Association of metabolic dysfunction-associated fatty liver disease with kidney disease

N-terminal propeptide of type 3 collagen-based sequential algorithm can identify high-risk steatohepatitis and fibrosis in MAFLD

BACKGROUND AND AIMS

With metabolic dysfunction-associated fatty liver disease (MAFLD) incidence and prevalence sharply increasing globally, there is an urgent need for non-invasive diagnostic tests to accurately screen high-risk MAFLD patients for liver inflammation and fibrosis. We aimed to develop a novel sequential algorithm based on N-terminal propeptide of type 3 collagen (PRO-C3) for disease risk stratification in patients with MAFLD.

METHODS

A derivation and independent validation cohort of 327 and 142 patients with biopsy-confirmed MAFLD were studied. We compared the diagnostic performances of various non-invasive scores in different disease states, and a novel sequential algorithm was constructed by combining the best performing non-invasive scores.

RESULTS

For patients with high-risk progressive steatohepatitis (i.e., steatohepatitis + NAFLD activity score ≥ 4 + F ≥ 2), the AUROC of FAST score was 0.801 (95% confidence interval (CI): 0.739-0.863), and the negative predictive value (NPV) was 0.951. For advanced fibrosis (≥ F3) and cirrhosis (F4), the AUROCs of ADAPT and Agile 4 were 0.879 (95%CI 0.825-0.933) and 0.943 (95%CI 0.892-0.994), and the NPV were 0.972 and 0.992. Sequential algorithm of ADAPT + Agile 4 combination was better than other combinations for risk stratification of patients with severe fibrosis (AUROC = 0.88), with similar results in the validation cohort. Meanwhile, in all subgroup analyses (stratifying by sex, age, diabetes, NAS, BMI and ALT), ADAPT + Agile 4 had a good diagnostic performance.

CONCLUSIONS

The new sequential algorithm reliably identifies liver inflammation and fibrosis in MAFLD, making it easier to exclude low-risk patients and recommending high-risk MAFLD patients for clinical trials and emerging pharmacotherapies.

MAFLD and NAFLD in the prediction of incident chronic kidney disease

Whether metabolic dysfunction-associated fatty liver disease (MAFLD) can replace nonalcoholic fatty liver disease (NAFLD) is under debate. This study evaluated which definition better predicted incident chronic kidney disease (CKD). This was a 5.3-year (range, 2.8-8.3) retrospective cohort study of 21,713 adults who underwent at least two serial health examinations. Cox analyses were used to compare the risk of incident CKD among non-fatty liver disease (FLD) without metabolic dysregulation (MD; reference), non-FLD with MD, MAFLD-only, NAFLD-only, or both-FLD groups. Non-FLD with MD group (hazard ratio [HR] 1.23, 95% confidence interval [CI] 1.00-1.53), both-FLD group (HR 1.50, 95% CI 1.19-1.89), and MAFLD-only group (HR 1.97, 95% CI 1.49-2.60), but not NAFLD-only group (HR 1.06, 95% CI 0.63-1.79) demonstrated an increased risk of CKD. The increased risk of CKD was significant in MAFLD subgroups with overweight/obesity (HR 2.94, 95% CI 1.91-4.55), diabetes (HR 2.20, 95% CI 1.67-2.90), MD only (HR 1.50, 95% CI 1.19-1.89), excessive alcohol consumption (HR 2.71, 95% CI 2.11-3.47), and viral hepatitis (HR 2.38, 95% CI 1.48-3.84). The switch from NAFLD to MAFLD criteria may identify a greater number of individuals at CKD risk. The association was also significant in MAFLD patients with excessive alcohol consumption or viral hepatitis.

Metabolic dysfunction-associated fatty liver disease is associated with an increase in systolic blood pressure over time: linear mixed-effects model analyses

Metabolic dysfunction-associated fatty liver disease (MAFLD), a new feature of fatty liver (FL) disease that is defined as FL with overweight/obesity, type 2 diabetes mellitus or metabolic dysregulation, has been reported to be associated with the development of diabetes mellitus, chronic kidney disease and cardiovascular disease. However, the association between MAFLD and hypertension remains unclear. We investigated the association between MAFLD and systolic blood pressure (SBP) over a 10-year period in 28,990 Japanese subjects who received annual health examinations. After exclusion of subjects without data for SBP and abdominal ultrasonography at baseline, a total of 17,021 subjects (men/women: 10,973/6048; mean age: 49 years) were recruited. Linear mixed-effects model analyses using diagnoses of FL, nonalcoholic fatty liver disease (NAFLD) or MAFLD and age, sex, SBP, use of anti-hypertensive drugs, levels of uric acid and estimated glomerular filtration rate, family history of hypertension and habits of current smoking and alcohol drinking at baseline as well as the duration of the observation period and the interaction between each covariate and the duration of the observation period showed that the significant association of change in SBP over time with diagnosis of MAFLD (estimate: 0.223 mmHg/year, P < 0.001) was greater than that with diagnoses of FL (estimate: 0.196 mmHg/year, P < 0.001) and NAFLD (estimate: 0.203 mmHg/year, P < 0.001). Furthermore, the rate of increase in SBP over time was higher in subjects with MAFLD than in subjects without FL and subjects with FL who had no MAFLD. In conclusion, MAFLD is significantly associated with an increase in SBP over time. The presence of metabolic dysfunction-associated fatty liver disease (MAFLD) is significantly associated with an increase in systolic blood pressure over time.

