Serum alanine aminotransferase levels decrease further with carbohydrate than fat restriction in insulin-resistant adults

Effect of a Low-Calorie Dietary Intervention on Liver Health and Body Weight in Adults with Metabolic-Dysfunction Associated Steatotic Liver Disease (MASLD) and Overweight/Obesity: A Systematic Review and Meta-Analysis

INTRODUCTION

Metabolic-dysfunction Associated Steatotic Liver Disease (MASLD) is a common cause of chronic liver disease. This review assessed the efficacy of a Low-Calorie Diet (LCD) on liver health and body weight in people living with MASLD and obesity.

METHODS

The study was registered with PROSPERO (CRD42021296501), and a literature search was conducted using multiple databases. The key inclusion criteria were randomised controlled trials or cohort studies, obesity/overweight and MASLD. Two authors screened abstracts, reviewed full texts and performed data extraction and quality assessment. The primary outcome was the change in the serum ALT, and secondary outcomes included the changes in the serum AST, intrahepatic lipid content (IHL), quantified non-invasively via MRI/MRS, and body weight.

RESULTS

Fifteen studies were included. The LCD reduced body weight by 9.1 kg versus the control (95%CI: -12.4, -5.8) but not serum ALT (-5.9 IU/L, -13.9, 2.0). Total Dietary Replacement (TDR) reduced IHL by -9.1% vs. the control (-15.6%, -2.6%). The Mediterranean-LCD for ≥12 months reduced ALT (-4.1 IU/L, -7.6, -0.5) and for 24 months reduced liver stiffness versus other LCDs. The Green-Mediterranean-LCD reduced IHL, independent of body weight. Limited studies assessed those of Black or Asian ethnicity, and there was heterogeneity in the methods assessing the liver fat content and fibrosis.

CONCLUSIONS

In people with MASLD and obesity, an LCD intervention reduces IHL and body weight. Trials should focus on the recruitment of Black and Asian ethnicity participants.

Bariatric Surgery Associates with Nonalcoholic Steatohepatitis/Hepatocellular Carcinoma Amelioration via SPP1 Suppression

Nonalcoholic steatohepatitis (NASH) is one of the most common chronic liver diseases worldwide and no effective drugs or treatments have been approved for disease management. Recently, bariatric surgery (BS) is considered to be a novel disease-modifying therapy for NASH and liver metabolic diseases, according to clinical follow-up studies. Despite the revealment of physiopathological alterations, underlying mechanisms and key factors remain indeterminate. This study included multiple bulk RNA-sequencing datasets to investigate transcriptome variation in one-year follow-up BS and diet management (Diet) NASH patients' liver biopsies. Liver functions, fibrosis, and carcinogenesis were predicted in liver samples via hallmark-based function enrichment analysis. Key factors generated from multi-dataset comparison were further assessed with hepatocellular carcinoma (HCC) progression and prognosis. BS leads to active gene expression alterations in NASH liver in comparison to diet management (Diet). Both approaches reduce cell stress and immune response, whereas BS contributes to higher metabolic levels and lower apoptosis levels. The macrophage infiltration, adipose accumulation, and fibroblast activation were revealed to be lower in post-BS NASH livers, further demonstrating positive correlations mutually. Seven key genes (MNDA, ALOX5AP, PECAM1, SPP1, CD86, FGF21, CSTA) were screened out as potential macrophage-associated and carcinogenetic factors suppressed by BS. SPP1 was identified as a crucial factor participating in BS intervened NASH-HCC progression. This study determined that BS exerts potentially superior protective functions in NASH livers compared to diet management. SPP1 may serve as a novel factor to study the functionalities of BS on NASH patients.

Low fat diet versus low carbohydrate diet for management of non-alcohol fatty liver disease: A systematic review

Although there is a consensus on beneficial effects of a low calorie diet in management of non-alcoholic fatty liver disease, the optimal composition of diet has not yet been elucidated. The aim of this review is to summarize the results of current randomized controlled trials evaluating the effects of low fat diet (LFD) vs. low carbohydrate diet (LCD) on NAFLD. This is a systematic review of all the available data reported in published clinical trials up to February 2022. The methodological quality of eligible studies was assessed, and data were presented aiming specific standard measurements. A total of 15 clinical trial studies were included in this systematic review. There is an overall lack of consensus on which dietary intervention is the most beneficial for NAFLD patients. There is also an overall lack of consensus on the definition of the different restrictive diets and the percentage of macronutrient restriction recommended. It seems that low calorie diets, regardless of their fat and carbohydrate composition, are efficient for liver enzyme reduction. Both LCD and LFD have similar effects on liver enzymes change; however, this improvement tends to be more marked in LFD. All calorie restrictive dietary interventions are beneficial for reducing weight, liver fat content and liver enzymes in individuals with NAFLD. Low fat diets seem to be markedly successful in reducing transaminase levels. Further research is needed to explore diet intensity, duration and long-term outcome.

One size does not fit all; practical, personal tailoring of the diet to NAFLD patients

Different dietary regimens for weight loss have developed over the years. Since the most evidenced treatment for non-alcoholic fatty liver disease (NAFLD) is weight reduction, it is not surprising that more diets targeting obesity are also utilized for NAFLD treatment. However, beyond the desired weight loss effects, one should not ignore the dietary composition of each diet, which may not necessarily be healthy or safe over the long term for hepatic and extrahepatic outcomes, especially cardiometabolic outcomes. Some of these diets are rich in saturated fat and red meat, are very strict, and require close medical supervision. Some may also be very difficult to adhere to for long periods, thus reducing the patient's motivation. The evidence for a direct benefit to NAFLD by restrictive diets such as very-low-carb, ketogenic, very-low-calorie diets, and intermittent fasting is scarce, and the long-term safety has not been tested. Nowadays, the approach is that the diet should be tailored to the patient's cultural and personal preferences. There is strong evidence for the independent protective association of NAFLD with a diet based on healthy eating patterns of minimally-processed foods, low in sugar and saturated fat, high in polyphenols, and healthy types of fats. This leads to the conclusion that a Mediterranean diet should serve as a basis that can be restructured into other kinds of diets. This review will elaborate on the different diets and their role in NAFLD. It will provide a practical guide to tailor the diet to the patients without compromising its composition and safety.

Associations of body shape index (ABSI) and hip index with liver, metabolic, and inflammatory biomarkers in the UK Biobank cohort

Associations of liver, metabolic, and inflammatory biomarkers in blood with body shape are unclear, because waist circumference (WC) and hip circumference (HC) are dependent on overall body size, resulting in bias. We have used the allometric "a body shape index" (ABSI = WC_(mm)[Formula: see text]Weight_(kg)^-2/3[Formula: see text]Height_(m)^5/6) and hip index (HI_women = HC_(cm)[Formula: see text]Weight_(kg)^-0.482[Formula: see text]Height_(cm)^0.310, HI_men = HC_(cm)[Formula: see text]Weight_(kg)^-2/5[Formula: see text]Height_(cm)^1/5), which are independent of body mass index (BMI) by design, in multivariable linear regression models for 121,879 UK Biobank men and 135,559 women. Glucose, glycated haemoglobin (HbA1c), triglycerides, low-density-lipoprotein cholesterol, apolipoprotein-B, alanine aminotransferase (ALT), gamma-glutamyltransferase, and lymphocytes were associated positively with BMI and ABSI but inversely with HI. High-density-lipoprotein cholesterol and apolipoprotein-A1 were associated inversely with BMI and ABSI but positively with HI. Lipid-related biomarkers and ALT were associated only with HI in obese men. C-reactive protein, neutrophils, monocytes, and alkaline phosphatase were associated positively, while bilirubin was associated inversely, with BMI and ABSI but not with HI. Associations were consistent within the clinical reference ranges but were lost or changed direction for low or high biomarker levels. Our study confirms associations with waist and hip size, independent of BMI, for metabolic biomarkers but only with waist size for inflammatory biomarkers, suggesting different contribution of the mechanistic pathways related to body shape.

