Prevalence and Profile of Nonalcoholic Fatty Liver Disease in Lean Adults: Systematic Review and Meta-Analysis

Gut Microbiota and Genetic Polymorphisms Appear to Drive Disease Expression of Nonalcoholic Fatty Liver Disease in Lean Individuals

Background/Objectives

There are very few comparative studies worldwide between 'lean' and 'nonlean/obese nonalcoholic fatty liver disease (NAFLD)' patients analyzing the differences in gut microbiome, genotype, and serum bile acids. Our aim was to compare the genotype, gut microbiome, bile acid profile, and metabolic patterns of lean NAFLD and obese NAFLD patients with special reference to hepatic fibrosis.

Methods

Both lean and obese NAFLD patients diagnosed by ultrasonography along with matched controls were included. Genotyping, fecal microbiome analysis and estimation of serum total bile acid levels were done for patients as well as controls.

Results

Biochemical and metabolic patterns of lean and obese NAFLD patients were comparable. Lean NAFLD patients had lower fasting plasma glucose (FPG) and homoeostasis model assessment-insulin resistance (HOMA-IR), although the proportions of patients having elevated HOMA-IR and metabolic syndrome (MS) were comparable. Noninvasive scores of liver fibrosis were also comparable. A greater proportion of lean NAFLD patients had the PNPLA3 rs738409 (G/G) genotype. However, there was no association of genetic polymorphisms with steatosis or fibrosis. Nonlean and lean NAFLD patients had comparable serum total bile acid levels. On microbiome analysis, lean NAFLD patients were found to have distinct expression of bacterial species while beta diversity was found to be significantly different across all groups.

Conclusion

Lean NAFLD patients were found to have the PNPLA3 rs738409 (G/G) genotype. Lean NAFLD patients were also found to have unique gut microbial signatures, while beta diversity significantly differed across all groups. Differential expression of gut microbiota and genetic polymorphisms could underlie the pathogenesis of lean NAFLD.

Metabolic dysfunction-associated steatotic liver disease, metabolic alcohol-related liver disease, and incident dementia: a nationwide cohort study : MASLD, MetALD, and dementia risk

BACKGROUND

The relationship between the newly proposed steatotic liver disease (SLD) subtypes-metabolic dysfunction-associated steatotic liver disease (MASLD) and metabolic alcohol-associated liver disease (MetALD)-and dementia is understudied. We evaluated the dementia risk associated with these subtypes.

METHODS

This retrospective cohort study included 296,001 participants aged over 60 who underwent health examinations between 2009 and 2010. Participants were categorized into non-SLD (reference), MASLD, and MetALD groups and followed up until dementia onset, death, or December 31, 2019. SLD was defined by a fatty liver index ≥ 30, with (i) MASLD based on cardiometabolic risk factors, and (ii) MetALD as MASLD with moderate alcohol intake. Outcomes included overall dementia, Alzheimer's disease (AD), and vascular dementia (VaD). Subdistribution hazard ratios (SHRs) was calculated using the Fine-Gray model, treating death as a competing risk.

RESULTS

Over 7,430,253 person-years of follow-up, 11,345 dementia cases occurred (10,863 AD and 2,159 VaD). Adjusted SHRs for MASLD were 1.10 (1.07-1.13) for AD and 1.20 (1.13-1.27) for VaD. For MetALD, SHRs were 0.90 (0.87-0.94) for AD and 1.53 (1.40-1.66) for VaD. Dementia risk in both MASLD and MetALD increased over longer periods, with MetALD initially linked to increased VaD risk and decreased AD risk, which reversed after three years.

CONCLUSIONS

MASLD and MetALD were associated with increased risks of AD and VaD; MetALD showing a stronger association with VaD. Understanding the distinct effects of different SLD subtypes on dementia is crucial for improving risk assessment and management strategies.

Leptin acutely increases hepatic triglyceride secretion in patients with lipodystrophy

BACKGROUND AND AIMS

Metreleptin ameliorates hepatic steatosis partially independent of its anorexic action. We previously showed that metreleptin increases hepatic very low-density lipoprotein triglycerides (VLDL1-TG) export in rodents and healthy humans requiring intact hepatic autonomic innervation. The primary aim of this study was to investigate whether metreleptin has anti-steatotic properties in patients with lipodystrophy by increasing VLDL1-TG export. In addition, we present a case of generalized lipodystrophy undergoing metreleptin treatment after liver transplantation, a model for hepatic autonomic denervation.

METHODS

In this randomized, placebo-controlled, crossover trial (EudraCT 2017-003014-22) we assessed the acute effects of a single metreleptin injection in 10 patients (8 females, 2 males; mean age ± SD: 49 ± 14 yrs; 9 familial partial and 1 generalized lipodystrophy) on hepatic VLDL1-TG secretion and hepatocellular lipid content (HCL) measured via an intravenous fat emulsion test and 1H-magnetic resonance spectroscopy, respectively.

RESULTS

We found that a single injection of metreleptin increased hepatic VLDL1-TG secretion by 75 % (mean difference ± SD: +219 ± 149 mg/h metreleptin vs. placebo; p = 0.001), without significant changes in HCL within 3 h (mean difference ± SD: -8 ± 14 % metreleptin vs. placebo, p = 0.14). Metreleptin therapy in a patient with generalized lipodystrophy following liver transplantation failed to ameliorate hepatic steatosis despite improving glucose and lipid metabolism.

CONCLUSIONS

Leptin acutely increases hepatic VLDL1-TG secretion in patients with lipodystrophy, likely contributing to metreleptin's body weight-independent anti-steatotic effects. The case report suggests that intact autonomic liver innervation may be required for this action, warranting further research.

Lean MASLD and Cardiovascular Disease: A Review

Metabolic-associated steatotic liver disease (MASLD), formerly known as nonalcoholic fatty liver disease, is prevalent worldwide and is highly associated with cardiovascular disease (CVD). Lean MASLD is defined by hepatic steatosis and cardiometabolic risk factors in individuals with a body mass index below 25 in Western populations or below 23 in Asian populations. Paradoxically, some studies indicate that lean MASLD is associated with an elevated risk of cardiovascular (CV) disease and CV mortality compared with nonlean MASLD. Lean MASLD patients exhibit distinctive metabolic, genetic, and microbiome profiles contributing to increased visceral adiposity, sarcopenia, hepatic fibrosis, systemic inflammation, and endothelial dysfunction. This review examines the epidemiology, pathophysiology, and CV outcomes associated with lean MASLD, addressing discrepancies in the literature. Furthermore, it highlights current clinical guidelines, emphasizes lifestyle modifications, and discusses emerging pharmacotherapies as potential treatment options.

The liver-brain axis in metabolic dysfunction-associated steatotic liver disease

Metabolic dysfunction-associated steatotic liver disease (MASLD) affects around 30% of the global population. Studies suggest that MASLD is associated with compromised brain health and cognitive dysfunction, initiating a growing interest in exploring the liver-brain axis mechanistically within MASLD pathophysiology. With the prevalence of MASLD increasing at an alarming rate, leaving a large proportion of people potentially at risk, cognitive dysfunction in MASLD is a health challenge that requires careful consideration and awareness. This Review summarises the current literature on cognitive function in people with MASLD and discusses plausible causes for its impairment. It is likely that a multifaceted spectrum of factors works collectively to affect cognition in patients with MASLD. We describe the role of inflammation, vascular disease, and brain ageing and neurodegeneration as possible key players. This Review also highlights the need for future studies to identify the optimal test for diagnosing cognitive dysfunction in patients with MASLD, to examine the correlation between MASLD progression and the severity of cognitive dysfunction, and to evaluate whether new MASLD-targeted therapies also improve brain dysfunction.

ACSS2 and metabolic diseases: from lipid metabolism to therapeutic target

Elevated incidence of metabolic disorders has been reported worldwide in the recent decade, highlighting the need for developing efficient therapies. These diseases result from a complex interplay of various factors that contribute to disease progression, complications, and resistance to current treatment options. Acetyl-CoA Synthetase Short Chain Family Member 2 (ACSS2) is a nucleo-cytosolic enzyme with both lipogenic and metabolic regulatory roles. Studies on ACSS2 have shown that it is involved in pathways commonly dysregulated in metabolic disorders, leading to fat deposition and disrupted cellular signaling. Although multiple studies have suggested a role of ACSS2 in the metabolic rewiring during tumorigenesis, few studies have examined its involvement in the pathophysiology of metabolic diseases. Recent evidence indicates that ACSS2 may contribute to the pathogenesis of various metabolic disorders making its examination of great interest and potentially aiding in the development of new therapeutic strategies. The objective of this review is to summarize the current understanding of ACSS2's role in metabolic disorders and its potential as a therapeutic target.

