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

The Asian Pacific association for the study of the liver clinical practice guidelines for the diagnosis and management of metabolic dysfunction-associated fatty liver disease

Metabolic dysfunction-associated fatty liver disease (MAFLD) affects over one-fourth of the global adult population and is the leading cause of liver disease worldwide. To address this, the Asian Pacific Association for the Study of the Liver (APASL) has created clinical practice guidelines focused on MAFLD. The guidelines cover various aspects of the disease, such as its epidemiology, diagnosis, screening, assessment, and treatment. The guidelines aim to advance clinical practice, knowledge, and research on MAFLD, particularly in special groups. The guidelines are designed to advance clinical practice, to provide evidence-based recommendations to assist healthcare stakeholders in decision-making and to improve patient care and disease awareness. The guidelines take into account the burden of clinical management for the healthcare sector.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

A systematic review and meta-analysis of randomized controlled trials: effects of mediterranean diet and low-fat diet on liver enzymes and liver fat content of NAFLD

Background: Non-alcoholic fatty liver disease (NAFLD) has emerged as a leading cause of several chronic diseases, imposing a significant global economic burden. The Mediterranean diet (MD) and low-fat diet (LFD) are the two primary recommended dietary patterns that exhibit distinct positive effects on treating NAFLD. Objective: To investigate which of the two diets, MD and LFD, is more effective in the treatment of NAFLD. Methods: Randomized controlled trials (RCTs) up to April 2024 were searched for in PubMed, Web of Science, Medline, Scopus and Embase. Interventions included MD or LFD, with primary outcome measures being intrahepatic lipid, liver stiffness, triglycerides, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, alanine aminotransferase, gamma-glutamyl transferase, and homeostasis model assessment of insulin resistance. Secondary outcomes included weight, waist circumference, and body mass index. Use of random effects meta-analysis to assess outcomes of interest. Results: meta-analysis revealed no significant differences between MD and LFD in improving liver enzymes, liver fat, and related indices in NAFLD patients. Our findings provide compelling evidence for patients and healthcare professionals, allowing patients to choose a dietary pattern that aligns with their preferences and disease conditions. In summary, both MD and LFD can equivalently ameliorate NAFLD in the short term. Conclusions: Our results show that MD and LFD have similar therapeutic effects on liver enzymes and liver fat content in patients with NAFLD in the short term. Furthermore, our meta-analysis results have also opened up a new avenue of thought as to whether similar effects are achieved by alternating MD and LFD on alternate days.

Anthocyanins as Adjuvant Treatment for Non-alcoholic Fatty Liver Disease: A Systematic Review and Meta-Analysis

Recent studies suggest a role for anthocyanins in the treatment of non-alcoholic fatty liver disease (NAFLD). The purpose of the present review was to assess the effect of anthocyanins as an adjuvant treatment in patients with NAFLD. The literature search was conducted on MEDLINE/PubMed, the Cochrane Central Register of Controlled Trials (CENTRAL), the Web of Science, and Scopus without language or time limits up to March 27, 2024. The primary outcomes included the severity of liver fibrosis and the level of liver transaminases. Secondary outcomes included obesity and lipid profile assessments. Standardized mean differences (SMDs) with 95% CIs were calculated for numerical outcomes. Five studies were included. The pooled effect sizes showed lower levels of liver fibrosis and liver transaminases in the anthocyanin group, but the difference was nonsignificant and small in size. The same result was obtained with anthropometric measurements of total cholesterol, low-density lipoprotein, and serum triglycerides, where effect sizes ranged from negligible to medium in magnitude but were all nonsignificant. The anthocyanin group showed a significantly lower body fat percentage (SMD = -0.41 (95%CI: -0.76; -0.06), P = 0.021). Currently, no evidence is available on the efficacy of anthocyanins in improving liver fibrosis or dyslipidemia in patients with NAFLD. There is limited evidence that anthocyanins can lower body fat percentages, but the effect was not reflected in the pooled results of other obesity indices. The few available clinical trials showed several limitations and variations regarding the doses of anthocyanins. Future clinical trials should avoid the limitations of the current studies and provide evidence supporting or refuting the use of anthocyanins in NAFLD patients.

Effect of different exercise modalities on nonalcoholic fatty liver disease: a systematic review and network meta-analysis

Physical exercise intervention can significantly improve the liver of patients with Non-alcoholic fatty liver disease (NAFLD), but it is unknown which exercise mode has the best effect on liver improvement in NAFLD patients. Therefore, we systematically evaluated the effect of exercise therapy on liver and blood index function of NAFLD patients through network meta-analysis (NMA). Through systematic retrieval of PubMed, Cochrane Library, Web of Science, EBSCO, and CNKI (National Knowledge Infrastructure), two reviewers independently screened the literature, extracted data, and assessed the risk of bias of the included studies by means of databases from inception to January 2023. The NMA was performed using the inconsistency model. A total of 43 studies, 2070 NAFLD patients were included: aerobic training (n = 779), resistance training (n = 159), high-intensity interval training (n = 160), aerobic training + resistance training (n = 96). The results indicate that aerobic training + resistance training could significantly improve serum total cholesterol (TC) (Surface under the cumulative ranking curve (SUCRA) = 71.7), triglyceride (TG) (SUCRA = 96.8), low-density lipoprotein cholesterol (LDL-C) (SUCRA = 86.1) in patients with NAFLD including triglycerides. Aerobic training is the best mode to improve ALT (SUCRA = 83.9) and high-density lipoprotein cholesterol (HDL-C) (SUCRA = 72.3). Resistance training is the best mode to improve aspartate transaminase (AST) (SUCRA = 81.7). Taking various benefits into account, we believe that the best modality of exercise for NAFLD patients is aerobic training + resistance training. In our current network meta-analysis, these exercise methods have different effects on the six indicators of NAFLD, which provides some reference for further formulating exercise prescription for NAFLD patients.

Dietary approaches to stop hypertension (DASH) diet improves hepatic fibrosis, steatosis and liver enzymes in patients with non-alcoholic fatty liver disease: a randomized controlled trial

PURPOSE

Recent evidence suggests that adherence to dietary approaches to stop hypertension (DASH) diet can be effective in managing non-alcoholic fatty liver disease (NAFLD). We investigated the effect of DASH diet on hepatic fibrosis, steatosis and liver enzymes in patients with NAFLD.

METHODS

This 12-week randomized controlled trial was conducted among seventy patients with NAFLD who were randomly assigned into two groups including intervention group (DASH diet containing 50-55% carbohydrate, 15-20% protein, and 30% total fat) and the control group (a healthy diet containing 50-55% carbohydrate, 15-20% protein, and 30% total fat). Both diets were calorie-restricted (500-700 kcal lower than the energy requirement). The primary outcomes included hepatic fibrosis, hepatic steatosis, alanine transaminase (ALT), aspartate transaminase (AST) and gamma-glutamyl transpeptidase (GGT).

RESULTS

At the baseline, there was no significant difference between two groups in the level of hepatic fibrosis (P = 0.63), hepatic steatosis (P = 0.53), ALT (P = 0.93), AST (P = 0.18) and GGT (P = 0.76). A significant reduction was found in the intervention group compared to the control group in hepatic fibrosis (23 grades reduction vs. 7 grades reduction; P = 0.008) and hepatic steatosis (31 grades reduction vs. 9 grades reduction; P = 0.03) after intervention. In addition, a significant change was observed in the intervention group compared to control group in ALT ( - 8.50 ± 8.98 vs.  - 2.09 ± 7.29; P = 0.002), and AST ( - 5.79 ± 6.83 vs.  - 0.51 ± 6.62; P = 0.002).

CONCLUSIONS

Adherence to DASH diet may be effective in management of NAFLD.

TRIAL REGISTRATION

The trial was registered on 06 February 2022 at Iranian Registry of Clinical Trials (IRCT20170117032026N3) with URL: https://www.irct.ir/trial/60887 .

Effects of Egg Consumption on Subjects with SLD or Hypertension: A MICOL Study

BACKGROUND

Steatotic liver disease (SLD) is defined as a fat accumulation in more than 5% of hepatocytes; it can progress to non-alcoholic steatohepatitis (NASH), associated with an increased state of inflammation. The aim of this study was to explore the protective effects of eating eggs and any association with SLD and hypertension (HTN).