Non-alcoholic Fatty Liver Disease and Carbohydrate Restricted Diets: A Case Report and Literature Review

Non-alcoholic fatty liver disease is the accumulation of excessive fat in the liver. Various treatment options are available to manage the condition, among which carbohydrate restriction has been shown to reduce liver fat accumulation, liver inflammation, serum liver enzyme levels, and hepatic de-novo lipogenesis in people with non-alcoholic fatty liver disease. Here, we present a case report of a 25-year-old South Asian patient presenting with right upper quadrant pain, fatigue, and headaches. After confirmation of non-Alcoholic fatty liver disease (NAFLD) diagnosis by biopsy, the patient initiated a low-carbohydrate diet. Four months after which significant improvement was noticed in clinical and laboratory parameters. Peer-reviewed publications were then sourced from online databases to explore the efficacy of low-carbohydrate diets for NAFLD. Our results were compared with the existing data. However, limited literature existed for such an intervention in the South Asian population therefore, the case report is novel. Combined with findings from the literature, our results from the case report supported our hypothesis that carbohydrate restriction might promote a reduction in hepatic fat accumulation and inflammation in patients with NAFLD and diabetes in various ethnicities including South Asians.

Fasting Ketonuria and the Risk of Incident Nonalcoholic Fatty Liver Disease With and Without Liver Fibrosis in Nondiabetic Adults

INTRODUCTION

Dietary carbohydrate restriction or ketogenic diets are known to be beneficial in preventing liver fat accumulation. However, the effect of ketonemia on the risk of nonalcoholic fatty liver disease (NAFLD) in nondiabetic population is largely unknown. We investigated the association between fasting ketonuria and the risk of incident NAFLD in healthy adults.

METHODS

A cohort of 153,076 nondiabetic Koreans with no hepatic steatosis and low probability of fibrosis at baseline was followed for a median of 4.1 years. The outcome was incident hepatic steatosis with or without liver fibrosis, and it was assessed by liver ultrasound and noninvasive fibrosis indices, including fibrosis-4 and the NAFLD fibrosis score (NFS). Parametric proportional hazard models were used to estimate hazard ratios (HRs) for outcome according to ketonuria status.

RESULTS

Within 677,702.1 person-years of follow-up, 31,079 subjects developed hepatic steatosis. Compared with no ketonuria (reference), fasting ketonuria was significantly associated with a decreased risk of incident hepatic steatosis, with multivariable-adjusted HRs (95% confidence interval) of 0.81 (0.78-0.84). The corresponding HRs for incident hepatic steatosis with intermediate-to-high NFS were 0.79 (0.69-0.90). Similar associations were observed replacing NFS with fibrosis-4. In addition, the presence of persistent ketonuria at both baseline and subsequent visit was associated with the greatest decrease in the adjusted HR for incident NAFLD.

DISCUSSION

Ketonuria was associated with a reduced risk of developing incident hepatic steatosis with and without intermediate-to-high probability of advanced fibrosis in a large cohort of nondiabetic healthy individuals. The role of hyperketonemia in the prevention of NAFLD requires further exploration.

Dietary Approaches for Management of Non-Alcoholic Fatty Liver Disease: A Clinician's Guide

Non-alcoholic fatty liver disease (NAFLD) is closely associated with obesity, insulin resistance, and hyperlipidemia. There is strong clinical evidence that reduction in at least 5-7% total body weight is associated with improvement in hepatic steatosis and regression of fibrosis, with weight loss representing the primary approach to treatment. This guide reviews recent data on dietary approaches studied in NAFLD management. The strongest evidence currently supports a hypocaloric diet to induce weight loss and subsequent improvement in liver enzymes and histology, as well as a Mediterranean diet, which can lead to improvement in steatosis even in the absence of weight reduction. The purpose of this paper is to provide clinicians with tools to engage patients in conversations about nutrition in the setting of NAFLD, ultimately guiding suitable personalized dietary recommendations.

Current treatment paradigms and emerging therapies for NAFLD/NASH

Non-alcoholic fatty liver disease (NAFLD) is one the fastest emerging manifestations of the metabolic syndrome worldwide. Non-alcoholic steatohepatitis (NASH), the progressive form of NAFLD, may culminate into cirrhosis and hepatocellular cancer (HCC) and is presently a leading cause of liver transplant. Although a steady progress is seen in understanding of the disease epidemiology, pathogenesis and identifying therapeutic targets, the slowest advancement is seen in the therapeutic field. Currently, there is no FDA approved therapy for this disease and appropriate therapeutic targets are urgently warranted. In this review we discuss the role of lifestyle intervention, pharmacological agents, surgical approaches, and gut microbiome, with regard to therapy for NASH. In particular, we focus the role of insulin sensitizers, thyroid hormone mimetics, antioxidants, cholesterol lowering drugs, incretins and cytokines as therapeutic targets for NASH. We highlight these targets aiming to optimize the future for NASH therapy.

ESPEN practical guideline: Clinical nutrition in liver disease

BACKGROUND

The Practical guideline is based on the current scientific ESPEN guideline on Clinical Nutrition in Liver Disease.

METHODS

It has been shortened and transformed into flow charts for easier use in clinical practice. The guideline is dedicated to all professionals including physicians, dieticians, nutritionists and nurses working with patients with chronic liver disease.

RESULTS

A total of 103 statements and recommendations are presented with short commentaries for the nutritional and metabolic management of patients with (i) acute liver failure, (ii) alcoholic steatohepatitis, (iii) non-alcoholic fatty liver disease, (iv) liver cirrhosis, and (v) liver surgery/transplantation. The disease-related recommendations are preceded by general recommendations on the diagnostics of nutritional status in liver patients and on liver complications associated with medical nutrition.

CONCLUSION

This practical guideline gives guidance to health care providers involved in the management of liver disease to offer optimal nutritional care.

A Fad too Far? Dietary Strategies for the Prevention and Treatment of NAFLD

Nonalcoholic fatty liver disease (NAFLD) is a major health problem, and its prevalence has increased in recent years, concurrent with rising rates of obesity and other metabolic diseases. Currently, there are no FDA-approved pharmacological therapies for NAFLD, and lifestyle interventions, including weight loss and exercise, remain the cornerstones for treatment. Manipulating diet composition and eating patterns may be a sustainable approach to NAFLD treatment. Dietary strategies including Paleolithic, ketogenic, Mediterranean, high-protein, plant-based, low-carbohydrate, and intermittent fasting diets have become increasingly popular because of their purported benefits on metabolic disease. This review highlights what is currently known about these popular dietary approaches in the management of NAFLD in clinical populations with mechanistic insight from animal studies. It also identifies key knowledge gaps to better inform future preclinical and clinical studies aimed at the treatment of NAFLD.

