Metabolic risk factors and incident advanced liver disease in non-alcoholic fatty liver disease (NAFLD): A systematic review and meta-analysis of population-based observational studies

Corosolic acid inhibits cancer progression by decreasing the level of CDK19-mediated O-GlcNAcylation in liver cancer cells

Diabetes is an important risk factor for liver cancer, but its mechanism is unknown. Corosolic acid (CA) has been proven to have both hypoglycemic and antitumor effects, so revealing the function of CA can help us understand the relationship between diabetes and liver cancer. In previous studies, we confirmed that CA can effectively inhibit the expression of YAP, an important oncoprotein in HCC cells, and the proliferation of HCC cells. In addition, we also found that O-GlcNAcylation plays an indispensable role in HCC tumorigenesis. However, it is not clear whether CA can inhibit the effect of O-GlcNAcylation on HCC cells. In this study, the antitumor ability of CA was investigated by inhibiting the O-GlcNAcylation level and its corresponding mechanism. The results showed that HG (high glucose) could promote the proliferation of liver cancer cells, while CA could inhibit cell growth under HG conditions and tumor growth in a xenotransplantation model. CA can inhibit the activation of the HBP pathway and reduce the expression of YAP and OGT under HG conditions. Importantly, we found that CA can reduce YAP expression and O-GlcNAcylation by inhibiting the activity of CDK19. Overexpression of CDK19 partially reversed the CA-induced decrease in YAP and O-GlcNAcylation. This is the first evidence that CA can reduce the proliferative capacity of cells with high glucose levels and further inhibit tumor growth by inactivating the CDK19/YAP/O-GlcNAcylation pathway, suggesting that CA is a candidate drug for the development of treatments against diabetes-associated liver cancer.

Screening for nonalcoholic fatty liver disease-when, who and how?

Nonalcoholic fatty liver disease (NAFLD) is becoming a frequent liver disease, especially in patients with metabolic syndrome and especially in Western countries. Complications of NAFLD comprise progressive fibrosis, cirrhosis and hepatocellular carcinoma. NAFLD also represents an independent risk factor for cardiovascular disease, extrahepatic neoplasia and other organ damage, such as renal insufficiency. Given the epidemiological importance of the disease, new developments in specific treatment of the disease and the wide availability of noninvasive techniques in estimating steatosis and fibrosis, NAFLD should be subject to screening programs, at least in countries with a high prevalence of the disease. The review discusses prerequisites for screening, cost-effectiveness, current guideline recommendations, suitability of techniques for screening and propositions for the following questions: Who should be screened? Who should perform screening? How should screening be performed? It is time for a screening program in patients at risk for NAFLD.

A synthetic peptide AWRK6 ameliorates metabolic associated fatty liver disease: involvement of lipid and glucose homeostasis

Metabolic associated fatty liver disease (MAFLD) is the leading common chronic liver disease affecting more than one-quarter of the population worldwide, but no pharmacological therapy was approved specifically. A synthetic peptide AWRK6 developed in our group based on the antimicrobial peptide Dybowskin-2CDYa was found to attenuated diabetes as a novel GLP-1 receptor agonist candidate. The effects of AWRK6 on MAFLD and its underlying mechanisms were investigated in this paper. In high energy diet (HED)-induced MAFLD mice, obesity and hepatic steatosis were alleviated by AWRK6 via intraperitoneal injection. The biochemistry measurements data indicated that the abnormal lipid metabolism was relieved and the glucose metabolism was improved significantly. Further, the phosphorylation of liver PI3K/AKT/AMPK/ACC was elevated significantly by AWRK6 treatment. Moreover, the effects of AWRK6 on lipid accumulation and insulin sensitivity in human cells were verified using oleic acid-induced HepG2 fatty liver cell model and insulin-induced HepG2 cells, respectively. These in vitro and in vivo results demonstrated that the peptide AWRK6 ameliorates MAFLD by improving lipid and glucose metabolism homeostasis, and it is mediated by the PI3K/AKT/AMPK/ACC signaling pathway. Thus, AWRK6 has a potential in preventing MAFLD.

Metabolic risk factors, genetic predisposition, and risk of severe liver disease in Chinese: a prospective study of 0.5 million people

BACKGROUND

Metabolic risk factors have been shown to be associated with severe liver disease (SLD) in Chinese populations. However, there is limited evidence on the combined impact of these factors, or the genetic variants associated with SLD.

OBJECTIVES

We examined the associations of combined metabolic risk factors with risks of SLD, both overall and by genetic predisposition to SLD.

