Management of nonalcoholic fatty liver disease: weight control

Dietary trans-fatty acid induced NASH is normalized following loss of trans-fatty acids from hepatic lipid pools

Previous experiments in mice showed that dietary trans-fats could play a role in non-alcoholic steatohepatitis (NASH) yet little is known about the accumulation trans-fats in hepatic lipid pools in relationship to liver injury. NASH is also associated with obesity yet improves with only modest weight loss. To distinguish the role of obesity versus sustained consumption of a trans-fat containing diet in causing NASH, mice with obesity and NASH induced by consuming a high trans-fat diet for 16 weeks were subsequently fed standard chow or maintained on trans-fat chow for another 8 weeks. The accumulation, partitioning and loss of trans-fats in the major hepatic lipid pools during and after trans-fat consumption were determined. Obese mice switched to standard chow remained obese but steatohepatitis improved. trans-fats were differentially incorporated into the major hepatic lipid pools and the loss of trans-fats after crossover to control chow was greatest in the cholesteryl ester pool. In summary, dietary changes can improve the biochemical and histopathological changes of NASH despite persistent obesity in mice. Analysis of hepatic lipids confirmed that dietary trans-fats accumulate in the major lipid pools and are released differentially with diet normalization. The substantial loss of trans-fats from the cholesteryl ester pool in parallel with improvement in NASH suggests that this pool of trans-fats could play a role in the pathogenesis of NASH.

Mechanisms and implications of age-related changes in the liver: nonalcoholic Fatty liver disease in the elderly

Nonalcoholic fatty liver disease (NAFLD) is hepatic steatosis associated with metabolic abnormalities such as overweight/central obesity, insulin resistance, type 2 diabetes (T2D), and dyslipidemia. NAFLD is becoming the most common liver disease in contemporary society, with the highest prevalence in those over 60 years. NAFLD pathology ranges from simple steatosis to a necroinflammatory fibrosing disorder called steatohepatitis (SH), the latter associated with high risk of developing cirrhosis, often occuring in the seventh to ninth decades of life. While the main health implications of NAFLD are increased risk of developing T2D, cardiovascular diseases, and common cancers, there is substantantially increased standardized mortality, and deaths from decompensated cirrhosis and hepatocellular carcinoma (HCC). Little is known about the interactive effects of ageing and NAFLD, with most studies focusing on the younger population. This paper summarises the epidemiology, pathogenesis, and clinical course of NAFLD, with particular attention to persons over age 60 years. An approach to the management of NASH and its complications in the elderly, will also be presented here.

Weight reduction for non-alcoholic fatty liver disease

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is becoming a wide spread liver disease. The present recommendations for treatment are not evidence-based. Some of them are various weight reduction measures with diet, exercise, drug, or surgical therapy.

OBJECTIVES

To assess the benefits and harms of intended weight reduction for patients with NAFLD.

SEARCH STRATEGY

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, The Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, PubMed, EMBASE, Science Citation Index Expanded, Chinese Biomedicine Database, and ClinicalTrials.gov until February 2011.

SELECTION CRITERIA

We included randomised clinical trials evaluating weight reduction with different measures versus no intervention or placebo in NAFLD patients.

DATA COLLECTION AND ANALYSIS

We extracted data independently. We calculated the odds ratio (OR) for dichotomous data and calculated the mean difference (MD) for continuous data, both with 95% confidence intervals (CI).

MAIN RESULTS

The review includes seven trials; five on aspects of lifestyle changes (eg, diet, physical exercise) and two on treatment with a weight reduction drug 'orlistat'. In total, 373 participants were enrolled, and the duration of the trials ranged from 1 month to 1 year. Only one trial on lifestyle programme was judged to be of low risk of bias. We could not perform meta-analyses for the main outcomes as they were either not reported or there were insufficient number of trials for each outcome to be meta-analysed. We could meta-analyse the available data for body weight and body mass index only. Adverse events were poorly reported.

AUTHORS' CONCLUSIONS

The sparse data and high risk of bias preclude us from drawing any definite conclusion on lifestyle programme or orlistat for treatment of NAFLD. Further randomised clinical trials with low risk of bias are needed to test the beneficial and harmful effects of weight reduction for NAFLD patients. The long-term prognosis of development of fibrosis, mortality, and quality of life should be studied.