Post hoc analyses of surrogate markers of non-alcoholic fatty liver disease (NAFLD) and liver fibrosis in patients with type 2 diabetes in a digitally supported continuous care intervention: an open-label, non-randomised controlled study

OBJECTIVE

One year of comprehensive continuous care intervention (CCI) through nutritional ketosis improves glycosylated haemoglobin(HbA1c), body weight and liver enzymes among patients with type 2 diabetes (T2D). Here, we report the effect of the CCI on surrogate scores of non-alcoholic fatty liver disease (NAFLD) and liver fibrosis.

METHODS

This was a non-randomised longitudinal study, including adults with T2D who were self-enrolled to the CCI (n=262) or to receive usual care (UC, n=87) during 1 year. An NAFLD liver fat score (N-LFS) >-0.640 defined the presence of fatty liver. An NAFLD fibrosis score (NFS) of >0.675 identified subjects with advanced fibrosis. Changes in N-LFS and NFS at 1 year were the main endpoints.

RESULTS

At baseline, NAFLD was present in 95% of patients in the CCI and 90% of patients in the UC. At 1 year, weight loss of ≥5% was achieved in 79% of patients in the CCI versus 19% of patients in UC (p<0.001). N-LFS mean score was reduced in the CCI group (-1.95±0.22, p<0.001), whereas it was not changed in the UC (0.47±0.41, p=0.26) (CCI vs UC, p<0.001). NFS was reduced in the CCI group (-0.65±0.06, p<0.001) compared with UC (0.26±0.11, p=0.02) (p<0.001 between two groups). In the CCI group, the percentage of individuals with a low probability of advanced fibrosis increased from 18% at baseline to 33% at 1 year (p<0.001).

CONCLUSIONS

One year of a digitally supported CCI significantly improved surrogates of NAFLD and advanced fibrosis in patients with T2D.

TRIAL REGISTRATION NUMBER

NCT02519309; Results.

Intestinal permeability after Mediterranean diet and low-fat diet in non-alcoholic fatty liver disease

BACKGROUND

In non-alcoholic fatty liver disease (NAFLD), a high-fat or high-fructose diet increases intestinal permeability and promotes derangement of the gut-liver axis. We hypothesize that, diet could be able to modulate intestinal permeability in patients with NAFLD.

AIM

To detect diet-induced modification of intestinal permeability in patients with NAFLD undergoing a Mediterranean diet or a low-fat diet.

METHODS

The current study was a dietary intervention for non-diabetic, patients with biopsy-verified NAFLD and increased transaminases. A crossover design was employed: participants underwent 16 weeks of Mediterranean diet, 16 wk of free wash-out, and 16 weeks of low-fat diet. Both diets were hypocaloric and no consumption of supplements was allowed. All patients were followed bimonthly by a dietitian. Evaluations of clinical and metabolic parameters were completed at baseline and at the end of each dietary period. Intestinal permeability was assessed by chromium-51 ethylene diamine tetraacetate excretion testing (51Cr-EDTA).

RESULTS

Twenty Caucasian patients, 90% male, median age 43 years, body mass index (BMI) 30.9, with biopsy-verified NAFLD were enrolled. At the end of 16 weeks of a Mediterranean diet, a significant reduction in mean body weight (-5.3 ± 4.1 kg, P = 0.003), mean waist circumference (-7.9 ± 4.9 cm, P = 0.001), and mean transaminase levels [alanine aminotransferase (ALT) -28.3 ± 11.9 IU/L, P = 0.0001; aspartate aminotransferase (AST) -6.4 ± 56.3 IU/L, P = 0.01] were observed. These benefits were maintained after 16 wk of wash-out and also after 16 wk of low-fat diet, without further improvements. Fourteen of the 20 patients had intestinal permeability alteration at baseline (mean percentage retention of 51Cr-EDTA = 5.4%), but no significant changes in intestinal permeability were observed at the end of the 16 wk of the Mediterranean diet or 16 wk of the low-fat diet.

CONCLUSION

Mediterranean diet is an effective strategy for treating overweight, visceral obesity and serum transaminase in patients with NAFLD. If the Mediterranean diet can improve intestinal permeability in patients with NAFLD, it deserves further investigation.

ESPEN guideline on clinical nutrition in liver disease

This update of evidence-based guidelines (GL) aims to translate current evidence and expert opinion into recommendations for multidisciplinary teams responsible for the optimal nutritional and metabolic management of adult patients with liver disease. The GL was commissioned and financially supported by ESPEN. Members of the guideline group were selected by ESPEN. We searched for meta-analyses, systematic reviews and single clinical trials based on clinical questions according to the PICO format. The evidence was evaluated and used to develop clinical recommendations implementing the SIGN method. A total of 85 recommendations were made for the nutritional and metabolic management of patients with acute liver failure, severe alcoholic steatohepatitis, non-alcoholic fatty liver disease, liver cirrhosis, liver surgery and transplantation as well as nutrition associated liver injury distinct from fatty liver disease. The recommendations are preceded by statements covering current knowledge of the underlying pathophysiology and pathobiochemistry as well as pertinent methods for the assessment of nutritional status and body composition.

Treatment of NAFLD with diet, physical activity and exercise

Lifestyle intervention can be effective when treating non-alcoholic fatty liver diseases (NAFLD) patients. Weight loss decreases cardiovascular and diabetes risk and can also regress liver disease. Weight reductions of ⩾10% can induce a near universal non-alcoholic steatohepatitis resolution and fibrosis improvement by at least one stage. However, modest weight loss (>5%) can also produce important benefits on the components of the NAFLD activity score (NAS). Additionally, we need to explore the role of total calories and type of weight loss diet, micro- and macronutrients, evidence-based benefits of physical activity and exercise and finally support these modifications through established behavioural change models and techniques for long-term maintenance of lifestyle modifications. Following a Mediterranean diet can reduce liver fat even without weight loss and is the most recommended dietary pattern for NAFLD. The Mediterranean diet is characterised by reduced carbohydrate intake, especially sugars and refined carbohydrates (40% of the calories vs. 50-60% in a typical low fat diet), and increased monounsaturated and omega-3 fatty acid intake (40% of the calories as fat vs. up-to 30% in a typical low fat diet). Both TV sitting (a reliable marker of overall sedentary behaviour) and physical activity are associated with cardio-metabolic health, NAFLD and overall mortality. A 'triple hit behavioural phenotype' of: i) sedentary behaviour, ii) low physical activity, and iii) poor diet have been defined. Clinical evidence strongly supports the role of lifestyle modification as a primary therapy for the management of NAFLD and NASH. This should be accompanied by the implementation of strategies to avoid relapse and weight regain.

Liver fat: a relevant target for dietary intervention? Summary of a Unilever workshop

Currently it is estimated that about 1 billion people globally have non-alcoholic fatty liver disease (NAFLD), a condition in which liver fat exceeds 5 % of liver weight in the absence of significant alcohol intake. Due to the central role of the liver in metabolism, the prevalence of NAFLD is increasing in parallel with the prevalence of obesity, insulin resistance and other risk factors of metabolic diseases. However, the contribution of liver fat to the risk of type 2 diabetes mellitus and CVD, relative to other ectopic fat depots and to other risk markers, is unclear. Various studies have suggested that the accumulation of liver fat can be reduced or prevented via dietary changes. However, the amount of liver fat reduction that would be physiologically relevant, and the timeframes and dose-effect relationships for achieving this through different diet-based approaches, are unclear. Also, it is still uncertain whether the changes in liver fat per se or the associated metabolic changes are relevant. Furthermore, the methods available to measure liver fat, or even individual fatty acids, differ in sensitivity and reliability. The present report summarises key messages of presentations from different experts and related discussions from a workshop intended to capture current views and research gaps relating to the points above.