METHODS

The study population involved 486,828 participants of the prospective China Kadoorie Biobank aged 30-79 years from 10 diverse areas in China without a history of cancer or liver disease at baseline. Cox regression was used to estimate adjusted HRs for SLD associated with combined metabolic risk factors (central adiposity, physical inactivity, and diabetes) by stratum of genetic risk [assessed separately by a PNPLA3 variant (rs738409) and a BMI genetic risk score].

RESULTS

During ∼10 years of follow-up, 3279 incident cases of SLD were recorded. The overall mean BMI was 23.8 kg/m2 (SD, 3.4 kg/m2), and 5.9% participants had diabetes. Compared with those with 3 metabolic factors, participants with 2, 1, and 0 metabolic factors had 31% (HR, 0.69; 95% CI: 0.65-0.73), 43% (HR, 0.57; 95% CI: 0.53-0.60), and 52% (HR, 0.48; 95% CI: 0.42-0.56) lower risks of SLD, respectively. For both BMI and nonalcoholic fatty liver disease variants, participants with fewer metabolic factors had a lower risk of SLD, lower levels of gamma-glutamyl transferase, and lower fatty liver index scores, in participants with low and high genetic risks (P value for interaction > 0.05).

CONCLUSIONS

In relatively lean Chinese adults, individuals with fewer metabolic risk factors had a lower relative risk of SLD and a more favorable profile of liver biomarkers across all strata of genetic risk.

Dietary Risks for Liver Mortality in NAFLD: Global Burden of Disease Data

Nonalcoholic fatty liver disease (NAFLD) is a common but complex chronic liver disease, driven by environmental and genetic factors. We assessed metabolic and dietary risk factor associations with NAFLD liver mortality using the Global Burden of Disease (GBD) 2017 data. NAFLD liver deaths were calculated (per 100,000) as age‐standardized rates (ASRs) from 195 countries and territories (21 GBD regions; 7 GBD superregions). Dietary risks included low intake of fruits, vegetables, legumes, whole grains, nuts/seeds, milk, fiber, calcium, seafood omega‐3 fatty acids, and polyunsaturated fatty acids, and high intake of red meat, processed meat, sugar‐sweetened beverages, trans fatty acids, and sodium. Metabolic risks included high low‐density lipoprotein cholesterol, systolic blood pressure (BP), fasting glucose (FG), body mass index (BMI), as well as low bone mineral density and impaired kidney function (IKF). Socio‐demographic index (SDI)–adjusted partial Spearman correlation coefficients and multivariable generalized linear regression models/bidirectional stepwise selection (significance level for entry, 0.2; for stay, 0.05) determined the associations. The ASR for NAFLD liver deaths was 2.3 per 100,000 (2017) and correlated with dietary risk factors (0.131, −0.010‐0.267) and metabolic risk factors (SDI‐adjusted = 0.225, 95% CI 0.086‐0.354). High intake of sugar‐sweetened beverages and red meat (0.358, 0.229‐0.475; 0.162, 0.022‐0.296), and low intake of nuts/seed and milk (0.154, 0.014‐0.289; 0.145, 0.004‐0.280) was significant for NAFLD liver deaths. Other risk factors for liver death included IKF (0.402, 0.276‐0.514), increased BMI (0.353, 0.223‐0.407), FG (0.248, 0.111‐0.376), and BP (0.163, 0.022‐0.297). High intake of trans fatty acids (2.84% increase [1.65%‐4.03%]) was the largest associated risk of NAFLD liver deaths. In addition to metabolic risks, dietary risks independently drive the global burden of NAFLD‐related liver mortality. Conclusion: These data provide additional support for policies to improve dietary environment for NAFLD burden reduction.

Non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) has a global prevalence of 25% and is a leading cause of cirrhosis and hepatocellular carcinoma. NAFLD encompasses a disease continuum from steatosis with or without mild inflammation (non-alcoholic fatty liver), to non-alcoholic steatohepatitis (NASH), which is characterised by necroinflammation and faster fibrosis progression than non-alcoholic fatty liver. NAFLD has a bidirectional association with components of the metabolic syndrome, and type 2 diabetes increases the risk of cirrhosis and related complications. Although the leading causes of death in people with NAFLD are cardiovascular disease and extrahepatic malignancy, advanced liver fibrosis is a key prognostic marker for liver-related outcomes and overall mortality, and can be assessed with combinations of non-invasive tests. Patients with cirrhosis should be screened for hepatocellular carcinoma and oesophageal varices. There is currently no approved therapy for NAFLD, although several drugs are in advanced stages of development. Because of the complex pathophysiology and substantial heterogeneity of disease phenotypes, combination treatment is likely to be required for many patients with NAFLD. Healthy lifestyle and weight reduction remain crucial to the prevention and treatment of NAFLD.