Lean MASLD and IBD: Exploring the Intersection of Metabolic Dysfunction and the Gut-Liver Axis

Metabolic dysfunction-associated steatotic liver disease (MASLD) challenges traditional paradigms by manifesting in lean individuals. The link between MASLD and inflammatory bowel disease (IBD) underscores the importance of the gut-liver axis in disease progression and chronic inflammation. This study evaluates MASLD prevalence, clinical characteristics, and diagnostic predictors in lean individuals with and without IBD. This prospective study included 387 lean patients. Hepatic steatosis and fibrosis were assessed using vibration-controlled transient elastography (VCTE). Anthropometric, clinical and biological data were compared. The subgroup analyses focused on MASLD patients with and without IBD. MASLD was present in 34.1% of lean individuals and 46.3% of those who were lean with IBD. MASLD patients had increased visceral adiposity (CUN-BAE: 31.21 ± 5.42 vs. 24.57 ± 6.49, p < 0.001) and metabolic dysfunction, including dyslipidemia and elevated fasting glucose. IBD-MASLD patients exhibited greater hepatic steatosis and systemic inflammation. CUN-BAE outperformed FLI and HSI in predicting liver steatosis, especially in IBD patients (AUC = 0.806). Lean MASLD, particularly in IBD patients, highlights the need for tailored diagnostic and management strategies. The gut-liver axis plays a key role in disease progression, and the CUN-BAE index demonstrates superior accuracy for identifying liver steatosis.

Triterpenoids from Chios Mastiha Resin Against MASLD-A Molecular Docking Survey

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease without an approved pharmacological approach for its prevention/treatment. Based on the modified Delphi process, NAFLD was redefined as metabolic dysfunction-associated steatotic liver disease (MASLD) to highlight the metabolic aspect of liver pathogenesis. Chios mastiha (Pistacia lentiscus var. Chia, Anacardiaceae) resin demonstrated promising results in MASLD treatment. In this paper, molecular docking was applied to test 16 compounds from Chios mastiha as potential ligands for the receptors GR, LXRα, LXRβ, PPARα PPARγ, MC4R, AMPK, and VEGFR2, whose up- and down-regulation interfere with MASLD development and progression. The observed compounds had moderate and high affinity for LXR, GR, MC4R, and PPARγ in comparison to proven ligands, while their affinity for PPARα, AMPK, and VEGFR was less pronounced. The combination of active compounds from Chios mastiha rather than a single molecule may have a superior ability to control the intertwined MASLD metabolic pathways.

Central Obesity is an Independent Determinant of Advanced Fibrosis in Lean Patients With Nonalcoholic Fatty Liver Disease

Background

The current definition of lean is based on body mass index (BMI). However, BMI is an imperfect surrogate for adiposity and provides no information on central obesity (CO). Hence, we explored the differences in clinical profile and liver disease severity in lean patients with nonalcoholic fatty liver disease (NAFLD) with and without CO.

Methods

One hundred seventy lean patients with NAFLD (BMI <23 kg/m2) were divided into two groups depending upon the presence or absence of CO (waist circumference ≥80 cm in females and ≥90 cm in males). Noninvasive assessment of steatosis was done by ultrasound and controlled attenuation parameter (CAP), while fibrosis was assessed with FIB-4 and liver stiffness measurement (LSM). FibroScan-AST (FAST) score was used for non-invasive prediction of NASH with significant fibrosis.

Results

Of 170 patients with lean NAFLD, 96 (56.5%) had CO. Female gender (40.6% vs. 17.6%, P = 0.001), hypertriglyceridemia (58.3% vs. 39.2%, P = 0.01) and metabolic syndrome (23.9% vs. 4.1%, P < 0.001) were more common in the CO group. There was a poor correlation between BMI and waist circumference (r = 0.24, 95% CI: 0.09-0.38). Grade 2-3 steatosis on ultrasound was significantly more common in CO patients (30% vs. 12.3%, P = 0.007). CAP [312.5 (289.8-341) dB/m vs. 275 (248-305.1) dB/m, P = 0.002], FAST score [0.42 (0.15-0.66) vs. 0.26 (0.11-0.39), P = 0.04], FIB-4 and LSM were higher in those with CO. Advanced fibrosis was more prevalent among CO patients using FIB-4 (19.8% vs 8.1%, P = 0.03) and LSM (9.5% vs. 0, P = 0.04). CO was independently associated with advanced fibrosis after adjusting for BMI and metabolic risk factors (aOR: 3.11 (1.10-8.96), P = 0.03). Among these 170 patients, 142 fulfilled metabolic dysfunction associated steatotic liver disease (MASLD) criteria. CO was also an independent risk factor for advanced fibrosis in MASLD (3.32 (1.23-8.5), P = 0.02).

Conclusion

Lean patients with NAFLD or MASLD and CO have more severe liver disease compared to those without CO.

Non-obese non-alcoholic fatty liver disease and the risk of chronic kidney disease: a systematic review and meta-analysis

Background

Data on risk of developing chronic kidney disease (CKD) between non-obese and obese non-alcoholic fatty liver disease (NAFLD) patients are limited. We aimed to reveal the risk difference of incident CKD between non-obese and obese NAFLD patients.

Methods

We searched PubMed, Embase, and Web of Science databases for studies which reported the incidence of CKD in non-obese and obese NAFLD from inception to 10 March 2024. The primary and secondary outcomes were pooled. Subgroup analysis was used to examine the heterogeneity.

Results

A total of 15 studies were incorporated. The incidence of CKD in non-obese and obese NAFLD were 1,450/38,720 (3.74%) and 3,067/84,154 (3.64%), respectively. Non-obese NAFLD patients had a comparable risk of CKD as obese NAFLD (odds ratio [OR] 0.92, 95% confidence interval [95% CI] [0.72-1.19], I2 = 88%). No differences in estimated glomerular filtration rate and serum creatinine between non-obese and obese NAFLD were found. The mean differences (MD) and 95% CI were 0.01 [-0.02 to 0.04] and 0.50 [-0.90 to 1.90], respectively. In subgroup analyses, non-obese NAFLD had higher eGFR when diagnosed with ultrasound (MD 1.45, 95% CI [0.11-2.79], I2 = 21%). Non-obese NAFLD had higher creatinine in non-Asian (MD 0.06, 95% CI [0.01-0.11], I2 = 55%) and when taking BMI > 30 as the criterion for obesity (MD 0.06, 95% CI [0.00-0.12], I2 = 76%). The occurrence of CKD did not differ when non-obese NAFLD were categorized into overweight and normal-weight types.

Conclusions

Non-obese NAFLD patients experienced the same risk of CKD compared to obese NAFLD.

Steatotic liver disease among lean and non-lean individuals in Southern Lao PDR: a cross-sectional study of risk factors

BACKGROUND

Steatotic liver disease (SLD) prevalence is rising worldwide, linked to insulin resistance and obesity. SLD prevalence can surpass 10% even among those with normal weight. In Lao People's Democratic Republic (Lao PDR), where Opisthorchis viverrini (OV) trematode infection and type 2 diabetes mellitus (T2DM) are common, infection related liver morbidity such as cholangiocarcinoma (CCA) is high, but data on SLD prevalence is lacking. The objective of this study was to estimate the prevalence and explore determinants of SLD in rural southern Lao PDR for lean and non-lean populations.

METHOD

A cross-sectional community-based study assessed SLD prevalence using abdominal ultrasonography (US). Factors investigated for association with SLD were identified by interview, serological tests (Hepatitis B surface antigen (HBsAg); lipids and HbA1c), anthropometrical measurements, and parasitological assessments (OV infection). Uni- and multivariable logistic regression analyses with SLD as endpoint were conducted separately for lean (body mass index (BMI) <23.0 kg/m2) and non-lean (BMI ≥ 23.0 kg/m2) participants.

RESULT

2,826 participants were included. SLD prevalence was 27.1% (95% confidence interval (95% CI) 24.0%-30.4%), higher among non-lean (39.8%) than lean individuals (17.4%). Lean individuals with OV infection had a statistically significant association with lower odds of SLD (adjusted odds ratio (aOR) 0.49, 95% CI 0.33 - 0.73). T2DM showed a significant positive association with SLD in both lean (aOR 3.58, 95% CI 2.28 - 5.63) and non-lean individuals (aOR 3.31, 95% CI 2.31 - 4.74) while dyslipidemia was significantly associated only in the non-lean group (aOR 1.83, 95% CI 1.09 - 3.07). Females participants exhibited elevated odds of SLD in both lean (aOR 1.43, 95% CI 1.02 - 2.01) and non-lean SLD (aOR 1.50, 95% CI 1.12 - 2.01).