Randomized Controlled Trial of a MUFA or Fiber-Rich Diet on Hepatic Fat in Prediabetes

CONTEXT

Increased prevalence of type 2 diabetes mellitus and prediabetes worldwide is attributed in part to an unhealthy diet.

OBJECTIVE

To evaluate whether 12 weeks of high monounsaturated fatty acid (MUFA) or fiber-rich weight-maintenance diet lowers hepatic fat and improves glucose tolerance in people with prediabetes.

DESIGN

Subjects underwent a [6, 6-2H2]-labeled 75-g oral glucose tolerance test to estimate hepatic insulin sensitivity and liver fat fraction (LFF) using magnetic resonance spectroscopy before and after intervention.

SETTING

Mayo Clinic Clinical Research Trials Unit.

PARTICIPANTS

43 subjects with prediabetes.

INTERVENTION

Subjects were randomized into three isocaloric weight-maintaining diets containing MUFA (olive oil), extra fiber, and standard US food (control-habitual diet).

OUTCOME MEASURES

LFF, glucose tolerance, and indices of insulin action and secretion.

RESULTS

Body weight was maintained constant in all groups during the intervention. Glucose and hormonal concentrations were similar in all groups before, and unchanged after, 12 weeks of intervention. LFF was significantly lower after intervention in the MUFA group (P < 0.0003) but remained unchanged in the fiber (P = 0.25) and control groups (P = 0.45). After 12 weeks, LFF was significantly lower in the MUFA than in the control group (P = 0.01), but fiber and control groups did not differ (P = 0.41). Indices of insulin action and secretion were not significantly different between the MUFA and control groups after intervention (P ≥ 0.11), but within-group comparison showed higher hepatic (P = 0.01) and total insulin sensitivity (P < 0.04) with MUFA.

CONCLUSIONS

Twelve weeks of a MUFA diet decreases hepatic fat and improves both hepatic and total insulin sensitivity.

Nutritional Approaches to Achieve Weight Loss in Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) can range in spectrum from simple hepatic steatosis to nonalcoholic steatohepatitis (NASH), which is characterized by lipotoxicity, hepatocellular ballooning, and inflammation and can progress to cirrhosis. Weight loss is the cornerstone treatment for NAFLD and NASH. Various randomized controlled trials have shown that weight loss of ≥5-10% leads to significant improvements in hepatic steatosis. Diets high in sodium and fructose have been implicated in the pathogenesis of NAFLD. Although some clinical studies suggest that an isocaloric high-fructose diet does not worsen NAFLD, these clinical studies are often short in duration. More recently, the Dietary Approaches to Stop Hypertension diet, a sodium-restricted diet, has been associated with less prevalence of NAFLD and has been shown to improve NAFLD. In addition, the Mediterranean diet has been promising in improving hepatic steatosis, and a larger randomized controlled trial is currently enrolling subjects. For those who are unable to pursue weight loss through dietary approaches, bariatric surgery has been shown to improve hepatic steatosis and steatohepatitis. This method has been variable in improving hepatic fibrosis. In conclusion, weight loss is crucial to the improvement of NAFLD and NASH, and patients should attempt various diets in an attempt to achieve weight loss.

Nutrition Interventions for Chronic Liver Diseases and Nonalcoholic Fatty Liver Disease

The progressively increasing rates of obesity have led to a worldwide epidemic of nonalcoholic fatty liver disease (NAFLD), the hepatic manifestation of the metabolic syndrome. It is currently the most common cause of liver disease worldwide and projected to be the leading indication for liver transplantation in the United States by 2020. NAFLD is associated with both liver-related and overall mortality. Undoubtedly, nutrition interventions are key in the treatment of NAFLD, to reverse the disease, and prevent disease progression, complications, and associated comorbidities, including cardiovascular disease and diabetes.

Novel phenotypes of prediabetes?

This article describes phenotypes observed in a prediabetic population (i.e. a population with increased risk for type 2 diabetes) from data collected at the University hospital of Tübingen. We discuss the impact of genetic variation on insulin secretion, in particular the effect on compensatory hypersecretion, and the incretin-resistant phenotype of carriers of the gene variant TCF7L2 is described. Imaging studies used to characterise subphenotypes of fat distribution, metabolically healthy obesity and metabolically unhealthy obesity are described. Also discussed are ectopic fat stores in liver and pancreas that determine the phenotype of metabolically healthy and unhealthy fatty liver and the recently recognised phenotype of fatty pancreas. The metabolic impact of perivascular adipose tissue and pancreatic fat is discussed. The role of hepatokines, particularly that of fetuin-A, in the crosstalk between these organs is described. Finally, the role of brain insulin resistance in the development of the different prediabetes phenotypes is discussed.

The effects of low carbohydrate diets on liver function tests in nonalcoholic fatty liver disease: A systematic review and meta-analysis of clinical trials

Background:

Although several observational and experimental studies have examined the effects of low carbohydrate diets (LCDs) on nonalcoholic fatty liver disease (NAFLD), there are considerable inconsistencies among studies. We summarized the effect of LCDs on liver function tests, including intrahepatic lipid content (IHLC), alanine transaminase (ALT), aspartate aminotransferases (AST), and gamma-glutamyl transferase (GGT) in patients with NAFLD.

Materials and Methods:

PubMed, ISI Web of Science, Scopus, and Google Scholar databases were searched for relevant publications until July 2014, resulting in ten relevant papers that were included in meta-analysis. Related articles were found by searching Medical Subject Heading terms of “NAFLD” in combination with “low carbohydrate”. For this meta-analysis, we used mean differences and standard errors of liver function biomarkers. Summary effect and corresponding confidence interval (CI) were estimated using random effect models. Heterogeneity between studies was assessed using Cochran's Q- and I-squared tests.

Results:

Our search led to ten eligible papers that evaluated serum ALT levels (n = 238), nine reported serum AST levels (n = 216), five reported serum GGT concentrations (n = 91), and four assessed IHLC (n = 50). LCD decreased IHLC by −11.53% (95% CI: −18.10, −4.96; I² = 83.2%). However, the effect of LCD on liver enzymes was not significant. Mean differences for the effects of LCDs on ALT, AST, and GGT were −4.35 IU/L (95% CI: −12.91, 4.20; I² = 87.9%), −1.44 IU/L (95% CI: −4.98, 2.10; I² = 61.4%), and −7.85 IU/L (95% CI: −29.65, 13.96; I² = 99.4%), respectively.

Conclusion:

LCD consumption in subjects with NAFLD led to a significant reduction in IHLC, but did not significantly affect the concentration of liver enzymes.