METHODS

The study cohort included 908 participants assessed in the fourth recall of the MICOL study, grouped into four groups, based on NALFD and/or HTN.

RESULTS

The prevalence of HTN and SLD among participants was 31.61%. Overall, the results indicated a statistical significance of egg consumption, showing a protective role against the two disease conditions, in both the raw and adjusted models (RRR = 0.34, p = 0.009, 0.15 to 0.76 95% C.I.).

CONCLUSIONS

Many differences were found among the groups, and the protective role of eating eggs was amply demonstrated. We can conclude that it is unwise to demonize the intake of this food and its nutritional properties, in contrast with previous reports in the literature.

Effect of exercise and pharmacotherapy on non-alcoholic fatty liver disease

OBJECTIVES

Nonalcoholic fatty liver disease is one of the emerging liver diseases affecting 20%-30% of the population creating a burden on public health worldwide and has been associated with the causation of multiple diseases. Besides exercise, several drugs are being used in patients based on clinical evidence especially vitamin E, a potent antioxidant to reduce the oxidative stress responsible for the development and progression of nonalcoholic fatty liver disease. This study aims at evaluating the effect of exercise and pharmacotherapy on nonalcoholic fatty liver disease.

DESIGN

A prospective follow-up study with purposive sampling was done at a liver clinic for 3 months. Baseline characteristics such as anthropometric measurements and biochemical parameters were recorded and compared after 3 months to determine the effect of therapy. Descriptive analysis using a parametric test was used to assess the change in biochemical parameters and a non-parametric test was applied to find out the association between non-pharmacological and pharmacological approaches.

RESULTS

Out of 177 patients, 67.2 % were male and 32.8% were female with the mean age ±SD of 46.8 ± 12.06 years. Mean ± SD weight and body mass index of the patients were changed from 74.88 ± 11.61 kg to 72.37 ± 11.61 kg and from 28.41 ± 4.02 kg/m2 to 27.31 ± 4.58 kg/m2 respectively which was found to be statistically significant. There was a significant change in all the biochemical parameters with the p-value < 0.05 through both non-pharmacological and pharmacological approaches.

CONCLUSION

Nonalcoholic fatty liver disease management through exercise and pharmacotherapy shows significant improvement in biochemical parameters indicating that alone or in combination with both approaches play an effective role in treating nonalcoholic fatty liver disease.

The effects of high-intensity interval training and Iranian propolis extract on serum levels of TRPV4 and CYP2E1 proteins in patients with nonalcoholic fatty liver

INTRODUCTION

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of liver failure, fibrosis, cirrhosis, and liver cancer, which can eventually lead to death.

AIM

To investigate the effects of high-intensity interval training (HIIT) and iranian propolis extract on serum levels of transient receptor potential cation channel subfamily V member 4 (TRPV4) and cytochrome P450 2E1 (CYP2E1) proteins in patients with NAFLD.

METHODS

Thirty-two patients with NAFLD (mean±standard deviation of age: 45.1±3.6 years; body mass index: 30.0±3.6 kg/m2) were assigned in a randomized control trial to one of the following groups: HIIT (n=8), propolis supplement (n=8), propolis + HIIT (n=8), and controls (n=8). The subjects participated in eight weeks of HIIT (one bout of 1-min intervals at 80-95% of the maximal heart-rate, interspersed by two min at 50-55% of the reserve heart-rate). The Propolis supplement was taken three times a day by the patients in the form of 50 mg tablet after the main meals. Body composition, liver injury test (eg; Alanine- and Aspartate- aminotransferase levels), liver ultrasound and serum levels of TRPV4 and CYP2E1 were measured before and after intervention. One-way analysis of variance was used to compare post-tests among the groups.

RESULTS

HIIT significantly reduced serum levels of TRPV4 protein (p=0.001). The reduction in CYP2E1 was not significant in HIIT group (p=0.075). Propolis consumption had no significant effect on serum levels of CYP2E1 protein (p=0.059), and TRPV4 (p=0.072). There was a significant decrease in TRPV4 and CYP2E1 in the HIIT (p=0.001) and propolis supplement (p=0.032) groups.

CONCLUSION

HIIT and propolis supplementation can be used to reduce TRPV4 and CYP2E1, which in turn reduces oxidative stress and inflammation in patients with NAFLD.

Meta-analysis: Impact of intragastric balloon therapy on NAFLD-related parameters in patients with obesity

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is a leading cause of chronic liver disease affecting approximately 25% of adults in the western world. Intragastric balloon (IGB) is an endoscopic bariatric therapy -a therapeutic endoscopic tool that has shown promise in inducing weight loss. Its role in the treatment of NAFLD is yet to be established.

AIM

To evaluate the effect of IGB as a treatment option in NAFLD.

METHODS

We searched MEDLINE (PubMed) and EMBASE from inception to September 2022. We included studies evaluating the impact of IGB on obesity with the assessment of one or more liver-related outcomes and studies primarily evaluating the impact of IGB on NAFLD. We included comparative and non-comparative studies; primary outcomes were liver-related NAFLD surrogates.

RESULTS

We included 19 studies with 911 patients. IGB demonstrated an effect on NAFLD parameters including NAFLD activity score (NAS): mean difference (MD): -3.0 [95% CI: -2.41 to -3.59], ALT: MD: -10.40 U/L [95% CI: -7.31 to -13.49], liver volume: MD -397.9 [95% CI: -212.78 to 1008.58] and liver steatosis: MD: -37.76 dB/m [95% CI: -21.59 to -53.92]. There were significant reductions in non-liver-related outcomes of body weight, BMI, glycated haemoglobin and HOMA-IR.

CONCLUSION

Intragastric balloons may play an important role in addressing the treatment gap in NAFLD management.

Impact of Combination Antiretroviral Treatment on Liver Metabolic Health in HIV-Infected Persons

In the last three decades, there has been a considerable improvement in human immunodeficiency virus (HIV) therapy. Acquired immunodeficiency syndrome (AIDS) is no longer a common cause of death for people living with HIV (PLWH) in developed countries, and co-infections with hepatitis viruses can be effectively managed. However, metabolic syndrome and metabolic dysfunction-associated steatotic liver disease (MASLD) are emerging threats these days, especially as the HIV-positive population gets older. The factors for MASLD development in PLWH are numerous, including non-specific (common for both HIV-positive and negative) and virus-specific. We focus on what is known for both, and in particular, on the burden of antiretroviral therapy (ART) for metabolic health and liver damage. We review data on contemporary drugs, including different groups and some particular agents in those groups. Among current ART regimens, the switch from tenofovir disoproxil fumarate (TDF) to tenofovir alafenamide fumarate (TAF) and particularly its combination with integrase inhibitors (INSTIs) appear to have the most significant impact on metabolic disturbances by increasing insulin resistance, which over the years promotes the evolution of the cascade leading to metabolic syndrome (MetS), MASLD, and eventually metabolic dysfunction-associated steatohepatitis (MASH).

A Novel Prescription Digital Therapeutic Option for the Treatment of Metabolic Dysfunction-Associated Steatotic Liver Disease

Background and Aims

Metabolic dysfunction-associated steatotic liver disease and metabolic dysfunction-associated steatohepatitis are pressing public health problems occurring alongside the rising prevalence of obesity and diabetes. This feasibility study explored the use of a novel prescription digital therapeutic (PDT) in this patient population.

Methods

A prospective, open-label study was conducted at two hepatology clinics. Eligible patients had a baseline FibroScan controlled attenuation parameter >274 dB/m. Participants were given access to a PDT containing a novel form of cognitive behavioral therapy designed to treat cardiometabolic disease. Laboratory assessments, FibroScan, and magnetic resonance imaging proton density fat fraction (MRI-PDFF) imaging were conducted preintervention and postintervention.

Results

Twenty-two participants were enrolled. Mean baseline fat fraction on MRI-PDFF was 18.7%. After the 90-day intervention, the mean relative reduction in MRI-PDFF was -16.2% (P = .011) in those with baseline PDFF ≥10%. Mean alanine transaminase decreased by -17.1 IU/L (P = .002). Participants achieved an average total body weight loss of -2.9% (P = .008) and controlled attenuation parameter score was reduced by -18.8 dB/m (P = .021). No serious or device-related adverse events were reported. An average improvement in health-related quality of life of +2.2 Healthy Days per month (P = .500) and high treatment satisfaction (mean Net Promoter Score of +75) were reported.