Combination of type IV collagen 7S, albumin concentrations, and platelet count predicts prognosis of non-alcoholic fatty liver disease

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease and affects approximately 25% of the general global adult population. The prognosis of NAFLD patients with advanced liver fibrosis is known to be poor. It is difficult to assess disease progression in all patients with NAFLD; thus, it is necessary to identify patients who will show poor prognosis.

AIM

To investigate the efficacy of non-invasive biomarkers for predicting disease progression in patients with NAFLD.

METHODS

We investigated biomarkers associated with mortality in patients with NAFLD who visited the Kawasaki Medical School General Medical Center from 1996 to 2018 and underwent liver biopsy and had been followed-up for > 1 year. Cumulative overall mortality and liver-related events during follow-up were calculated using the Kaplan-Meier analysis and compared using log-rank testing. We calculated the odds ratio and performed receiver operating characteristic curve analysis with logistic regression analysis to determine the optimal cut-off value with the highest prognostic ability.

RESULTS

We enrolled 489 patients who were followed-up for a period of 1-22.2 years. In total, 13 patients died (2.7% of total patients enrolled); 7 patients died due to liver-related causes. Poor prognosis was associated with liver fibrosis on histological examination but not with inflammation or steatosis. Blood biomarkers associated with mortality were platelet counts, albumin levels, and type IV collagen 7S levels. The optimal cutoff index for predicting total mortality was a platelet count of 15 × 10⁴/μL, albumin level of 3.5 g/dL, and type IV collagen 7S level of 5 mg/dL. In particular, only one-factor patients with NAFLD presenting with platelet counts ≤ 15 × 10⁴/μL, albumin levels ≤ 3.5 g/dL, or type IV collagen 7S ≥ 5 mg/dL showed 5-year, 10-year, and 15-year survival rates of 99.7%, 98.3%, and 94%, respectively. However, patients with two factors had lower 5-year and 10-year survival rates of 98% and 43%, respectively. Similarly, patients with all three factors showed the lowest 5-year and 10-year survival rates of 53% and 26%, respectively.

CONCLUSION

A combination of the three non-invasive biomarkers is a useful predictor of NAFLD prognosis and can help identify patients with NAFLD who are at a high risk of all-cause mortality.

Nutrigenetic Interactions Might Modulate the Antioxidant and Anti-Inflammatory Status in Mastiha-Supplemented Patients With NAFLD

Non-alcoholic fatty liver disease (NAFLD) is the most common liver disease with no therapeutic consensus. Oxidation and inflammation are hallmarks in the progression of this complex disease, which also involves interactions between the genetic background and the environment. Mastiha is a natural nutritional supplement known to possess antioxidant and anti-inflammatory properties. This study investigated how a 6-month Mastiha supplementation (2.1 g/day) could impact the antioxidant and inflammatory status of patients with NAFLD, and whether genetic variants significantly mediate these effects. We recruited 98 patients with obesity (BMI ≥ 30 kg/m²) and NAFLD and randomly allocated them to either the Mastiha or the placebo group for 6 months. The anti-oxidative and inflammatory status was assessed at baseline and post-treatment. Genome-wide genetic data was also obtained from all participants, to investigate gene-by-Mastiha interactions. NAFLD patients with severe obesity (BMI > 35kg/m²) taking the Mastiha had significantly higher total antioxidant status (TAS) compared to the corresponding placebo group (P value=0.008). We did not observe any other significant change in the investigated biomarkers as a result of Mastiha supplementation alone. We identified several novel gene-by-Mastiha interaction associations with levels of cytokines and antioxidant biomarkers. Some of the identified genetic loci are implicated in the pathological pathways of NAFLD, including the lanosterol synthase gene (LSS) associated with glutathione peroxidase activity (Gpx) levels, the mitochondrial pyruvate carrier-1 gene (MPC1) and the sphingolipid transporter-1 gene (SPNS1) associated with hemoglobin levels, the transforming growth factor‐beta‐induced gene (TGFBI) and the micro-RNA 129-1 (MIR129-1) associated with IL-6 and the granzyme B gene (GZMB) associated with IL-10 levels. Within the MAST4HEALTH randomized clinical trial (NCT03135873, www.clinicaltrials.gov) Mastiha supplementation improved the TAS levels among NAFLD patients with severe obesity. We identified several novel genome-wide significant nutrigenetic interactions, influencing the antioxidant and inflammatory status in NAFLD.

