Lean NAFLD: An Underrecognized Outlier. ACTA ACUST UNITED AC. 2016;15:134-139. [PMID: 27668144 DOI: 10.1007/s11901-016-0302-1]

Metabolic dysfunction associated fatty liver disease in healthy weight individuals

Metabolic dysfunction associated fatty liver disease (MAFLD) is an increasing public health problem, affecting one third of the global population. Contrary to conventional wisdom, MAFLD is not exclusive to obese or overweight individuals. Epidemiological studies have revealed a remarkable prevalence among healthy weight individuals, leading investigations into the genetic, lifestyle, and dietary factors that contribute to the development of MAFLD in this population. This shift in perspective requires reconsideration of preventive strategies, diagnostic criteria and therapeutic approaches tailored to address the unique characteristics of MAFLD healthy weight individuals. It also underscores the importance of widespread awareness and education, within the medical community and among the general population, to promote a more inclusive understanding of liver metabolic disorders. With this review, we aim to provide a comprehensive exploration of MAFLD in healthy weight individuals, encompassing epidemiological, pathophysiological, and clinical aspects.

Disease severity and antiviral response in patients with chronic hepatitis B with non-obese NAFLD

BACKGROUND

The burden of nonalcoholic fatty liver disease (NAFLD) is growing in patients with chronic hepatitis B (CHB). NAFLD is typically associated with obesity, however, it is increasingly being identified in non-obese patients. This study aimed to investigate disease severity and antiviral response in non-obese patients with CHB with NAFLD (CHB + NAFLD).

METHODS

A total of 809 patients with CHB + NAFLD were prospectively recruited and followed up for 3 years. NAFLD was diagnosed by transient elastography and defined as controlled attenuation parameter ≥248 dB/m, in the absence of excessive alcohol intake. Obesity status was defined by the Asian body mass index (BMI) cutoff of 25 kg/m2. Metabolic abnormality was defined by the presence of dyslipidemia, hypertension or diabetes. Fibrosis staging was defined according to the EASL-ALEH guidelines, with fibrosis progression defined as ≥1-stage increment.

RESULTS

In the total cohort (median age 40 years, 59.0% antiviral-treated), 33.3% were non-obese. Non-obese patients were less metabolically abnormal than obese patients (60.2% vs 72.0%, P = 0.003). After 3-year follow up, the rate of fibrosis progression was comparable between non-obese and obese patients (17.5% vs 21.9% in the total cohort, P = 0.145; 15.7% vs 14.6% in antiviral-treated cohort with persistent viral suppression, P = 0.795). No significant differences in virological and biochemical responses were observed between non-obese and obese patients (P >0.05 for all).

CONCLUSION

Approximately one third of CHB + NAFLD patients were non-obese. Non-obese patients, while less metabolically abnormal, had a similar risk for fibrosis progression as obese patients. Obesity status did not impact the efficiency of antiviral therapy.

Osteosarcopenic adiposity (OSA) phenotype and its connection with cardiometabolic disorders: Is there a cause-and-effect?

The objectives were to examine if there is a causal relationship between osteosarcopenic adiposity (OSA) syndrome (coexistence of osteopenia/osteoporosis, sarcopenia, and excess adiposity) and cardiometabolic disorders or if these disorders initiate the development of OSA and its worsening. The search was conducted in PubMed, Scopus, and Web of Science to include articles up to the end of 2023. Of n=539 articles retrieved, n=15 met the eligibility criteria. Only studies conducted in adults and with all three body composition compartments (bone, muscle/lean, adipose) measured were considered. The results revealed that several cardiometabolic disorders, namely, hypertension, dyslipidemia (elevated total and LDL-cholesterol, lower HDL-cholesterol), insulin resistance, hyperglycemia, lower serum vitamin D, and some inflammatory markers were accompanied by OSA. In most cases, the OSA phenotype was associated with worse outcomes than cases with healthy or less impaired body composition. Our initial questions about the reciprocal cause-and-effect relationships could be surmised with more certainty for the OSA and some cardiovascular risks (hypertension, dyslipidemia) and some metabolic abnormalities (several inflammatory markers). The results of this review underscore the importance of body composition in health and from a clinical perspective, all three body composition compartments should be measured by standardized technologies using regulated diagnostic criteria to identify OSA. Randomized trials and prospective studies in diverse groups of older and younger individuals are necessary to determine if the relationships between OSA and clinical endpoints are causal and reversible through intervention and to uncover the mechanisms.

Liver steatosis in patients with transfusion-dependent thalassaemia

We evaluated the prevalence and the clinical associations of liver steatosis (LS) in patients with transfusion-dependent thalassaemia (TDT). We considered 301 TDT patients (177 females, median age = 40.61 years) enrolled in the Extension-Myocardial Iron Overload in Thalassaemia Network, and 25 healthy subjects. Magnetic resonance imaging was used to quantify iron overload and hepatic fat fraction (FF) by T2* technique and cardiac function by cine images. The glucose metabolism was assessed by the oral glucose tolerance test (OGTT). Hepatic FF was significantly higher in TDT patients than in healthy subjects (median value: 1.48% vs. 0.55%; p = 0.013). In TDT, hepatic FF was not associated with age, gender, serum ferritin levels or liver function parameters, but showed a weak inverse correlation with high-density lipoprotein cholesterol. The 36.4% of TDT patients showed LS (FF >3.7%). Active hepatitis C virus (HCV) infection, increased body mass index and hepatic iron were independent determinants of LS. A hepatic FF >3.53% predicted the presence of an abnormal OGTT. Hepatic FF was not correlated with cardiac iron, biventricular volumes or ejection fractions, but was correlated with left ventricular mass index. In TDT, LS is a frequent finding, associated with iron overload, increased weight and HCV, and conveying an increased risk for the alterations of glucose metabolism.

Loss of mitochondrial adaptation associates with deterioration of mitochondrial turnover and structure in metabolic dysfunction-associated steatotic liver disease

BACKGROUND

Obesity and type 2 diabetes frequently have metabolic dysfunction-associated steatotic liver disease (MASLD) including steatohepatitis (MASH). In obesity, the liver may adapt its oxidative capacity, but the role of mitochondrial turnover in MASLD remains uncertain.

METHODS

This cross-sectional study compared individuals with class III obesity (n = 8/group) without (control, OBE CON; NAFLD activity score: 0.4 ± 0.1) or with steatosis (OBE MASL, 2.3 ± 0.4), or MASH (OBE MASH, 5.3 ± 0.3, p < 0.05 vs. other groups). Hepatic mitochondrial ultrastructure was assessed by transmission electron microscopy, mitochondrial respiration by high-resolution respirometry, biomarkers of mitochondrial quality control and endoplasmic reticulum (ER) stress by Western Blot.

RESULTS

Mitochondrial oxidative capacity was 31 % higher in OBE MASL, but 25 % lower in OBE MASH (p < 0.05 vs. OBE CON). OBE MASH showed ~1.5fold lower mitochondrial number, but ~1.2-1.5fold higher diameter and area (p < 0.001 vs. other groups). Biomarkers of autophagy (p62), mitophagy (PINK1, PARKIN), fission (DRP-1, FIS1) and fusion (MFN1/2, OPA1) were reduced in OBE MASH (p < 0.05 vs. OBE CON). OBE MASL showed lower p62, p-PARKIN/PARKIN, and p-DRP-1 (p < 0.05 vs. OBE CON). OBE MASL and MASH showed higher ER stress markers (PERK, ATF4, p-eIF2α-S51/eIF2α; p < 0.05 vs. OBE CON). Mitochondrial diameter associated inversely with fusion/fission biomarkers and with oxidative capacity, but positively with H2O2.

CONCLUSION

Humans with hepatic steatosis already exhibit impaired mitochondrial turnover, despite upregulated oxidative capacity, and evidence for ER stress. In MASH, oxidative stress likely mediates progressive decline of mitochondrial turnover, ultrastructure and respiration indicating that mitochondrial quality control is key for energy metabolism and may have potential for targeting MASH. ClinGovTrial:NCT01477957.

Clinical correlates of CT imaging-derived phenotypes among lean and overweight patients with hepatic steatosis

The objective of this study is to define CT imaging derived phenotypes for patients with hepatic steatosis, a common metabolic liver condition, and determine its association with patient data from a medical biobank. There is a need to further characterize hepatic steatosis in lean patients, as its epidemiology may differ from that in overweight patients. A deep learning method determined the spleen-hepatic attenuation difference (SHAD) in Hounsfield Units (HU) on abdominal CT scans as a quantitative measure of hepatic steatosis. The patient cohort was stratified by BMI with a threshold of 25 kg/m2 and hepatic steatosis with threshold SHAD ≥  - 1 HU or liver mean attenuation ≤ 40 HU. Patient characteristics, diagnoses, and laboratory results representing metabolism and liver function were investigated. A phenome-wide association study (PheWAS) was performed for the statistical interaction between SHAD and the binary characteristic LEAN. The cohort contained 8914 patients-lean patients with (N = 278, 3.1%) and without (N = 1867, 20.9%) steatosis, and overweight patients with (N = 1863, 20.9%) and without (N = 4906, 55.0%) steatosis. Among all lean patients, those with steatosis had increased rates of cardiovascular disease (41.7 vs 27.8%), hypertension (86.7 vs 49.8%), and type 2 diabetes mellitus (29.1 vs 15.7%) (all p < 0.0001). Ten phenotypes were significant in the PheWAS, including chronic kidney disease, renal failure, and cardiovascular disease. Hepatic steatosis was found to be associated with cardiovascular, kidney, and metabolic conditions, separate from overweight BMI.