Conclusion

After 90 days of digitally delivered cognitive behavioral therapy, improvements were observed in multiple endpoints without any adverse device effects. The safety, efficacy, and usability data observed strengthen the hypothesis that PDTs provide a scalable tool to address unmet behavioral treatment needs in metabolic dysfunction-associated steatotic liver disease and metabolic dysfunction-associated steatohepatitis (ClinicalTrials.gov number, NCT05357248).

Plasma Fatty Acid Composition, Oxidative and Inflammatory Status, and Adherence to the Mediterranean Diet of Patients with Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) is a complex and increasingly prevalent cardiometabolic disorder worldwide. As of today, NAFLD is a pathology without specific pharmacological treatment, with the Mediterranean diet (MedDiet) being the most widely used approach for its management. The objective of this study is to assess the effects of adherence to the Mediterranean diet on fatty acid plasma levels, as well as on the oxidative and inflammatory status of NAFLD patients. A total of 100 adult patients (40-60 years old) diagnosed with NAFLD and from the Balearic Islands, Spain, were classified into three groups according to their adherence to the MedDiet. Consumption was assessed using a validated 143-item semiquantitative Food Frequency Questionnaire. Food items (g/day) were categorised according to their processing using the NOVA system. Anthropometrics, blood pressure, aminotransferases, Dietary Inflammatory Index (DII), inflammatory biomarkers, and fatty acid levels were measured in the plasma of NAFLD patients. High adherence to the MedDiet is associated to a highly plant-based diet, low ultra-processed food (UPF) consumption, low intake of dietary lipids, low intake of animal fats, high intake of monounsaturated fatty acid (MUFA; mainly palmitoleic acid), low intake of saturated fatty acids (SFAs; practically all dietary SFAs), low intake of trans-fatty acids, high intake of omega-3 fatty acids (mainly eicosapentaenoic acid), a higher n-6:n-3 in ratio, low intake of omega-6 fatty acids, and a low level of interleukin-6 (IL-6). High adherence to the MedDiet is related to a better fatty acid profile in the plasma, fewer SFAs and more MUFA and polyunsaturated fatty acids (PUFAs), a plasma biochemical profile, better proinflammatory status, and decreased ultra-processed food consumption of NAFLD patients.

Effect of Cornus mas L. fruit extract on blood pressure, anthropometric and body composition indices in patients with non-alcoholic fatty liver disease: A double-blind randomized controlled trial

BACKGROUND & AIMS

Obesity is linked to the pathogenesis of non-alcoholic fatty liver disease (NAFLD). Patients with NAFLD are at increased risk for hypertension. Some investigations have hypothesized that Cornus mas L. fruit can improve obesity and hypertension. We investigated the effect of C. mas L. fruit extract on blood pressure, anthropometric and body composition indices in patients with NAFLD.

METHODS

This 12-week double-blind randomized controlled trial was conducted on fifty patients with NAFLD. Patients received 20 cc/d C. mas L. fruit extract or placebo. We measured diastolic blood pressure (DBP), systolic blood pressure (SBP), weight, waist circumference (WC), hip circumference (HC), waist-to-hip ratio (WHR), body fat mass (BFM), body fat percent (BFP) and fat free mass (FFM) before and after intervention.

RESULTS

Treatment group compared to control group showed a significant reduction in DBP (-8.62 ± 11.86 mmHg vs. 0.53 ± 8.53 mmHg; P_crude = 0.003; P_adjucted = 0.03) and SBP (-8.63 ± 14.37 mmHg vs. 0.0 ± 12.67 mmHg; P_crude = 0.02; P_adjucted = 0.02). We found no difference between groups in weight, WC, HC, WHR, BFM, BFP and FFM (P > 0.05). After adjusting for confounding factors, a significant reduction was observed in treatment group compared to control group in BFM (-0.2 ± 3.9 kg vs. 0.7 ± 2.4 kg; P = 0.01) and BFP (-0.2 ± 4.9% vs. 0.8 ± 2.8%; P = 0.02).

CONCLUSIONS

C. mas L. fruit extract statistically reduced blood pressure and body fat. However, it had no effect on other anthropometric and body composition indices. Studies with larger sample sizes and higher dosages of extract are needed.

TRIAL REGISTRATION

Registered on 30/9/2018 at Iranian Registry of Clinical Trials IRCT20180419039359N1 (https://www.irct.ir/trial/30707).

Impact of Health Related QoL and Mediterranean Diet on Liver Fibrosis in Patients with NAFLD

Patients with non-alcoholic fatty liver disease (NAFLD) display impaired health-related quality of life (HRQoL) that is often linked to an unhealthy dietary pattern. The aim of this work was to investigate the impact of HRQoL and adherence to the Mediterranean diet on the risk of liver fibrosis (LF) in patients with NAFLD. LF was assessed in 244 patients through transient elastography (FibroScan®530. Echosens, Paris, France). Significant LF was defined according to liver stiffness measurements (LSM) values ≥ 7.1 kPa. The Mediterranean diet score and the Short Form-36 questionnaires were also completed. The median age was 54 (44-62) years and 57% of participants were male. A total of 42 (17.2%) participants had LSM ≥ 7.1 kPa and showed increased GGT (p = 0.001), glucose (p < 0.001), and triglycerides levels (p = 0.015) compared to those with LSM ≤7.0 kPa. Moreover, patients with significant LF had significantly lower scores related to Physical Functioning (p < 0.001) and Role Physical (p < 0.001). In the logistic regression analysis, lower role physical and lower adherence to the MedDiet (p = 0.001 and p = 0.009, respectively), after adjusting for age, diabetes, and obstructive sleep apnea, were associated with an increased risk of significant LF. Low adherence to MedDiet and low role physical may influence the risk of significant liver fibrosis in patients with NAFLD.

Nutraceutical approaches to non-alcoholic fatty liver disease (NAFLD): A position paper from the International Lipid Expert Panel (ILEP)

Non-Alcoholic Fatty Liver Disease (NAFLD) is a common condition affecting around 10-25% of the general adult population, 15% of children, and even > 50% of individuals who have type 2 diabetes mellitus. It is a major cause of liver-related morbidity, and cardiovascular (CV) mortality is a common cause of death. In addition to being the initial step of irreversible alterations of the liver parenchyma causing cirrhosis, about 1/6 of those who develop NASH are at risk also developing CV disease (CVD). More recently the acronym MAFLD (Metabolic Associated Fatty Liver Disease) has been preferred by many European and US specialists, providing a clearer message on the metabolic etiology of the disease. The suggestions for the management of NAFLD are like those recommended by guidelines for CVD prevention. In this context, the general approach is to prescribe physical activity and dietary changes the effect weight loss. Lifestyle change in the NAFLD patient has been supplemented in some by the use of nutraceuticals, but the evidence based for these remains uncertain. The aim of this Position Paper was to summarize the clinical evidence relating to the effect of nutraceuticals on NAFLD-related parameters. Our reading of the data is that whilst many nutraceuticals have been studied in relation to NAFLD, none have sufficient evidence to recommend their routine use; robust trials are required to appropriately address efficacy and safety.

Higher carbohydrate intake in relation to non-alcoholic fatty liver disease in patients with type 2 diabetes

Background

Non-alcoholic fatty liver disease (NAFLD) is an overlooked complication of type 2 diabetes (T2D). Current recommendations for the management of NAFLD are mainly focused on weight reduction, overlooking the role of macronutrient composition. Although dietary carbohydrates play a major role in intrahepatic fat synthesis, their association with the progression of liver steatosis has not been fully investigated in patients with T2D.

Aim

To investigate the association between higher carbohydrate intake and the presence of liver steatosis in patients with T2D.

Methods

This cross-sectional study included men and women aged 18-60 years diagnosed with T2D. Anthropometric measurements, hepatic steatosis assessment using the controlled attenuation parameter (CAP), blood samples, and dietary data were analyzed. Participants were divided into two groups: NAFLD and NAFLD-free. A two-sample t-test was used to evaluate the differences between the two groups. Stepwise multiple linear regression models adjusted for potential confounders were used to determine the association between CAP values and higher carbohydrate intake.

Results

In total, 358 participants were included. NAFLD was present in 79.3% of the participants. Body mass index, waist circumference, ALT, HbA1c, and triglycerides showed direct, while HDL-Cholesterol revealed inverse associations with CAP values. No significant relationship was found between carbohydrate intake and steatosis in the total study sample; however, multiple linear regression analysis revealed a significant relationship between carbohydrate intake and CAP values in patients aged ≤50 years.