The nonlinear relationship between thyroid function parameters and metabolic dysfunction-associated fatty liver disease

BACKGROUND

The relationship between thyroid function parameters and metabolic dysfunction-associated fatty liver disease (MAFLD) remains controversial. Additionally, little is known about the relationship between thyroid function parameters and MAFLD in the Chinese population.

METHODS

We conducted a retrospective cross-sectional study involving 177,540 individuals with thyroid function tests and MAFLD diagnosis from 2010-2018. The association between thyroid function parameters and MAFLD was evaluated on a continuous scale with restricted cubic spline (RCS) models and by the prior-defined centile categories with multivariable-adjusted logistic regression models. Thyroid function parameters included free triiodothyronine (FT3), free tetra-iodothyronine (FT4), and thyroid stimulating hormone (TSH). Additionally, fully adjusted RCS models stratified by sex, age, and location were studied.

RESULTS

In the RCS models, the risk of MAFLD increased with higher levels of FT3 when FT3 <5.58pmol/L, while the risk of MAFLD decreased with higher levels of FT3 when FT3 ≥5.58pmol/L (P nonlinearity <0.05). While RCS analysis suggested that the FT4 levels had a negative association with MAFLD (P nonlinearity <0.05), indicating an increase in FT4 levels was associated with a decreased risk of MAFLD. RCS analysis suggested an overall positive association between the concentration of TSH and MAFLD risk (P nonlinearity <0.05). The rising slope was sharper when the TSH concentration was less than 1.79uIU/mL, which indicated the association between TSH and MAFLD risk was tightly interrelated within this range. The multivariable logistic regression showed that populations in the 81st-95th centile had the highest risk of MAFLD among all centiles of FT3/TSH, with the 1st-5th centile as the reference category.

CONCLUSIONS

Our study suggested nonlinear relationships between thyroid function parameters and MAFLD. Thyroid function parameters could be additional modifiable risk factors apart from the proven risk factors to steer new avenues regarding MAFLD prevention and treatment.

Liver fibrosis and MAFLD: the exploration of multi-drug combination therapy strategies

In recent years, the prevalence of metabolic-associated fatty liver disease (MAFLD) has reached pandemic proportions as a leading cause of liver fibrosis worldwide. However, the stage of liver fibrosis is associated with an increased risk of severe liver-related and cardiovascular events and is the strongest predictor of mortality in MAFLD patients. More and more people believe that MAFLD is a multifactorial disease with multiple pathways are involved in promoting the progression of liver fibrosis. Numerous drug targets and drugs have been explored for various anti-fibrosis pathways. The treatment of single medicines is brutal to obtain satisfactory results, so the strategies of multi-drug combination therapies have attracted increasing attention. In this review, we discuss the mechanism of MAFLD-related liver fibrosis and its regression, summarize the current intervention and treatment methods for this disease, and focus on the analysis of drug combination strategies for MAFLD and its subsequent liver fibrosis in recent years to explore safer and more effective multi-drug combination therapy strategies.

Prevalence and Risk Factors of Metabolic-Associated Fatty Liver Disease Among Hospital Staff

Background

The prevalence of metabolism-related fatty liver disease (MAFLD) has been rarely reported in hospital staffs. The aim of this study was to assess the prevalence and risk factors for MAFLD in hospital staffs aged ≥18 years.

Methods

Based on type B ultrasonic, hospital staffs who underwent medical examinations at the second Affiliated Hospital of Hainan Medical University from January 2022 to March 2022 were classified into health control group (661 subjects) and MAFLD group (223 subjects), demographic, biochemical and blood examination information were compared between 2 groups. Independent risk factors for MAFLD were determined by logistic regression. Predictive values of risk factors of MAFLD were evaluated by receiver operating characteristic (ROC) curves.

Results

The prevalence of MAFLD was 33.7%. Older age (OR=1.08, p<0.001), H. pylori infection (OR=0.234, p=0.02), triglyceride-glucose (TyG) (OR=7.001, p<0.001), low-density lipoprotein cholesterol (LDL-C) (OR=2.076, p=0.028), red blood cell (RBC) (OR=2.386, p=0.001), eating out (OR=0.048, p=0.001), regular exercise (OR=23.017, p<0.001), and overweight (OR=3.891, p=0.003) were independently associated factors for MAFLD. The AUC of model predicting MAFLD is 0.910 [95% CI (0.886, 0.934)], with 0.794 sensitivity, 0.908 specificity. The diagnostic value of model was higher in the female MAFLD group after stratified analysis according to gender. The model showed that TyG was the factor contributing more to MAFLD. The diagnostic value of TyG was higher in the female MAFLD group than male MAFLD group.

Conclusion

The prevalence of MAFLD among hospital staffs was 33.7%. TyG can be used to predict MAFLD especially for female hospital staffs for early intervention.