Non-invasive hepatic fat quantification: Can multi-echo Dixon help?

Objective

To evaluate the diagnostic accuracy of multi-echo Dixon magnetic resonance imaging (MRI) in hepatic fat quantification, in comparison with that of magnetic resonance spectroscopy (MRS), on 3.0-T MRI.

Materials and Methods

Fifty-five adults with no known liver disease underwent MRI in a 3.0-T scanner for determination of the hepatic fat fraction, with two techniques: multi-echo Dixon, in a manually drawn region of interest (ROI) and in the entire liver parenchyma (automated segmentation); and MRS. The diagnostic accuracy and cutoff value for multi-echo Dixon were determined, with MRS being used as the reference standard.

Results

The mean fat fraction obtained by multi-echo Dixon in the manually drawn ROI and in the entire liver was 5.2 ± 5.8% and 6.6 ± 5.2%, respectively, whereas the mean hepatic fat fraction obtained by MRS was 5.7 ± 6.4%. A very strong positive correlation and good agreement were observed between MRS and multi-echo Dixon, for the ROI (r = 0.988, r2 = 0.978, p < 0.001) and for the entire liver parenchyma (r = 0.960, r2 = 0.922, p < 0.001). A moderate positive correlation was observed between the hepatic fat fraction and body mass index of the participants, regardless of the fat estimation technique employed.

Conclusion

For hepatic fat quantification, multi-echo Dixon MRI demonstrated a very strong positive correlation and good agreement with MRS (often considered the gold-standard noninvasive technique). Because multi-echo Dixon MRI is more readily available than is MRS, it can be used as a rapid tool for hepatic fat quantification, especially when the hepatic fat distribution is not homogeneous.

Triglyceride glucose-waist circumference: the optimum index to screen nonalcoholic fatty liver disease in non-obese adults

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is easily neglected in the non-obese population. TyG index (triglyceride glucose Index) and TG/HDL-c (triglyceride to high-density lipoprotein cholesterol) are new indicators to evaluate insulin resistance (IR). Fibroscan is a non-invasive way to assess hepatic steatosis [by control attenuation parameters (CAP)] and fibrosis [by liver stiffness measurement (LSM)].The purpose of this study was to explore the correlation of TyG and its combination with obesity indicators [TyG-waist circumference (WC), TyG-body mass index (BMI)] and TG/HDL-c with CAP and LSM.

METHOD

One thousand seven hundred seventy-six adults (age ≥ 20 years, BMI < 30 kg/m2) in the National Health and Nutrition Examination Survey (NHANES) 2017-2018 were included. The correlations of CAP and LSM to the indexes were assessed by generalized linear models.. Receiver operating characteristic (ROC) curve was performed to evaluate the diagnostic capability of the indicators on NAFLD and liver stiffness.

RESULTS

Survey-weighted percentage of NAFLD in non-obese was 38.6%. In the fully adjusted models, there were positive associations of TyG, TyG-BMI, TyG-WC and TG/HDL-c to CAP, with the βs of 24.810, 0.704, 0.29 and 2.983 (all p < 0.05), respectively. There were positive associations of TyG, TyG-BMI, TyG-WC, and TG/HDL-c to NAFLD, with ORs of 3.387, 1.03, 1.010 and 1.281 ((all p < 0.05)).The positive association was detected for TG/HDL-c and TyG-WC and LSM with βs of 0.057 and 0.004(p = 0.021 and p = 0.003).TyG-WC were positively associated with liver stiffness with OR of 1.006(95%CI = 1.002, 1.012). Furthermore, the TyG-WC had the strongest diagnostic capability (ROC = 0.806; 95%CI: 0.785-0.826) on NAFLD in non-obese participants, with a specificity of 0.737 and sensitivity of 0.746.

CONCLUSION

In US non-obese population, the TyG, TyG-BMI, TyG-WC, and TG/HDL-c are positively correlated with CAP and NAFLD. TyG-WC has clinical importance in identifying NAFLD in the non-obese population.

Non-alcoholic Steatohepatitis in Asians: Current Perspectives and Future Directions

Non-alcoholic steatohepatitis (NASH) is a subset of non-alcoholic fatty liver disease (NAFLD), which, apart from excess fat in the liver, may be characterised by some level of inflammatory infiltration and fibrogenesis, occasionally progressing to liver cirrhosis or hepatocellular carcinoma (HCC). The objective of the current review is to elucidate the rising prevalence, the role of microbiome and genetics in pathogenesis, diagnostic challenges, and novel treatment alternatives for NASH. Newer diagnostic techniques are being developed since using liver biopsy in a larger population is not a reasonable option and is primarily restricted to clinical research, at least in developing countries. Besides these technical challenges, another important factor leading to deviation from guideline practice is the lack of health insurance coverage in countries like India. It leads to reluctance on the part of physicians and patients to delay required tests to curb out-of-pocket expenditure. There is no cure for NASH, with liver transplantation remaining the last option for those who progress to end-stage liver disease (ESLD) or are detected with early-stage HCC. Thus, lifestyle modification remains the only viable option for many, but compliance and long-term adherence remain major challenges. In obese individuals, bariatric surgery and weight reduction have shown favourable results. In patients with less severe obesity, endoscopic bariatric metabolic therapies (EBMT) are rapidly emerging as less invasive therapies. However, access and acceptability remain poor for these weight reduction methods. Therefore, intense research is being conducted for potential newer drug classes with several agents currently in phase II or III of clinical development. Some of these have demonstrated promising results, such as a reduction in hepatic fat content, and attenuation of fibrosis with an acceptable tolerability profile in phase II studies. The developments in the management of NASH have been fairly encouraging. Further well-designed long-term prospective studies should be undertaken to generate evidence with definitive results.

Metabolic and Risk Profiles of Lean and Non-Lean Hepatic Steatosis among US Adults

Hepatic steatosis can occur in lean individuals, while its metabolic and risk profiles remain unclear. We aimed to characterize the clinical and risk profiles of lean and non-lean steatosis. This cross-sectional study included 1610 patients with transient elastography-assessed steatosis. The metabolic and risk profiles were compared. Compared to their non-lean counterparts, lean subjects with steatosis had a lower degree of fibrosis (F0-F1: 91.9% vs. 80.9%), had a lower prevalence of diabetes (27.9% vs. 32.8%), dyslipidemia (54.7% vs. 60.2%) and hypertension (50.0% vs. 51.3%), and had higher levels of high-density lipoprotein cholesterol while lower fasting insulin and homeostatic model assessment for insulin resistance (all p < 0.05). Of the 16 potential risk factors, being Hispanic was associated with higher odds of non-lean steatosis but not with lean steatosis (odds ratio (OR): 2.07 vs. 0.93), while excessive alcohol consumption had a different trend in the ratio (OR: 1.47 vs.6.65). Higher waist-to-hip ratio (OR: 7.48 vs. 2.45), and higher waist circumference (OR: 1.14 vs. 1.07) showed a stronger positive association with lean steatosis than with non-lean steatosis (all P_{heterogeneity} < 0.05). Although lean individuals with steatosis presented a healthier metabolic profile, both lean and non-lean steatosis had a significant proportion of metabolic derangements. In addition, the etiological heterogeneity between lean and non-lean steatosis may exist.

Perilipin5 protects against non-alcoholic steatohepatitis by increasing 11-Dodecenoic acid and inhibiting the occurrence of ferroptosis

BACKGROUND

Non-alcoholic steatohepatitis (NASH) is a major contributor to liver cirrhosis and hepatocellular carcinoma. There remains no effective pharmacological therapy. The hepatic lipid metabolism and fatty acid β-oxidation are regulated by Perilipin5 (Plin5). However, it is yet unknown how Plin5 affects NASH and the molecular process.

METHODS

High-fat, high-cholesterol and high-fructose (HFHC) diets were used to mimic the progression of NASH in wild type (WT) mice and Plin5 knockout (Plin5 KO) mice. The degree of ferroptosis was measured by detecting the expression of key genes of ferroptosis and the level of lipid peroxide. The degree of NASH was judged by observing the morphology of the liver, detecting the expression of inflammation and fibrosis related genes of liver damage. Plin5 was overexpressed in the liver of mice by tail vein injection of adenovirus, and the process of NASH was simulated by methionine choline deficiency (MCD) diet. The occurrence of ferroptosis and NASH was detected by the same detection method. Targeted lipidomics sequencing was used to detect the difference in free fatty acid expression in the WT Plin5 KO group. Finally, it was verified in cell experiments to further study the effect of free fatty acids on ferroptosis of hepatocytes.