Importance of non-invasive liver fibrosis scores for mortality and complications development in individuals with type 2 diabetes

AIMS

To evaluate the non-alcoholic fatty liver disease (NAFLD) fibrosis score (NFS) and Fibrosis-4 score (FIB4) as predictors of complications development and mortality in a cohort of type 2 diabetes.

METHODS

554 type 2 diabetic subjects had NFS and FIB4 calculated at baseline. Multivariate Cox and Poisson analyses evaluated the associations between fibrosis scores and the occurrence of microvascular and cardiovascular complications, and all-cause mortality.

RESULTS

According to recommended cut-offs of NFS, 12.8% had advanced fibrosis and 45.9% had absence of advanced fibrosis and of FIB4, 3.8% and 86.1%, respectively. During a median follow-up of 11 years, 217subjects died, 172 had cardiovascular events (CVEs), 184 had renal events, and 139 had retinopathy and 185 neuropathy events. As continuous variables, both scores predicted all-cause mortality: NFS, HR: 1.30 (p = 0.032) and FIB4, HR: 1.24 (p = 0.021); an increased NFS implied in a significant 90% excess risk of mortality, whereas a higher FIB4 in a borderline 69% higher risk. The scores were mainly predictors of mortality in women and for non-cardiovascular deaths. The NFS was a predictor of renal events, mainly for renal function deterioration.

CONCLUSIONS

The NFS and FIB4 predicted all-cause mortality, particularly in women and for non-cardiovascular causes. The NFS predicted adverse renal outcomes. These liver fibrosis scores may improve stratification risk in individuals with diabetes and NAFLD.

Progression from Nonalcoholic Fatty Liver to Nonalcoholic Steatohepatitis Cirrhosis Confirmed by Liver Histology after 14 Years

A 44-year-old patient progressed from nonalcoholic fatty liver (NAFL) to nonalcoholic steatohepatitis (NASH) cirrhosis. She was diagnosed with NAFL via a liver biopsy. At 56 years old, she was diagnosed with NASH stage 3 via a second liver biopsy. One year later, she was diagnosed with NASH cirrhosis via a third liver biopsy. This is the first study to report the gradual deterioration of liver histology shown via three liver biopsies and fibrosis markers in a patient who progressed from NAFL to NASH cirrhosis. Following menopause, it is necessary to be aware of the rapid development of liver fibrosis.

Nonalcoholic fatty liver disease as a metabolic disease in humans: A literature review

AIMS

To conduct a systematic literature review to identify recent epidemiological, biomarker, genetic and clinical evidence that expands our understanding of nonalcoholic fatty liver disease (NAFLD) as a metabolic disorder.

MATERIALS AND METHODS

We performed a literature search using PubMed to identify trials, observational studies and meta-analyses published in the past 5 years.

RESULTS

A total of 95 publications met prespecified inclusion criteria and reported on the interplay between NAFLD/nonalcoholic steatohepatitis (NASH) and metabolic dysfunction, in terms of disease burden and/or epidemiology (n = 10), pathophysiology, risk factors and associated conditions (n = 29), diagnosis and biomarkers (n = 34), and treatment approaches (n = 22). There is a growing body of evidence on the links between NAFLD/NASH pathogenesis and mechanisms of metabolic dysfunction, through liver lipid accumulation, insulin resistance, inflammation, apoptosis, and fibrogenic remodelling within the liver. The frequent co-occurrence of NAFLD with obesity, metabolic syndrome and type 2 diabetes supports this premise. Therapeutic approaches originally envisaged for type 2 diabetes or obesity (such as glucagon-like peptide-1 receptor agonists, sodium-glucose co-transporter-2 inhibitors, insulin sensitizers and bariatric surgery) have shown promising signs of benefit for patients with NAFLD/NASH.

CONCLUSIONS

Given the complex interplay between NAFLD and metabolic dysfunction, there is an urgent need for multidisciplinary collaboration and established protocols for care of patients with NAFLD that are individualized and ideally support reduction of overall metabolic risk as well as treatment for NASH.

Uncovering undiagnosed liver disease: prevalence and opportunity for intervention in a population attending colonoscopy

OBJECTIVE

Due to high rates of obesity and alcohol consumption, the prevalence of fatty liver disease is increasing. There is no widely adopted approach to proactively screen for liver disease in the community. We aimed to assess the burden of potentially undiagnosed liver disease in individuals attending for colonoscopy to develop a pathway to identify and manage individuals with undiagnosed liver disease.