Protective effects of black onion polysaccharide on liver and kidney injury in T2DM rats through the synergistic impact of hypolipidemic and antioxidant abilities

In this study, the synergistic effects of black onion on the hypolipidemic and antioxidant activities in T2DM rats induced by a high-fat-diet and alloxan were investigated. The results showed that the fasting blood glucose of diabetic rats was significantly decreased after treatment with black onion polysaccharide (p < 0.01). Blood lipid analysis indicated that black onion polysaccharide could significantly improve the abnormal metabolism of blood lipids caused by diabetes. In addition, the MDA and ROS of the diabetic rats treated with black onion polysaccharide were significantly reduced; moreover, SOD was increased, indicating the excellent antioxidant activity of black onion polysaccharide. A histological examination clearly showed that black onion polysaccharide could improve the histological morphology of the liver and kidney. Furthermore, the indices of liver and kidney function were restored. These results indicate that black onion polysaccharide can reduce blood glucose and simultaneously show synergistic effects of hypoglycemic and antioxidant activities in diabetic rats. Therefore, black onion polysaccharide may alleviate liver and kidney function injury by improving the "two-hit" mechanism and can thus be used as a potential functional food to prevent diabetes and its complications.

Relationship between Chewing Status and Fatty Liver Diagnosed by Liver/Spleen Attenuation Ratio: A Cross-Sectional Study

This cross-sectional study investigated the relationship between chewing status and fatty liver among Japanese adults. Between April 2018 and March 2021, 450 individuals (352 males, 98 females; mean age 54.7 years) were recruited at the Asahi University Hospital Human Health Center. Chewing status was evaluated using a self-reported questionnaire. Liver/spleen (L/S) attenuation ratio < 0.9 on computed tomography was considered to indicate fatty liver, which was present in 69 participants (15%). Compared with participants without fatty liver, those with fatty liver had higher proportion of 25.0 (kg/m2) ≤ body mass index (BMI) (p < 0.001), higher serum hemoglobin A1c (HbA1c) (p < 0.001), higher systolic blood pressure (p < 0.001), higher diastolic blood pressure (p < 0.001), and lower serum high-density lipoprotein cholesterol (HDL cholesterol) (p = 0.011). Significant differences were also found in chewing status (p < 0.001) and eating speed (p = 0.011). Presence of fatty liver was positively associated with BMI (25.0 ≤; odds ratio [OR], 5.048; 95% confidence interval [CI], 2.550−9.992), serum HbA1c (OR, 1.937; 95% CI, 1.280−2.930), and chewing status (poor; OR, 8.912; 95% CI, 4.421−17.966) after adjusting for sex, age, BMI, serum HbA1c, systolic blood pressure, diastolic blood pressure, serum HDL cholesterol, chewing status, and eating speed. Poor chewing status was positively associated with L/S attenuation ratio. These results indicate a positive relationship between poor chewing status and fatty liver diagnosed by L/S attenuation ratio in Japanese adults.

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.

Fully connected neural network-based serum surface-enhanced Raman spectroscopy accurately identifies non-alcoholic steatohepatitis

BACKGROUND/PURPOSE OF THE STUDY

There is a need to find a standardized and low-risk diagnostic tool that can non-invasively detect non-alcoholic steatohepatitis (NASH). Surface enhanced Raman spectroscopy (SERS), which is a technique combining Raman spectroscopy (RS) with nanotechnology, has recently received considerable attention due to its potential for improving medical diagnostics. We aimed to investigate combining SERS and neural network approaches, using a liver biopsy dataset to develop and validate a new diagnostic model for non-invasively identifying NASH.

METHODS

Silver nanoparticles as the SERS-active nanostructures were mixed with blood serum to enhance the Raman scattering signals. The spectral data set was used to train the NASH classification model by a neural network primarily consisting of a fully connected residual module.

RESULTS

Data on 261 Chinese individuals with biopsy-proven NAFLD were included and a prediction model for NASH was built based on SERS spectra and neural network approaches. The model yielded an AUROC of 0.83 (95% confidence interval [CI] 0.70-0.92) in the validation set, which was better than AUROCs of both serum CK-18-M30 levels (AUROC 0.63, 95% CI 0.48-0.76, p = 0.044) and the HAIR score (AUROC 0.65, 95% CI 0.51-0.77, p = 0.040). Subgroup analyses showed that the model performed well in different patient subgroups.

CONCLUSIONS

Fully connected neural network-based serum SERS analysis is a rapid and practical tool for the non-invasive identification of NASH. The online calculator website for the estimated risk of NASH is freely available to healthcare providers and researchers ( http://www.pan-chess.cn/calculator/RAMAN_score ).