CONCLUSION

SLD prevalence is notably high among Laotian adults in rural areas, particularly in females and in non-lean individuals. Lean individuals with OV infection exhibited lower SLD prevalence. SLD was more prevalent in individuals with T2DM, independent of BMI. SLD adds to the burden of infection-related liver morbidity in Lao PDR.

Liver diseases and hepatocellular carcinoma in the Asia-Pacific region: burden, trends, challenges and future directions

Globally, nearly half of deaths from cirrhosis and chronic liver diseases (CLD) and three-quarters of deaths from hepatocellular carcinoma (HCC) occur in the Asia-Pacific region. Chronic hepatitis B is responsible for the vast majority of liver-related deaths in the region. Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most common form of CLD, affecting an estimated 30% of the adult population. Compared with people of European descent, people from the Asia-Pacific region carry more genetic variants associated with MASLD and its progression. Alcohol is a fast-growing cause of CLD and HCC in Asia as a result of the rising per-capita consumption of alcohol. Drug-induced liver injury is under-recognized and probably has a high prevalence in this region. The epidemiological and outcome data of acute-on-chronic liver failure are heterogeneous, and non-unified definitions across regions contribute to this heterogeneity. CLDs are severely underdiagnosed, and effective treatments and vaccinations are underutilized. In this Review, we highlight trends in the burden of CLD and HCC in the Asia-Pacific region and discuss the rapidly changing aetiologies of liver disease. We examine the multiple gaps in the care cascade and propose mitigating strategies and future directions.

Associations of an overall healthy lifestyle with the risk of metabolic dysfunction-associated fatty liver disease

BACKGROUND

Metabolic dysfunction-associated fatty liver disease (MAFLD) affects up to one-third of the global population. Since no approved pharmacotherapy for MAFLD is available, lifestyle modification remains the cornerstone of clinical care. Our study aims to evaluate the association of an overall healthy lifestyle with MAFLD risk.

METHODS

We conducted an analysis of 327,387 participants from UK biobank. An overall healthy lifestyle score including six evidence-based lifestyles (diet, alcohol consumption, physical activity, sedentary behavior, sleep, and smoking) was assessed by questionnaires. MAFLD and its subtypes were diagnosed by blood biochemistry, ICD codes, and medication information from touchscreen and verbal interview. The prevalence ratios (PRs) and risk ratios (RRs) were estimated by Poisson regression models with robust variance.

RESULTS

In the cross-sectional analysis, the PR (95% CI) was 0.83 (0.83 to 0.84) for MAFLD, and 0.83 (0.83 to 0.84) for MAFLD-overweight/obesity (MAFLD-O), 0.68 (0.66 to 0.70) for MAFLD-lean/normal weight and metabolic dysfunction (P-value for heterogeneity < 0.001), and 0.71 (0.71 to 0.72) for MAFLD-type 2 diabetes mellitus (MAFLD-T2D); and 0.68 (0.66 to 0.71) for dual (or more) etiology fatty liver disease (MAFLD-dual) and 0.83 (0.83 to 0.84) for single etiology MAFLD (MAFLD-single) (P-value for heterogeneity < 0.001) for one additional point in the overall healthy lifestyle score. During a median follow-up of 4.4 years, the RR (95% CI) was 0.83 (0.81 to 0.85) for MAFLD, and 0.83 (0.81 to 0.85) for MAFLD-O, 0.71 (0.62 to 0.81) for MAFLD-L, and 0.68 (0.64 to 0.72) for MAFLD-T2D (P-value for heterogeneity < 0.001); and 0.83 (0.81 to 0.85) for MAFLD-dual and 0.70 (0.58 to 0.85) for MAFLD-single (P-value for heterogeneity = 0.08) for one additional point in the overall healthy lifestyle score. These findings were validated in a prospective analysis among 15,721 participants with revisit data, and also supported by fatty liver index and proton density fat fraction data.

CONCLUSIONS

An overall healthy lifestyle that includes six evidence-based factors was strongly associated with lower MAFLD risk, especially the subtypes with multiple etiologies.

Drivers of cardiovascular disease in metabolic dysfunction-associated steatotic liver disease: the threats of oxidative stress

Non-alcoholic fatty liver disease (NAFLD), now known as metabolic-associated steatotic liver disease (MASLD), is the most common liver disease worldwide, with a prevalence of 38%. In these patients, cardiovascular disease (CVD) is the number one cause of mortality rather than liver disease. Liver abnormalities per se due to MASLD contribute to risk factors such as dyslipidemia and obesity and increase CVD incidents. In this review we discuss hepatic pathophysiological changes the liver of MASLD leading to cardiovascular risks, including liver sinusoidal endothelial cells, insulin resistance, and oxidative stress with a focus on glutathione metabolism and function. In an era where there is an increasingly robust recognition of what causes CVD, such as the factors included by the American Heart Association in the recently developed PREVENT equation, the inclusion of liver disease may open doors to how we approach treatment for MASLD patients who are at risk of CVD.

METS-IR, a Novel Simple Insulin Resistance Index, is Associated with NAFLD in Patients with Type 2 Diabetes Mellitus

Purpose

Substantial evidence has established a strong association between non-alcoholic fatty liver disease (NAFLD), type 2 diabetes mellitus (T2DM) and insulin resistance (IR). Insulin resistance metabolic score (METS-IR) is a new and more effective comprehensive indicator for measuring IR. Our aim was to investigate the relationship between METS-IR and NAFLD in T2DM population.

Patients and methods

This cross-sectional study included 1097 adult patients with T2DM. Anthropometric measurements and biochemical indicators were collected, and the NAFLD was diagnosed by ultrasound. The METS-IR was calculated. Based on the presence of NAFLD, the population was divided into non-NAFLD and NAFLD groups. The relationship between METS-IR and NAFLD was evaluated.

Results

Compared with the non-NAFLD group, the METS-IR was higher in the NAFLD group (P < 0.001). The incidence rate of NAFLD increased across the quartiles of the METS-IR (P < 0.001). Spearman correlation analysis showed that METS-IR was positively correlated with NAFLD (Correlation Coefficient: 0.441, P < 0.001). The binary logistic regression analysis indicated that METS-IR was independently associated with NAFLD (OR: 1.120, 95% CI 1.080-1.161). Furthermore, the area under the receiver operating characteristic curve of the METS-IR was 0.781 (95% CI 0.746-0.817) and relatively higher than other evaluation variables.

Conclusion

In patients with T2DM, METS-IR is closely associated with NAFLD, and might be a valuable predictor of NAFLD. Further research is needed to verify this association.

Correlation between Serum Levels of Nitric Oxide and Adropin and Erectile Dysfunction in Males with Nonalcoholic Fatty Liver Disease: An Observational Study

The current study aimed to evaluate the serum levels of nitric oxide (NO) and adropin in males with non-alcoholic fatty liver disease (NAFLD) induced erectile dysfunction (ED) and NAFLD patients without ED and controls. The current study selected 165 participants from the hepatology department from November 2021 to November 2022. The patients were either suffering from NAFLD with normal liver functions or non-alcoholic steatohepatitis with abnormal liver functions. They were diagnosed by abdominal ultrasonography. Participants were evaluated using the validated Arabic version of the International Index of Erectile Function (ArIIEF-5), the Arabic form of the Generalized Anxiety Disorder-7 (GAD-7) questionnaire and the Patient Health Questionnaire-9 (PHQ-9). Noteworthy, there were significant positive correlations between ArIIEF-5 score, NO, adropin and total testosterone (r = 0.380, p = 0.001; r = 0.507, p =  < 0.001; r = 0.246, p = 0.038, respectively). Meanwhile, there were significant negative correlations between ArIIEF-5 score, creatinine, duration of the disease and scores of GAD-7 and PHQ-9 (r = -0.656, p =  < 0.001; r = -0.368, p = 0.002; r = -0.663, p =  < 0.001; r = -0.248, p = 0.037, respectively). Finally, a linear regression analysis revealed that GAD-7, creatinine, and adropin were the only strong independent predictors of ArIIEF-5, as the 95% confidence interval in the form of upper and lower bounds was -0.349, -0.843, p < 0.001, -6.507, -18.402, p < 0.001, 0.476, 0.117, and p 0.002, respectively. Impaired NO and adropin levels play a potential role in the development of ED in patients with NAFLD.

Characterizing Nonalcoholic Fatty Liver Disease (NAFLD) in Lean Individuals at a Tertiary Care Hospital: A Cross-sectional Study

Background

Fat accumulation in the liver is affecting 38% of the global population. It can also occur in normal-weight individuals, termed lean non-alcoholic fatty liver disease (NAFLD). This study examines Asian and Western body mass index (BMI) criteria, as well as metabolic dysfunction-associated fatty liver disease (MAFLD) and metabolic dysfunction-associated steatotic liver disease (MASLD) diagnostic guidelines, in lean fatty liver cases within a healthcare setting.

