y)
文摘It is estimated that 30% of the adult population in Japan is affected by nonalcoholic fatty liver disease (NAFLD). Fatty changes of the liver are generally diagnosed using imaging methods such as abdominal ultrasonography (US) and computed tomography (CT), but the sensitivity of these imaging techniques is low in cases of mild steatosis. Alanine aminotransferase levels may be normal in some of these patients, warranting the necessity to establish a set of parameters useful for detecting NAFLD, and the more severe form of the disease, nonalcoholic steatohepatitis (NASH). Although liver biopsy is currently the gold standard for diagnosing progressive NASH, it has many drawbacks, such as sampling error, cost, and risk of complications. Furthermore, it is not realistic to perform liver biopsies on all NAFLD patients. Diagnosis of NASH using various biomarkers, scoring systems and imaging methods, such as elastography, has recently been attempted. The NAFIC score, calculated from the levels of ferritin, fasting insulin, and type IV collagen 7S, is useful for the diagnosis of NASH, while the NAFLD fibrosis score and the FIB-4 index are useful for excluding NASH in cases of advanced fibrosis. This article reviews the limitations and merits of liver biopsy and noninvasive diagnostic tests in the diagnosis of NAFLD/NASH.
基金Supported by The Basic Science Research Program through the National Research Foundation of South Koreafunded by the Ministry of Education,Science and Technology,No.2012R1A1A1005326
文摘Nonalcoholic fatty liver disease(NAFLD)is a frequent cause of chronic liver diseases,ranging from simple steatosis to nonalcoholic steatohepatitis(NASH)-related liver cirrhosis.Although liver biopsy is still the gold standard for the diagnosis of NAFLD,especially for the diagnosis of NASH,imaging methods have been increasingly accepted as noninvasive alternatives to liver biopsy.Ultrasonography is a well-established and costeffective imaging technique for the diagnosis of hepatic steatosis,especially for screening a large population at risk of NAFLD.Ultrasonography has a reasonable accuracy in detecting moderate-to-severe hepatic steatosis although it is less accurate for detecting mild hepatic steatosis,operator-dependent,and rather qualitative.Computed tomography is not appropriate for general population assessment of hepatic steatosis given its inaccuracy in detecting mild hepatic steatosis and potential radiation hazard.However,computed tomography may be effective in specific clinical situations,such as evaluation of donor candidates for hepatic transplantation.Magnetic resonance spectroscopy and magnetic resonance imaging are now regarded as the most accurate practical methods of measuring liver fat in clinical practice,especially for longitudinal followup of patients with NAFLD.Ultrasound elastography and magnetic resonance elastography are increasingly used to evaluate the degree of liver fibrosis in patients with NAFLD and to differentiate NASH from simple steatosis.This article will review current imaging methods used to evaluate hepatic steatosis,including the diagnostic accuracy,limitations,and practical applicability of each method.It will also briefly describe the potential role of elastography techniques in the evaluation of patients with NAFLD.
文摘Nonalcoholic fatty liver disease (NAFLD) is a condition in which excess fat accumulates in the liver of a patient with no history of alcohol abuse or other causes for secondary hepatic steatosis. The pathogenesis of NAFLD and nonalcoholic steatohepatitis (NASH) has not been fully elucidated. The “two-hit“ hypothesis is probably a too simplified model to elaborate complex pathogenetic events occurring in patients with NASH. It should be better regarded as a multiple step process, with accumulation of liver fat being the first step, followed by the development of necroinflammation and fibrosis. Adipose tissue, which has emerged as an endocrine organ with a key role in energy homeostasis, is responsive to both central and peripheral metabolic signals and is itself capable of secreting a number of proteins. These adipocyte-specific or enriched proteins, termed adipokines, have been shown to have a variety of local, peripheral, and central effects. In the current review, we explore the role of adipocytokines and proinflammatory cytokines in the pathogenesis of NAFLD. We particularly focus on adiponectin, leptin and ghrelin, with a brief mention of resistin, visfatin and retinol-binding protein 4 among adipokines, and tumor necrosis factor-α, interleukin (IL)-6, IL-1, and briefly IL-18 among proinflammatory cytokines. We update their role in NAFLD, as elucidated in experimental models and clinical practice.