Nonalcoholic Fatty Liver Disease and Chronic Kidney Disease: Epidemiology, Pathogenesis, and Clinical and Research Implications

Nonalcoholic fatty liver disease (NAFLD) has become the most common cause of chronic liver disease worldwide, affecting up to ~30% of adult populations. NAFLD defines a spectrum of progressive liver conditions ranging from simple steatosis to nonalcoholic steatohepatitis (NASH), cirrhosis, and hepatocellular carcinoma, which often occur in close and bidirectional associations with metabolic disorders. Chronic kidney disease (CKD) is characterized by anatomic and/or functional renal damage, ultimately resulting in a reduced glomerular filtration rate. The physiological axis linking the liver and kidneys often passes unnoticed until clinically significant portal hypertension, as a major complication of cirrhosis, becomes apparent in the form of ascites, refractory ascites, or hepatorenal syndrome. However, the extensive evidence accumulated since 2008 indicates that noncirrhotic NAFLD is associated with a higher risk of incident CKD, independent of obesity, type 2 diabetes, and other common renal risk factors. In addition, subclinical portal hypertension has been demonstrated to occur in noncirrhotic NAFLD, with a potential adverse impact on renal vasoregulation. However, the mechanisms underlying this association remain unexplored to a substantial extent. With this background, in this review we discuss the current evidence showing a strong association between NAFLD and the risk of CKD, and the putative biological mechanisms underpinning this association. We also discuss in depth the potential pathogenic role of the hepatorenal reflex, which may be triggered by subclinical portal hypertension and is a poorly investigated but promising research topic. Finally, we address emerging pharmacotherapies for NAFLD that may also beneficially affect the risk of developing CKD in individuals with NAFLD.

Interplay between metabolic dysfunction-associated fatty liver disease and chronic kidney disease: Epidemiology, pathophysiologic mechanisms, and treatment considerations

The recently proposed nomenclature change from non-alcoholic fatty liver disease to metabolic dysfunction-associated fatty liver disease (MAFLD) has resulted in the reappraisal of epidemiological trends and associations with other chronic diseases. In this context, MAFLD appears to be tightly linked to incident chronic kidney disease (CKD). This association may be attributed to multiple shared risk factors including type 2 diabetes mellitus, arterial hypertension, obesity, dyslipidemia, and insulin resistance. Moreover, similarities in their molecular pathophysiologic mechanisms can be detected, since inflammation, oxidative stress, fibrosis, and gut dysbiosis are highly prevalent in these pathologic states. At the same time, lines of evidence suggest a genetic predisposition to MAFLD due to gene polymorphisms, such as the PNPLA3 rs738409 G allele polymorphism, which may also propagate renal dysfunction. Concerning their management, available treatment considerations for obesity (bariatric surgery) and novel antidiabetic agents (glucagon-like peptide 1 receptor agonists, sodium-glucose co-transporter 2 inhibitors) appear beneficial in preclinical and clinical studies of MAFLD and CKD modeling. Moreover, alternative approaches such as melatonin supplementation, farnesoid X receptor agonists, and gut microbiota modulation may represent attractive options in the future. With a look to the future, additional adequately sized studies are required, focusing on preventing renal complications in patients with MAFLD and the appropriate management of individuals with concomitant MAFLD and CKD.

Spotlight on liver macrophages for halting liver disease progression and injury

INTRODUCTION

Over the past two decades, understanding of hepatic macrophage biology has provided astounding details of their role in the progression and regression of liver diseases. The hepatic macrophages constitute resident macrophages, Kupffer cells, and circulating bone marrow monocyte-derived macrophages, which play a diverse role in liver injury and repair. Imbalance in the macrophage population leads to pathological consequences and is responsible for the initiation and progression of acute and chronic liver injuries. Further, distinct populations of hepatic macrophages and their high heterogeneity make their complex role enigmatic. The unique features of distinct phenotypes of macrophages have provided novel biomarkers for defining the stages of liver diseases. The distinct mechanisms of hepatic macrophages polarization and recruitment have been at the fore front of research. In addition, the secretome of hepatic macrophages and their immune regulation has provided clinically relevant therapeutic targets.

AREAS COVERED

Herein we have highlighted the current understanding in the area of hepatic macrophages, and their role in the progression of liver injury.

EXPERT OPINION

It is essential to ascertain the physiological and pathological role of evolutionarily conserved distinct macrophage phenotypes in different liver diseases before viable approaches may see a clinical translation.

Old and new classes of glucose-lowering agents as treatments for non-alcoholic fatty liver disease: A narrative review

Non-alcoholic fatty liver disease (NAFLD) has become the most common chronic liver disease with a global prevalence of about 55% in people with type 2 diabetes mellitus (T2DM). T2DM, obesity and NAFLD are three closely inter-related pathological conditions. In addition, T2DM is one of the strongest clinical risk factors for the faster progression of NAFLD to non-alcoholic steatohepatitis (NASH), cirrhosis and hepatocellular carcinoma. Increasing evidence suggests that newer classes of glucose-lowering drugs, such as peroxisome proliferator-activated receptor agonists, glucagon-like peptide-1 receptor agonists, dipeptidyl peptidase-4 inhibitors or sodium-glucose cotransporter-2 inhibitors, could reduce the rates of NAFLD progression. This narrative review aims to briefly summarize the recent results from randomized controlled trials testing the efficacy and safety of old and new glucose-lowering drugs for the treatment of NAFLD or NASH in adults both with and without coexisting T2DM.