Downregulation of matrix metalloproteinase-9 by melatonin during prevention of alcohol-induced liver injury in mice

Matrix metalloproteinases (MMPs) have been implicated in inflammatory and degradative processes in several diseases. The study aims to explore the mechanism of MMP-9 regulation in alcohol-induced acute liver injury and its protection by melatonin in mice. Alcohol-induced acute liver injury was induced in female Balb/C mice by ethanol administration and protection studies were carried out with a well-known antioxidant molecule, melatonin. Degree of liver injury was monitored by histological and biochemical analysis of liver tissues. Oral administration of ethanol in mouse caused significant increase in alanine amino transferase (ALT) activity in serum. Depletion of glutathione and enhancement of lipid peroxidation as well as protein oxidation was observed in liver tissues following ethanol treatment. However, melatonin exhibited potent hepatoprotective activity by inhibiting ALT activity and oxidative stress. Additionally, MMP-9 expression was increased by ethanol in a dose and time dependent manner in liver tissue and serum. Increased secretion of proMMP-9 was strongly correlated with the expression of proinflammatory cytokines e.g., tumor necrosis factor (TNF)-α, interleukin (IL)-1β and IL6. Melatonin showed hepatoprotective role by downregulation of MMP-9 and upregulation of tissue inhibitor of metalloproteases (TIMP-1) expression in liver tissue. Nuclear factor (NF)-κB, plays an important role in inducing inflammatory genes during oxidative stress, thus the role of NF-κB in ethanol-induced liver injury was investigated. Ethanol induced nuclear translocation of NF-κB and increased degradation of inhibitor of NF-κB (IκBα) in liver tissues. Moreover, ethanol-induced NF-κB translocation into nucleus was inhibited significantly by melatonin. This is the first study to elucidate the induction of MMP-9 expression by NF-κB-dependent pathway in ethanol-induced acute liver injury in mice. This study also identifies the novel role of melatonin in hepatoprotection via MMP-9 down regulation.

Prevalência de doença hepática não-alcoólica em crianças e adolescentes obesos: uma revisão sistemática

OBJETIVO: Revisar publicações que investigaram a prevalência de doença hepática gordurosa não-alcoólica (DHGNA) em crianças. FONTES DE DADOS: Bancos de dados Medline (versão PubMed) e Latin American and Caribbean Centre on Health Sciences Information (LILACS), considerando-se o período de 1997 a 2008. Aplicou-se a combinação dos seguintes descritores: "nonalcoholic fatty liver disease", "hepatic steatosis", "nonalcoholic steatohepatitis", "overweight children", "overweight adolescent", "pediatric obesity", "children obesity", "childhood obesity". SÍNTESE DOS DADOS: Foram selecionados 14 artigos: cinco transversais, um caso-controle e oito de coorte. A concordância entre os avaliadores na classificação da qualidade dos artigos foi considerada ótima (k=0,81), com intervalo de confiança de 95% (0,52-1,00; p<0,001); porém, apenas um estudo foi considerado de excelente qualidade. Todos os estudos demonstraram associação entre obesidade e DHGNA, com prevalências variando de 3,0 a 60,3%. Os artigos analisados indicam que as alterações bioquímicas e de imagem são rapidamente normalizadas com a programação da perda ponderal por meio de dieta e exercício físico. Observam-se prevalências maiores em meninos, com o aumento da idade. Uma associação relatada com frequência foi a da resistência insulínica com a progressão da DHGNA. CONCLUSÕES: São necessários estudos cuidadosamente desenhados para esclarecer a relação entre obesidade e DHGNA na infância. Recomenda-se que todas as crianças obesas sejam rastreadas, já que a DHGNA representa a maior causa de agravo hepático na infância.

Nonalcoholic fatty liver disease in children living in the obeseogenic society

BACKGROUND

The problem of obesity in children has grown considerably in recent years in the United States as well as the rest of the world. This has resulted in a marked increase in the prevalence of nonalcoholic liver disease in the pediatric age group. Nonalcoholic fatty liver disease (NAFLD) is currently the most common hepatic disorder seen in pediatric hepatology practice.

DATA SOURCES

We have reviewed the most recent literature regarding the prevalence, pathogenesis as well as the most recent advances in the diagnostic and therapeutic modalities of NAFLD in children.

RESULTS

NAFLD affects a substantial portion of the population including children.

CONCLUSIONS

The rising incidence of NAFLD, nonalcoholic steatohepatitis (NASH) and cirrhosis emphasizes the need for effective treatment options. The lack of complete understanding of the pathogenesis of NAFLD still limits our ability to develop novel therapeutic modalities that can target the metabolic derangements implicated in the development of the disorder.