文摘Objective： To investigate the relationship between alanine aminotransferase （ALT） levels and metabolic syndrome （MS） in nonalcoholic fatty liver disease （NAFLD）. Methods： A total of 26527 subjects who received medical health checkup in our hospital from January 2005 to July 2007 were enrolled in the study. The diagnosis of fatty liver was based on ultrasound imaging. MS was defined according to the criteria of the Adult Treatment Panel III. ALT, triglyceride （TG）, high density lipoprotein cholesterol （HDL-c）, fasting plasma glucose （FPG）, height, weight, waist circumference （WC）, systolic blood pressure （SBP） and diastolic blood pressure （DBP） were measured in each subject to analyze the relationship between MS and ALT activity Results： （1） The prevalence of NAFLD in men （30.94%） was significantly higher than that in women （15.65%）; （2） The incidence of MS in NAFLD （33.83%） was significantly greater than that in non-NAFLD （10.62%）; （3） Of the 6470 subjects with NAFLD, in the age-adjusted partial correlation analysis, there were statistically significant correlations between the ALT levels and most metabolic risk factors in each sex （P〈0.01）, except that ALT levels multiple stepwise regression analysis, SBP lost its significance, and had no correlation with HDL-c in women. Moreover, in the WC, body mass index （BMI）, age, DBP, TG and FPG were independently associated with ALT levels in both sexes （P〈0.05）. HDL-c remained significant and was independently related to ALT levels in men; （4） ALT levels were significantly higher in subjects with MS compared to those without MS （P〈0.001）. Mean ALT levels increased with the number of MS components in each sex （P〈0.05 for trend）. Conclusion： We found a strong relationship between ALT levels and MS in NAFLD and revealed that the cluster of MS components might be the predictor for ALT elevations.
文摘Nonalcoholic fatty liver disease(NAFLD)/nonalcoholic steatohepatitis(NASH) is considered to be a hepatic manifestation of metabolic syndrome, and its incidence is rapidly increasing worldwide. It is currently the most common chronic liver disease. NASH can progress to liver cirrhosis and hepatocellular carcinoma, and may result in liver-related death. Currently, the principal treatment for NAFLD/NASH is lifestyle modification by diet and exercise. However, pharmacological therapy is indispensable because obese patients with NAFLD often have difficulty maintaining improved lifestyles. The pathogenesis of NAFLD/NASH has not been completely elucidated. However, insulin resistance, inflammatory cytokines, and oxidative stress are thought to be important in the development and/or progression of the disease. Currently, insulin sensitizers(thiazolidinediones) and antioxidants(vitamin E) seem to be the most promising therapeutic agents for NAFLD/NASH, and lipid-lowering drugs, pentoxifylline, angiotensin receptor blockers, and n-3 polyunsaturated fatty acids also have promise. However, there is a lack of consensus regarding the most effective and appropriate pharmacotherapy for NAFLD/NASH. Animal experiments suggest that herbal medicines and natural products may be promising therapeutic agents for NAFLD/NASH, but their efficacy and safety are yet to be investigated in human studies. In this paper, we review the existing and potential pharmacological therapies for NAFLD/NASH.
基金Supported by National Key Basic Research Development Program,No.2012CB524905National Science and Technology Support Plan Project,No.2012BAI06B04+4 种基金National Natural Science Foundation of China,No.30900677,No.81070315,No.81070366,No.81100278,No.81170378,No.81230012 and No.81270487Zhejiang Provincial Natural Science Foundation of China,No.Y2090463 and No.Y2110026International Science and Technology Cooperation Projects of Zhejiang Province,No.2013C24010Science Foundation of Health Bureau of Zhejiang Province,No.2009A070 and No.2012RCA026Specialized Research Fund for the Doctoral Program of Higher Education,No.20090101120110
文摘Nonalcoholic fatty liver disease(NAFLD)has emerged as a common public health problem in recent decades.However,the underlying mechanisms leading to the development of NAFLD are not fully understood.The endoplasmic reticulum(ER)stress response has recently been proposed to play a crucial role in both the development of steatosis and progression to nonalcoholic steatohepatitis.ER stress is activated to regulate protein synthesis and restore homeostatic equilibrium when the cell is stressed due to the accumulation of unfolded or misfolded proteins.However,delayed or insufficient responses to ER stress may turn physiological mechanisms into pathological consequences,including fat accumulation,insulin resistance,inflammation,and apoptosis,all of which play important roles in the pathogenesis of NAFLD.Therefore,understanding the role of ER stress in the pathogenesis of NAFLD has become a topic of intense investigation.This review highlights the recent findings linking ER stress signaling pathways to the pathogenesis of NAFLD.
文摘Nonalcoholic fatty liver disease(NAFLD)is quickly becoming one of the most prominent causes of liver disease worldwide.The increasing incidence of NAFLD is tied to the obesity epidemic and the subsequent metabolic derangements brought along with it.Current efforts to elucidate the mechanism and causes of the disease have answered some questions,but much remains unknown about NAFLD.The aim of this article is to discuss the current knowledge regarding the pathogenesis of the disease,as well as the current and future diagnostic,preventative,and therapeutic options available to clinicians for the management of NAFLD.