Conclusion

In patients with T2D, higher carbohydrate intake was associated with liver steatosis in those aged 50 years and below. Further studies are required to confirm the causality between carbohydrate intake and liver steatosis.

A Healthful Plant-Based Diet Is Associated with Lower Odds of Nonalcoholic Fatty Liver Disease

There is little evidence for the associations of the overall plant-based diet index (PDI), the healthful PDI (hPDI), and the unhealthful PDI (uPDI) with the odds of nonalcoholic fatty liver disease (NAFLD). We present a nationwide cross-sectional study among US adults aged 18 years or older. Diet was assessed by 24-h recalls. Overall PDI, hPDI, and uPDI were constructed based on 18 food groups. NAFLD was defined based on controlled attenuation parameter derived via transient elastography (TE) in the absence of other causes of chronic liver disease. Among 3900 participants with eligible TE examination, 1686 were diagnosed with NAFLD. The overall PDI was not associated with NAFLD prevalence (comparing extreme tertiles of PDI score OR = 1.03, 95% CI 0.76, 1.38, ptrend = 0.609). However, hPDI was inversely (OR = 0.50, 95% CI 0.35, 0.72, ptrend < 0.001), while uPDI was positively associated with odds of NAFLD (OR = 1.37, 95% CI 0.93, 2.02, ptrend = 0.009) in the multivariable-adjusted models without body mass index (BMI). After further adjustment for BMI, only the association of hPDI with NAFLD remained statistically significant (OR = 0.64, 95% CI 0.46, 0.87, ptrend = 0.006). Such inverse association appeared stronger in non-Hispanic whites, but not in other racial/ethnic groups (pinteraction = 0.009). Our findings suggest that a plant-based diet rich in healthy plant foods might be associated with lower odds of NAFLD, particularly among US non-Hispanic whites. Clinical trials and cohort studies to validate our findings are needed.

Carotenoids in orange carrots mitigate non-alcoholic fatty liver disease progression

Background

Carotenoids are abundant in colored fruits and vegetables. Non-alcoholic fatty liver disease (NAFLD) is a global burden and risk factor for end-stage hepatic diseases. This study aims to compare the anti-NAFLD efficacy between carotenoid-rich and carotenoid-deficient vegetables.

Materials and methods

Male C57BL/6J mice were randomized to one of four experimental diets for 15 weeks (n = 12 animals/group): Low-fat diet (LFD, 10% calories from fat), high-fat diet (HFD, 60% calories from fat), HFD with 20% white carrot powders (HFD + WC), or with 20% orange carrot powders (HFD + OC).

Results

We observed that carotenoids in the orange carrots reduced HFD-induced weight gain, better than white carrots. Histological and triglyceride (TG) analyses revealed significantly decreased HFD-induced hepatic lipid deposition and TG content in the HFD + WC group, which was further reduced in the HFD + OC group. Western blot analysis demonstrated inconsistent changes of fatty acid synthesis-related proteins but significantly improved ACOX-1 and CPT-II, indicating that orange carrot carotenoids had the potential to inhibit NAFLD by improving β-oxidation. Further investigation showed significantly higher mRNA and protein levels of PPARα and its transcription factor activity.

Conclusion

Carotenoid-rich foods may display more potent efficacy in mitigating NAFLD than those with low carotenoid levels.

The Role of STAMP2 in Pathogenesis of Chronic Diseases Focusing on Nonalcoholic Fatty Liver Disease: A Review

Nonalcoholic fatty liver disease (NAFLD) is a major health issue. NAFLD can progress from simple hepatic steatosis to nonalcoholic steatohepatitis (NASH). NASH can progress to cirrhosis or hepatocellular carcinoma. Unfortunately, there is no currently approved pharmacologic therapy for NAFLD patients. The six transmembrane protein of prostate 2 (STAMP2), a metalloreductase involved in iron and copper homeostasis, is well known for its critical role in the coordination of glucose/lipid metabolism and inflammation in metabolic tissues. We previously demonstrated that hepatic STAMP2 could be a suitable therapeutic target for NAFLD. In this review, we discuss the emerging role of STAMP2 in the dysregulation of iron metabolism events leading to NAFLD and suggest therapeutic strategies targeting STAMP2.

Adherence to Mediterranean Diet and NAFLD in Patients with Metabolic Syndrome: The FLIPAN Study

Unhealthy diet is an important factor in the progression of non-alcoholic fatty liver disease (NAFLD). Previous studies showed the benefits of a Mediterranean diet (MedDiet) on Metabolic syndrome (MetS), type 2 diabetes mellitus (T2DM), and cardiovascular diseases, which usually have a pathophysiological relationship with NAFLD. To assess the effect of adherence to a MedDiet on NAFLD in MetS patients after lifestyle intervention, this multicentre (Mallorca and Navarra, Spain) prospective randomized trial, with personalized nutritional intervention based on a customized MedDiet, coupled with physical activity promotion was performed to prevent, and reverse NAFLD among patients with MetS. The current analysis included 138 patients aged 40 to 60 years old, Body Mass Index (BMI) 27-40 kg/m2, diagnosed with NAFLD using MRI, and MetS according to the International Diabetes Federation (IDF). A validated food frequency questionnaire was used to assess dietary intake. Adherence to Mediterranean diet by means of a 17-item validated questionnaire, anthropometrics, physical activity, blood pressure, blood biochemical parameters, and intrahepatic fat contents (IFC) were measured. The independent variable used was changes in MedDiet adherence, categorized in tertiles after 6 months follow-up. Subjects with high adherence to the MedDiet showed higher decreases in BMI, body weight, WC, SBP, DBP, and IFC. An association between improvement in adherence to the MedDiet and amelioration of IFC after 6-month follow-up was observed. High adherence to the MedDiet is associated with better status of MetS features, and better values of IFC.

Endoplasmic reticulum stress in innate immune cells - a significant contribution to non-alcoholic fatty liver disease

Liver disease and its complications affect millions of people worldwide. NAFLD (non-alcoholic fatty liver disease) is the liver disease associated with metabolic dysfunction and consists of four stages: steatosis with or without mild inflammation (NAFLD), non-alcoholic steatohepatitis (NASH), fibrosis, and cirrhosis. With increased necroinflammation and progression of liver fibrosis, NAFLD may progress to cirrhosis or even hepatocellular carcinoma. Although the underlying mechanisms have not been clearly elucidated in detail, what is clear is that complex immune responses are involved in the pathogenesis of NASH, activation of the innate immune system is critically involved in triggering and amplifying hepatic inflammation and fibrosis in NAFLD/NASH. Additionally, disruption of endoplasmic reticulum (ER) homeostasis in cells, also known as ER stress, triggers the unfolded protein response (UPR) which has been shown to be involved to inflammation and apoptosis. To further develop the prevention and treatment of NAFLD/NASH, it is imperative to clarify the relationship between NAFLD/NASH and innate immune cells and ER stress. As such, this review focuses on innate immune cells and their ER stress in the occurrence of NAFLD and the progression of cirrhosis.

Effects of Calorie Restricted Diet on Oxidative/Antioxidative Status Biomarkers and Serum Fibroblast Growth Factor 21 Levels in Nonalcoholic Fatty Liver Disease Patients: A Randomized, Controlled Clinical Trial

Oxidative stress plays a fundamental role in the development and progression of nonalcoholic fatty liver disease (NAFLD). This study aimed to investigate the effects of a calorie-restricted (CR) diet on oxidative/anti-oxidative status in patients with NAFLD and the potential mediating role of fibroblast growth factor 21 (FGF-21) in this regard. This randomized, controlled clinical trial was carried out on sixty patients with NAFLD aged 20 to 60 years with body mass index (BMI) ranging from 25 to 35 kg/m2. Participants were randomly assigned to either the CR diet group (received a prescribed low-calorie diet for twelve weeks, n = 30) or the control group (n = 30). Fasting blood samples, anthropometric measurements, dietary intake, and physical activity data were collected for all participants at baseline and at the end of the trial. Significant reductions in weight, BMI, waist circumference, and serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were observed in the CR diet group compared to the control group (all p < 0.05). Liver steatosis grade, serum levels of malondialdehyde (MDA), total antioxidant capacity (TAC), and FGF-21, as well as erythrocyte superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities did not show significant changes in the CR group when compared to the controls at the end of the study (p > 0.05). CR diet with moderate weight loss has some favorable effects on NAFLD but was not able to modify oxidative/anti-oxidative status in these patients. Future studies are warranted to target the effects of long-term interventions with a greater weight loss in this patient population.