Fatty liver disease reverses the obesity paradox in chronic kidney disease stages 3-5: A follow-up study of NHANES III

High body mass index (BMI) has been associated with better survival in patients with end-stage kidney disease. Individuals with fatty liver disease (FLD) have a higher risk of chronic kidney disease. It remains unclear whether the survival benefit of high BMI in patients with chronic kidney disease is present when there is concomitant FLD. This study used the data set from the Third American National Health and Nutrition Examination Survey and the corresponding survival data. The Cox proportional hazards model was used to evaluate the effect of BMI on mortality. A total of 12,445 participants were included. The prevalence of FLD was 39.8%. The median follow-up time (with interquartile range) was 22.8 (20.8-24.8) years. During this period, 3749 (30.1%, 14.4 of 1000 person-year) deaths were observed. Among these, 1169 (31.2%) died within the first 10 years. The Cox regression analysis showed that the BMI level was not associated with 25-year mortality in patients with decreased glomerular filtration rate (GFR < 60 ml/min/1.73 m² ), but 10-year mortality was significantly lower in patients with BMI ≥ 25 kg/m² than in those with BMI < 25 kg/m² (p = 0.049). Multivariate analysis showed BMI ≥ 25 kg/m² was an independent protective factor for 10-year mortality (hazard ratio [HR] 0.691, 95% confidence interval [CI] 0.559-0.856; p = 0.001). This protective effect of higher BMI was lost in patients with FLD (HR 0.884, 95% CI 0.585-1.335; p = 0.557) but persisted in the non-FLD group (HR 0.625, 95% CI 0.479-0.816; p = 0.001). The survival benefit of overweight/obesity for patients with decreased GFR, which was attenuated by the presence of FLD, only existed in the first decade.

Role of the cGAS-STING pathway in systemic and organ-specific diseases

Cells are equipped with numerous sensors that recognize nucleic acids, which probably evolved for defence against viruses. Once triggered, these sensors stimulate the production of type I interferons and other cytokines that activate immune cells and promote an antiviral state. The evolutionary conserved enzyme cyclic GMP-AMP synthase (cGAS) is one of the most recently identified DNA sensors. Upon ligand engagement, cGAS dimerizes and synthesizes the dinucleotide second messenger 2',3'-cyclic GMP-AMP (cGAMP), which binds to the endoplasmic reticulum protein stimulator of interferon genes (STING) with high affinity, thereby unleashing an inflammatory response. cGAS-binding DNA is not restricted by sequence and must only be >45 nucleotides in length; therefore, cGAS can also be stimulated by self genomic or mitochondrial DNA. This broad specificity probably explains why the cGAS-STING pathway has been implicated in a number of autoinflammatory, autoimmune and neurodegenerative diseases; this pathway might also be activated during acute and chronic kidney injury. Therapeutic manipulation of the cGAS-STING pathway, using synthetic cyclic dinucleotides or inhibitors of cGAMP metabolism, promises to enhance immune responses in cancer or viral infections. By contrast, inhibitors of cGAS or STING might be useful in diseases in which this pro-inflammatory pathway is chronically activated.

Lower serum copper concentrations are associated with higher prevalence of nonalcoholic steatohepatitis: a matched case-control study

BACKGROUND AND AIM

Copper is an essential trace element involved in oxidative stress reactions and energy metabolism. While nonalcoholic fatty liver disease (NAFLD) is closely related to metabolic dysfunction, the role of copper in the development of simple steatosis (NAFL) and nonalcoholic steatohepatitis (NASH) is still unclear. We aimed to compare serum copper levels between patients with simple steatosis and those with NASH.

METHODS AND RESULTS

We studied 102 patients with biopsy-proven NASH (cases) and 102 NAFL controls, who were matched for age, sex, and residential city. Multivariable conditional logistic analysis was performed to explore associations between serum copper levels and the presence of NASH. Serum copper levels were significantly lower in patients with NASH than in those with matched NAFL controls (15.53 ± 2.41 μmol/l vs. 16.34 ± 3.23 μmol/l; P = 0.029). This intergroup difference in serum copper levels was more pronounced in men than in women. The per unit, per SD, and per doubling of serum copper levels were associated, respectively, with an approximately 20, 40, and 90% decrease in risk of having NASH, even after adjustment for potential confounding factors.

CONCLUSION

Lower serum copper concentrations are significantly associated with higher prevalence of NASH among biopsied-proven NAFLD patients, particularly in men.

Early biochemical observations point to nutritional strategies to manage non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is the most prevalent liver disease globally. The first stage of NAFLD is steatosis, the accumulation of triacylglycerols within hepatocytes. Inflammation and oxidative stress both contribute to progression to more severe disease. In 2004 Clinical Science published two papers reporting on fatty acids and oxidative stress markers in the livers of patients with NAFLD; both these papers are highly cited. One paper reported an altered pattern of fatty acids within the livers of patients with NAFLD; there was a lower contribution of polyunsaturated fatty acids (PUFAs) including both n - 6 and n - 3 PUFAs and an altered balance between n - 6 and n - 3 PUFAs in favour of the former. Ratios of precursor PUFAs to their long chain more unsaturated derivatives were altered in NAFLD and were interpreted to indicate a reduced activity of the pathway of synthesis of long chain highly unsaturated PUFAs. The authors interpreted their findings to indicate that a low hepatic content of n - 3 PUFAs has a causal role in NAFLD. The second paper reported lower hepatic antioxidant defences and increased markers of oxidative stress in NAFLD, consistent with a role for oxidative stress in the disease. Many studies have now explored the effect of supplemental n - 3 PUFAs or antioxidants, including vitamin E, in patients with NAFLD with some benefits being reported. There remains much interest in n - 3 PUFAs and antioxidants as preventive and therapeutic strategies in NAFLD and therefore it seems likely that citation of the two papers from 2004 will be sustained.