Lifestyle modification as the primary treatment of NASH

This article reviews the rationale and data behind recommending lifestyle changes to prevent and reverse NASH, focusing specifically on changes that lead to increased physical activity in sedentary patients, changes in dietary habits, and decreased calorie consumption to achieve gradual and sustained weight loss in those who are overweight or obese. In a culture that values avoiding even minimal exertion these are not easy changes to make. Ultimately, the success of care providers in helping patients to recognize and overcome these barriers depends on a patient's motivation, but clinicians can be more persuasive and able to bolster this motivation when armed with a conviction based on data that establish this to be the best course of action for patients with NASH.

Effect of a lifestyle intervention in patients with abnormal liver enzymes and metabolic risk factors

BACKGROUND AND AIM

Non-alcoholic fatty liver disease associated with insulin resistance is the most common cause of abnormal liver tests in clinical practice. To date, practical and effective strategies to improve the metabolic profile of this large group of patients have not been well characterised. We sought to assess the effect at 3 months of a behavior change-based lifestyle intervention on the metabolic profile of patients characterised by elevated liver enzymes.

METHODS

A total of 152 patients with elevated liver enzymes, central obesity and a range of metabolic risk factors were randomised to either a moderate- (6 sessions/10 weeks) or low-intensity (3 sessions/4 weeks) lifestyle counselling intervention or control group.

RESULTS

There was improvement in all metabolic risk factors in the moderate-intensity group, versus a smaller number of changes in the low-intensity intervention group and no change in any metabolic risk factors in control subjects. Reduction in liver enzymes was greatest in the moderate-intensity intervention group and least in the control group. The likelihood of elevated alanine aminotransferase (ALT) levels in both the moderate and low-intensity groups was reduced by over 70% compared to controls. The proportion of subjects achieving weight loss (>or= 2%) was significantly higher in the moderate-intensity intervention group (66%) versus the low-intensity intervention group (39%; P < 0.05) and controls (29%; P < 0.001).

CONCLUSIONS

Moderate and even low-intensity lifestyle counselling interventions targeting improvement in physical activity and nutritional behaviors and modest weight loss are a practical and effective method for improving the health of patients with elevated liver enzymes and a range of metabolic risk factors.

Nonalcoholic fatty liver disease decrease in obese adolescents after multidisciplinary therapy

BACKGROUND

Despite the increasing prevalence of nonalcoholic fatty liver disease, its pathogenesis and clinical significance remain poorly defined and there is no ideal treatment.

OBJECTIVE

The aim of this study was to assess the short-term (12-week) multidisciplinary therapy on visceral adiposity and nonalcoholic fatty liver disease control.

METHODS

We evaluated and compared the distribution of visceral adiposity and nonalcoholic fatty liver disease, by ultrasonography, in 73 post-puberty obese participants (17.01+/-1.6 years old; body mass index 36.54+/-2.86 kg/m), submitted to a multidisciplinary treatment without medications, at the beginning and after 12 weeks of intervention. Descriptive and one-way analysis of variance, and paired t-test were performed.

RESULTS

The results indicated that after intervention the adolescents had a significant reduction in visceral adiposity (4.05+/-1.55 to 3.37+/-1.44) and nonalcoholic fatty liver disease prevalence (from 52 to 29% on the right side and from 48 to 29% on the left side). It is a positive result because nonalcoholic fatty liver disease can progress to cirrhosis, even in children and adolescents.

CONCLUSIONS

The short-term treatment suggests a profound impact on the control of obesity-related co-morbidities in young people.

Tratamento multidisciplinar reduz o tecido adiposo visceral, leptina, grelina e a prevalência de esteatose hepática não alcoólica (NAFLD) em adolescentes obesos

O objetivo do presente estudo foi avaliar as alterações promovidas, por intervenção multidisciplinar, nas concentrações plasmáticas de grelina e leptina, adiposidade visceral e prevalência de esteatose hepática não alcoólica (NAFLD), em adolescentes obesos. Foram avaliados 28 adolescentes obesos, 16 meninas (IMC 34,58 ± 3,86kg/m²) e 12 meninos (IMC 37,08 ± 3,17kg/m²), com idade entre 15 e 19 anos, quanto à concentração de leptina, grelina, insulina, assim como a adiposidade visceral e o diagnóstico de NAFLD pelo método de ultra-sonografia. Os resultados demonstraram redução significante na concentração circulante de grelina e leptina e na adiposidade visceral (p < 0,01). Houve ainda redução percentual na prevalência de NAFLD, sendo este um resultado relevante, visto que esta doença pode progredir para cirrose, tanto em crianças quanto em adolescentes obesos. Este tipo de tratamento demonstrou ser eficiente na melhora do perfil metabólico e hormonal, contribuindo para o controle da obesidade e suas co-morbidades em adolescentes obesos.