Nutrition and Chronic Liver Disease

Malnutrition is common in chronic liver diseases and worsens the patient's prognosis. Many liver disorders are associated with nutritional deficiencies. Some of the main factors that can lead to malnutrition in patients with chronic liver disease include decreased lipid absorption and reduced albumin production. In addition, these patients are sometimes candidates for a liver transplant that requires nutritional intervention after surgery to improve their prognosis. Thus, it is very important to recognise malnutrition in patients with liver failure in order to resolve it, mainly by a complete history of the patient, dietary survey, determination of muscle mass and a subjective assessment. To ensure a good nutritional status, exercise and lifestyle changes are considered, including dietary modifications, especially with a Mediterranean pattern. This article reviews these topics, including dietary modifications before and after liver transplantation. Additionally, nutritional recommendations are offered to patients with metabolic hepatic steatosis.

Natural Compounds for Counteracting Nonalcoholic Fatty Liver Disease (NAFLD): Advantages and Limitations of the Suggested Candidates

The booming prevalence of nonalcoholic fatty liver disease (NAFLD) in adults and children will threaten the health system in the upcoming years. The "multiple hit" hypothesis is the currently accepted explanation of the complex etiology and pathophysiology of the disease. Some of the critical pathological events associated with the development of NAFLD are insulin resistance, steatosis, oxidative stress, inflammation, and fibrosis. Hence, attenuating these events may help prevent or delay the progression of NAFLD. Despite an increasing understanding of the mechanisms involved in NAFLD, no approved standard pharmacological treatment is available. The only currently recommended alternative relies on lifestyle modifications, including diet and physical activity. However, the lack of compliance is still hampering this approach. Thus, there is an evident need to characterize new therapeutic alternatives. Studies of food bioactive compounds became an attractive approach to overcome the reticence toward lifestyle changes. The present study aimed to review some of the reported compounds with beneficial properties in NAFLD; namely, coffee (and its components), tormentic acid, verbascoside, and silymarin. We provide details about their protective effects, their mechanism of action in ameliorating the critical pathological events involved in NAFLD, and their clinical applications.

Is there a role of lipid-lowering therapies in the management of fatty liver disease?

Atherogenic dyslipidemia is characterized by increased triglyceride-rich lipoproteins and low high-density lipoprotein cholesterol concentrations. It is highly prevalent in non-alcoholic fatty liver disease (NAFLD) and contributes to the increased cardiovascular risk associated with this condition. Alongside insulin resistance it plays an important pathogenetic role in NAFLD/non-alcoholic steatohepatitis (NASH) development and progression. It has been shown that cholesterol-lowering reduces cardiovascular risk more in NAFLD vs non-NAFLD high-risk individuals. This evidence highlights the importance of effective lipid modulation in NAFLD. In this narrative review the effects of the most commonly used lipid-lowering therapies on liver outcomes alongside their therapeutic implications in NAFLD/NASH are critically discussed. Preclinical and clinical evidence suggests that statins reduce hepatic steatosis, inflammation and fibrosis in patients with NAFLD/NASH. Most data are derived from observational and small prospective clinical studies using changes in liver enzyme activities, steatosis/fibrosis scores, and imaging evidence of steatosis as surrogates. Also, relevant histologic benefits were noted in small biopsy studies. Atorvastatin and rosuvastatin showed greater benefits, whereas data for other statins are scarce and sometimes conflicting. Similar studies to those of statins showed efficacy of ezetimibe against hepatic steatosis. However, no significant anti-inflammatory and anti-fibrotic actions of ezetimibe have been shown. Preclinical studies showed that fibrates through peroxisome proliferator-activated receptor (PPAR)α activation may have a role in NAFLD prevention and management. Nevertheless, no relevant benefits have been noted in human studies. Species-related differences in PPARα expression and its activation responsiveness may help explain this discrepancy. Omega-3 fatty acids reduced hepatic steatosis in numerous heterogeneous studies, but their benefits on hepatic inflammation and fibrosis have not been established. Promising preliminary data for the highly purified eicosapentaenoic acid require further confirmation. Observational studies suggest that proprotein convertase subtilisin/kexin9 inhibitors may also have a role in the management of NAFLD, though this needs to be established by future prospective studies.

Lactobacillus plantarum MA2 Ameliorates Methionine and Choline-Deficient Diet Induced Non-Alcoholic Fatty Liver Disease in Rats by Improving the Intestinal Microecology and Mucosal Barrier

Non-alcoholic fatty liver disease (NAFLD) has become a highly concerned health issue in modern society. Due to the attentions of probiotics in the prevention of NAFLD, it is necessary to further clarify their roles. In this study, the methionine and choline-deficient (MCD) diet induced NAFLD rats model were constructed and treated with strain L. plantarum MA2 by intragastric administration once a day at a dose of 1 × 10⁸ cfu/g.bw. After 56 days of the therapeutic intervention, the lipid metabolism and the liver pathological damage of the NAFLD rats were significantly improved. The content of total cholesterol (TC) and total triglyceride (TG) in serum were significantly lower than that in the NAFLD group (p < 0.05). Meanwhile, the intestinal mucosal barrier and the structure of intestinal microbiota were also improved. The villi length and the expression of claudin-1 was significantly higher than that in the NAFLD group (p < 0.05). Then, by detecting the content of LPS in the serum and the LPS-TLR4 pathway in the liver, we can conclude that Lactobacillus plantarum MA2 could reduce the LPS by regulating the gut microecology, thereby inhibit the activation of LPS-TLR4 and it downstream inflammatory signaling pathways. Therefore, our studies on rats showed that L. plantarum MA2 has the potential application in the alleviation of NAFLD. Moreover, based on the application of the strain in food industry, this study is of great significance to the development of new therapeutic strategy for NAFLD.

Effect of green-Mediterranean diet on intrahepatic fat: the DIRECT PLUS randomised controlled trial

OBJECTIVE

To examine the effectiveness of green-Mediterranean (MED) diet, further restricted in red/processed meat, and enriched with green plants and polyphenols on non-alcoholic fatty liver disease (NAFLD), reflected by intrahepatic fat (IHF) loss.

DESIGN

For the DIRECT-PLUS 18-month randomized clinical trial, we assigned 294 participants with abdominal obesity/dyslipidaemia into healthy dietary guidelines (HDG), MED and green-MED weight-loss diet groups, all accompanied by physical activity. Both isocaloric MED groups consumed 28 g/day walnuts (+440 mg/day polyphenols provided). The green-MED group further consumed green tea (3-4 cups/day) and Mankai (a Wolffia globosa aquatic plant strain; 100 g/day frozen cubes) green shake (+1240 mg/day total polyphenols provided). IHF% 18-month changes were quantified continuously by proton magnetic resonance spectroscopy (MRS).

RESULTS

Participants (age=51 years; 88% men; body mass index=31.3 kg/m²; median IHF%=6.6%; mean=10.2%; 62% with NAFLD) had 89.8% 18-month retention-rate, and 78% had eligible follow-up MRS. Overall, NAFLD prevalence declined to: 54.8% (HDG), 47.9% (MED) and 31.5% (green-MED), p=0.012 between groups. Despite similar moderate weight-loss in both MED groups, green-MED group achieved almost double IHF% loss (-38.9% proportionally), as compared with MED (-19.6% proportionally; p=0.035 weight loss adjusted) and HDG (-12.2% proportionally; p<0.001). After 18 months, both MED groups had significantly higher total plasma polyphenol levels versus HDG, with higher detection of Naringenin and 2-5-dihydroxybenzoic-acid in green-MED. Greater IHF% loss was independently associated with increased Mankai and walnuts intake, decreased red/processed meat consumption, improved serum folate and adipokines/lipids biomarkers, changes in microbiome composition (beta-diversity) and specific bacteria (p<0.05 for all).

CONCLUSION

The new suggested strategy of green-Mediterranean diet, amplified with green plant-based proteins/polyphenols as Mankai, green tea, and walnuts, and restricted in red/processed meat can double IHF loss than other healthy nutritional strategies and reduce NAFLD in half.