RESULTS

In various NASH models, hepatic Plin5 was dramatically reduced. Plin5 knockout (KO) worsened NASH-associated characteristics in mice given a high-fat/high-cholesterol (HFHC) diet, such as lipid accumulation, inflammation and hepatic fibrosis. It has been shown that ferroptosis is involved in NASH progression. We revealed that Plin5 KO in mice aggravated the degree of ferroptosis in NASH models. Conversely, overexpression of Plin5 significantly alleviated ferroptosis and further ameliorated progression of MCD-induced NASH. Analysis of livers obtained from HFHC diet-fed mice by targeted lipidomics revealed that 11-Dodecenoic acid was significantly decreased in Plin5 KO mice. Addition of 11-Dodecenoia acid to Plin5 knockdown hepatocytes effectively prevented ferroptosis.

CONCLUSION

Our study demonstrates that Plin5 protects against NASH progression by increasing 11-Dodecenoic acid level and further inhibiting ferroptosis, suggesting that Plin5 has therapeutic potential as a target for the management of NASH.

The bidirectional impacts of alcohol consumption and MAFLD for progressive fatty liver disease

Nonalcoholic fatty liver disease (NAFLD), once considered a benign condition, has been associated with several cardiometabolic complications over the past two decades. The worldwide prevalence of NAFLD is as high as 30%. NAFLD requires the absence of a "significant alcohol intake." Conflicting reports have suggested that moderate alcohol consumption may be protective; therefore, the diagnosis of NAFLD previously relied on negative criteria. However, there has been a significant increase in alcohol consumption globally. Apart from the rise in alcohol-related liver disease (ARLD), alcohol, a major toxin, is associated with an increased risk of several cancers, including hepatocellular carcinoma. Alcohol misuse is a significant contributor to disability-adjusted life years. Recently, the term metabolic dysfunction-associated fatty liver disease (MAFLD) was proposed instead of NAFLD to include the metabolic dysfunction responsible for the major adverse outcomes in patients with fatty liver disease. MAFLD, dependent on the "positive diagnostic criteria" rather than previous exclusion criteria, may identify individuals with poor metabolic health and aid in managing patients at increased risk of all-cause and cardiovascular mortality. Although MAFLD is less stigmatizing than NAFLD, excluding alcohol intake may increase the risk of already existing underreported alcohol consumption in this subgroup of patients. Therefore, alcohol consumption may increase the prevalence of fatty liver disease and its associated complications in patients with MAFLD. This review discusses the effects of alcohol intake and MAFLD on fatty liver disease.

The interaction of T2DM and BMI with NASH in recipients of liver transplants: an SRTR database analysis

BACKGROUND

NASH-related liver transplants are increasing because of the obesity epidemic, but the influence of T2DM on various levels of BMI among NASH recipients is unclear.

RESEARCH DESIGN AND METHODS

We analyzed data retrieved from SRTR on 4,515 patients. We divided patients by BMI into five groups: normal weight; overweight; class 1 obesity; class 2 obesity; and class 3 obesity. Statistical analysis was done.

RESULTS

Patients in the NASH group with T2DM had a lower patient and graft survival than patients without T2DM (5-year patient and graft survival: 77.5% vs. 79.8%; P = 0.001 and 76.4% vs. 78.2%; P = 0.002, respectively). Multivariate Cox proportional regression showed an independent association between T2DM and decreased patient and graft survival (HR, 1.170; P = 0.015 and HR, 1.133; P = 0.048, respectively). In the lean and the class 3 obesity NASH groups, patients with T2DM had lower patient and graft survival than the patients without T2DM. In the class 3 obesity NASH group, T2DM was independently associated with decreased patient survival (HR, 1.581; P = 0.027).

CONCLUSION

Our research reveals that the focus of the post-transplantation treatment should be different for different BMI patients.

Utility of Human Relevant Preclinical Animal Models in Navigating NAFLD to MAFLD Paradigm

Fatty liver disease is an emerging contributor to disease burden worldwide. The past decades of work established the heterogeneous nature of non-alcoholic fatty liver disease (NAFLD) etiology and systemic contributions to the pathogenesis of the disease. This called for the proposal of a redefinition in 2020 to that of metabolic dysfunction-associated fatty liver disease (MAFLD) to better reflect the current understanding of the disease. To date, several clinical cohort studies comparing NAFLD and MAFLD hint at the relevancy of the new nomenclature in enriching for patients with more severe hepatic injury and extrahepatic comorbidities. However, the underlying systemic pathogenesis is still not fully understood. Preclinical animal models have been imperative in elucidating key biological mechanisms in various contexts, including intrahepatic disease progression, interorgan crosstalk and systemic dysregulation. Furthermore, they are integral in developing novel therapeutics against MAFLD. However, substantial contextual variabilities exist across different models due to the lack of standardization in several aspects. As such, it is crucial to understand the strengths and weaknesses of existing models to better align them to the human condition. In this review, we consolidate the implications arising from the change in nomenclature and summarize MAFLD pathogenesis. Subsequently, we provide an updated evaluation of existing MAFLD preclinical models in alignment with the new definitions and perspectives to improve their translational relevance.

Non-alcoholic fatty liver disease (NAFLD) in lean individuals - Single centre large cohort clinicopathologic and immunophenotypic study

BACKGROUND

Non-alcoholic fatty liver disease is one of the most common causes of chronic liver diseases and occurs even in lean individuals having normal or low body mass index (BMI). Crucial issue is understanding the clinical, pathobiologic and metabolic characteristics in comparison to obese patients. Very few studies have compared clinicopathological characteristics between lean and obese. Published literature is generally in a small cohort of patients, rarely included over-weight as separate category, and most often had non-standardized use of BMI criteria with discordant conclusions. There is very sparse published literature on liver biopsy-confirmed cohort and that to from Asia; also, none had explored the role of mediators such as stellate cells, progenitor cells and macrophages.

AIMS

To evaluate the prevalence of NAFLD in lean patients in a large cohort of histology-confirmed NAFLD, and explore clinico-pathological spectrum of lean NAFLD in comparison to over-weight and obese. Also, to investigate role of hepatic stellate cells, macrophage polarization and their relation to hepatic progenitor cells, in particular the relation to fibrosis and to different BMI categories.

METHODS

Prospective analysis of eleven-year retrospective cross-sectional data of all consecutive patients of NAFLD diagnosed in the period between the year 2011 and 2021. All histologically confirmed cases of NAFLD fulfilling inclusion and exclusion criteria were stratified to three groups according to BMI based on Asian criteria. Demographic, lab, metabolic, and histological comparisons between lean and overweight-obese patients were performed. Histological grading and staging of NAFLD components were performed by NAS-CRN score. Immunohistochemical and image analysis-based assessment and quantification of stellate cells, progenitor cells, and macrophage polarization was performed. Appropriate statistical methods were applied, and study was approved by the Institutional ethics committee.

RESULTS

Lean patients with biopsy-proven diagnosis constituted 21 % (n = 267) of total NAFLD (n = 1273). Other groups were-over-weight patients (232;18.2 %), and the highest were obese patients (774; 60.8 %). 13.9 % of the lean patients with NAFLD were under-weight with BMI<18.5 kg/m2. Lean patients had significantly lower BMI and waist circumference along with lesser fasting glucose levels in comparison to the other groups. Rest of the metabolic parameters were nearly similar. Lean patients showed higher serum ALT levels, and histological characteristics such as ballooning of hepatocytes and steatosis were also more marked in comparison to other groups. Lobular inflammation and advanced fibrosis were significantly less common in lean patients with NASH related cirrhosis found in only 20.9 % of them. Immunophenotypic studies revealed the inter-relationship of HPCs, HSCs, and macrophages was influenced by the stage of fibrosis and not by the BMI.

CONCLUSIONS

Prevalence of NAFLD in lean individuals in a histological-confirmed patient cohort was 21 %. (n = 267/1273). Major strengths of this study are large cohort of lean individuals from a single center, inclusion of only histology-confirmed cases, Asia specific BMI criteria usage, comparative clinical, metabolic, immune-morphologic and image analysis-based characterization, inclusion of over-weight in addition to obese patients, and investigating cross-talk of principal patho-physiologic markers.