DESIGN

The OSCAR Study was a cross-sectional study recruiting patients attending for colonoscopy. Patients' metabolic and liver risk factors were measured. The prevalence of undiagnosed significant fatty liver disease was measured using the Fatty Liver Index (FLI) and Fibrosis-4 score (FIB-4).

RESULTS

1429 patients (mean age 59±14 years; 48.8% men) were recruited. 73.3% were overweight/obese, 12.7% had diabetes and 17.9% had metabolic syndrome. 19% were consuming more than recommenced alcohol levels (<14 units/week) and 41% had an AUDIT-C score ≥5. After excluding those with known liver disease, 43.2% of the cohort had a high FLI (high likelihood of fatty liver). 5.3% of these had a high FIB-4 score (>2.67, high probability of advanced fibrosis) and 90% of these were previously undiagnosed. 818 patients had a predicted 10-year cardiovascular event risk of ≥10%, however only 377 (46.1%) were on statin therapy.

CONCLUSION

High levels of obesity, metabolic dysfunction and undiagnosed fatty liver disease were found in individuals attending for colonoscopy. Clinical encounters in the endoscopy unit may represent an opportunity to risk assess for liver and metabolic disease and provide an environment to develop targeted interventions.

Vibration-Controlled Transient Elastography and Controlled Attenuation Parameter for the Diagnosis of Liver Steatosis and Fibrosis in Patients with Nonalcoholic Fatty Liver Disease

Vibration-Controlled Transient Elastography (VCTE) with Controlled Attenuation Parameter (CAP) is a widely used non-invasive technique for concomitant assessment of liver steatosis and fibrosis in patients with nonalcoholic fatty liver disease (NAFLD). We aimed to evaluate the level both of hepatic steatosis and fibrosis as well as the associated risk factors in patients referred to our unit with clinically suspected NAFLD or diagnosed by abdominal ultrasonography. Two hundred four patients were prospectively included in this study and assessed by VCTE with CAP. The final analysis included 181 patients with reliable liver stiffness measurements (LSMs) (53% female, mean age 57.62 ± 11.8 years and BMI 29.48 ± 4.85 kg/m²). According to the cut-off values for steatosis grading, there were 10 (5.5%) patients without steatosis (S0), 30 (16.6%) with mild (S1), 45 (24.9%) moderate (S2), and 96 (53%) severe (S3) steatosis. Based on LSM, there were 73 (40.3%) patients without fibrosis (F0), 42 (23.2%) with mild (F1), 32 (17.7%) significant (F2), 19 (10.5%) advanced (F3) fibrosis, and 15 (8.3%) with cirrhosis (F4). In addition, we found an association between several metabolic components and hepatic steatosis and fibrosis. Thus, in the multivariate analysis, higher BMI, fasting plasma glucose, triglycerides, low-density lipoprotein cholesterol, and serum uric were associated with increased CAP. Furthermore, higher serum uric acid and alpha-fetoprotein together with lower platelets count and albumin levels were associated with increased LSM. The assessment of steatosis and fibrosis using VCTE and CAP should be performed in all patients with suspected or previously diagnosed NAFLD in units with available facilities.

Metabolic Spectrum of Liver Failure in Type 2 Diabetes and Obesity: From NAFLD to NASH to HCC

Liver disease is the spectrum of liver damage ranging from simple steatosis called as nonalcoholic fatty liver disease (NAFLD) to hepatocellular carcinoma (HCC). Clinically, NAFLD and type 2 diabetes coexist. Type 2 diabetes contributes to biological processes driving the severity of NAFLD, the primary cause for development of chronic liver diseases. In the last 20 years, the rate of non-viral NAFLD/NASH-derived HCC has been increasing rapidly. As there are currently no suitable drugs for treatment of NAFLD and NASH, a class of thiazolidinediones (TZDs) drugs for the treatment of type 2 diabetes is sometimes used to improve liver failure despite the risk of side effects. Therefore, diagnosis, prevention, and treatment of the development and progression of NAFLD and NASH are important issues. In this review, we will discuss the pathogenesis of NAFLD/NASH and NAFLD/NASH-derived HCC and the current promising pharmacological therapies of NAFLD/NASH. Further, we will provide insights into "adipose-derived adipokines" and "liver-derived hepatokines" as diagnostic and therapeutic targets from NAFLD to HCC.