TRIAL REGISTRATION NUMBER

NCT03020186.

Berberine mitigates nonalcoholic hepatic steatosis by downregulating SIRT1-FoxO1-SREBP2 pathway for cholesterol synthesis

OBJECTIVE

To investigate effects of berberine (BBR) on cholesterol synthesis in HepG2 cells with free fatty acid (FFA)-induced steatosis and to explore the underlying mechanisms.

METHODS

A steatosis cell model was induced in HepG2 cell line fed with FFA (0.5 mmol/L, oleic acid:palmitic acid = 2:1), and then treated with three concentrations of BBR; cell viability was assessed with cell counting kit-8 assays. Lipid accumulation in cells was observed through oil red O staining and total cholesterol (TC) content was detected by TC assay. The effects of BBR on cholesterol synthesis mediators were assessed by Western blotting and quantitative polymerase chain reaction. In addition, both silent information regulator 1 (SIRT1) and forkhead box transcription factor O1 (FoxO1) inhibitors were employed for validation.

RESULTS

FFA-induced steatosis was successfully established in HepG2 cells. Lipid accumulation and TC content in BBR groups were significantly lower (P < 0.05, P < 0.01), associated with significantly higher mRNA and protein levels of SIRT1(P < 0.05, P < 0.01), significantly lower sterol regulatory element-binding protein 2 (SREBP2) and 3-hydroxy 3-methylglutaryl-CoA reductase levels (P < 0.05, P < 0.01), as well as higher Acetyl-FoxO1 protein level (P < 0.05, P < 0.01) compared to the FFA only group. Both SIRT1 inhibitor SIRT1-IN-1 and FoxO1 inhibitor AS1842856 blocked the BBR-mediated therapeutic effects. Immunofluorescence showed that the increased SIRT1 expression increased FoxO1 deacetylation, and promoted its nuclear translocation.

CONCLUSION

BBR can mitigate FFA-induced steatosis in HepG2 cells by activating SIRT1-FoxO1-SREBP2 signal pathway. BBR may emerge as a potential drug candidate for treating nonalcoholic hepatic steatosis.

Non-Alcoholic Fatty Liver Disease and Its Association With Diabetes Mellitus

There is a bidirectional relationship between non-alcoholic fatty liver disease (NAFLD) and type 2 diabetes mellitus (T2DM). The liver has a vital role in the pathophysiology of both diseases as it leads to the development of insulin resistance (IR), which in turn results in NAFLD and T2DM. It has been shown that T2DM increases the risk of NAFLD progression. Furthermore, the presence of NAFLD raises the probability of T2DM complications, which explains the increased rates of NAFLD screening in patients with T2DM. In addition, there are common management options for the two diseases. Lifestyle changes can play a role in the initial management of both diseases. Medications that are used to treat T2DM are also used in the management of NAFLD, such as metformin, thiazolidinediones (TZD), glucagon-like peptide-1 (GLP-1) analogues, and dipeptidyl peptidase-4 (DPP4) inhibitors. Bariatric surgery is often used as a last resort and has shown promising results. Lifestyle interventions with diet and exercise are important postoperatively to maintain the weight loss. There are many novel treatments that are being investigated for the treatment of NAFLD, targeting multiple pathophysiologic pathways. This review aims to shed some light on the intricate relationship between NAFLD and T2DM and how IR links both diseases. We also try to raise awareness among clinicians about this relationship and how the presence of one disease should raise a high index of suspicion for the existence of the other.

High Prevalence of Pre-Existing Liver Abnormalities Identified Via Autopsies in COVID-19: Identification of a New Silent Risk Factor?

A high prevalence of hepatic pathology (in 17 of 19 cases) was reported in post-mortem (PM) examinations of COVID-19 patients, undertaken between March 2020 and February 2021 by a single autopsy pathologist in two English Coronial jurisdictions. The patients in our cohort demonstrated high levels of recognised COVID-19 risk factors, including hypertension (8/16, 50%), type 2 diabetes mellitus (8/16, 50%) and evidence of arteriopathy 6/16 (38%). Hepatic abnormalities included steatosis (12/19; 63%), moderate to severe venous congestion (5/19; 26%) and cirrhosis (4/19; 21%). A subsequent literature review indicated a significantly increased prevalence of steatosis (49%), venous congestion (34%) and cirrhosis (9.3%) in COVID-19 PM cases, compared with a pre-pandemic PM cohort (33%, 16%, and 2.6%, respectively), likely reflecting an increased mortality risk in SARS-CoV-2 infection for patients with pre-existing liver disease. To corroborate this observation, we retrospectively analysed the admission liver function test (LFT) results of 276 consecutive, anonymised COVID-19 hospital patients in our centre, for whom outcome data were available. Of these patients, 236 (85.5%) had significantly reduced albumin levels at the time of admission to hospital, which was likely indicative of pre-existing chronic liver or renal disease. There was a strong correlation between patient outcome (length of hospital admission or death) and abnormal albumin at the time of hospital admission (p = 0.000012). We discuss potential mechanisms by which our observations of hepatic dysfunction are linked to a risk of COVID-19 mortality, speculating on the importance of recently identified anti-interferon antibodies.

The effect of pomegranate extract on anthropometric indices, serum lipids, glycemic indicators, and blood pressure in patients with nonalcoholic fatty liver disease: A randomized double-blind clinical trial

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease. The beneficial effects of pomegranate have been shown on insulin resistance and obesity, which are linked to NAFLD pathogenesis. The aim of this study was to investigate the efficacy of pomegranate extract in patients with NAFLD. Forty-four NAFLD patients were randomly assigned to receive two pomegranate extract tablets or placebo for 12 weeks. Anthropometric measurements, serum lipids, glycemic indicators, and blood pressure were assessed at baseline and the end of the study. Pomegranate was associated with a reduction in the total cholesterol (p ˂ .001), triglyceride (p ˂ .001), low-density lipoprotein cholesterol (LDL-C)-to-high-density lipoprotein cholesterol (HDL-C) ratio (p ˂ .003), fasting blood sugar (p ˂ .001), homeostatic model assessment of insulin resistance (p = .02), diastolic blood pressure (p = .04), weight (p ˂ .001), body mass index (p ˂ .001), and waist circumference (p = .002), as compared to placebo. A significant increase was observed in serum HDL-C (p ˂ .001) after intervention with the pomegranate extract. However, no significant difference was shown between the two groups in serum insulin and LDL-C. The pomegranate extract supplement could be used as a complementary therapy along with existing therapies to improve glycemic indicators, serum lipids, anthropometric indices, and blood pressure in patients with nonalcoholic fatty liver.

Effect of Mediterranean diet on liver enzymes: a systematic review and meta-analysis of randomised controlled trials

Elevated levels of liver enzymes are the main markers of liver dysfunction. Liver enzymes are the important indicators of non-alcoholic fatty liver disease (NAFLD) in the general population. Previous randomised clinical trials (RCT) investigated the effects of Mediterranean diet (MedDiet) as a plant-based diet on features of NAFLD like liver enzymes, but their results are contradictory. This study aimed to systematically review and meta-analyse RCT investigating the effect of MedDiet on liver enzymes. PubMed, Web of Science, Scopus and Google Scholar were searched until December 2020. A total of ten RCT (n 705 participants) evaluating the effect of MedDiet on liver enzymes including aspartate aminotransferase (AST), alanine transaminase (ALT) and γ-glutamyltransferase (GGT) were included. A random effects model was used to estimate the pooled effect size. To evaluate the heterogeneity among the included studies, the Cochran's Q-test and I-squared test were used. The MedDiet significantly reduced AST (weighted mean difference (WMD) = -0·38 IU/l; 95 % CI - 0·73, -0·03 IU/l; P = 0·03) and GGT (WMD = -0·16 IU/l; 95 % CI - 0·32, -0·006 IU/l; P = 0·04) but had no significant effect on ALT (WMD = -0·55 IU/l; 95 % CI - 1·25, 0·13 IU/l; P = 0·11). However, sensitivity analysis revealed that the overall effects of MedDiet on AST, GGT and ALT were significantly influenced by removing some studies. There was no publication bias based on Begg's and Egger's tests. Generally, MedDiet can improve liver enzymes. To better conclusion, further RCT investigating the effect of MedDiet on liver enzymes, especially in patients with NAFLD, are still required.