Materials and methods

This study was cross-sectional included 111 lean patients diagnosed with NAFLD using either ultrasound or VCTE from January 2023 to March 2024. Anthropometric, laboratory and non-invasive liver fibrosis evaluation parameters were used. The study assessed clinical characteristics and metabolic risk factors of patients with BMI ≤ 23 kg/m2 and BMI between 23 and ≤ 25 kg/m2 using MASLD and MAFLD diagnostic criteria.

Results

The cohort included NAFLD patients with a mean age of 43.3 years (±13.2 years). Of the participants, 33% were diagnosed through ultrasonography, whereas 67% diagnosis were made via Fibro scan. Majority were male 92 (83%), while females were 19 (17%) of the entire group. The lean NAFLD criteria for Asia and the West were satisfied by 43 (39%) persons with a BMI ≤ 23 kg/m2 and 68 (61%) individuals with a BMI between 23 and ≤ 25 kg/m2, respectively. The average body mass index (BMI) was 23.0 ± 1.5 kg/m2. Diabetes was observed in 16%, hypertension 11%, and ischemic heart disease in 2%. Out of the total individuals, 92 satisfied the MASLD-MAFLD criteria, whereas 18 did not qualify the MAFLD criteria for diagnosis and were classed as MASLD-Alone. Elevated triglycerides, insulin resistance (HOMA-IR ≥ 2), and three or more cardiometabolic risk factors (CMRF) were significant in the MASLD-MAFLD group compared to the MASLD-Alone group (p < 0.05). Comparing BMI criteria, no significant differences were found in terms of fibrosis between the Western and Asian lean NAFLD BMI criteria's (p = 0.243).

Conclusion

Lean NAFLD is a major global health concern. Applying non-Asian BMI criteria (BMI ≤ 25 kg/m2) for lean Asians improves early detection and intervention for at-risk individuals. Accurate use of MAFLD and MASLD criteria is essential to prevent confusion in diagnosing lean NAFLD. Further multicenter investigations with larger sample numbers are required to corroborate these results in our community.

How to cite this article

Nazir S, Abbas Z, Gazder DP, et al. Characterizing Nonalcoholic Fatty Liver Disease (NAFLD) in Lean Individuals at a Tertiary Care Hospital: A Cross-sectional Study. Euroasian J Hepato-Gastroenterol 2024;14(2):198-204.

Natural history of lean and non-lean metabolic dysfunction-associated steatotic liver disease

BACKGROUND

Conflicting evidence regarding the prognosis of lean metabolic dysfunction-associated steatotic liver disease (MASLD) has raised substantial questions.

AIM

This study aimed to elucidate the prognosis of lean MASLD by conducting a comprehensive analysis of a vast Asian cohort.

METHODS

This study used a nationwide, population-based database and analyzed 2.9 million patients. The primary endpoints were liver-related events (LREs) and cardiovascular events (CVEs) in patients with lean MASLD, non-lean MASLD, and normal liver control groups.

RESULTS

The median observation period was 4.2 years. The 5-year incidence values of LREs in the lean MASLD, non-lean MASLD, and normal liver control groups were 0.065%, 0.039%, and 0.006%, respectively. The LRE risk of lean MASLD was significantly higher than that of normal liver control (adjusted hazard ratio [aHR]: 5.94, 95% confidence interval [CI]: 3.95-8.92) but comparable to that of non-lean MASLD (aHR: 1.35, 95% CI: 0.87-2.08). By contrast, for CVEs, the non-lean MASLD group exhibited a higher 5-year cumulative incidence rate (0.779%) than the lean MASLD (0.600%) and normal liver control (0.254%) groups. The lean MASLD group had a reduced risk of CVEs compared with the non-lean MASLD group (aHR, 0.73; 95% CI: 0.64-0.84), and comparable risk of CVEs to the normal liver control group (aHR, 0.99; 95% CI: 0.88-1.12).

CONCLUSION

Lean MASLD exhibits a similar LRE risk and a lower CVE risk to non-lean MASLD. Therefore, follow-up and treatment strategies should be tailored to the specific MASLD condition.

Metabolic dysfunction-associated steatotic liver disease: A silent pandemic

The worldwide epidemiology of non-alcoholic fatty liver disease (NAFLD) is showing an upward trend, parallel to the rising trend of metabolic syndrome, owing to lifestyle changes. The pathogenesis of NAFLD has not been fully understood yet. Therefore, NAFLD has emerged as a public health concern in the field of hepatology and metabolisms worldwide. Recent changes in the nomenclature from NAFLD to metabolic dysfunction-associated steatotic liver disease have brought a positive outlook changes in the understanding of the disease process and doctor-patient communication. Lifestyle changes are the main treatment modality. Recently, clinical trial using drugs that target 'insulin resistance' which is the driving force behind NAFLD, have shown promising results. Further translational research is needed to better understand the underlying pathophysiological mechanism of NAFLD which may open newer avenues of therapeutic targets. The role of gut dysbiosis in etiopathogenesis and use of fecal microbiota modification in the treatment should be studied extensively. Prevention of this silent epidemic by spreading awareness and early intervention should be our priority.

Association of the habitual dietary intake with the fatty liver index and effect modification by metabotypes in the population-based KORA-Fit study

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is an emerging threat for public health with diet being a major risk factor in disease development and progression. However, the effects of habitual food consumption on fatty liver are still inconclusive as well as the proposed role of the individuals' metabolic profiles. Therefore, the aim of our study is to examine the associations between diet and NAFLD with an emphasis on the influence of specific metabotypes in the general population.

METHODS

A total of 689 participants (304 men and 385 women) of the KORA-Fit (S4) survey, a follow-up study of the population-based KORA cohort study running in the Region of Augsburg, Germany, were included in this analysis. Dietary information was derived from repeated 24-h food lists and a food frequency questionnaire. The intake of energy and energy-providing nutrients were calculated using the national food composition database. The presence of fatty liver was quantified by the fatty liver index (FLI), and metabotypes were calculated using K-means clustering. Multivariable linear regression models were used for the analysis of habitual food groups and FLI; for the evaluation of macronutrients, energy substitution models were applied.

RESULTS

A higher consumption of nuts and whole grains, and a better diet quality (according to Alternate Healthy Eating Index and Mediterranean Diet Score) were associated with lower FLI values, while the intake of soft drinks, meat, fish and eggs were associated with a higher FLI. The isocaloric substitution of carbohydrates with polyunsaturated fatty acids was associated with a decreased FLI, while substitution with monounsaturated fatty acids and protein showed increased FLI. Statistically significant interactions with the metabotype were observed for most food groups.

CONCLUSION

The consumption of plant-based food groups, including nuts and whole grains, and diet quality, were associated with lower FLI values, whereas the intake of soft drinks and products of animal origin (meat, fish, eggs) were associated with a higher FLI. The observed statistically significant interactions with the metabotype for most food groups could help to develop targeted prevention strategies on a population-based level if confirmed in independent prospective studies.

Non-alcoholic fatty liver modifies associations of body mass index and waist circumference with cardiometabolic risk: The CARDIA study

Background

Non-alcoholic fatty liver disease (NAFLD) is recognized as a prevalent determinant of cardiometabolic diseases. The association between NAFLD and obesity warrants further research on how NAFLD modifies associations between body mass index (BMI) and Waist circumference (WC) with cardiometabolic risk (CMR).

Objective

This study assessed whether NAFLD modifies associations between BMI and WC with 5-year changes in CMR in 2366 CARDIA study participants.

Methods

Non-contrast CT was used to quantify liver attenuation, with ≤51 Hounsfield Units (HU) used to define NAFLD in the absence of secondary causes of excess liver fat. The dependent variable was the average Z score of fasting glucose, insulin, triglycerides [log], (-) high-density lipoprotein cholesterol (HDL-C), and systolic blood pressure(SBP). Multivariable linear regression was used to estimate the associations between BMI and WC with CMR. Effect modification by NAFLD was assessed by an interaction term between NAFLD and BMI or WC.

Results

The final sample had 539 (23%) NAFLD cases. NAFLD modified the association of BMI and WC with CMR (interaction p < 0.0001 for both). BMI and WC were associated with CMR in participants without NAFLD (p < 0.001), but not among those with NAFLD. Participants with NAFLD and normal BMI and WC had CMR estimates that were higher than those without NAFLD in the obese categories. Among those without NAFLD the 5 years CMR change estimate was 0.09 (95% CI: 0.062, 0.125) for BMI ≥30 kg/m2 compared to -0.06 (-0.092, -0.018) for BMI < 25 kg/m2, and among those with NAFLD, these estimates were 0.15 (0.108, 0.193) and 0.16 (-0.035, 0.363).