Low skeletal muscle mass is associated with more severe histological features of non-alcoholic fatty liver disease in male

BACKGROUND/PURPOSE OF THE STUDY

Although low skeletal muscle mass is associated with non-alcoholic fatty liver disease (NAFLD), it is currently uncertain whether there are associations between weight-adjusted appendicular skeletal muscle (ASM%), severity of histological features of NAFLD, and the patatin-like phospholipase domain-containing 3 (PNPLA3) rs738409 polymorphism. Our aim was to test for a possible influence of the PNPLA3 rs738409 variant on the association between ASM% and severity of NAFLD histological features.

METHODS

We enrolled 401 Chinese male with biopsy-proven NAFLD. Using a bioelectrical-impedance body composition analyzer (BIA, Inbody 720, Japan Inc., Tokyo), we calculated the ASM% as the percentage of total appendicular skeletal muscle mass (ASM, kg)/total body mass (kg) × 100.

RESULTS

Compared to those with high ASM%, patients with low ASM% (≤ 30.6, i.e., the median value of distribution of the whole sample) had a greater severity of individual histological features of NAFLD. These patients also had a higher risk of severe steatosis and non-alcoholic steatohepatitis (NASH) (adjusted-odds ratio [OR] 2.34, 95% CI 1.39-3.93, and adjusted-OR 2.22, 95% CI 1.30-3.77) even after adjusting for age, body mass index, diabetes, and serum creatinine levels. Carriage of the G allele of PNPLA3 rs738409 plus low ASM% was associated with a higher risk of severe steatosis and presence of liver fibrosis (OR 3.02, 95% CI 1.46-6.26, p = 0.003 and OR 2.18, 95% CI 1.03-4.60, p = 0.041 respectively), and there was a non-significant but borderline increased risk of NASH (OR 2.00, 95% CI 0.98-4.06, p = 0.056).

CONCLUSIONS

Low ASM% and the presence of a G allele within PNPLA3 rs738409 is associated with more severe histological features of NAFLD.

Atherogenic index of plasma is an independent predictor of metabolic-associated fatty liver disease in patients with type 2 diabetes

Background

Metabolic-associated fatty liver disease (MAFLD), formerly known as non-alcoholic fatty liver disease, is the leading cause of liver disease that can ultimately lead to cirrhosis. Identifying a screening marker for early diagnosis of MAFLD in patients with type 2 diabetes (T2D) can reduce the risk of morbidity and mortality. This study investigated the association between the atherogenic index of plasma (AIP) and MAFLD in patients with T2D.

Method

A retrospective case–control study was conducted and medical records of patients with T2D were assessed. The baseline characteristics, anthropometric indices, laboratory measurements including liver functions tests, fasting blood sugar, HbA1C, lipid profile were documented.

Results

Out of 2547 patients with T2D, 824 (32.4%) had MAFLD. The multivariate logistic regression analysis showed a significant difference in female-to-male ratio (1.11 vs. 1.33, OR = 0.347, P-value < 0.001), ALT (42.5 ± 28.1 vs. 22.4 ± 11.1, OR = 1.057, P-value < 0.001), and AIP (0.6 ± 0.3 vs. 0.5 ± 0.3, OR = 5.057, P-value < 0.001) between MAFLD and non-MAFLD groups, respectively. According to the AIP quartile, the prevalence of MAFLD increased significantly in patients with higher AIP quartiles (P-value < 0.001). Also, we found a cut-off of 0.54 for AIP in predicting MAFLD in patients with T2D (sensitivity = 57.8%, specificity = 54.4%).

Conclusion

In this study, we found that AIP is a good and independent predictor for MAFLD in patients with T2D which could help physicians in early diagnosis and follow-up of patients with T2D.

Omega-3 fatty acids and metabolic partitioning of fatty acids within the liver in the context of nonalcoholic fatty liver disease

PURPOSE OF REVIEW

Nonalcoholic fatty liver disease (NAFLD) is now the most prevalent form of liver disease globally, affecting about 25% of the world's adult population. It is more common in those living with obesity, where it may affect as many as 80% of individuals. The aim of this article is to describe recent human studies evaluating the influence of omega-3 fatty acids on de novo lipogenesis (DNL) and hepatic fatty acid partitioning between incorporation into triacylglycerols (TAGs) and β-oxidation, to discuss the relevance of these effects in the context of NAFLD, and to provide an overview of the mechanisms that might be involved.

RECENT FINDINGS

The omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) decrease hepatic DNL and partition fatty acids away from TAG synthesis and toward β-oxidation. EPA and DHA affect multiple hepatic transcription factors resulting in down-regulation of the DNL pathway and upregulation of β-oxidation. The net result is decreased accumulation of hepatic TAG and lowering of circulating TAG concentrations. Human trials demonstrate that EPA and DHA can decrease liver fat in patients with NAFLD.

SUMMARY

Increased intake of EPA and DHA may reduce the likelihood of hepatic TAG accumulation and could be used to reduce liver fat in patients with NAFLD.