Evidence-Based Aerobic Exercise Training in Metabolic-Associated Fatty Liver Disease: Systematic Review with Meta-Analysis

Background: This meta-analysis evaluates the overall effect of the non-pharmacological intervention, aerobic exercise, upon serum liver enzymes levels, glucose metabolism and anthropometric measures amongst patients with metabolic associated fatty liver disease (MAFLD). It also examines whether the effects on these outcomes are moderated by the aerobic training protocol when considered according to the American College of Sports Medicine (ACSM) recommended FITT (frequency, intensity, time, type) principles. Approach and Results: Fifteen randomized control trials were included in the meta-analysis. Compared with usual care, continuous and interval training showed significant efficacy in alanine aminotransferase (ALT) level improvement (MD = −2.4, 95% CI: −4.34 to −0.46 p = 0.015, I² = 9.1%). Interventions based on all types of aerobic exercise protocols showed significant improvement of intrahepatic triglycerides (MD = −4.0557, 95% CI: −5.3711 to −2.7403, p < 0.0001, I² = 0%) and BMI (MD = −0.9774, 95% CI: −1.4086 to −0.5462, p < 0.0001, I² = 0). Meta-regression analysis demonstrated a significant correlation between total intervention time and ALT level (for all aerobic protocols: 6.0056, se = 2.6896, z = 2.2329, p = 0.02; as well as for continuous and interval aerobic protocols: 5.5069, se = 2.7315, z = 2.016, p = 0.04). Conclusions: All types of aerobic exercise protocols are effective at improving intrahepatic triglycerides and lead to a reduction in body mass index. In addition, continuous and interval aerobic exercise may be more effective at improving ALT ≤12 weeks intervention time benefits the management of MAFLD.

Triglycerides to high-density lipoprotein cholesterol ratio for diagnosing nonalcoholic fatty liver disease

BACKGROUND

Nonalcoholic Fatty Liver Disease (NAFLD) is a widespread disease in the western world. It can develop into more serious pathological conditions (i.e. liver cirrhosis). Therefore it is important to diagnose it in order to prevent this evolution. For diagnosis it is possible to use both imaging methods and biomarkers, such as the Triglycerides To High-Density Lipoprotein Cholesterol Ratio (TG/HDL-C). Aim of our study is to determine whether TG/HDL-C ratio is significantly associated with NAFLD and Metabolic Syndrome (MetS).

METHODS

We recruited 231 patients, 131 with and 100 without NAFLD. The Body Mass Index had been calculated and different laboratory parameters had been obtained. TG/HDL-C ratio was calculated for each.

RESULTS

In our sample HDL-C was not significantly reduced in NAFLD group (p = 0.49), but higher TG and TG/HDL-C ratio were significantly associated with NAFLD: in both p < 0.001. According to receiver operating characteristic curve, the best cut-off of TG/HDL-C in NAFLD population was 1.64 [area under the curve (AUC) 0.675 (95% CI 0.604-0.746), p < 0.001]. TG/HDL-C higher ratio was significantly associated with MetS (p < 0.001). The best cut-off of TG/HDL-C in patients with MetS was 2.48 [AUC 0.871 (95% CI 0.808-0.935), p < 0.001].

CONCLUSIONS

We demonstrated that higher TG/HDL-C ratio is associated with NAFLD and MetS. Though nowadays TG/HDL-C ratio is not a criteria for NAFLD diagnosis, we believe that in the future it could be used as a reliable non-invasive marker in routine diagnostics of NAFLD.

Non-alcoholic fatty liver disease (NAFLD)/non-alcoholic steatohepatitis (NASH)-related liver fibrosis: mechanisms, treatment and prevention

Liver fibrosis is the excessive expression and accumulation of extracellular matrix proteins in the liver. Fibrotic scarring occurs as the consequence of chronic injury and inflammation. While the successful treatment of hepatitis B and C reduced the burden of liver disease related to viral hepatitis, non-alcoholic fatty liver disease (NAFLD) or non-alcoholic steatohepatitis (NASH) are nowadays the leading causes of hepatic fibrosis worldwide. Although basic research activities have significantly advanced our understanding of the molecular disease pathogenesis, the present therapeutic options for fibrosis are still limited. In advanced disease stages, liver transplantation often remains the only curative treatment. This highlights the necessity of preventive strategies to avoid complications of fibrosis, particularly cirrhosis, portal hypertension and liver cancer. Lifestyle modifications (weight loss, exercise, healthy diet) are the basis for prevention and treatment of NAFLD-associated fibrosis. In the present review, we discuss recent advances in antifibrotic prevention and therapy. In particular, we review the current concepts for antifibrotic drug candidates in the treatment of NAFLD and NASH. While some compounds aim at reverting pathogenic liver metabolism, an alternative approach is to disconnect the injury (e.g., NAFLD) from inflammation and/or fibrosis. Investigational drugs typically target metabolic pathways, insulin resistance, hepatocyte death, inflammatory cell recruitment or activation, the gut-liver axis, matrix expression or matrix turnover. While several promising drug candidates failed in phase 2 or 3 clinical trials (including elafibranor, emricasan and selonsertib), promising results with the farnesoid X receptor agonist obeticholic acid, the pan-PPAR agonist lanifibranor and the chemokine receptor CCR2/CCR5 inhibitor cenicriviroc support the expectation of an effective pharmacological therapy for liver fibrosis in the near future. Tackling NAFLD-associated fibrosis from different directions by combinatorial drug treatment and effective lifestyle changes hold the greatest prospects.