Conclusions

NAFLD modifies associations of BMI and WC with CMR. Compared with BMI and WC, NAFLD was more strongly associated with CMR. In the presence of NAFLD, BMI and WC were not associated with CMR. These findings have implications for clinical screening guidelines.

Natural history of metabolic dysfunction-associated steatotic liver disease

Metabolic dysfunction-associated steatotic liver disease (MASLD), which has been the term for non-alcoholic fatty liver disease (NAFLD) since June 2023, represents the most common liver disease worldwide and is a leading cause of liver-related morbidity and mortality. A thorough knowledge of the disease's natural history is required to promptly stratify patients' risks, since MASLD is a multifaceted disorder with a broad range of clinical phenotypes. The histological disease spectrum ranges from isolated hepatic steatosis, currently named as metabolic dysfunction-associated steatotic liver (MASL), to metabolic dysfunction-associated steatohepatitis (MASH) and eventually may accumulate hepatic fibrosis and develop cirrhosis and/or hepatocellular carcinoma (HCC). Several risk factors for fibrosis progression have been identified, while the disease's progression displays notable dynamism and bidirectionality. When compared to the general population, all MASLD histological stages are substantially related with greater overall mortality, and this association exhibits a disease severity-dependent pattern. Interestingly, the fibrosis stage is the most accurate predictor of mortality among MASLD patients. The mortality attributed to MASLD predominantly stems from issues linked with the liver and cardiovascular system, as well as HCC and extrahepatic cancers. In light of the disease natural course, it is crucial to prioritize the identification of at-risk patients for disease progression in order to effectively address and change modifiable risk factors, hence mitigating disease complications. Further investigation is required to define the phenotype of rapid progressors more precisely as well as to improve risk stratification for HCC in non-cirrhotic individuals.

Hepatic Fibrosis and Cancer: The Silent Threats of Metabolic Syndrome

Metabolic dysfunction-associated steatotic (fatty) liver disease (MASLD), previously termed non-alcoholic fatty liver disease, is a worldwide epidemic that can lead to hepatic inflammation, fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). The disease is typically a component of the metabolic syndrome that accompanies obesity, and is often overlooked because the liver manifestations are clinically silent until late-stage disease is present (i.e., cirrhosis). Moreover, Asian populations, including Koreans, have a higher fraction of patients who are lean, yet their illness has the same prognosis or worse than those who are obese. Nonetheless, ongoing injury can lead to hepatic inflammation and ballooning of hepatocytes as classic features. Over time, fibrosis develops following activation of hepatic stellate cells, the liver's main fibrogenic cell type. The disease is usually more advanced in patients with type 2 diabetes mellitus, indicating that all diabetic patients should be screened for liver disease. Although there has been substantial progress in clarifying pathways of injury and fibrosis, there no approved therapies yet, but current research seeks to uncover the pathways driving hepatic inflammation and fibrosis, in hopes of identifying new therapeutic targets. Emerging molecular methods, especially single cell sequencing technologies, are revolutionizing our ability to clarify mechanisms underlying MASLD-associated fibrosis and HCC.

Physiologically Based Pharmacokinetic (PBPK) Model Predictions of Disease Mediated Changes in Drug Disposition in Patients with Nonalcoholic Fatty Liver Disease (NAFLD)

PURPOSE

This study was designed to verify a virtual population representing patients with nonalcoholic fatty liver disease (NAFLD) to support the implementation of a physiologically based pharmacokinetic (PBPK) modeling approach for prediction of disease-related changes in drug pharmacokinetics.

METHODS

A virtual NAFLD patient population was developed in GastroPlus (v.9.8.2) by accounting for pathophysiological changes associated with the disease and proteomics-informed alterations in the abundance of metabolizing enzymes and transporters pertinent to drug disposition. The NAFLD population model was verified using exemplar drugs where elimination is influenced predominantly by cytochrome P450 (CYP) enzymes (chlorzoxazone, caffeine, midazolam, pioglitazone) or by transporters (rosuvastatin, 11C-metformin, morphine and the glucuronide metabolite of morphine).

RESULTS

PBPK model predictions of plasma concentrations of all the selected drugs and hepatic radioactivity levels of 11C-metformin were consistent with the clinically-observed data. Importantly, the PBPK simulations using the virtual NAFLD population model provided reliable estimates of the extent of changes in key pharmacokinetic parameters for the exemplar drugs, with mean predicted ratios (NAFLD patients divided by healthy individuals) within 0.80- to 1.25-fold of the clinically-reported values, except for midazolam (prediction-fold difference of 0.72).

CONCLUSION

A virtual NAFLD population model within the PBPK framework was successfully developed with good predictive capability of estimating disease-related changes in drug pharmacokinetics. This supports the use of a PBPK modeling approach for prediction of the pharmacokinetics of new investigational or repurposed drugs in patients with NAFLD and may help inform dose adjustments for drugs commonly used to treat comorbidities in this patient population.

Metabolic-dysfunction associated steatotic liver disease-related diseases, cognition and dementia: A two-sample mendelian randomization study

BACKGROUND

The results of current studies on metabolic-dysfunction associated steatotic liver disease (MASLD)-related diseases, cognition and dementia are inconsistent. This study aimed to elucidate the effects of MASLD-related diseases on cognition and dementia.

METHODS

By using single-nucleotide polymorphisms (SNPs) associated with different traits of NAFLD (chronically elevated serum alanine aminotransferase levels [cALT], imaging-accessed and biopsy-proven NAFLD), metabolic dysfunction-associated steatohepatitis, and liver fibrosis and cirrhosis, we employed three methods of mendelian randomization (MR) analysis (inverse-variance weighted [IVW], weighted median, and MR-Egger) to determine the causal relationships between MASLD-related diseases and cognition and dementia. We used Cochran's Q test to examine the heterogeneity, and MR-PRESSO was used to identify outliers (NbDistribution = 10000). The horizontal pleiotropy was evaluated using the MR-Egger intercept test. A leave-one-out analysis was used to assess the impact of individual SNP on the overall MR results. We also repeated the MR analysis after excluding SNPs associated with confounding factors.

RESULTS

The results of MR analysis suggested positive causal associations between MASLD confirmed by liver biopsy (p of IVW = 0.020, OR = 1.660, 95%CI = 1.082-2.546) and liver fibrosis and cirrhosis (p of IVW = 0.009, OR = 1.849, 95%CI = 1.169-2.922) with vascular dementia (VD). However, there was no evidence of a causal link between MASLD-related diseases and cognitive performance and other types of dementia (any dementia, Alzheimer's disease, dementia with lewy bodies, and frontotemporal dementia). Sensitivity tests supported the robustness of the results.

CONCLUSIONS

This two-sample MR analysis suggests that genetically predicted MASLD and liver fibrosis and cirrhosis may increase the VD risk. Nonetheless, the causal effects of NAFLD-related diseases on VD need more in-depth research.

The metabolic profiles and body composition of non-obese metabolic associated fatty liver disease

Background/purpose

Metabolic-associated fatty liver disease (MAFLD) is a major cause of chronic liver disease worldwide and is generally thought to be closely related to obesity and diabetes. However, it also affects non-obese individuals, particularly in Asian cultures.

Methods

Healthy physical examination subjects and MAFLD patients were included in the endocrinology department of Jiangsu Provincial Hospital of Traditional Chinese Medicine. MAFLD was defined as fatty liver in imaging without virus infection, drug, alcohol, or other known causes of chronic liver disease. Non-obese MAFLD was defined as MAFLD in non-obese subjects (BMI<25 kg/m2).

Results

The final analysis comprised 1047 participants in total. Of 946 MAFLD patients, 162 (17.12%) were diagnosed with non-obese MAFLD. Non-obese MAFLD patients were older, had lower alanine aminotransferase (ALT), triglyceride, and waist circumference, but had higher high density lipoprotein cholesterol (HDL-c) than obese MAFLD patients. Compared with non-obese healthy controls, non-obese MAFLD patients had higher BMI, ALT, gamma-glutamyl transferase (GGT), uric acid (UA), triglycerides (TG), and low density lipoprotein cholesterol (LDL-c). In terms of body composition, body fat mass (BFM), waist-hip ratio (WHR), percent body fat (PBF), visceral fat area (VFA), and fat mass index (FMI) were lower in non-obese healthy controls than non-obese MAFLD patients. A binary logistic regression analysis revealed that non-obese MAFLD was linked with lower GGT and higher HDL-c.