MAFLD and CKD: An Updated Narrative Review

Accumulating evidence now indicates that non-alcoholic fatty liver disease (NAFLD), which is the most common chronic liver disease observed in clinical practice worldwide, is independently associated with an increased risk of incident chronic kidney disease (CKD). Given that NAFLD is linked to insulin resistance, obesity and type 2 diabetes mellitus, an international panel of experts have recently proposed a name change from NAFLD to metabolic associated fatty liver disease (MAFLD). Since the diagnostic criteria for NAFLD and MAFLD are different, observational studies assessing the potential concordance (or even superiority) of MAFLD, compared with NAFLD, in detecting patients at increased risk of hepatic and extra-hepatic complications (including CKD) are required. Hence, in the last two years, some observational studies have investigated the potential relationship between MAFLD and CKD. The result is that, at present, evidence regarding the concordance or even superiority of MAFLD, compared with NAFLD, in detecting patients at higher risk of CKD is still preliminary, although some data indicate that MAFLD identifies patients with CKD as accurately as NAFLD. In this narrative review, we will discuss: (a) the epidemiological evidence assessing the association between NAFLD and risk of incident CKD, (b) the epidemiological data investigating the association between MAFLD and risk of CKD and (c) the biological mechanisms underlying the association between NAFLD/MAFLD and CKD.

Lifestyle Interventions for Non-Obese Patients Both with, and at Risk, of Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease occurring in non-obese subjects (the so-called non-obese NAFLD) is a highly prevalent but neglected liver condition, which is closely associated with metabolic disorders and suboptimal lifestyles. Landmark studies have shown that lifestyle interventions are potentially beneficial in decreasing the risk of developing non-obese NAFLD and in ameliorating NAFLD in non-obese individuals with pre-existing NAFLD. Lifestyle interventions usually refer to changes in eating habits and physical activity, both of which have a powerful effect on non-obese NAFLD and on risk factors for non-obese NAFLD. However, to date, patients and health-care professionals have a poor awareness and understanding of non-obese NAFLD and the beneficial effects of lifestyle interventions in this patient population. The aim of this narrative review is to briefly discuss the evidence for the effects of lifestyle changes and what changes are needed amongst medical personnel and other stakeholders in order to raise awareness of non-obese NAFLD.

Metabolic dysfunction-associated fatty liver disease and risk of incident chronic kidney disease: A nationwide cohort study

AIMS

The recently proposed metabolic dysfunction-associated fatty liver disease (MAFLD) has been suggested to better reflect the metabolic components of fatty liver disease (FLD), compared to nonalcoholic fatty liver disease (NAFLD). This study investigated whether MAFLD identifies a higher proportion of individuals at risk of developing chronic kidney disease (CKD).

METHODS

268,946 participants aged 40-64 years, who underwent National Health Insurance Service health examinations between 2009 and 2015 were included. Participants were categorized by presence of FLD, according to MAFLD or NAFLD. In participants with FLD, participants were categorized into three groups: non-metabolic risk (non-MR) NAFLD, MAFLD but not NAFLD, and overlapping FLD. Incident CKD was defined as the occurrence of eGFR < 60 mL/min/1.73m² or proteinuria (≥ trace) on two consecutive health examinations.

RESULTS

73,726 (27.4%) and 88,762 (33.0%) participants had NAFLD and MAFLD, respectively. During a median follow-up of 5.1 years, CKD occurred in 8,335 (6.2/1,000 person-years) participants. Compared to non-NAFLD participants, the adjusted hazard ratio (aHR) for incident CKD was 1.33 (95% CI, 1.27-1.39; P < 0.001) for participants with NAFLD. Compared to non-MAFLD participants, the aHR for participants with MAFLD was 1.39 (95% CI, 1.33-1.46; P < 0.001). When the analysis was confined to participants with FLD, compared to non-MR NAFLD participants, the aHRs for participants with MAFLD but not NAFLD, and those with overlapping FLD were 1.18 (95% CI, 1.01-1.39; P = 0.040) and 1.36 (95% CI, 1.19-1.54; P < 0.001), respectively.

CONCLUSION

MAFLD identified a higher proportion of individuals at risk of developing CKD than NAFLD.

A Novel Noninvasive Diagnostic Model of HBV-Related Inflammation in Chronic Hepatitis B Virus Infection Patients With Concurrent Nonalcoholic Fatty Liver Disease

Background and Aims

Patients with chronic hepatitis B virus infection (CBI) with concurrent nonalcoholic fatty liver disease (NAFLD) is becoming increasingly common in clinical practice, and it is quite important to identify the etiology when hepatitis occurs. A noninvasive diagnostic model was constructed to identify patients who need antihepatitis B virus (HBV) therapies [histologic activity index (HAI) ≥ 4] in patients with CBI with concurrent NAFLD by analyzing clinical routine parameters.