Hepatocyte Mitochondrial Dynamics and Bioenergetics in Obesity-Related Non-Alcoholic Fatty Liver Disease

PURPOSE OF THE REVIEW

Mitochondrial dysfunction has long been proposed to play a crucial role in the pathogenesis of a considerable number of disorders, such as neurodegeneration, cancer, cardiovascular, and metabolic disorders, including obesity-related insulin resistance and non-alcoholic fatty liver disease (NAFLD). Mitochondria are highly dynamic organelles that undergo functional and structural adaptations to meet the metabolic requirements of the cell. Alterations in nutrient availability or cellular energy needs can modify their formation through biogenesis and the opposite processes of fission and fusion, the fragmentation, and connection of mitochondrial network areas respectively. Herein, we review and discuss the current literature on the significance of mitochondrial adaptations in obesity and metabolic dysregulation, emphasizing on the role of hepatocyte mitochondrial flexibility in obesity and NAFLD.

RECENT FINDINGS

Accumulating evidence suggests the involvement of mitochondrial morphology and bioenergetics dysregulations to the emergence of NAFLD and its progress to non-alcoholic steatohepatitis (NASH). Most relevant data suggests that changes in liver mitochondrial dynamics and bioenergetics hold a key role in the pathogenesis of NAFLD. During obesity and NAFLD, oxidative stress occurs due to the excessive production of ROS, leading to mitochondrial dysfunction. As a result, mitochondria become incompetent and uncoupled from respiratory chain activities, further promoting hepatic fat accumulation, while leading to liver inflammation, insulin resistance, and disease's deterioration. Elucidation of the mechanisms leading to dysfunctional mitochondrial activity of the hepatocytes during NAFLD is of predominant importance for the development of novel therapeutic approaches towards the treatment of this metabolic disorder.

Association between non-alcoholic fatty liver disease and metabolically healthy deterioration across different body shape phenotypes at baseline and change patterns

Non-alcoholic fatty liver disease (NAFLD) is a hepatic manifestation of metabolic syndrome (MetS), and the relationship between NAFLD and metabolic deterioration remains unclear. This study aimed to investigate dynamic changes in metabolically healthy phenotypes and to assess the impact of non-alcoholic fatty liver disease (NAFLD) on the conversion from metabolically healthy (MH) to metabolically unhealthy (MU) phenotypes across body shape phenotypes and phenotypic change patterns. We defined body shape phenotypes using both the body mass index (BMI) and waist circumference (WC) and defined metabolic health as individuals scoring ≤ 1 on the NCEP-ATP III criteria, excluding WC. A total of 12,910 Chinese participants who were MH at baseline were enrolled in 2013 and followed-up in 2019 or 2020. During a median follow-up of 6.9 years, 27.0% (n = 3,486) of the MH individuals developed an MU phenotype. According to the multivariate Cox analyses, NAFLD was a significant predictor of conversion from the MH to MU phenotype, independent of potential confounders (HR: 1.12; 95% confidence interval: 1.02–1.22). For the MH-normal weight group, the relative risk of NAFLD in phenotypic conversion was 1.21 (95% CI 1.03–1.41, P = 0.017), which was relatively higher than that of MH-overweight/obesity group (HR: 1.14, 95% CI 1.02–1.26, P = 0.013). Interestingly, the effect of NAFLD at baseline on MH deterioration was stronger in the “lean” phenotype group than in the “non-lean” phenotype group at baseline and in the “fluctuating non-lean” phenotype change pattern group than in the “stable non-lean” phenotype change pattern group during follow-up. In conclusion, lean NAFLD is not as benign as currently considered and requires more attention during metabolic status screening.

Clinical Factors Associated with Non-Obese Nonalcoholic Fatty Liver Disease Detected among US Adults in the NHANES 2017-2018

NAFLD can occur in non-obese individuals with BMI < 25 kg/m2. Our goal was to examine the prevalence and clinical factors associated with non-obese NAFLD using vibration-controlled transient elastography (VCTE) with controlled attenuation parameter which estimates steatosis and fibrosis among US adults. We aggregated data from the 2017−2018 cycle of NHANES and included adults (age ≥ 20 years) with BMI < 25 kg/m2 with complete data for the survey, medical examination, and VCTE along with controlled attenuation parameter (CAP). We excluded participants with risks of other liver diseases. We considered patients to have non-obese NAFLD if CAP was >285 dB/m, or non-obese NAFLD fibrosis if this CAP criteria was met and liver stiffness was >8.6 kPa. We calculated the adjusted OR and 95% CI for associations with non-obese NAFLD using multivariable logistic regression. The prevalence of non-obese NAFLD was 6.2% and Asian Americans (12.2%) had the highest non-obese NAFLD prevalence. Clinical factors associated with non-obese NAFLD were advanced age and metabolic syndrome (ORadjusted = 6.8, 95% CI 3.0−15.5). In a separate model, we found elevated glucose (ORadjusted = 4.1, 95% CI 2.1−7.9), triglycerides (ORadjusted = 3.8, 95% CI 1.7−8.5), and truncal fat (100-unit increase ORadjusted = 1.07, 95% CI: 1.04−1.10) were associated with higher odds of non-obese NAFLD. Meanwhile, low physical activity (ORadjusted = 2.9, 95% CI 1.2−7.1) was also positively associated with non-obese NAFLD. Non-obese NAFLD is prevalent in the US and is highly associated with metabolic conditions and syndrome. Our results support the importance of considering racial/ethnic differences when investigating NAFLD in a clinical setting.

Clinical and Laboratory Characteristics of Normal Weight and Obese Individuals with Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) has had, over the past few decades, a progressively growing prevalence among the general population all over the world, in parallel with metabolic conditions such as type 2 diabetes mellitus (T2DM), dyslipidemia, and obesity. However, NAFLD is also detected in 10−13% of subjects with a body mass index (BMI) ≤ 25 kg/m² (lean-NAFLD), whose major risk factors remain unknown. In this study, we aimed to characterize the clinical features and associated risk factors of lean-NAFLD in comparison with obese-NAFLD patients. Consecutive patients diagnosed with NAFLD by vibration-controlled transient elastography and controlled attenuation parameter were prospectively enrolled. Biological and clinical data obtained from the participants were stratified according to their BMI in two groups: lean-NAFLD and obese-NAFLD. In total, 331 patients (56.8% males) were included in the final analysis. Most of the subjects were obese-NAFLD (n = 258, 77.9%) and had a higher prevalence of T2DM, dyslipidemia, and components of the metabolic syndrome, together with abnormal biological parameters. Regarding liver stiffness measurements, the proportion of subjects with at least significant fibrosis (≥F2) was approximately twofold higher among obese-NAFLD (43.81%) in comparison with lean-NAFLD patients (23.29%). Moreover, obese individuals had a higher risk for liver fibrosis (OR = 2.6, 95%, CI 1.5−4.42, p < 0.001) than lean individuals. Although associated metabolic conditions and at least significant liver fibrosis were present in approximately one-quarter of the patients, these were more frequent among obese-NAFLD patients. Therefore, individualized screening strategies for NAFLD should be established according to BMI.

Comparison in the development of colorectal cancer after screening colonoscopy between elderly and younger population

BACKGROUND AND AIMS

This study aimed to evaluate and compare the incidence of colorectal cancer (CRC) in elderly participants aged ≥75 years and those <75 years who had previously undergone a colonoscopy.

METHODS

This retrospective cohort study was conducted at the Center for Preventive Medicine at St. Luke's International Hospital in Japan. All participants who underwent screening colonoscopy between 2005 and 2015 were included and followed up until 2020. Our primary outcome was the identification of CRC as confirmed by pathology after screening colonoscopy. We compared the development of CRC between the two groups using survival analyses. A sub-analysis to evaluate the incidence of CRC among participants with and without neoplastic polyp resection at initial colonoscopy was also performed.

RESULTS

A total of 8350 participants were enrolled; the median follow-up period was 2982 days (interquartile range:1932-4141), mean age was 52.5 years (SD: 11.5) and 5274 (61.3%) participants were men. The incidence of CRC during the follow-up period was 82 (0.95%) among all participants and 11 (4.31%) among the elderly participants. Elderly participants showed a significantly higher incidence of CRC than the other group [hazard ratio, 2.56; 95% confidence interval (CI), 1.14-5.75]. The sub-analysis showed that out of 2878 participants with a neoplastic polyp at the initial colonoscopy, 52 (1.81%) developed CRC (hazard ratio, 2.85; 95% CI, 1.16-6.98).

CONCLUSIONS

A repeat colonoscopy might be warranted in people with high activities of daily living and few comorbidities, especially if there is a history of neoplastic polypectomy at the first colonoscopy.

Serum anandamide level as a potential indicator for nonalcoholic fatty liver disease severity

INTRODUCTION AND AIM

Nonalcoholic fatty liver disease (NAFLD) is a very common disease, ranging from simple steatosis to nonalcoholic steatohepatitis (NASH) and is considered the hepatic expression of metabolic syndrome. Liver biopsy is currently considered the gold standard in diagnosis of NAFLD; however, it is an invasive technique and carries many risks. The serum anandamide level is recently discovered to play an important role as the potential indicator for NAFLD severity. The purpose of the study is to determine the association of endocannabinoid metabolite anandamide and NAFLD severity and to investigate its association with anthropometric and metabolic features in NAFLD patients.