Conclusion

In this study cohort, non-obese MAFLD was present at a prevalence of 13.90%. In contrast to non-obese healthy controls, non-obese MAFLD patients exhibited different metabolic profiles, but they also had different body compositions.

From complement to complosome in non-alcoholic fatty liver disease: When location matters

Non-alcoholic fatty liver disease (NAFLD) is a growing public health threat and becoming the leading cause of liver transplantation. Nevertheless, no approved specific treatment is currently available for NAFLD. The pathogenesis of NAFLD is multifaceted and not yet fully understood. Accumulating evidence suggests a significant role of the complement system in the development and progression of NAFLD. Here, we provide an overview of the complement system, incorporating the novel concept of complosome, and summarise the up-to-date evidence elucidating the association between complement dysregulation and the pathogenesis of NAFLD. In this process, the extracellular complement system is activated through various pathways, thereby directly contributing to, or working together with other immune cells in the disease development and progression. We also introduce the complosome and assess the evidence that implicates its potential influence in NAFLD through its direct impact on hepatocytes or non-parenchymal liver cells. Additionally, we expound upon how complement system and the complosome may exert their effects in relation with hepatic zonation in NAFLD. Furthermore, we discuss the potential therapeutic implications of targeting the complement system, extracellularly and intracellularly, for NAFLD treatment. Finally, we present future perspectives towards a better understanding of the complement system's contribution to NAFLD.

What Is New in Metabolic Dysfunction-Associated Steatotic Liver Disease in Lean Individuals: From Bench to Bedside

Metabolic dysfunction-associated steatotic liver disease (MASLD) affects more than 30% of the world's adult population. While it is associated with obesity and metabolic syndrome, emerging evidence has shown that a substantial number of MASLD patients have a normal body mass index ("lean individuals with MASLD"). In this article, we provide an overview of the definition, epidemiology, pathogenesis, and clinical outcomes associated with lean individuals with MASLD and updates on current management.

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.

The interplay of metabolic dysfunction-associated fatty liver disease and viral hepatitis on liver disease severity: A large community-based study in a viral endemic area

BACKGROUND AND AIM

The prevalence of metabolic dysfunction-associated fatty liver disease (MAFLD) and its interplay with hepatitis B virus (HBV) and hepatitis C virus (HCV) in terms of liver disease severity is elusive.

METHODS

A mass surveillance program was conducted in a viral hepatitis endemic area. The objective was to identify MAFLD/non-MAFLD subjects with advanced liver disease.

RESULTS

Two thousand two hundred and forty-two (41.7%) of the 5378 subjects were identified as having MAFLD, and 375 (7.0%) had advanced liver disease. The proportions of anti-HCV and HBsAg seropositivity were 19.3% and 9.7%, respectively. The proportions of advanced fibrosis in subjects with non-viral hepatitis (NBNC), HBV and HCV infection were 2.8%, 5.7% and 23.4%, respectively. Subjects with MAFLD had a significantly higher proportion of advanced fibrosis (8.7% vs 5.7%, P < 0.001). Factors associated with advanced fibrosis included age (odds ratio [OR]/95% confidence interval [CI]: 4.8/3.7-6.0, P < 0.001), male sex (OR/CI: 1.3/1.0-1.7, P = 0.019), anti-HCV seropositivity (OR/CI: 5.9/4.6-7.5, P = 0.019), MAFLD-lean metabolic dysregulation (MS) (OR/CI: 2.6/1.3-5.2, P = 0.005; compared with the non-MAFLD group) and MAFLD-diabetes (OR/CI: 1.5/1.1-2.1, P = 0.008; compared with the non-MAFLD group). MAFLD did not aggravate liver disease severity in patients with viral hepatitis. However, among NBNC subjects, factors associated with advanced liver disease included MAFLD-lean MS group (OR/CI: 9.1/2.4-34.6, P = 0.001; compared with non-MAFLD group) and MAFLD-DM group (OR/CI: 2.0/1.2-3.2, P = 0.004; compared with non-MAFLD group).

CONCLUSIONS

MAFLD patients with diabetes and metabolic dysregulation had a higher risk of advanced liver disease. The effect was more significant in non-viral hepatitis subjects in a community level.

Gastrointestinal cancers in lean individuals with non-alcoholic fatty liver disease: A systematic review and meta-analysis

BACKGROUND & AIMS

Obesity and non-alcoholic fatty liver disease (NAFLD) are known risk factors for gastrointestinal (GI) cancers. However, GI carcinogenesis in lean NAFLD patients remains unclear. This systematic review and meta-analysis aims to investigate the association between lean NAFLD and GI cancer risk.

METHODS

PubMed, Embase and Cochrane Library databases were systematically searched (from inception date to April 2023) for cohort studies assessing GI cancers in lean (body mass index [BMI] < 25 kg/m2 or < 23 kg/m2 in Asians) and non-lean (BMI ≥25 kg/m2 or ≥ 23 kg/m2 in Asians) NAFLD individuals. Data from eligible studies were extracted, and meta-analysis was carried out using a random effects model to obtain risk ratios (RRs) with 95% confidence intervals (CIs). Subgroup analyses, meta-regressions and sensitivity analyses were also performed. This study was registered in PROSPERO (CRD42023420902).

RESULTS

Eight studies with 56,745 NAFLD individuals (11% were lean) and 704 cases of incident GI cancers were included. Lean NAFLD was associated with higher risk of hepatic (RR 1.77, 95% CI 1.15-2.73), pancreatic (RR 1.97, 95% CI 1.01-3.86) and colorectal cancers (RR 1.53, 95% CI 1.12-2.09), compared to non-lean NAFLD. No significant differences were observed for oesophagus, gastric, biliary and small intestine cancers.

CONCLUSIONS

This study shows that lean NAFLD patients have an increased risk of liver, pancreatic and colorectal cancers compared to non-lean NAFLD patients, emphasizing the need to explore tailored cancer prevention strategies for this specific patient group. Further research is required to explore the mechanisms underlying the association between lean NAFLD and specific GI cancers.

Mechanisms and Therapeutic Strategies for MAFLD Targeting TLR4 Signaling Pathways

BACKGROUND

Metabolic-associated fatty liver disease (MAFLD) is one of the most common chronic liver diseases. The underlying pathophysiological mechanisms are intricate and involve various factors. Unfortunately, there is currently a lack of available effective treatment options. Toll-like receptors (TLRs) are a group of pattern-recognition receptors that are responsible for activating the innate immune system. Research has demonstrated that TLR4 plays a pivotal role in the progression of MAFLD by facilitating the pathophysiological mechanisms.

SUMMARY

Lipid peroxidation, pro-inflammatory factors, insulin resistance (IR), and dysbiosis of intestinal microbiota are considered as the pathogenic mechanisms of MAFLD. This review summarizes the impact of TLR4 signaling pathways on the progression of MAFLD, specifically in relation to lipid metabolic disorders, IR, oxidative stress, and gut microbiota disorders. Additionally, we emphasize the potential therapeutic approaches for MAFLD that target TLR4 signaling pathways, including the use of plant extracts, traditional Chinese medicines, probiotics, pharmaceuticals such as peroxisome proliferator-activated receptor antagonists and farnesol X agonists, and lifestyle modifications such as dietary changes and exercise also considered. Furthermore, TLR4 signaling pathways have also been linked to the lean MAFLD.

KEY MESSAGES

TLR4 plays a crucial role in MAFLD by triggering IR, buildup of lipids, imbalance in gut microbiota, oxidative stress, and initiation of immune responses. The mitigation of MAFLD can be accomplished by suppressing the TLR4 signaling pathway. In the future, it could potentially emerge as a therapeutic target for the condition.

Prevalence and risk factors of nonalcoholic fatty liver disease, high-risk nonalcoholic steatohepatitis, and fibrosis among lean United States adults: NHANES 2017-2020

Background

Nonalcoholic fatty liver disease (NAFLD) is a growing public health concern worldwide. Early detection and management of modifiable risk factors are critical to mitigating its impact. This study aimed to investigate the prevalence and risk factors of NAFLD, nonalcoholic steatohepatitis (NASH), and fibrosis among lean adults in the United States (US), using the latest National Health and Nutrition Examination Survey (NHANES) dataset from 2017-2020.

Methods

Using controlled attenuation parameter scores of ≥285 dB/m, we assessed the age-adjusted prevalence of lean NAFLD. To determine the age-adjusted prevalence of high-risk NASH and significant fibrosis, we used the FibroScan-aspartate aminotransferase (FAST) score (cutoffs 0.35 and 0.67) and vibration-controlled transient elastography (liver stiffness measurement ≥8 kPa). Multivariate logistic regression was used to identify potential risk factors.