Low serum vitamin D concentrations are associated with obese but not lean NAFLD: a cross-sectional study

Background

A low serum vitamin D concentration has been reported to be associated with an increased risk of non-alcoholic fatty liver disease (NAFLD); however, whether lean or obese individuals show a similar association between vitamin D and NAFLD remains speculative. This study aimed to explore the relationship between serum vitamin D concentration and NAFLD in lean and obese Chinese adults.

Methods

This cross-sectional study included 2538 participants (1360 men and 1178 women) who underwent health checkups at the First Affiliated Hospital, Zhejiang University School of Medicine in 2019. NAFLD was diagnosed by liver ultrasound excluding other causes. The association of serum vitamin D concentration with NAFLD was analyzed in lean and obese participants.

Results

The overall prevalence of NAFLD was 33.61% (13.10% in lean and 53.32% in obese) in this study population. The serum vitamin D levels of obese NAFLD patients were lower than those of obese NAFLD-free controls. However, the serum vitamin D levels of lean NAFLD patients were comparable to those of lean NAFLD-free controls. Serum vitamin D level was negatively correlated with the prevalence of NAFLD in obese but not lean participants. Serum vitamin D level was independently associated with the risk of NAFLD in obese participants, with an adjusted odds ratio (95% CI) of 0.987 (0.981–0.993). However, serum vitamin D level was not related to the risk of NAFLD in lean participants.

Conclusions

A low serum vitamin D level is associated with NAFLD in obese but not lean participants.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12937-021-00690-9.

Dynamic Chronological Changes in Serum Triglycerides Are Associated With the Time Point for Non-alcoholic Fatty Liver Disease Development in the Nationwide Korean Population Cohort

Background: We investigated the effects of anthropometric, laboratory, and lifestyle factors on the development of non-alcoholic fatty liver disease (NAFLD) in a nationwide, population-based, 4-year retrospective cohort.

Methods: The propensity score-matched study and control groups contained 1,474 subjects who had data in the Korean National Health Insurance Service-National Sample Cohort in 2009, 2011, and 2013. NAFLD was defined using medical records of a diagnosis confirmed by primary clinicians and meeting two previously validated fatty liver prediction models. Chronological changes in anthropometric variables, laboratory results, and lifestyle factors during two periods were compared between patient and control groups in order to find out parameters with consistent dynamics in pre-NAFLD stage which was defined as period just before the NAFLD development.

Results: Among the 5 anthropometric, 10 laboratory, and 3 lifestyle factors, prominent chronological decremental changes in serum triglycerides were consistently observed during the pre-NAFLD stage, although the degrees of changes were more predominant in men (−9.46 mg/dL) than women (−5.98 mg/dL). Furthermore, weight and waist circumference changes during the pre-NAFLD stage were noticeable only in women (+0.36 kg and +0.9 cm for weight and waist circumference, respectively), which suggest gender difference in NAFLD.

Conclusion: Early screening strategies for people with abrupt chronological changes in serum triglycerides to predict NAFLD development before the progression is recommended.

NAFLD and Cardiovascular Diseases: Epidemiological, Mechanistic and Therapeutic Considerations

Overwhelming evidence suggests an association of cardiovascular disease (CVD) with non-alcoholic fatty liver disease (NAFLD); however, the underlying mechanisms remain largely speculative. It is, however, likely that common mechanisms contribute to the development of CVD and NAFLD, with lifestyle factors such as smoking, sedentary lifestyle with poor nutrition habits and physical inactivity being major candidates. These behavioral factors, on a predisposing genetic background, trigger changes in gut microbiota, inflammation, dyslipidemia and oxidative stress, leading to metabolic syndrome, diabetes and obesity as well as atherosclerosis. Treatment options to counteract both the progression and development of CVD and NAFLD include lifestyle interventions, optimal medical therapy of comorbid conditions and, as final possibility, bariatric surgery. As no causal pharmacotherapy of NAFLD is available, further research is urgently needed to address the unmet need of a growing population with NAFLD and CVD.