Lifestyle changes for the treatment of nonalcoholic fatty liver disease: a review of observational studies and intervention trials

Nonalcoholic fatty liver disease (NAFLD) is emerging as a major public health problem because of its association with increased cardiovascular and liver-related morbidity and mortality. Both genetic factors and lifestyle contribute to the pathogenesis of NAFLD. Lifestyle, including dietary habits and physical activity, is a modifiable risk factor and thus represents the main target for the prevention and treatment of NAFLD. In this review, we summarize the evidence regarding nutritional aspects (i.e. total energy intake, saturated fat and carbohydrates intake, certain foods or drinks and dietary patterns as a whole) in the treatment of NAFLD. In addition, we analyze the evidence concerning the independent effect of physical activity, including aerobic and resistance training, in the treatment of NAFLD. A therapeutic algorithm according to results from intervention trials is also provided for clinicians and other healthcare professionals involved in the management of NAFLD.

Carbohydrate intake and nonalcoholic fatty liver disease: fructose as a weapon of mass destruction

Excessive accumulation of triglycerides (TG) in liver, in the absence of significant alcohol consumption is nonalcoholic fatty liver disease (NAFLD). NAFLD is a significant risk factor for developing cirrhosis and an independent predictor of cardiovascular disease. High fructose corn syrup (HFCS)-containing beverages were associated with metabolic abnormalities, and contributed to the development of NAFLD in human trials. Ingested carbohydrates are a major stimulus for hepatic de novo lipogenesis (DNL) and are more likely to directly contribute to NAFLD than dietary fat. Substrates used for the synthesis of newly made fatty acids by DNL are primarily glucose, fructose, and amino acids. Epidemiological studies linked HFCS consumption to the severity of fibrosis in patients with NAFLD. New animal studies provided additional evidence on the role of carbohydrate-induced DNL and the gut microbiome in NAFLD. The excessive consumption of HFCS-55 increased endoplasmic reticulum stress, activated the stress-related kinase, caused mitochondrial dysfunction, and increased apoptotic activity in the liver. A link between dietary fructose intake, increased hepatic glucose transporter type-5 (Glut5) (fructose transporter) gene expression and hepatic lipid peroxidation, MyD88, TNF-α levels, gut-derived endotoxemia, toll-like receptor-4, and NAFLD was reported. The lipogenic and proinflammatory effects of fructose appear to be due to transient ATP depletion by its rapid phosphorylation within the cell and from its ability to raise intracellular and serum uric acid levels. However, large prospective studies that evaluated the relationship between fructose and NAFLD were not performed yet.

Review article: the management of paediatric nonalcoholic fatty liver disease

BACKGROUND

Paediatric nonalcoholic fatty liver disease (NAFLD) is a major public health concern given the recent increase in its prevalence and link to obesity and other metabolic comorbidities. Current treatment strategies involve lifestyle changes. Other surgical and pharmacologic interventions have been proposed; however, limited randomised controlled trials (RCTs) in the paediatric population restrict their use.

AIM

To review the current management of paediatric NAFLD, including lifestyle and pharmacologic interventions, and to formulate recommendations for study design for future studies.

METHODS

A MEDLINE, Pubmed and Cochrane Review database search used a combination of keywords, including NAFLD, nonalcoholic steatohepatitis (NASH), paediatric, treatments, lifestyle changes, bariatric surgery, orlistat, metformin, thiazolidinediones, vitamin E, cysteamine bitartrate, ursodeoxycholic acid (UDCA), probiotics, omega-3 fatty acids, pentoxyfylline, farnesoid X receptor agonist and toll-like receptor modifiers. The articles were selected based on their relevance to the review.

RESULTS

Lifestyle interventions involving diet and exercise remain first-line treatment for paediatric NAFLD. Bariatric surgery, orlistat, insulin sensitisers and UDCA have been evaluated but are not recommended as first or second-line therapy. Medications such as cysteamine bitartrate, probiotics, polyunsaturated fats and pentoxyfilline share beneficial effects in trials, however, there is a paucity of adequately powered RCTs in which liver histology is evaluated. Vitamin E has been shown to be effective and safe in improving NASH histology in children.

CONCLUSIONS

Lifestyle intervention should be first-line treatment for paediatric NAFLD. Vitamin E should be considered for those with biopsy-proven NASH or borderline NASH failing first-line therapy. Other therapeutics show promising results but require larger RCTs with convincing endpoints. Improved screening techniques, objective validated inclusion criteria and outcome measures as well as rigour in study design are necessary for propelling therapeutic discovery.

Practical approaches to the nutritional management of nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is the hepatic manifestation of metabolic syndrome and a serious health burden worldwide which increases risk of cirrhosis, type 2 diabetes mellitus (T2DM), and cardiovascular complications. Current epidemics of obesity, unhealthy dietary patterns, and sedentary lifestyles, all contribute to the high prevalence of NAFLD. Dietary patterns and nutrients are important contributors to the development, progression, and treatment of NAFLD. A healthy diet is beneficial for all NAFLD patients beyond weight reduction. Generally, hypercaloric diets, especially rich in trans/saturated fat and cholesterol, high consumption of red and processed meat, and fructose-sweetened beverages seem to increase the risk of progression toward nonalcoholic steatohepatitis (NASH), whereas reducing caloric intake and high-glycemic index (GI) foods, increasing consumption of monounsaturated fatty acids, omega-3 fatty acids, fibers, and specific protein sources such as fish and poultry have preventive and therapeutic effects. Therefore, nutrition serves as a major route of prevention and treatment of NAFLD, and patients with NAFLD should have an individualized diet recommendation. In this review, the evidence linking macronutrients to NAFLD are discussed.

Management of nonalcoholic fatty liver disease: an evidence-based clinical practice review

AIM

To build a consensus among Chilean specialists on the appropriate management of patients with nonalcoholic fatty liver disease (NAFLD) in clinical practice.

METHODS

NAFLD has now reached epidemic proportions worldwide. The optimal treatment for NAFLD has not been established due to a lack of evidence-based recommendations. An expert panel of members of the Chilean Gastroenterological Society and the Chilean Hepatology Association conducted a structured analysis of the current literature on NAFLD therapy. The quality of the evidence and the level of recommendations supporting each statement were assessed according to the recommendations of the United States Preventive Services Task Force. A modified three-round Delphi technique was used to reach a consensus among the experts.

RESULTS

A group of thirteen experts was established. The survey included 17 open-ended questions that were distributed among the experts, who assessed the articles associated with each question. The levels of agreement achieved by the panel were 93.8% in the first round and 100% in the second and third rounds. The final recommendations support the indication of lifestyle changes, including diet and exercise, for all patients with NAFLD. Proven pharmacological therapies include only vitamin E and pioglitazone, which can be used in nondiabetic patients with biopsy-proven nonalcoholic steatohepatitis (the progressive form of NAFLD), although the long-term safety and efficacy of these therapies have not yet been established.

CONCLUSION

Current NAFLD management is rapidly evolving, and new pathophysiology-based therapies are expected to be introduced in the near future. All NAFLD patients should be evaluated using a three-focused approach that considers the risks of liver disease, diabetes and cardiovascular events.