Development and initial validation of the nonalcoholic fatty liver disease self-management questionnaire

The prevalence of nonalcoholic fatty liver disease (NAFLD) is increasing, and self-management is essential to improve health outcomes in this population. Despite the importance of self-management, there is no instrument to assess it in patients with NAFLD. The purpose of this study was to develop and validate an initial version of a self-management questionnaire for patients with NAFLD. This was a methodological and psychometric study conducted between April and November 2019. The NAFLD self-management questionnaire was developed after a theoretical and literature review and focus group interviews in three phases: (1) item generation, (2) item evaluation, and (3) psychometric evaluation. Participants (N = 155) were recruited from a hospital in Seoul, South Korea. Items were generated based on clinical NAFLD guidelines and the individual and family self-management theory. Construct validity was assessed using exploratory factor analysis. Six-factors were extracted from 22 items: lifestyle management, medical treatment compliance, management of medication and dietary supplements, alcohol consumption management, sleep management, and family support. These factors accounted for 67.4% of the total variance; each factor had an eigenvalue greater than 1, and Cronbach's alpha for the scale was 0.87. The NAFLD self-management questionnaire showed acceptable initial validity and reliability. The instrument can prove useful in the formulation of tailored interventions based on individual patients' care needs. Furthermore, it may be used as an indicator of health outcomes in this population.

Endoplasmic Reticulum Stress and Autophagy in the Pathogenesis of Non-alcoholic Fatty Liver Disease (NAFLD): Current Evidence and Perspectives

PURPOSE OF REVIEW

Non-alcoholic fatty liver disease (NAFLD) is one of the most common causes of chronic liver disease with rising prevalence worldwide. Herein, we provide a comprehensive overview of the current knowledge supporting the role of ER stress and autophagy processes in NAFLD pathogenesis and progression. We also highlight the interrelation between these two pathways and the impact of ER stress and autophagy modulators on NAFLD treatment.

RECENT FINDINGS

The pathophysiological mechanisms involved in NAFLD progression are currently under investigation. The endoplasmic reticulum (ER) stress and the concomitant unfolded protein response (UPR) seem to contribute to its pathogenesis mainly due to high ER content in the liver which exerts significant metabolic functions and can be dysregulated. Furthermore, disruption of autophagy processes has also been identified in NAFLD. The crucial role of these two pathways in NAFLD is underlined by the fact that they have recently emerged as promising targets of therapeutic interventions. There is a greater need for finding the natural/chemical compounds and drugs which can modulate the ER stress pathway and autophagy for the treatment of NAFLD. Clarifying the inter-relation between these two pathways and their interaction with inflammatory and apoptotic mechanisms will allow the development of additional therapeutic options which can better target and reprogram the underlying pathophysiological pathways, aiming to attenuate NAFLD progression.

Jian-Gan-Xiao-Zhi Decoction Alleviates Inflammatory Response in Nonalcoholic Fatty Liver Disease Model Rats through Modulating Gut Microbiota

BACKGROUND

Jian-Gan-Xiao-Zhi decoction (JGXZ), composed of Salvia miltiorrhiza Bunge, Panax notoginseng, Curcuma zedoaria, and other 9 types of herbs, has demonstrated beneficial effects on nonalcoholic fatty liver disease (NAFLD). However, the mechanisms behind JGXZ's impact on NAFLD remain unknown.

METHODS

In this study, a NAFLD rat model induced by a high-fat diet (HFD) received oral treatment of JGXZ (8 or 16 g crude herb/kg) for 12 weeks. The therapeutic effects of JGXZ on NAFLD model rats were investigated through blood lipid levels and pathological liver changes. 16S rRNA analysis was used to study the changes in gut microbiota after JGXZ treatment. The expressions of occludin and tight junction protein 1 (ZO-1) in the colon were investigated using immunostaining to study the effects of JGXZ on gut permeability. The anti-inflammatory effects of JGXZ were also studied through measuring the levels of IL-1β, IL-6, and TNF-α in the serum and liver.

RESULTS

JGXZ treatment could decrease body weight and ameliorate dyslipidemia in NAFLD model rats. H&E and Oil Red O staining indicated that JGXZ reduced steatosis and infiltration of inflammatory cells in the liver. 16S rRNA analysis showed that JGXZ impacted the diversity of gut microbiota, decreasing the Firmicutes-to-Bacteroidetes ratio, and increasing the relative abundance of probiotics, such as Alloprevotella, Lactobacillus, and Turicibacter. Gut permeability evaluation found that the expressions of ZO-1 and occludin in the colon were increased after JGXZ treatment. Moreover, JGXZ treatment could decrease the levels of IL-1β, IL-6, and TNF-α in the serum and liver.

CONCLUSIONS

Our study illustrated that JGXZ could ameliorate NAFLD through modulating gut microbiota, decreasing gut permeability, and alleviating inflammatory response.

Lifestyle weight-loss intervention may attenuate methylation aging: the CENTRAL MRI randomized controlled trial

Background

DNA methylation age (mAge), a methylation biomarker for the aging process, might serve as a more accurate predictor of morbidity and aging status than chronological age. We evaluated the role of multiple factors, including fat deposition, cardiometabolic risk factors and lifestyle weight-loss intervention, on the deviation of mAge from chronological age (mAge deviation) or 18-month change in mAge (∆mAge). In this sub-study of the CENTRAL magnetic resonance imaging weight-loss trial, we evaluated mAge by a validated 240-CpG-based prediction formula at baseline and after 18-month intervention of either low fat (LF) or mediterranean/low carbohydrate (MED/LC) diets.

Results

Among 120 CENTRAL participants with abdominal obesity or dyslipidemia, mAge (mean ± SD: 60.3 ± 7.5 years) was higher than the chronological age (48.6 ± 9.3 years) but strongly correlated (r = 0.93; p = 3.1 × 10^–53). Participants in the lowest tertile of mAge deviation from their chronological age had significantly lower waist-circumference, visceral adipose tissue, intrahepatic fat (IHF) content, fasting-glucose and HOMA-IR, as compared with participants in the highest sex-specific residual tertile (p < 0.05 for all). IHF% remained associated with greater mAge deviation after further adjustments (β = 0.23; p = 0.02). After 18-month weight-loss lifestyle intervention, mAge remained significantly correlated with chronological age (r = 0.94, p = 1.5 × 10^–55). mAging occurred, with no difference between lifestyle intervention groups (∆ = 0.9 ± 1.9 years in MED/LC vs. ∆ = 1.3 ± 1.9 years in LF; p = 0.2); however, we observed a mAging attenuation in successful weight losers (> 5% weight loss) vs. weight-loss failures ( ∆ = 0.6 years vs. ∆ = 1.1 years; p = 0.04), and in participants who completed the trial with healthy liver fat content (< 5% IHF) vs. participants with fatty liver (∆ = 0.6 years vs. ∆ = 1.8 years; p = 0.003). Overall, 18 months of weight-loss lifestyle intervention attenuated the mAging of the men, mainly the older, by 7.1 months than the expected (p < 0.05).

Conclusions

Lifestyle weight-loss intervention may attenuate mAging. Deviation of mAge from chronological age might be related to body fat distribution and glycemic control and could indicate biological age, health status and the risk for premature cardiometabolic diseases.

Trial registration: ClinicalTrials.gov NCT01530724. Registered 10 February 2012, https://clinicaltrials.gov/ct2/show/study/NCT01530724.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13148-021-01038-0.