METHODOLOGY

A case-control study on 36 NAFLD biopsy-proven NAFLD patients and 15 healthy volunteers. They were subjected to full clinical history and examination, laboratory tests, abdominal ultrasound and serological testing of anadamide.

RESULTS

The anadamide level was significantly higher among NAFLD subgroups (simple steatosis and NASH) vs. the normal group (1.1, 0.29 vs. 0.2 P value = 0.00085), with cutoff 0.58 in the NASH group (accuracy 89%; sensitivity 66% and specificity 100%) (P value < 0.01).

CONCLUSION

Anandamide could be a specific serum marker for NASH and can be used to detect NAFLD severity.

Risk factors of nonalcoholic fatty liver disease in lean body mass population: A systematic review and meta-analysis

The pathophysiology and risk factors of nonalcoholic fatty liver disease (NAFLD) among lean patients is poorly understood and therefore investigated. We performed a meta-analysis of observational studies. Of 1175 articles found through searching from Medline/PubMed, Banglajol, and Google Scholar by two independent investigators, 22 were selected. Data from lean (n = 6768) and obese (n = 9253) patients with NAFLD were analyzed; lean (n = 43 398) and obese (n = 9619) subjects without NAFLD served as controls. Age, body mass index, waist circumference, systolic blood pressure, and diastolic blood pressure (DBP) had significantly higher estimates in lean NAFLD patients than in lean non-NAFLD controls. Fasting blood sugar [MD(mean difference) 5.17 mg/dl, 95% CI(confidence interval) 4.14-6.16], HbA1c [MD 0.29%, 95% CI 0.11-0.48], and insulin resistance [HOMA-IR] [MD 0.49 U, 95% CI 0.29-0.68]) were higher in lean NAFLD patients than in lean non-NAFLD controls. All components of the lipid profile were raised significantly in the former group except high-density lipoprotein. An increased uric acid (UA) level was found to be associated with the presence of NAFLD among lean. Cardio-metabolic profiles of nonlean NAFLD patients significantly differs from the counter group. However, the magnitude of the difference of lipid and glycemic profile barely reached statistical significance when subjects were grouped according to lean and nonlean NAFLD. But DBP (slope: 0.19, P < 0.037), HOMA-IR (slope: 0.58, P < 0.001), and UA (slope: 0.36, P = 0.022) were significantly higher if NAFLD was present compared to that of non-NAFLD group. Lean and nonlean NAFLD patients are metabolically similar and share common risk factors.

Modified AST to platelet ratio index improves APRI and better predicts advanced fibrosis and liver cirrhosis in patients with non-alcoholic fatty liver disease

AIMS

Advanced fibrosis (AF) and liver cirrhosis (LC) are important milestones in non-alcoholic fatty liver disease (NAFLD). FIB-4, NFS and BARD are validated scores with good accuracy in detecting AF and LC. APRI does not have similar predictive accuracy. While a modification (m-APRI) improves its use in viral hepatitis, this has yet to be evaluated in NAFLD. This study compares diagnostic performance of aforementioned scores in predicting AF and LC in NAFLD.

METHODS

Consecutive NAFLD patients undergoing Transient Elastography (TE) using Echosens® Fibroscan® for fibrosis staging were included. Cut-off liver stiffness measurements for AF and LC were 7.9 kPa and 11.5 kPa respectively. Anthropometric and laboratory tests done within 3 months were used. Diagnostic performances of scores were analyzed by standard statistical tests.

RESULTS

161 patients qualified for the study. Mean age was 60.2 ± 14 years, BMI 26.8 ± 4.6 kg/m². M-probe was used in 113, XL in 48. Optimal cut-offs of m-APRI for AF and LC were 5.84 and 9 respectively. Area under receiver operator characteristic curves (AUROC) for prediction of AF at optimal cut-off points were m-APRI 0.84, APRI 0.80, FIB-4: 0.77, NFS 0.77 and BARD 0.65. For prediction of LC, AUROC were m-APRI: 0.83, APRI: 0.76, FIB-4: 0.81, NFS: 0.77 and BARD: 0.66. m-APRI was significantly superior to all scores compared in detecting AF (p < 0.05 for all) and superior to APRI (p = 0.008) and BARD (p = 0.007) in predicting LC. There was no significant difference between m-APRI and FIB-4 or NFS in prediction of LC.

CONCLUSIONS

For prediction of AF in NAFLD, m-APRI outperforms BARD, APRI, NFS and FIB-4, while for the prediction of cirrhosis, m-APRI is superior to APRI and BARD but comparable to NFS and FIB-4.

Lean NAFLD: an underrecognized and challenging disorder in medicine

Classically, Non-Alcoholic Fatty Liver Disease (NAFLD) has been thought to be driven by excessive weight gain and obesity. The overall greater awareness of this disorder has led to its recognition in patients with normal body mass index (BMI). Ongoing research has helped to better understand potential causes of Lean NAFLD, the risks for more advanced disease, and potential therapies. Here we review the recent literature on prevalence, risk factors, severity of disease, and potential therapeutic interventions.

Prevalence, Predictors, and Severity of Lean Nonalcoholic Fatty Liver Disease in Patients Living With Human Immunodeficiency Virus

BACKGROUND

The burden of nonalcoholic fatty liver disease (NAFLD) is growing in people living with human immunodeficiency virus (HIV). NAFLD is associated with obesity; however, it can occur in normoweight (lean) patients. We aimed to investigate lean NAFLD in patients living with HIV.

METHODS

We included patients living with HIV mono-infection from 3 prospective cohorts. NAFLD was diagnosed by transient elastography (TE) and defined as controlled attenuation parameter ≥248 dB/m, in absence of alcohol abuse. Lean NAFLD was defined when a body mass index was <25 kg/m2. Significant liver fibrosis was defined as TE ≥7.1 kPa. The presence of diabetes, hypertension, or hyperlipidemia defined metabolically abnormal patients.

RESULTS

We included 1511 patients, of whom 57.4% were lean. The prevalence of lean NAFLD patients in the whole cohort was 13.9%. NAFLD affected 24.2% of lean patients. The proportions of lean NAFLD patients who were metabolically abnormal or had elevated alanine aminotransferase (ALT) were higher than among those who were lean patients without NAFLD (61.9% vs 48.9% and 36.7% vs 24.2%, respectively). Lean NAFLD patients had a higher prevalence of significant liver fibrosis than lean patients without NAFLD (15.7% vs 7.6%, respectively). After adjusting for sex, ethnicity, hypertension, CD4 cell count, nadir CD4 <200µ/L, and time since HIV diagnosis, predictors of NAFLD in lean patients were age (adjusted OR [aOR], 1.29; 95% confidence interval [CI], 1.04-1.59), high triglycerides (aOR, 1.34; 95% CI, 1.11-1.63), and high ALT (aOR, 1.15; 95% CI, 1.05-1.26), while a high level of high-density lipoprotein cholesterol was protective (aOR, 0.45; 95% CI, .26-.77).

CONCLUSIONS

NAFLD affects 1 in 4 lean patients living with HIV mono-infection. Investigations for NAFLD should be proposed in older patients with dyslipidemia and elevated ALT, even if normoweight.

Seeing the fetus from a DOHaD perspective: discussion paper from the advanced imaging techniques of DOHaD applications workshop held at the 2019 DOHaD World Congress

Advanced imaging techniques are enhancing research capacity focussed on the developmental origins of adult health and disease (DOHaD) hypothesis, and consequently increasing awareness of future health risks across various subareas of DOHaD research themes. Understanding how these advanced imaging techniques in animal models and human population studies can be both additively and synergistically used alongside traditional techniques in DOHaD-focussed laboratories is therefore of great interest. Global experts in advanced imaging techniques congregated at the advanced imaging workshop at the 2019 DOHaD World Congress in Melbourne, Australia. This review summarizes the presentations of new imaging modalities and novel applications to DOHaD research and discussions had by DOHaD researchers that are currently utilizing advanced imaging techniques including MRI, hyperpolarized MRI, ultrasound, and synchrotron-based techniques to aid their DOHaD research focus.

A significant association of non-obese non-alcoholic fatty liver disease with osteosarcopenic obesity in females 50 years and older

BACKGROUND & AIMS

Osteosarcopenic obesity (OSO) encompassing obesity, sarcopenia and osteopenia, is due to redistribution or infiltration of fat into muscle and bone. This cross-sectional study evaluated the association between OSO and non-alcoholic fatty liver disease (NAFLD).

METHODS

Obesity, sarcopenia and osteopenia was defined using the percentage of body fat mass, reduced muscle mass, and the percentage of young adult mean < 80%, measured by dual-energy x-ray absorptiometry, respectively. Non-obese and obese NAFLD was diagnosed by ultrasound and body mass index cut-off point (25 kg/m²). A total of 619 subjects ≥ 50 years who completed health checkups were divided into obesity group including OSO and sarcopenic obesity (SO) alone phenotype, and non-obesity group that did not belong to any phenotype, including standard (St).