Combination of alcohol and fructose exacerbates metabolic imbalance in terms of hepatic damage, dyslipidemia, and insulin resistance in rats

Although both alcohol and fructose are particularly steatogenic, their long-term effect in the development of a metabolic syndrome has not been studied in vivo. Consumption of fructose generally leads to obesity, whereas ethanol can induce liver damage in the absence of overweight. Here, Sprague-Dawley rats were fed ad libitum for 28 days on five diets: chow (control), liquid Lieber-DeCarli (LDC) diet, LDC +30%J of ethanol (L-Et) or fructose (L-Fr), and LDC combined with 30%J ethanol and 30%J fructose (L-EF). Body weight (BW) and liver weight (LW) were measured. Blood and liver samples were harvested and subjected to biochemical tests, histopathological examinations, and RT-PCR. Alcohol-containing diets substantially reduced the food intake and BW (≤3^rd week), whereas fructose-fed animals had higher LW than controls (P<0.05). Additionally, leukocytes, plasma AST and leptin levels were the highest in the fructose-administered rats. Compared to the chow and LDC diets, the L-EF diet significantly elevated blood glucose, insulin, and total-cholesterol levels (also vs. the L-Et group). The albumin and Quick-test levels were the lowest, whereas ALT activity was the highest in the L-EF group. Moreover, the L-EF diet aggravated plasma triglyceride and reduced HDL-cholesterol levels more than 2.7-fold compared to the sum of the effects of the L-Et and L-Fr diets. The decreased hepatic insulin clearance in the L-EF group vs. control and LDC groups was reflected by a significantly decreased C-peptide:insulin ratio. All diets except the control caused hepatosteatosis, as evidenced by Nile red and H&E staining. Hepatic transcription of insulin receptor substrate-1/2 was mainly suppressed by the L-Fr and L-EF diets. The L-EF diet did not enhance the mitochondrial β-oxidation of fatty acids (Cpt1α and Ppar-α expressions) compared to the L-Et or L-Fr diet. Together, our data provide evidence for the coaction of ethanol and fructose with a high-fat-diet on dyslipidemia and insulin resistance-accompanied liver damage.

Mediterranean diet and non-alcoholic fatty liver disease: new therapeutic option around the corner?

Non-alcoholic fatty liver disease (NAFLD) represents the most common chronic liver disease in Western countries, being considered as the hepatic manifestation of metabolic syndrome. NAFLD has a common pathogenic background to that of metabolic syndrome, and shares many risk factors such as obesity, hypertension, insulin resistance and dyslipidemia. Although there is no currently available evidence-based established treatment for NAFLD, all the recommendations from the medical associations indicate that the most effective treatment is to reduce weight through lifestyle modifications. Diet, indeed, plays a key role in the management of NAFLD patients, as both the quantity and quality of the diet have been reported to have a beneficial role in the onset and severity of the liver disease. Among all the diets that have been proposed, a Mediterranean diet was the most effective dietary option for inducing weight loss together with beneficial effects on all the risk factors associated with metabolic syndrome and NAFLD. Over the last few years, research has demonstrated a beneficial effect of a Mediterranean diet in NAFLD. In this review, we will examine all the available data on the association between diet, nutrients and the Mediterranean diet in association with onset and severity of NAFLD.

Mitohormesis: Promoting Health and Lifespan by Increased Levels of Reactive Oxygen Species (ROS)

Increasing evidence indicates that reactive oxygen species (ROS), consisting of superoxide, hydrogen peroxide, and multiple others, do not only cause oxidative stress, but rather may function as signaling molecules that promote health by preventing or delaying a number of chronic diseases, and ultimately extend lifespan. While high levels of ROS are generally accepted to cause cellular damage and to promote aging, low levels of these may rather improve systemic defense mechanisms by inducing an adaptive response. This concept has been named mitochondrial hormesis or mitohormesis. We here evaluate and summarize more than 500 publications from current literature regarding such ROS-mediated low-dose signaling events, including calorie restriction, hypoxia, temperature stress, and physical activity, as well as signaling events downstream of insulin/IGF-1 receptors, AMP-dependent kinase (AMPK), target-of-rapamycin (TOR), and lastly sirtuins to culminate in control of proteostasis, unfolded protein response (UPR), stem cell maintenance and stress resistance. Additionally, consequences of interfering with such ROS signals by pharmacological or natural compounds are being discussed, concluding that particularly antioxidants are useless or even harmful.

Pathophysiology of NASH: perspectives for a targeted treatment

Non alcoholic steatohepatitis (NASH) is the more severe form of nonalcoholic fatty liver disease. In NASH, fatty liver, hepatic inflammation, hepatocyte injury and fibrogenesis are associated, and this condition may eventually lead to cirrhosis. Current treatment of NASH relies on the reduction of body weight and increase in physical activity, but there is no pharmacologic treatment approved as yet. Emerging data indicate that NASH progression results from parallel events originating from the liver as well as from the adipose tissue, the gut and the gastrointestinal tract. Thus, dysfunction of the adipose tissue through enhanced flow of free fatty acids and release of adipocytokines, and alterations in the gut microbiome generate proinflammatory signals that underlie NASH progression. Additional 'extrahepatic hits' include dietary factors and gastrointestinal hormones. Within the liver, hepatocyte apoptosis, ER stress and oxidative stress are key contributors to hepatocellular injury. In addition, lipotoxic mediators and danger signals activate Kupffer cells which initiate and perpetuate the inflammatory response by releasing inflammatory mediators that contribute to inflammatory cell recruitment and development of fibrosis. Inflammatory and fibrogenic mediators include chemokines, the cannabinoid system, the inflammasome and activation of pattern-recognition receptors. Here we review the major mechanisms leading to appearance and progression of NASH, focusing on both extrahepatic signals and local inflammatory mechanisms, in an effort to identify the most promising molecular targets for the treatment of this condition.

Pathophysiology of NASH: perspectives for a targeted treatment

Non alcoholic steatohepatitis (NASH) is the more severe form of nonalcoholic fatty liver disease. In NASH, fatty liver, hepatic inflammation, hepatocyte injury and fibrogenesis are associated, and this condition may eventually lead to cirrhosis. Current treatment of NASH relies on the reduction of body weight and increase in physical activity, but there is no pharmacologic treatment approved as yet. Emerging data indicate that NASH progression results from parallel events originating from the liver as well as from the adipose tissue, the gut and the gastrointestinal tract. Thus, dysfunction of the adipose tissue through enhanced flow of free fatty acids and release of adipocytokines, and alterations in the gut microbiome generate proinflammatory signals that underlie NASH progression. Additional 'extrahepatic hits' include dietary factors and gastrointestinal hormones. Within the liver, hepatocyte apoptosis, ER stress and oxidative stress are key contributors to hepatocellular injury. In addition, lipotoxic mediators and danger signals activate Kupffer cells which initiate and perpetuate the inflammatory response by releasing inflammatory mediators that contribute to inflammatory cell recruitment and development of fibrosis. Inflammatory and fibrogenic mediators include chemokines, the cannabinoid system, the inflammasome and activation of pattern-recognition receptors. Here we review the major mechanisms leading to appearance and progression of NASH, focusing on both extrahepatic signals and local inflammatory mechanisms, in an effort to identify the most promising molecular targets for the treatment of this condition.

The role of diet and nutritional intervention for the management of patients with NAFLD

During the last few decades, the prevalence of obesity, insulin resistance and non-alcoholic fatty liver disease (NAFLD) have dramatically increased. Nutrition and modern lifestyle habits are intimately involved in this epidemiological change. Although lifestyle intervention can theoretically revert the metabolic disturbances and prevent the long term complications of NAFLD, its efficacy is diminished in clinical practice by poor implementation and reduced adherence to lifestyle intervention programs. In this article we summarize the main elements of dietary interventions for NAFLD, describe practical strategies to optimize efficacy and review potential nutritional strategies under development that hopefully will improve outcomes in the future.