Results

We found the age-adjusted prevalence of lean NAFLD to be 6.30%. Among lean US adults, the age-adjusted prevalence of high-risk NASH and significant fibrosis was 1.29% and 4.35%, respectively. Older age and metabolic comorbidities, such as hypertension, diabetes, and dyslipidemia were associated with NAFLD and its complications.

Conclusion

These findings suggest that the prevalence of NAFLD is of concern among lean individuals, particularly those aged 40 and older with metabolic comorbidities, while a targeted approach to screening and risk stratification for hepatic fibrosis upon lean NAFLD diagnosis is warranted.

Fibrosis-4 index is closely associated with clinical outcomes in acute cardioembolic stroke patients with nonvalvular atrial fibrillation

Liver cirrhosis is a confirmed risk factor for poor prognosis of stroke; however, the contribution of clinically inapparent liver fibrosis to cardioembolic stroke (CES) and its outcomes are poorly understood. This study aimed to investigate the associations between liver fibrosis-measured by the Fibrosis-4 (FIB-4) score-and stroke severity and short-term clinical outcomes of patients with acute CES due to nonvalvular atrial fibrillation (NVAF). A total of 522 patients were followed for a median of 90 days. We calculated the FIB-4 score and defined liver fibrosis as follows: likely advanced fibrosis (FIB-4 > 3.25), indeterminate advanced fibrosis (FIB-4, 1.45-3.25), and unlikely advanced fibrosis (FIB-4 < 1.45). Logistic regression analysis and Cox regression analysis were used to investigate the relations between the FIB-4 score and stroke severity, major disability at discharge, and all-cause mortality. Among these 522 acute CES patients with NVAF, the mean FIB-4 score (2.28) on admission reflected intermediate fibrosis, whereas liver enzymes were largely normal. In multivariate regression analysis, patients with advanced liver fibrosis were more likely to have a higher risk of severe stroke (OR = 2.21, 95% CI 1.04-3.54), major disability at discharge (OR = 4.59, 95% CI 1.88-11.18), and all-cause mortality (HR = 1.25, 95% CI 1.10-1.56) than their counterparts. Regarding sex, these associations were stronger in males but not significant in females. In patients with acute CES due to NVAF, advanced liver fibrosis is associated with severe stroke, major disability, and all-cause death. Our findings indicate that early screening and management of liver fibrosis may decrease stroke severity and risk of death in patients with NVAF, especially for male patients. Consequently, FIB-4 > 3.25 of male patients should receive ultrasound elastography to further determine the degree of liver fibrosis.

Lean Indian patients with non-alcoholic fatty liver disease (NAFLD) have less metabolic risk factors but similar liver disease severity as non-lean patients with NAFLD

INTRODUCTION

Although most patients with NAFLD are obese or overweight, some are lean with normal BMI. Our aim was to assess differences in clinicopathological profile and liver disease severity among lean and non-lean NAFLD.

METHODS

Data of 1040 NAFLD patients over last 10 years was analysed. BMI < 23 kg/m2 categorised lean patients. Non-invasive assessment of steatosis was done by ultrasound and controlled attenuation parameter (CAP) while fibrosis was assessed with FIB-4 and liver stiffness measurement (LSM). FibroScan-AST (FAST) score was used for non-invasive prediction of NASH with significant fibrosis. Histology was reported using NASH-CRN system.

RESULTS

149 (14.3%) patients were lean while 891 (85.7%) patients were non-lean. Diabetes mellitus [25 (16.7%) vs 152 (17.05%), p > 0.99], elevated triglycerides [81 (54.3%) vs 525 (58.9%), p = 0.33] and low HDL [71(47.6%) vs 479(53.7%), p = 0.18] were observed in a similar proportion. Lean patients were less likely to have central obesity [72 (48.3%) vs 788 (88.4%), p < 0.001], hypertension [16 (10.7%) vs 239(26.8%), p < 0.001] and metabolic syndrome [21 (14.09%) vs 290 (32.5%), p < 0.001]. No difference in steatosis assessment was noted using ultrasound (p = 0.55) or CAP (0.11). FAST [0.38 (0.18-0.66) vs 0.39 (0.27-0.73), p = 0.53], FIB-4 [1.08 (0.65-1.91) vs 1.09 (0.66-1.94), p = 0.94] and LSM [6.1 (4.8-7.9) vs 6.2 (4.7-8.6), p = 0.19) were similar. Liver biopsy was available in 149 patients [lean: 19 (12.7%), non-lean: 130 (87.3%)]. There was no difference in the number of patients with NASH [4 (21.05%) vs 20 (15.3%), p = 0.51], significant fibrosis [2 (10.5%) vs 32 (24.6%), p = 0.25] or advanced fibrosis [1 (5.26%) vs 18 (13.84%), p = 0.47].

CONCLUSION

Although metabolic co-morbidities are less common, there is no difference in liver disease severity among both groups.

Adipose Tissue Protects against Hepatic Steatosis in Male Rats Fed a High-Fat Diet plus Liquid Fructose: Sex-Related Differences

Non-alcoholic fatty liver disease is a sexual dimorphic disease, with adipose tissue playing an essential role. Our previous work showed that female rats fed a high-fat high-fructose diet devoid of cholesterol (HFHFr) developed simple hepatic steatosis dissociated from obesity. This study assessed the impact of the HFHFr diet on the male rat metabolism compared with data obtained for female rats. A total of 16 Sprague Dawley (SD) male rats were fed either a control (standard rodent chow and water) or HFHFr (high-fat diet devoid of cholesterol, plus 10% fructose in drinking water) diet for 3 months. Unlike female rats, and despite similar increases in energy consumption, HFHFr males showed increased adiposity and hyperleptinemia. The expression of hormone-sensitive lipase in the subcutaneous white adipose tissue was enhanced, leading to high free fatty acid and glycerol serum levels. HFHFr males presented hypertriglyceridemia, but not hepatic steatosis, partially due to enhanced liver PPARα-related fatty acid β-oxidation and the VLDL-promoting effect of leptin. In conclusion, the SD rats showed a sex-related dimorphic response to the HFHFr diet. Contrary to previous results for HFHFr female rats, the male rats were able to expand the adipose tissue, increase fatty acid catabolism, or export it as VLDL, avoiding liver lipid deposition.

Pathobiology of Metabolic-Associated Fatty Liver Disease

Metabolic-associated fatty liver disease (MAFLD), formerly known as nonalcoholic fatty liver disease, is highly associated with the metabolic syndrome. Given its high heterogeneity in patients along with unpredictable clinical outcomes, MAFLD is difficult to diagnose and manage. MAFLD is associated with obesity, diabetes, metabolic derangements, lipid disorders, cardiovascular disorders, sleep apnea, sarcopenia, gut dysbiosis, and sex hormone-related disorders. Identification of risk factors is imperative in understanding disease heterogeneity and clinical presentation to reliably diagnose and manage patients. The complexity of MAFLD pathobiology is discussed in this review in relation to its association with common metabolic and nonmetabolic disorders.

Mortality and Liver-Related Events in Lean Versus Non-Lean Nonalcoholic Fatty Liver Disease: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

Although approximately 40% of patients with nonalcoholic fatty liver disease (NAFLD) are nonobese or lean, little is known about the long-term clinical outcomes of lean NAFLD. We aimed to estimate the risk of mortality and adverse liver-related events in patients with lean NAFLD compared with those with non-lean NAFLD.

METHODS

We searched the PubMed, Embase, and Cochrane Library databases through May 2022 for articles reporting mortality and/or development of cirrhosis among lean and non-lean NAFLD patients. The relative risks (RRs) of all-cause mortality, cardiovascular mortality, liver-related mortality, and occurrence of decompensated cirrhosis or hepatocellular carcinoma were pooled using the random-effects model. We also performed subgroup analysis according to characteristics of the study population, methods of NAFLD diagnosis, study design, study region, and length of follow-up.

RESULTS

We analyzed 10 cohort studies involving 109,151 NAFLD patients. Patients with lean NAFLD had comparable risks for all-cause mortality (RR, 1.09; 95% confidence interval [CI], 0.66-1.90), cardiovascular mortality (RR, 1.12; 95% CI, 0.66-1.90), and adverse liver events including decompensated cirrhosis and hepatocellular carcinoma (RR, 0.81; 95% CI, 0.50-1.30). However, the risk of liver-related mortality was higher in patients with lean than non-lean NAFLD (RR, 1.88; 95% CI, 1.02-3.45).

CONCLUSIONS

This study highlights a higher risk of liver-related mortality in patients with lean NAFLD than those with non-lean NAFLD. This finding indicates that further understanding of the pathophysiology, risk factors of adverse outcomes, and genetic and ethnic variabilities of lean NAFLD phenotype is warranted for individualized treatment strategies in lean NAFLD patients.