RESULTS

Overall osteopenia and OSO were detected in only 10% and 1% in males, compared with 45% and 9% in females, respectively. Multivariate analysis for females demonstrated a significant association of OSO with non-obese NAFLD (odds ratio = 3.737, 95% confidence interval = 1.365-10.233, P = 0.010), while the association between SO alone and non-obese NAFLD was equivocal. The OSO phenotype had a significantly higher proportion of slower walking speed and weaker grip strength, compared to the St phenotype. The proportion of OSO increased with age in contrast to constant prevalence of non-obese NAFLD.

CONCLUSION

Non-obese NAFLD had a significant association with OSO in females, independent of plausible confounders. These results suggest that non-obese NAFLD might be an independent risk factor for OSO.

The metabolic profiles and body composition of lean metabolic associated fatty liver disease

BACKGROUND/PURPOSE

Metabolic associated fatty liver disease (MAFLD) is the commonest cause of chronic liver disease, which is associated with obesity and diabetes. However, it also occurs in lean individuals especially in Asian populations.

METHODS

The participants of Tzu Chi MAFLD cohort (TCMC) including health controls or MAFLD patients were enrolled. MAFLD was defined as fatty liver in imaging without hepatitis B virus, hepatitis C virus infection, drug, alcohol or other known causes of chronic liver disease. Lean MAFLD was defined as MAFLD in lean subjects (BMI < 23 kg/m²).

RESULTS

A total of 880 subjects were included for final analysis. Of 394 MAFLD patients, 65 (16.5%) patients were diagnosed as lean MAFLD. Lean MAFLD patients were elder, higher percentage of female gender, lower ALT, diastolic blood pressure, triglyceride, and waist circumference but higher HDL than non-lean MAFLD patients. Using binary regression analysis, elder age and lower waist circumference were associated with lean MAFLD. Compared with lean healthy controls, lean MAFLD patients had higher BMI, waist circumference, and percentage of hypertension. In body composition, fatty tissue index (FTI), lean tissue index (LTI) ,and total body water (TBW) were lower in lean MAFLD than non-lean MAFLD patients; but they were comparable with lean healthy controls.

CONCLUSIONS

The prevalence of lean MAFLD was 16.5% in this study population and it was higher in elder age, especially of female subjects. Lean MAFLD patients had different metabolic profiles compared with lean healthy controls, but different body composition compared with non-lean MAFLD patients.

Association between the Frequency of Daily Toothbrushing and Development of Nonalcoholic Fatty Liver Disease

Background &amp; Aim: This study aimed to evaluate the association between the frequency of daily toothbrushing and the development of nonalcoholic fatty liver disease (NAFLD).

METHODS

A retrospective longitudinal study was conducted from 2005 to 2012 at the Center for Preventive Medicine at St. Luke's International Hospital, Japan. Data on all participants who underwent a health checkup during the study period were collected. NAFLD was diagnosed by abdominal ultrasonography, and all participants who were diagnosed with NAFLD at the time of their initial visit, consumed alcohol in any amount, or had received only one health checkup were excluded. The questionnaire for the frequency of daily toothbrushing was conducted as part of health checkups. The primary outcome was the risk of developing NAFLD according to the frequency of daily toothbrushing (1-2 times a day or 3 times a day) compared to those who brush teeth once or less than once a day.

RESULTS

Data were collected from 25,804 people. A total of 3,289 (12.7%) participants developed NAFLD. The mean age was 45.2 years, and 6,901 (26.7%) of the participants were male. The risk of developing NAFLD significantly decreased with increased frequency of daily toothbrushing. Adjusted odds ratios (ORs) are as follows: brushing teeth 1-2 times a day (OR: 0.85, 95% confidence interval [CI]: 0.77-0.95) and 3 times a day (OR: 0.74, 95% CI: 0.67-0.82).

CONCLUSION

Frequent toothbrushing was shown to significantly reduce the risk of developing NAFLD.

NAFLD in type 2 diabetes mellitus: Still many challenging questions

Epidemiologic data consistently show that in patients with type 2 diabetes (T2DM) the prevalence of non-alcoholic fatty liver disease (NAFLD), including advanced fibrosis, is double compared to the general population, and it associates with high risk of liver-related morbidity (advanced fibrosis, hepatocellular carcinoma) and mortality, but also with other systemic consequences, such as cardiovascular (CV) disease, chronic kidney disease, and overall mortality. There are still many answers that need to be clarified regarding NAFLD in T2DM, including deciphering the complex pathogenetic mechanisms, the intertwined relationships with the extrahepatic organs and tissues (mainly heart, kidneys, adipose tissue, gut), the prognostic value of NAFLD for CV risk stratification, and more importantly, what would be the most appropriate screening algorithm, diagnostic method and therapeutic approach. We advocate here for proactive action, in order to identify NAFLD in a timely manner, and suggest a simple algorithm to be used in clinical practice, based on risk stratification and on experts' opinions. We discuss the current therapeutic options for NAFLD in T2DM, for which a multifactorial approach is needed, that concomitantly addresses the liver and the cardio-reno-metabolic disturbances.

Shifting perspectives – interplay between non-alcoholic fatty liver disease and insulin resistance in lean individuals

Non-alcoholic fatty liver disease (NAFLD) has become a significant public health burden affecting not only obese individuals but also people with normal weight. As opposed to previous beliefs, this particular subset of patients has an increased risk of all-cause mortality and worse outcomes than their obese counterparts. The development of NAFLD in lean subjects seems to be interconnected with metabolic phenotype, precisely visceral fat tissue, sarcopenia, and insulin resistance. Here, we summarize available data focusing on the co-dependent relationship between metabolic phenotype, insulin resistance, and development of NAFLD in lean individuals, suggesting more appropriate tools for measuring body fat distribution for the screening of patients at risk.

Oxidative Stress in NAFLD: Role of Nutrients and Food Contaminants

Non-alcoholic fatty liver disease (NAFLD) is often the hepatic expression of metabolic syndrome and its comorbidities that comprise, among others, obesity and insulin-resistance. NAFLD involves a large spectrum of clinical conditions. These range from steatosis, a benign liver disorder characterized by the accumulation of fat in hepatocytes, to non-alcoholic steatohepatitis (NASH), which is characterized by inflammation, hepatocyte damage, and liver fibrosis. NASH can further progress to cirrhosis and hepatocellular carcinoma. The etiology of NAFLD involves both genetic and environmental factors, including an unhealthy lifestyle. Of note, unhealthy eating is clearly associated with NAFLD development and progression to NASH. Both macronutrients (sugars, lipids, proteins) and micronutrients (vitamins, phytoingredients, antioxidants) affect NAFLD pathogenesis. Furthermore, some evidence indicates disruption of metabolic homeostasis by food contaminants, some of which are risk factor candidates in NAFLD. At the molecular level, several models have been proposed for the pathogenesis of NAFLD. Most importantly, oxidative stress and mitochondrial damage have been reported to be causative in NAFLD initiation and progression. The aim of this review is to provide an overview of the contribution of nutrients and food contaminants, especially pesticides, to oxidative stress and how they may influence NAFLD pathogenesis.

Diagnostic performance of fibroscan and computed tomography in 322 normal alanine aminotransferase non-obese non-alcoholic fatty liver disease patients diagnosed by ultrasound

AIMS OF THE STUDY

To compare the evaluation of various non-invasive examination include ultrasound, fibroscan and computed tomography (CT) in normal alanine aminotransferase (ALT) non-obese patients, to analyse the consistency and advantages among these non-invasive examination in non-alcoholic fatty liver disease (NAFLD) patients.

METHODS USED TO CONDUCT THE STUDY

About 322 cases of non-obese NAFLD patients (BMI < 25 kg/m² ) with normal ALT were enroled. All patients were diagnosed with fatty liver by abdominal ultrasonography. Meanwhile, computed tomography and fibroscan were used to evaluate the existence and severity of fatty liver.

RESULTS OF THE STUDY

A 47.52% and 67.70% patients who diagnosed as NAFLD by ultrasound were unable to be diagnosed with fatty liver in accordance with the standard of controlled attenuation parameter (CAP) value by fibroscan and liver/spleen density ratio (L/S ratio) by CT. The evaluation of NAFLD by CAP standard were influenced by several factors, while only age and Triglyceride (TG) may affect the judgement of fatty liver when CT was used. Liver stiffness measurement (LSM) affects the diagnostic coincidence rate of fibroscan, CT and ultrasound. Statistical difference could be found among different LSM groups in the severity of NAFLD evaluated by Fibroscan and CT.

CONCLUSIONS DRAWN FROM THE STUDY AND CLINICAL IMPLICATIONS

There is a discrepancy in the evaluation NAFLD by fibroscan, CT and ultrasound. LSM may affect the diagnostic coincidence rate of fibroscan, CT and ultrasound. Non-invasive assessment model including multiple clinical data and image results should be investigated in evaluating the degree of NAFLD. Interpretation of the diagnostic results about fibroscan, CT and ultrasound in the evaluation of NAFLD should take into account the specific clinical data of each patient.