Nonalcoholic Steatohepatitis: Case-Based Focused on Pediatric and Adult Guidelines

Nonalcoholic fatty liver disease (NAFLD) comprises a continuum of conditions associated with insulin resistance and obesity in the absence of secondary causes of hepatic steatosis (alcohol, medication, genetic disorders, hepatitis, etc.) The milder, benign form of NAFLD is simple fatty liver or steatosis. Fatty infiltration affects more than 5% of the liver.1 This is determined by histologic exam, direct quantification or imaging. The range progresses to nonalcoholic steatohepatitis (NASH) and culminates in fibrosis and cirrhosis. Histologic changes include ballooning degeneration of hepatocytes, the presence of Mallory bodies, macrovesicular steatosis, lobular or portal inflammation.2  NAFLD is now the foremost cause of childhood, adolescent and adult chronic hepatic disease. The pediatric and adult obesity epidemic makes NAFLD a potentially ubiquitous hepatic pathology amongst all patients.3,4,5 The increase of obese children and adults with obesity correlates to the rise of NAFLD cases. In adults, the rate of NAFLD increase is paired with the epidemics of obesity and Type 2 Diabetes (T2DM).4,5 Data proposes hepatic-related mortality may be due to NASH ultimately progressing to cirrhosis.3,4 NAFLD is linked to pediatric and adult cardiovascular risk and morbidity.4,6 Non-invasive biomarkers and the gold standard of liver biopsy not only diagnose but assist in targeted therapies.6 Most pharmacologic therapy for NAFLD is in trial stages for patients of all ages. Pioglitazone is favored in adults who have NAFLD/NASH and T2DM.7 The gut biome is also impactful. Lifestyle modifications of diet and exercise can reduce the public health burden of this disease.7,8,9,10 

Effects of Pterostilbene on Diabetes, Liver Steatosis and Serum Lipids

Pterostilbene, a phenolic compound derived from resveratrol, possesses greater bioavailability than its parent compound due to the presence of two methoxyl groups. In this review, the beneficial effects of pterostilbene on diabetes, liver steatosis and dyslipidemia are summarized. Pterostilbene is a useful bioactive compound in preventing type 1 diabetes, insulin resistance and type 2 diabetes in animal models. Concerning type 1 diabetes, the main mechanisms described to justify the positive effects of this phenolic compound are increased liver glycogen content and hepatic glucokinase and phosphofructokinase activities, the recovery of pancreatic islet architecture, cytoprotection and a decrease in serum and pancreatic pro-inflammatory cytokines. As for type 2 diabetes, increased liver glucokinase and glucose-6-phosphatase and decreased fructose-1,6-biphosphatase activities are reported. When insulin resistance is induced by diets, a greater activation of insulin signaling cascade has been reported, increased cardiotrophin-1 levels and liver glucokinase and glucose- 6-phosphatase activities, and a decreased fructose-1,6-biphosphatase activity. Data concerning pterostilbene and liver steatosis are scarce so far, but the reduction in oxidative stress induced by pterostilbene may be involved since oxidative stress is related to the progression of steatosis to steatohepatitis. Finally, pterostilbene effectively reduces total cholesterol, LDL-cholesterol and serum triglyceride levels, while increases HDL-cholesterol in animal models of dyslipidemia.

Association Between Hepatic Triglyceride Content and Coagulation Factors: The Netherlands Epidemiology of Obesity Study

OBJECTIVE

Whether hepatic triglyceride content (HTGC) contributes to hypercoagulability beyond total body fat (TBF) and visceral adipose tissue (VAT) is unclear. We, therefore, aimed to investigate the association between HTGC and coagulation factors (F)I (fibrinogen), VIII, IX, and XI while adjusting for TBF and VAT. Approach and Results: In this cross-sectional analysis of the NEO study (Netherlands Epidemiology of Obesity; n=6671), a random subset of participants underwent magnetic resonance imaging and magnetic resonance spectroscopy to assess VAT and HTGC (n=2580). We excluded participants without complete imaging and coagulation assessment, and with history of liver disease, venous thrombosis, or on anticoagulation. Mean differences in coagulation factor levels across HTGC quartiles were estimated by linear regression adjusted for age, sex, ethnicity, education, alcohol intake, physical activity, smoking, estrogen, and menopause, in addition to TBF and VAT. Among the 1946 participants included, median HTGC was 2.66% (interquartile range: 1.34%-6.27%). Coagulation factor levels increased dose-dependently across HTGC quartiles. Mean differences between the fourth and first quartiles were 14.7 mg/dL (95% CI, 2.1-27.2) for fibrinogen, 6.7 IU/dL (95% CI, 0.5-12.9) for FVIII, 26.1 IU/dL (95% CI, 22.4-29.8) for FIX, and 8.6 IU/dL (95% CI, 4.6-12.6) for FXI. With further adjustment for TBF and VAT, the dose-response association of HTGC with FIX persisted, whereas associations with other factors disappeared.

CONCLUSIONS

HTGC was associated with various coagulation factors, of which FIX remained associated with HTGC after adjustment for TBF and VAT. HTGC might contribute to venous thrombosis risk beyond total body and visceral fat through FIX levels.

Sex-Specific Metabolite Biomarkers of NAFLD in Youth: A Prospective Study in the EPOCH Cohort

CONTEXT

Nonalcoholic fatty liver disease (NAFLD) is the leading cause of chronic liver disease in developed nations. There are currently no accurate biomarkers of NAFLD risk in youth.

OBJECTIVE

Identify sex-specific metabolomics biomarkers of NAFLD in a healthy cohort of youth.

DESIGN/SETTING

This prospective study included 395 participants of the EPOCH cohort in Colorado, who were recruited 2006-2009 ("T1 visit") and followed for 5 years ("T2 visit"). We entered 767 metabolites measured at T1 into a reduced rank regression model to identify the strongest determinants of hepatic fat fraction (HFF) at T2, separately for boys and girls. We compared the capacity of metabolites versus conventional risk factors (overweight/obesity, insulin, alanine transaminase, aspartate transaminase) to predict NAFLD (HFF ≥5%) and high HFF (fourth vs first quartile) using area under the receiver operating characteristic curve (AUC).

RESULTS

Prevalence of NAFLD was 7.9% (8.5% of boys, 7.1% of girls). Mean ± SD HFF was 2.5 ± 3.1%. We identified 13 metabolites in girls and 10 metabolites in boys. Metabolites were in lipid, amino acid, and carbohydrate metabolism pathways. At T1, the metabolites outperformed conventional risk factors in prediction of high HFF but not NAFLD. At T2, the metabolites were superior to conventional risk factors as predictors of high HFF (AUC for metabolites vs conventional risk factors for boys: 0.9565 vs 0.8851, P = 0.02; for girls: 0.9450 vs 0.8469, P = 0.02) with similar trends for NAFLD, although the differences were not significant.

CONCLUSIONS

The metabolite profiles identified herein are superior predictors of high HFF when assessed 5 years prior and concurrently in a general-risk setting.

Delta-tocotrienol supplementation improves biochemical markers of hepatocellular injury and steatosis in patients with nonalcoholic fatty liver disease: A randomized, placebo-controlled trial

OBJECTIVE

The aim of this study was to examine the effects of delta-tocotrienol (δ-tocotrienol) supplementation on biochemical markers of hepatocellular injury and steatosis in patients with nonalcoholic fatty liver disease (NAFLD).

DESIGN

The study design was a two-group, randomized, double-blind, placebo-controlled trial. The patients with NAFLD were randomly assigned to receive δ-tocotrienol 300 mg twice daily or placebo for 24 weeks.

ENDPOINTS

The primary endpoints were change from baseline in fatty liver index (FLI) and homeostasis model of insulin resistance (HOMA-IR) after 24 weeks. Secondary endpoints included change from baseline in high sensitivity C-reactive protein (hs-CRP), malondialdehyde (MDA), alanine transaminase (ALT), aspartate transaminase (AST) and grading of hepatic steatosis on ultrasound. Between-group differences were tested for significance using ANCOVA. Mean differences (MD) with 95 % CIs are reported.

RESULTS

A total of 71 patients (tocotrienol=35, placebo=36) were randomized and included in the intention to treat analysis. Compared with placebo, δ-tocotrienol significantly reduced (MD [95 % CI]) FLI (-8.52 [-10.7, -6.3]; p < 0.001); HOMA-IR (-0.37 [-0.53, -0.21]; p < 0.001), hs-CRP (-0.61[-0.81, -0.42]; p < 0.001), MDA (-0.91 [-1.20, -0.63]; p < 0.001), ALT (-8.86 [-11.5, -6.2]; p < 0.001) and AST (-6.6 [-10.0, -3.08]; p < 0.001). Hepatic steatosis was also reduced by a significantly greater extent with tocotrienol than with placebo (p =0.047). No adverse events were reported.

CONCLUSION

δ-tocotrienol effectively improved biochemical markers of hepatocellular injury and steatosis in patients with NAFLD. δ-tocotrienol supplementation might be considered as a therapeutic option in the management of patients with NAFLD.

TRIAL REGISTRATION

Sri Lankan Clinical Trials Registry (SLCTR/2015/023, 2015-10-03).