Lifestyle interventions for the treatment of non-alcoholic fatty liver disease

The burden of non-alcoholic fatty liver disease (NAFLD) worldwide is a significant clinical and public health issue, affecting approximately one third of the Western population. This review assesses the effect and impact lifestyle interventions have on the treatment of this common condition. We review studies comparing the effect of calorie restriction and exercise programs, as well as comparison of lifestyle intervention with pharmaceutical intervention. Both calorie restriction and exercise programs are shown to be beneficial in improving features of metabolic syndrome and surrogate markers of NAFLD. The paucity of studies using histological improvement hinders the ability to conclude a benefit on improvement of histological NAFLD, although this is shown in a small number of studies. There is a need to extend the intervention period to show a sustained improvement with intervention as most studies have a follow up period of 12 months of less.

Nutritional management of insulin resistance in nonalcoholic fatty liver disease (NAFLD)

Nonalcoholic fatty liver disease (NAFLD) is an emerging global health concern. It is the most common form of chronic liver disease in Western countries, affecting both adults and children. NAFLD encompasses a broad spectrum of fatty liver disease, ranging from simple steatosis (NAFL) to nonalcoholic steatohepatitis (NASH), and is strongly associated with obesity, insulin resistance, and dyslipidemia. First-line therapy for NAFLD includes weight loss achieved through diet and physical activity. However, there is a lack of evidenced-based dietary recommendations. The American Diabetes Association's (ADA) recommendations that aim to reduce the risk of diabetes and cardiovascular disease may also be applicable to the NAFLD population. The objectives of this review are to: (1) provide an overview of NAFLD in the context of insulin resistance, and (2) provide a rationale for applying relevant aspects of the ADA recommendations to the nutritional management of NAFLD.

Dietary treatment of nonalcoholic steatohepatitis

PURPOSE OF REVIEW

Nonalcoholic steatohepatitis (NASH) is increasing in prevalence, in tandem with the U.S. obesity epidemic, in both children and adults. Identifying specific dietary components that drive NASH is important for successful management of this disease.

RECENT FINDINGS

Weight loss of 5-10% improves NASH. In addition, fructose and trans-fats, two components of the Western 'fast-food' diet, have unique metabolic effects that suggest they may be key contributors to NASH. However, further research is needed to clarify the utility of restricting these nutrients in treating NASH.

SUMMARY

Overall reductions in body weight, through reduced calorie intake and increased physical activity, are the current mainstays of NASH treatment. Reducing fructose and trans-fat intake, independent of weight loss, may be critical to improving or preventing progression of NASH.

Nonalcoholic fatty liver disease and the metabolic syndrome: clinical implications and treatment

The prevalence of nonalcoholic fatty liver disease (NAFLD) is expected to rise along with the global obesity epidemic. As NAFLD is the most common cause of chronic liver disease in the United States, it has become a major health concern. It affects all ethnicities, with the highest prevalence among the Hispanic population. Individuals with nonalcoholic steatohepatitis (NASH), the more serious form of NAFLD, are at increased risk of developing cirrhosis, hepatic decompensation, and hepatocellular carcinoma. Since NAFLD is intricately associated with the metabolic syndrome and insulin resistance, increased risk of cardiovascular disease and mortality become a real concern. It has recently been shown that current nutrition trends, such as increased consumption of high-fructose corn syrup and certain types of fats, may have an important role in the increased NAFLD prevalence. As there are no ideal treatment options available for NAFLD, a multifaceted treatment approach should be tailored to each individual patient.

The role of nutrients in the development, progression, and treatment of nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of liver disease in adults and children and is currently the third most common indication for liver transplantation in North America. Its pathogenesis is thought to be secondary to multiple "hits" derived from the dietary components, adipose tissue, immune system, and intestinal microbiota. Lack of physical activity may contribute as well. Nutrients may exert their effect directly or through alteration of the intestinal microbiota. Research focusing on specific dietary components predisposing to NAFLD has shown conflicting results. Total energy intake, and macronutrients, has been linked to the development of NAFLD. Fructose not only contributes to hepatic steatosis but may trigger inflammatory signals as well. Polyunsaturated fatty acids are thought to exert anti-inflammatory effects. The role of vitamins as well as minerals in this field is actively being investigated. In this review, we discuss the evidence-linking macronutrients (such as carbohydrates and fat in general and fructose, fiber, short chain fatty acids, polyunsaturated fatty, and choline specifically) and micronutrients (such as vitamin E and C and minerals) with the development and treatment of NAFLD. We also discuss the literature on physical activity and NAFLD.

Influence of a regular, standardized meal on clinical chemistry analytes

Background

Preanalytical variability, including biological variability and patient preparation, is an important source of variability in laboratory testing. In this study, we assessed whether a regular light meal might bias the results of routine clinical chemistry testing.

Methods

We studied 17 healthy volunteers who consumed light meals containing a standardized amount of carbohydrates, proteins, and lipids. We collected blood for routine clinical chemistry tests before the meal and 1, 2, and 4 hr thereafter.

Results

One hour after the meal, triglycerides (TG), albumin (ALB), uric acid (UA), phosphatase (ALP), Ca, Fe, and Na levels significantly increased, whereas blood urea nitrogen (BUN) and P levels decreased. TG, ALB, Ca, Na, P, and total protein (TP) levels varied significantly. Two hours after the meal, TG, ALB, Ca, Fe, and Na levels remained significantly high, whereas BUN, P, UA, and total bilirubin (BT) levels decreased. Clinically significant variations were recorded for TG, ALB, ALT, Ca, Fe, Na, P, BT, and direct bilirubin (BD) levels. Four hours after the meal, TG, ALB, Ca, Fe, Na, lactate dehydrogenase (LDH), P, Mg, and K levels significantly increased, whereas UA and BT levels decreased. Clinically significant variations were observed for TG, ALB, ALT, Ca, Na, Mg, K, C-reactive protein (CRP), AST, UA, and BT levels.

Conclusions

A significant variation in the clinical chemistry parameters after a regular meal shows that fasting time needs to be carefully considered when performing tests to prevent spurious results and reduce laboratory errors, especially in an emergency setting.

The role of diet and nutrient composition in nonalcoholic Fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in the developed world. NAFLD is tightly linked to insulin resistance and considered to be the hepatic manifestation of the metabolic syndrome. The cornerstone of any treatment regimen for patients with NAFLD is lifestyle modification focused on weight loss, exercise, and improving insulin sensitivity. Here we review the literature and discuss the role of diet and nutrient composition in the management of NAFLD. Because there are currently no specific dietary guidelines for NAFLD, this review proposes a dietary framework for patients with NAFLD based on the available evidence and extrapolates from dietary guidelines aimed at reducing insulin resistance and cardiovascular risk.

Lifestyle Modification through Dietary Intervention: Health Promotion of Patients with Non-Alcoholic Fatty Liver Disease

BACKGROUND

Prevalence of non-alcoholic fatty liver disease (NAFLD) is more common worldwide and no certain treatment apart from lifestyle modification has been established yet. Available data consistently show that energy intake is significantly higher in patients with NAFLD than in individuals with no evidence of fatty liver. Changing nutritional behaviors seems to be the primary approach for treatment, simultaneously addressing all the clinical and biochemical defects. This study was aimed to examine the effects of two different composition of low energy diet (diet I vs. diet II) on non-alcoholic fatty liver disease patients.