Effects of Dietary and Lifestyle Interventions on Liver, Clinical and Metabolic Parameters in Children and Adolescents with Non-Alcoholic Fatty Liver Disease: A Systematic Review

Non-alcoholic fatty liver disease (NAFLD) affects 5.5–10.3% of children worldwide, while in obese individuals, it increases to almost 34%. Pediatric NAFLD is consistently associated with metabolic syndrome and insulin resistance. As no pharmacological agents exist for the treatment of NAFLD, lifestyle modifications remain the only therapy. However, as not all overweight/obese children have NAFLD, high-quality data, focused exclusively on NAFLD population are needed. Therefore, the present systematic review assessed the efficacy of lifestyle (diet or exercise) based on randomized controlled clinical trials (RCTs) on liver, anthropometric, glucose, and lipid parameters in children, with imaging or biopsy-proven NAFLD. In general, the results were inconclusive and therefore no specific recommendations could be drawn. In most studies, differences were derived from within group comparisons, which are known to be highly misleading. However, both low-carbohydrate and low-fat diets could benefit liver outcomes, as long as weight loss is achieved, but not necessary glucose and lipid parameters. No RCTs were found on exercise alone, as compared to no intervention on pediatric NAFLD. Concerning diet plus exercise interventions, all studies led to improvements in liver outcomes accompanied with weight loss. Resolution of NAFLD was found in considerably high percentages, while improvements were also seen in glucose but were modest in lipid parameters.

Characterization of biopsy proven non-alcoholic fatty liver disease in healthy non-obese and lean population of living liver donors: The impact of uric acid

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is frequently seen among non-obese overweight individuals and lean subjects (those with normal body mass index). This study aimed to investigate prevalence and risk factors of biopsy proven NAFLD in a cluster of healthy non-obese and lean individuals.

METHODS AND MATERIALS

In a retrospective study, adult (>18 years) apparently healthy individuals who had donated liver to pediatric patients between July 2012 and October 2018 were included. Non-obese and lean individuals were defined as BMI<30kg/m² and BMI<25kg/m², respectively.

RESULTS

Totally 310 patients were included. Seventy-six individuals (24.5%) had NAFL and 30 patients (9.67%) had non-alcoholic steatohepatitis (NASH) among non-obese population. In multivariate regression analysis, only higher BMI was marginally associated with NASH in non-obese compared to those without NASH (Odds ratio: 2.52, 95% CI: 0.097-6.54; P=0.05). Totally, 246 individuals were lean. 55 individuals (22.3%) had NAFL and 20 individuals (8.2%) had NASH in their liver biopsies. In univariate analysis, serum triglyceride, cholesterol, LDL, ALT, alkaline phosphatase and uric acid were associated with NAFL among lean individuals (P<0.05). In regression analysis, serum uric acid was associated with NAFL (Odds ratio: 1.70, 95% CI: 1.18-2.45; P=0.004) and NASH in lean individuals (Odds ratio: 1.98, 95% CI: 1.27-3.10; P=0.003).

CONCLUSION

NAFLD/NASH is prevalent even in a healthy lean population when evaluated by liver biopsy. Higher BMI and serum uric acid were two major risks of NAFLD/NASH in non-obese and lean individuals.

Current and Future Treatments in the Fight Against Non-Alcoholic Fatty Liver Disease

Obesity is recognised as a risk factor for many types of cancers, in particular hepatocellular carcinoma (HCC). A critical factor in the development of HCC from non-alcoholic fatty liver disease (NAFLD) is the presence of non-alcoholic steatohepatitis (NASH). Therapies aimed at NASH to reduce the risk of HCC are sparse and largely unsuccessful. Lifestyle modifications such as diet and regular exercise have poor adherence. Moreover, current pharmacological treatments such as pioglitazone and vitamin E have limited effects on fibrosis, a key risk factor in HCC progression. As NAFLD is becoming more prevalent in developed countries due to rising rates of obesity, a need for directed treatment is imperative. Numerous novel therapies including PPAR agonists, anti-fibrotic therapies and agents targeting inflammation, oxidative stress and the gut-liver axis are currently in development, with the aim of targeting key processes in the progression of NASH and HCC. Here, we critically evaluate literature on the aetiology of NAFLD-related HCC, and explore the potential treatment options for NASH and HCC.

Review article: the emerging role of genetics in precision medicine for patients with non-alcoholic steatohepatitis

BACKGROUND

Non-alcoholic steatohepatitis (NASH) is a severe form of non-alcoholic fatty liver disease (NAFLD) characterised by liver fat accumulation, inflammation and progressive fibrosis. Emerging data indicate that genetic susceptibility increases risks of NAFLD, NASH and NASH-related cirrhosis.

AIMS

To review NASH genetics and discuss the potential for precision medicine approaches to treatment.

METHOD

PubMed search and inclusion of relevant literature.

RESULTS

Single-nucleotide polymorphisms in PNPLA3, TM6SF2, GCKR, MBOAT7 and HSD17B13 are clearly associated with NASH development or progression. These genetic variants are common and have moderate-to-large effect sizes for development of NAFLD, NASH and hepatocellular carcinoma (HCC). The genes play roles in lipid remodelling in lipid droplets, hepatic very low-density lipoprotein (VLDL) secretion and de novo lipogenesis. The PNPLA3 I148M variant (rs738409) has large effects, with approximately twofold increased odds of NAFLD and threefold increased odds of NASH and HCC per allele. Obesity interacts with PNPLA3 I148M to elevate liver fat content and increase rates of NASH. Although the isoleucine-to-methionine substitution at amino acid position 148 of the PNPLA3 enzyme inactivates its lipid remodelling activity, the effect of PNPLA3 I148M results from trans-repression of another lipase (ATGL/PNPLA2) by sequestration of a shared cofactor (CGI-58/ABHD5), leading to decreased hepatic lipolysis and VLDL secretion. In homozygous Pnpla3 I148M knock-in rodent models of NAFLD, targeted PNPLA3 mRNA knockdown reduces hepatic steatosis, inflammation and fibrosis.

CONCLUSION

The emerging genetic and molecular understanding of NASH paves the way for novel interventions, including precision medicines that can modulate the activity of specific genes associated with NASH.

Genetic Risk for Hepatic Fat among an Ethnically Diverse Cohort of Youth: The Exploring Perinatal Outcomes among Children Study

OBJECTIVE

To assess the importance of genetic and nongenetic risk factors contributing to hepatic fat accumulation in a multiethnic population of youth.

STUDY DESIGN

We investigated the relationship between genetic factors and hepatic fat fraction (HFF) in 347 children aged 12.5-19.5 years. We examined 5 single nucleotide polymorphisms previously associated with HFF and a weighted genetic risk score (GRS) and examined how these associations varied with ethnicity (Hispanic vs non-Hispanic white) and body mass index (BMI) category. We also compared how much variation in HFF was explained by genetic factors vs cardiometabolic factors (BMI z-score and the Homeostasis Model of Insulin Resistance) or diet.

RESULTS

PNPLA3 rs738409 and the GRS were each associated with HFF among Hispanic (β = 0.39; 95% CI, 0.16-0.62; P = .001; and β = 0.20; 95% CI, 0.05-0.34; P = .007, respectively) but not non-Hispanic white (β = 0.04; 95% CI, -0.18 to 0.26; P = .696; and β = 0.03; 95% CI, -0.09 to 0.14; P = .651, respectively) youth. Cardiometabolic risk factors explained more of the variation in HFF than genetic risk factors among non-lean Hispanic individuals (27.2% for cardiometabolic markers vs 6.4% for rs738409 and 4.3% for the GRS), and genetic risk factors were more important among lean individuals (2.7% for cardiometabolic markers vs 12.6% for rs738409 and 4.4% for the GRS).

CONCLUSIONS

Poor cardiometabolic health may be more important than genetic factors when predicting HFF in overweight and obese young populations. Genetic risk is an important contributor to pediatric HFF among lean Hispanics, but further studies are necessary to elucidate the strength of the association between genetic risk and HFF in non-Hispanic white youth.

Correlation between insulin resistance and liver histology in patients with nonalcoholic steatohepatitis with and without obesity

INTRODUCTION

Insulin resistance (IR) plays a central role in pathogenesis of nonalcoholic steatohepatitis (NASH). The aim of this study was to correlate histopathological grading and IR in overweight/obese patients with NASH as compared with lean NASH.

METHODS

Patients with NASH who underwent liver biopsy between January 2012 and December 2012 were included. Anthropometric, clinical, and biochemical features, necro-inflammatory grades, and fibrosis stage on liver biopsies were scored according to Brunt and non-alcoholic fatty liver disease (NAFLD) activity score (NAS).