Approach and Results

In total, 303 out of 502 patients with CBI with concurrent NAFLD proven by liver biopsy from January 2017 to December 2020 in the Tianjin Second People's Hospital were enrolled and they were divided into the HBV-related inflammation (HBV-I) group (HAI ≥ 4,176 cases) and the non-HBV-I group (HAI &lt; 4,127 cases) according to hepatic pathology. The univariate analysis and multivariate logistic regression analysis were performed on the two groups of patients, and then the HBV-I model of patients with CBI with concurrent NAFLD was constructed. The areas under receiver operating characteristic curves (AUROCs) were used to evaluate the parameters of the regression formula. Another 115 patients with CBI with concurrent NAFLD proven by liver biopsy from January 2021 to January 2022 were enrolled as the validation group. There were some statistical differences in demographic data, biochemical indicators, immune function, thyroid function, virology indicator, and blood routine indicators between the two groups (P &lt; 0.05) and liver stiffness measurement (LSM) in the HBV-I group was significantly higher than those in the non-HBV-I group (P &lt; 0.05). While controlled attenuation parameters (CAP) in the HBV-I group were lower than those in the non-HBV-I group (P &lt; 0.05); (2) We developed a novel model by logistic regression analysis: HBV-I = −0.020 × CAP + 0.424 × LSM + 0.376 × lg (HBV DNA) + 0.049 × aspartate aminotransferase (AST) and the accuracy rate was 82.5%. The area under the receiver operating characteristic (AUROC) is 0.907, the cutoff value is 0.671, the sensitivity is 89.30%, the specificity is 77.80%, the positive predictive value is 90.34%, and the negative predictive value is 81.89%; (3) The AUROC of HBV-I in the validation group was 0.871 and the overall accuracy rate is 86.96%.

Conclusion

Our novel model HBV-I [combining CAP, LSM, lg (HBV DNA), and AST] shows promising utility for predicting HBV-I in patients with CBI with concurrent NAFLD with high sensitivity, accuracy, and repeatability, which may contribute to clinical application.

Non-Alcoholic Fatty Liver Disease and Risk of Macro- and Microvascular Complications in Patients with Type 2 Diabetes

Non-alcoholic fatty liver disease (NAFLD) is considered the hepatic manifestation of metabolic syndrome. To date, NAFLD is the most frequent chronic liver disease seen day by day in clinical practice across most high-income countries, affecting nearly 25–30% of adults in the general population and up to 70% of patients with T2DM. Over the last few decades, it clearly emerged that NAFLD is a “multisystemic disease” and that the leading cause of death among patients with NAFLD is cardiovascular disease (CVD). Indeed, several observational studies and some meta-analyses have documented that NAFLD, especially its advanced forms, is strongly associated with fatal and non-fatal cardiovascular events, as well as with specific cardiac complications, including sub-clinical myocardial alteration and dysfunction, heart valve diseases and cardiac arrhythmias. Importantly, across various studies, these associations remained significant after adjustment for established cardiovascular risk factors and other confounders. Additionally, several observational studies and some meta-analyses have also reported that NAFLD is independently associated with specific microvascular conditions, such as chronic kidney disease and distal or autonomic neuropathy. Conversely, data regarding a potential association between NAFLD and retinopathy are scarce and often conflicting. This narrative review will describe the current evidence about the association between NAFLD and the risk of macro- and microvascular manifestations of CVD, especially in patients with T2DM. We will also briefly discuss the biological mechanisms underpinning the association between NAFLD and its advanced forms and macro- and microvascular CVD.

Integrated analysis of potential gene crosstalk between non-alcoholic fatty liver disease and diabetic nephropathy

BACKGROUND

Growing evidence indicates that non-alcoholic fatty liver disease (NAFLD) is related to the occurrence and development of diabetic nephropathy (DN). This bioinformatics study aimed to explore optimal crosstalk genes and related pathways between NAFLD and DN.

METHODS

Gene expression profiles were downloaded from Gene Expression Omnibus. CIBERSORT algorithm was employed to analyze the similarity of infiltrating immunocytes between the two diseases. Protein-protein interaction (PPI) co-expression network and functional enrichment analysis were conducted based on the identification of common differentially expressed genes (DEGs). Least absolute shrinkage and selection operator (LASSO) regression and Boruta algorithm were implemented to initially screen crosstalk genes. Machine learning models, including support vector machine, random forest model, and generalized linear model, were utilized to further identify the optimal crosstalk genes between DN and NAFLD. An integrated network containing crosstalk genes, transcription factors, and associated pathways was developed.

RESULTS

Four gene expression datasets, including GSE66676 and GSE48452 for NAFLD and GSE30122 and GSE1009 for DN, were involved in this study. There were 80 common DEGs between the two diseases in total. The PPI network built with the 80 common genes included 77 nodes and 83 edges. Ten optimal crosstalk genes were selected by LASSO regression and Boruta algorithm, including CD36, WIPI1, CBX7, FCN1, SLC35D2, CP, ZDHHC3, PTPN3, LPL, and SPP1. Among these genes, LPL and SPP1 were the most significant according to NAFLD-transcription factor network. Five hundred twenty-nine nodes and 1,113 edges comprised the PPI network of activated pathway-gene. In addition, 14 common pathways of these two diseases were recognized using Gene Ontology (GO) analysis; among them, regulation of the lipid metabolic process is closely related to both two diseases.

CONCLUSIONS

This study offers hints that NAFLD and DN have a common pathogenesis, and LPL and SPP1 are the most relevant crosstalk genes. Based on the common pathways and optimal crosstalk genes, our proposal carried out further research to disclose the etiology and pathology between the two diseases.