METHODS

In this double-blind randomized controlled trial, 44 ultrasonography-proven overweight non-alcoholic fatty liver disease patients were divided into two groups and received two low-energy diets (-500 kcal less than energy requirement individually) inc. diet I (Carbohydrate: Fat: Protein: 55:25:20) and diet II (Carbohydrate: Fat: Protein: 40:40:20) for six weeks. Anthropometric and biochemical measures as well as liver enzymes were assessed after 12 hours fasting.

RESULTS

After diet I and diet II, weight decreased significantly (%1.82 and %2.45, respectively). Liver enzymes and echogenicity decreased significantly by both diet I and diet II. Mean of triglyceride concentration decreased (%18.09) after diet II (P=0.023), while there was no significant change after diet I. Significant correlations were found between changes in aspartate aminotransferase with triglyceride and LDL-C diet I.

CONCLUSION

Low energy diets can decrease liver enzymes regardless of their composition, while diet II seems to be more effective than diet I in reduction of weight and triglyceride level.

Non-alcoholic fatty liver disease and cardiovascular risk: metabolic aspects and novel treatments

Non-alcoholic fatty liver disease (NAFLD) is usually a silent disease that occurs in a very high proportion of people with features of the metabolic syndrome, including overweight, insulin resistance and type 2 diabetes. Because obesity and type 2 diabetes are now extremely common in Westernised societies, it is likely that the prevalence of NAFLD increases markedly in the future. Although previously it was thought that NAFLD was harmless, it is now recognised that NAFLD can be a progressive liver condition that increases risk of cirrhosis, end-stage liver disease and hepatocellular carcinoma. Additionally, liver fat accumulation causes insulin resistance and increases risk of type 2 diabetes. Increasing evidence now shows NAFLD is a risk factor for cardiovascular disease (CVD). The purpose of this review is to briefly discuss the pathogenesis of NAFLD, to describe the relationship between NAFLD and CVD and the mechanisms linking both conditions and to discuss some of the treatment options (including lifestyle, nutrition and drugs) that may influence both NAFLD and risk of CVD.

Managing the combination of nonalcoholic fatty liver disease and metabolic syndrome

INTRODUCTION

Metabolic syndrome (MetS) and nonalcoholic fatty liver disease (NAFLD) are part of the same metabolic defect, both having insulin resistance as the main pathogenic mechanism and sharing similar outcomes (i.e., cardiovascular and liver-related mortality). The prevalence of NAFLD is expected to rise, owing to the increasing worldwide prevalence of obesity and MetS; therefore, the identification of factors responsible for disease progression is essential to devise therapeutic strategies.

AREAS COVERED

The available and potential future treatments for NAFLD in combination with MetS are reviewed in this paper, following an extensive literature search and personal experience.

EXPERT OPINION

All NAFLD patients should be evaluated for their metabolic, cardiovascular and liver-related risk. Weight loss through lifestyle intervention remains the most comprehensive and safe treatment of NAFLD and associated MetS; however, > 50% of patients fail to achieve target weight loss. Pharmacologic treatment seems to be important for these patients and for NAFLD cases with more advanced liver disease. It temporarily reverses metabolic alterations, but liver disease progresses after the treatment is stopped. Although current treatments are unsatisfactory, new drugs have been proposed and a few innovative compounds are in the pipeline of pharmaceutical companies. Before pharmacologic treatment can be routinely recommended for NAFLD, long-term randomized trials are needed, along with assessments of the safety and benefits of drugs on proper histological outcomes or validated surrogate markers. The intensive control of individual features of MetS remains mandatory.

Implications of central obesity-related variants in LYPLAL1, NRXN3, MSRA, and TFAP2B on quantitative metabolic traits in adult Danes

BACKGROUND

Two meta-analyses of genome-wide association studies (GWAS) have suggested that four variants: rs2605100 in lysophospholipase-like 1 (LYPLAL1), rs10146997 in neuroxin 3 (NRXN3), rs545854 in methionine sulfoxide reductase A (MSRA), and rs987237 in transcription factor activating enhancer-binding protein 2 beta (TFAP2B) associate with measures of central obesity. To elucidate potential underlying phenotypes we aimed to investigate whether these variants associated with: 1) quantitative metabolic traits, 2) anthropometric measures (waist circumference (WC), waist-hip ratio, and BMI), or 3) type 2 diabetes, and central and general overweight and obesity.

METHODOLOGY/PRINCIPAL FINDINGS

The four variants were genotyped in Danish individuals using KASPar®. Quantitative metabolic traits were examined in a population-based sample (n = 6,038) and WC and BMI were furthermore analyzed in a combined study sample (n = 13,507). Case-control studies of diabetes and adiposity included 15,326 individuals. The major G-allele of LYPLAL1 rs2605100 associated with increased fasting serum triglyceride concentrations (per allele effect (β) = 3%(1;5(95%CI)), p(additive) = 2.7×10(-3)), an association driven by the male gender (p(interaction) = 0.02). The same allele associated with increased fasting serum insulin concentrations (β = 3%(1;5), p(additive) = 2.5×10(-3)) and increased insulin resistance (HOMA-IR) (β = 4%(1;6), p(additive) = 1.5×10(-3)). The minor G-allele of rs10146997 in NRXN3 associated with increased WC among women (β = 0.55cm (0.20;0.89), p(additive) = 1.7×10(-3), p(interaction) = 1.0×10(-3)), but showed no associations with obesity related metabolic traits. The MSRA rs545854 and TFAP2B rs987237 showed nominal associations with central obesity; however, no underlying metabolic phenotypes became obvious, when investigating quantitative metabolic traits. None of the variants influenced the prevalence of type 2 diabetes.

CONCLUSION/SIGNIFICANCE

We demonstrate that several of the central obesity-associated variants in LYPLAL1, NRXN3, MSRA, and TFAP2B associate with metabolic and anthropometric traits in Danish adults. However, analyses were made without adjusting for multiple testing, and further studies are needed to confirm the putative role of LYPLAL1, NRXN3, MSRA, and TFAP2B in the pathophysiology of obesity.

Tributyltin and the obesogen metabolic syndrome in a salmonid

We conducted a dietary feeding study with juvenile chinook salmon (Oncorhynchus tshawytscha) to assess the potential for tributyltin (TBT) to elicit the obesogen response that has been described for mammals. The results show increases in whole-body lipid content, which is consistent with the obesogen response; however, we also observed associated parameters that were dissimilar. We found increases in body mass and alterations to several physiological parameters at doses between 0.4 and 3.5 ng/g fish/day (1.4-12 pmol/g fish/day) and reduced body mass at the highest dose after 55 days of exposure. Lipid related plasma parameters (plasma triacylglycerols, cholesterol, and lipase) exhibited monotonic increases over all doses while other values (glucose and insulin-like growth factor (IGF)) exhibited increases only for the low-dose treatments. The increases noted for several parameters in fish were opposite to those reported for the obesogen metabolic syndrome, which is characterized by a reduction in serum glucose, free fatty acids, and triglycerides. This is the first report of growth stimulation resulting from low-dose exposure to this pesticide, which is an unusual response for any animal exposed to an organic or organometallic xenobiotic. Because a number of environmental contaminants act as metabolic disruptors at very low doses, these results are noteworthy for a variety of species. Intuitively, enhanced growth and lipid storage may appear beneficial; however, for salmonids there are numerous potentially negative consequences for populations.