Management of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease is a very common medical condition, driven by a combination of genetic and lifestyle factors, ultimately producing a severe chronic liver disease and increased cardiovascular risk. Most people are asymptomatic for a long time, and their daily life is unaffected, leading to difficulty in identifying and managing people who slowly progress to non-alcoholic steatohepatitis (NASH), NASH-cirrhosis, and eventually hepatocellular carcinoma. Despite advances in the understanding of pathogenic mechanisms and the identification of liver fibrosis as the strongest factor in predicting disease progression, no specific treatments have been approved by regulatory agencies. Outside controlled trials, treatment is generally limited to lifestyle intervention aimed at weight loss. Pioglitazone remains the drug of choice to reduce progression of fibrosis in people with diabetes, although it is often used off-label in the absence of diabetes. Vitamin E is mainly used in children and may be considered in adults without diabetes. Several drugs are under investigation according to the agreed targets of reduced NASH activity without worsening of fibrosis or improving fibrosis without worsening of NASH. Anti-inflammatory, anti-fibrotic agents and metabolism modulators have been tested in either phase III or phase IIb randomized controlled trials; a few failed, and others have produced marginally positive results, but only a few are being tested in extension studies. The development of non-invasive, easily repeatable surrogate biomarkers and/or imaging tools is crucial to facilitate clinical studies and limit liver biopsy.

Phloretin ameliorates hepatic steatosis through regulation of lipogenesis and Sirt1/AMPK signaling in obese mice

Background

Phloretin is isolated from apple trees and could increase lipolysis in 3T3-L1 adipocytes. Previous studies have found that phloretin could prevent obesity in mice. In this study, we investigated whether phloretin ameliorates non-alcoholic fatty liver disease (NAFLD) in high-fat diet (HFD)-induced obese mice, and evaluated the regulation of lipid metabolism in hepatocytes.

Methods

HepG2 cells were treated with 0.5 mM oleic acid to induce lipid accumulation, and then treated with phloretin to evaluate the molecular mechanism of lipogenesis. In another experiment, male C57BL/6 mice were fed normal diet or HFD (60% fat, w/w) for 16 weeks. After the fourth week, mice were treated with or without phloretin by intraperitoneal injection for 12 weeks.

Results

Phloretin significantly reduced excessive lipid accumulation and decreased sterol regulatory element-binding protein 1c, blocking the expression of fatty acid synthase in oleic acid-induced HepG2 cells. Phloretin increased Sirt1, and phosphorylation of AMP activated protein kinase to suppress acetyl-CoA carboxylase expression, reducing fatty acid synthesis in hepatocytes. Phloretin also reduced body weight and fat weight compared to untreated HFD-fed mice. Phloretin also reduced liver weight and liver lipid accumulation and improved hepatocyte steatosis in obese mice. In liver tissue from obese mice, phloretin suppressed transcription factors of lipogenesis and fatty acid synthase, and increased lipolysis and fatty acid β-oxidation. Furthermore, phloretin regulated serum leptin, adiponectin, triglyceride, low-density lipoprotein, and free fatty acid levels in obese mice.

Conclusions

These findings suggest that phloretin improves hepatic steatosis by regulating lipogenesis and the Sirt-1/AMPK pathway in the liver.

Identifying High-Risk NASH Patients: What We Know so Far

Steatosis is a condition of hepatic fat overload that is associated with overweight and the metabolic syndrome. Nonalcoholic fatty liver disease (NAFLD) has become the most common liver disease with a global impact on healthcare. A proportion of NAFLD patients develops nonalcoholic steatohepatitis (NASH), liver fibrosis, cirrhosis or hepatocellular carcinoma (HCC). Identifying patients at risk for potentially life-threatening complications is crucial in their prevention, surveillance and treatment. In addition to hepatic disease progression (cirrhosis, portal hypertension, HCC), NAFLD patients are also at risk of cardiovascular and metabolic diseases as well as extrahepatic malignancies. Liver fibrosis is related to morbidity and mortality in NASH patients, and biomarkers, imaging techniques (ultrasound, elastography, MRI) as well as liver biopsy help in diagnosing fibrosis. In this review, we discuss the tools for identifying patients at risk and their reasonable application in clinical routine in order to stratify prevention and treatment of this emerging disease.