RESULTS

Of 42 patients, 33 (78.6%) had body mass index (BMI) ≥ 23 kg/m² (overweight/obese) while 9 had BMI < 23 kg/m² (lean). Mean fasting blood sugar (FBS) and HbA1c levels in overweight/obese patients with NASH were higher than in lean NASH (p < 0.05). The median homeostatic model assessment-estimated insulin resistance (HOMA-IR) among NASH patients with BMI ≥ 23 kg/m² was higher than among those with BMI < 23 kg/m² (3.02 [0.34-17.22] vs. 2 [0.52-5.26]; p = 0.045). However, fasting insulin levels were comparable among lean and overweight/obese patients with NASH. Metabolic syndrome could be predicted with 75% sensitivity and 85.3% specificity at a HOMA-IR cutoff value of 3.9. No significant difference was observed with regard to HOMA-IR levels with Brunt grades, Brunt staging, Brunt grades 1 and 2, Brunt scores < 2 and > 2, and NAS scores, and NAS scores < 4 and > 4.

CONCLUSIONS

Although IR was significantly higher in overweight/obese patients with NASH as compared with that in lean patients with NASH, there was no difference in the correlation of HOMA-IR with histology between these groups.

Liver involvement in patients with Gaucher disease types I and III

Background & aims

Gaucher disease (GD) is a multisystemic disease. Liver involvement in GD is not well characterised and ranges from hepatomegaly to cirrhosis and hepatocellular carcinoma. We aim to describe, and assess the effect of treatment, on the hepatic phenotype of a cohort of patients with GD types I and II.

Methods

Retrospective study based on the review of the medical files of the Gaucher Reference Centre of the Hospital de Clínicas de Porto Alegre, Brazil. Data from all GD types I and III patients seen at the centre since 2003 were analysed. Variables were compared as pre- (“baseline”) and post-treatment (“follow-up”).

Results

Forty-two patients (types I: 39, III: 3; female: 22; median age: 35 y; enzyme replacement therapy: 37; substrate reduction therapy: 2; non-treated: 3; median time on treatment-MTT: 124 months) were included. Liver enzyme abnormalities, hepatomegaly, and steatosis at baseline were seen in 19/28 (68%), 28/42 (67%), and 3/38 patients (8%), respectively; at follow-up, 21/38 (55%), 15/38 (39%) and 15/38 (39%). MRI iron quantification showed overload in 7/8 patients (treated: 7; MTT: 55 months), being severe in 2/7 (treated: 2/2; MTT: 44.5 months). Eight patients had liver biopsy (treated: 6; MTT: 58 months), with fibrosis in 3 (treated: 1; time on treatment: 108 months) and steatohepatitis in 2 (treated: 2; time on treatment: 69 and 185 months). One patient developed hepatocellular carcinoma.

Conclusions

GD is a heterogeneous disease that causes different patterns of liver damage even during treatment. Although treatment improves the hepatocellular damage, it is associated with an increased rate of steatosis. This study highlights the importance of a follow-up of liver integrity in these patients.

Nonalcoholic Fatty Liver Disease in Adults: Current Concepts in Etiology, Outcomes, and Management

Nonalcoholic fatty liver disease (NAFLD) is a spectrum of disease, extending from simple steatosis to inflammation and fibrosis with a significant risk for the development of cirrhosis. It is highly prevalent and is associated with significant adverse outcomes both through liver-specific morbidity and mortality but, perhaps more important, through adverse cardiovascular and metabolic outcomes. It is closely associated with type 2 diabetes and obesity, and both of these conditions drive progressive disease toward the more advanced stages. The mechanisms that govern hepatic lipid accumulation and the predisposition to inflammation and fibrosis are still not fully understood but reflect a complex interplay between metabolic target tissues including adipose and skeletal muscle, and immune and inflammatory cells. The ability to make an accurate assessment of disease stage (that relates to clinical outcome) can also be challenging. While liver biopsy is still regarded as the gold-standard investigative tool, there is an extensive literature on the search for novel noninvasive biomarkers and imaging modalities that aim to accurately reflect the stage of underlying disease. Finally, although no therapies are currently licensed for the treatment of NAFLD, there are interventions that appear to have proven efficacy in randomized controlled trials as well as an extensive emerging therapeutic landscape of new agents that target many of the fundamental pathophysiological processes that drive NAFLD. It is highly likely that over the next few years, new treatments with a specific license for the treatment of NAFLD will become available.

Hepatic Steatosis in Lean Patients: Risk Factors and Impact on Mortality

BACKGROUND

The prognostic impact of liver steatosis in obese patients is well established. Limited data on the risk factors for and impact of hepatic steatosis in lean patients are available.

AIMS

Assess risk factors for liver steatosis in lean patients and investigate its impact on survival.

METHODS

Patients without viral hepatitis and with a BMI ≤ 25 kg/m² undergoing liver stiffness measurement (LSM) and controlled attenuation parameter (CAP) by transient elastography were retrospectively identified. Clinical characteristics and laboratory test results were obtained at the time of LSM/CAP measurement. National death registry data were obtained in order to assess survival.

RESULTS

Among n = 218 lean patients, n = 97 (34.5%) showed significant liver steatosis (CAP ≥ 268 dB/m), while n = 184 (65.5%) had no or just mild steatosis (CAP < 268 dB/m). Patients with steatosis had higher GGT (238.0(± 450.3) vs. 112.1(± 180.0) IU/mL; p = 0.013), AST (63(± 67.4) vs. 38.5(± 32.9) IU/mL; p = 0.001), ALT (59.1(± 58.8) vs. 44.3(± 52.7) IU/mL; p = 0.048) and triglyceride levels (120.1(± 80.3) vs. 96.1(± 58.2) mg/dL; p = 0.014), and showed a trend toward more severe fibrosis (LSM 15.6(± 19.5) vs. 12.0(± 15.7) kPa; p = 0.115). In multivariate binary logistic regression analysis, only serum uric acid levels were independently associated with liver steatosis (odds ratio 1.43 per unit mg/dL; 95% CI 1.001-2.054; p = 0.049). During a mean follow-up of 38.9(± 10.6) months, n = 14 patients (5.0%) died. In the absence of advanced fibrosis, survival after 1 year was similar in patients without (98.7%) and with (98.6%) significant steatosis. Patients with advanced fibrosis had worse 1-year survival without concomitant significant steatosis (84.8%) than patients with steatosis (95.8%; log-rank p < 0.001).

CONCLUSIONS

High serum uric acid levels increase the risk of liver steatosis in lean patients. Liver fibrosis but not hepatic steatosis is a risk factor for impaired survival in lean patients.

Non-alcoholic fatty liver disease (NAFLD) in non-obese individuals

Individuals with non-alcoholic fatty liver disease (NAFLD) who lack classical risk factors also have the ability to develop nonalcoholic steatohepatitis (NASH) and progression to more advanced liver disease. The pathophysiology and risk factors for the development of NAFLD in non-obese persons are not fully understood but seem to be closely related to insulin resistance, atherogenic dyslipidaemia and alterations in body composition, with some patients harbouring predisposing genetic polymorphisms. In normal-weight individuals, also called 'lean', there is limited potential for effective lifestyle change in disease management. Additionally, biological mechanisms underlying the development of NASH in non-obese individuals may reveal novel targets for intervention. In this review, the authors discuss the clinical, histological and genetic features and risk factors for non-obese NAFLD and highlight gaps in knowledge and areas for future research.

iPla2β Deficiency Suppresses Hepatic ER UPR, Fxr, and Phospholipids in Mice Fed with MCD Diet, Resulting in Exacerbated Hepatic Bile Acids and Biliary Cell Proliferation

Background: Group VIA calcium-independent phospholipase A2 (iPla2β) regulates homeostasis and remodeling of phospholipids (PL). We previously showed that iPla2β^-/- mice fed with a methionine-choline-deficient diet (MCD) exhibited exaggerated liver fibrosis. As iPla2β is located in the endoplasmic reticulum (ER), we investigated the mechanisms for this by focusing on hepatic ER unfolded protein response (UPR), ER PL, and enterohepatic bile acids (BA). Methods: Female WT (wild-type) and iPla2β^-/- mice were fed with chow or MCD for 5 weeks. PL and BA profiles were measured by liquid chromatography-mass spectrometry. Gene expression analyses were performed. Results: MCD feeding of WT mice caused a decrease of ER PL subclasses, which were further decreased by iPla2β deficiency. This deficiency alone or combined with MCD downregulated the expression of liver ER UPR proteins and farnesoid X-activated receptor. The downregulation under MCD was concomitant with an elevation of BA in the liver and peripheral blood and an increase of biliary epithelial cell proliferation measured by cytokeratin 19. Conclusion: iPla2β deficiency combined with MCD severely disturbed ER PL composition and caused inactivation of UPR, leading to downregulated Fxr, exacerbated BA, and ductular proliferation. Our study provides insights into iPla2β inactivation for injury susceptibility under normal conditions and liver fibrosis and cholangiopathies during MCD feeding.