Genetic Predictors of Comorbid Course of COVID-19 and MAFLD: A Comprehensive Analysis

Metabolic-associated fatty liver disease (MAFLD) and its potential impact on the severity of COVID-19 have gained significant attention during the pandemic. This review aimed to explore the genetic determinants associated with MAFLD, previously recognized as non-alcoholic fatty liver disease (NAFLD), and their potential influence on COVID-19 outcomes. Various genetic polymorphisms, including PNPLA3 (rs738409), GCKR (rs780094), TM6SF2 (rs58542926), and LYPLAL1 (rs12137855), have been investigated in relation to MAFLD susceptibility and progression. Genome-wide association studies and meta-analyses have revealed associations between these genetic variants and MAFLD risk, as well as their effects on lipid metabolism, glucose regulation, and liver function. Furthermore, emerging evidence suggests a possible connection between these MAFLD-associated polymorphisms and the severity of COVID-19. Studies exploring the association between indicated genetic variants and COVID-19 outcomes have shown conflicting results. Some studies observed a potential protective effect of certain variants against severe COVID-19, while others reported no significant associations. This review highlights the importance of understanding the genetic determinants of MAFLD and its potential implications for COVID-19 outcomes. Further research is needed to elucidate the precise mechanisms linking these genetic variants to disease severity and to develop gene profiling tools for the early prediction of COVID-19 outcomes. If confirmed as determinants of disease severity, these genetic polymorphisms could aid in the identification of high-risk individuals and in improving the management of COVID-19.

Fibrotic Burden in the Liver Differs Across Metabolic Dysfunction-Associated Fatty Liver Disease Subtypes

BACKGROUND/AIMS

Metabolic dysfunction-associated fatty liver disease (MAFLD) is categorized into three subtypes: overweight/obese (OW), lean/normal weight with metabolic abnormalities, and diabetes mellitus (DM). We investigated whether fibrotic burden in liver differs across subtypes of MAFLD patients.

METHODS

This cross-sectional multicenter study was done in cohorts of subjects who underwent a comprehensive medical health checkup between January 2014 and December 2020. A total of 42,651 patients with ultrasound-diagnosed fatty liver were included. Patients were classified as no MAFLD, OW-MAFLD, lean-MAFLD, and DM-MAFLD. Advanced liver fibrosis was defined based on the nonalcoholic fatty liver disease fibrosis score (NFS) or fibrosis-4 (FIB-4) index.

RESULTS

The mean age of the patients was 50.0 years, and 74.1% were male. The proportion of patients with NFS-defined advanced liver fibrosis was the highest in DM-MAFLD (6.6%), followed by OW-MAFLD (2.0%), lean-MAFLD (1.3%), and no MAFLD (0.2%). The proportion of patients with FIB-4-defined advanced liver fibrosis was the highest in DM-MAFLD (8.6%), followed by lean-MAFLD (3.9%), OW-MAFLD (3.0%), and no MAFLD (2.0%). With the no MAFLD group as reference, the adjusted odds ratios (95% confidence intervals) for NFS-defined advanced liver fibrosis were 4.46 (2.09 to 9.51), 2.81 (1.12 to 6.39), and 9.52 (4.46 to 20.36) in OW-MAFLD, lean-MAFLD, and DM-MAFLD, respectively, and the adjusted odds ratios for FIB-4-defined advanced liver fibrosis were 1.03 (0.78 to 1.36), 1.14 (0.82 to 1.57), and 1.97 (1.48 to 2.62) in OW-MAFLD, lean-MAFLD, and DM-MAFLD.

CONCLUSIONS

Fibrotic burden in the liver differs across MAFLD subtypes. Optimized surveillance strategies and therapeutic options might be needed for different MAFLD subtypes.

Lean individuals with NAFLD have more severe liver disease and poorer clinical outcomes (NASH-CO Study)

BACKGROUND AND AIMS

The severity of liver injury and clinical outcomes in lean individuals with NAFLD is a subject of debate and very few studies have been performed in the general population. The aim of this study was to compare subject characteristics and mortality between lean and nonlean NAFLD in a community setting.

APPROACH AND RESULTS

The study population included 169,303 participants from the nationwide Constances cohort. Subjects with excessive alcohol consumption, viral hepatitis, or other liver diseases were excluded and 137,206 subjects were analyzed. The diagnosis of NAFLD and fibrosis was performed using the Fatty Liver Index and the Forns Index. The median follow-up was 3.58 years. The prevalence of NAFLD was 5.3% (95% CI: 5.2-5.4) in lean subjects, while 16.3% (95% CI: 15.7-16.8) of NAFLD subjects were lean. Despite their better metabolic profile, the prevalence of advanced fibrosis was significantly higher in lean than in nonlean NAFLD (3.7% vs. 1.7%, respectively, p < 0.01). Among NAFLD subjects and after adjustment for demographics, metabolic risk factors and lifestyle, lean status was associated with advanced fibrosis (OR=1.26, 95% CI: 1.20-1.65, p = 0.005), an increased risk of liver-related events (adjusted HR=5.84, 95% CI: 4.03-8.46), chronic kidney disease (adjusted HR=2.49, 95% CI: 1.49-4.16), and overall mortality (adjusted HR=3.01, 95% CI: 2.21-4.11). Liver-related events and overall mortality were related to the severity of fibrosis, both in lean and nonlean NAFLD subjects, whatever the usual risk factors.

CONCLUSION

This study in a large community-based cohort confirms that NAFLD in lean subjects is more severe for fibrosis, the progression of liver disease, chronic kidney disease, and overall mortality.

Ablation of the deubiquitinase USP15 ameliorates nonalcoholic fatty liver disease and nonalcoholic steatohepatitis

Nonalcoholic fatty liver disease (NAFLD) occurs due to the accumulation of fat in the liver, leading to fatal liver diseases such as nonalcoholic steatohepatitis (NASH) and cirrhosis. Elucidation of the molecular mechanisms underlying NAFLD is critical for its prevention and therapy. Here, we observed that deubiquitinase USP15 expression was upregulated in the livers of mice fed a high-fat diet (HFD) and liver biopsies of patients with NAFLD or NASH. USP15 interacts with lipid-accumulating proteins such as FABPs and perilipins to reduce ubiquitination and increase their protein stability. Furthermore, the severity of NAFLD induced by an HFD and NASH induced by a fructose/palmitate/cholesterol/trans-fat (FPC) diet was significantly ameliorated in hepatocyte-specific USP15 knockout mice. Thus, our findings reveal an unrecognized function of USP15 in the lipid accumulation of livers, which exacerbates NAFLD to NASH by overriding nutrients and inducing inflammation. Therefore, targeting USP15 can be used in the prevention and treatment of NAFLD and 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.

Non-alcoholic fatty liver disease is associated with an increased risk of type 2 diabetes

OBJECTIVE

Non-alcoholic fatty liver disease (NAFLD) has become the most common liver disease worldwide and represents the leading cause of liver-related morbidity and mortality. Its all-cause mortality is often driven by co-existing metabolic diseases such as type 2 diabetes (T2DM), which share many pathophysiological characteristics. The risk of developing T2DM among NAFLD patients in Germany is only poorly described.

METHODS

A cohort of 17 245 NAFLD patients and a propensity score-matched cohort of equal size were identified from the Disease Analyzer database (IQVIA) between 2005 and 2020. The incidence of T2DM was evaluated as a function of NAFLD during a 5-year study period using Cox-regression models.

RESULTS

Within 5 years of the index date, 18.8% and 11.7% of individuals with and without NAFLD were diagnosed with T2DM ( P  < 0.001). Regression analysis revealed a hazard ratio of 1.77 [95% confidence interval (CI), 1.68-1.88] for the development of T2DM among NAFLD patients. Subgroup analyses confirmed this association for all age groups (18-50, 51-60, 61-70 and >70 years), male and female patients, as well as normal weight (BMI < 25 kg/m 2 ), overweighted (BMI 25-30 kg/m 2 ) and obese (BMI > 30 kg/m 2 ) patients.

CONCLUSION

Our data revealed a significantly increased incidence of T2DM among NAFLD patients in Germany. Given the dramatically increasing global relevance of NAFLD, we believe that prevention and regular screening programs for T2DM in NAFLD patients could help to reduce its high mortality and morbidity in the future.

Mechanisms of non-alcoholic fatty liver disease development in normal-weight individuals

While non-alcoholic fatty liver disease (NAFLD) without inflammation or fibrosis is considered a relatively 'benign' disease, non-alcoholic steatohepatitis (NASH), by contrast, is characterized by marked inflammation in addition to lipid accumulation, and may include fibrosis, progression to cirrhosis and hepatocellular carcinoma. Obesity and type II diabetes are frequently associated with NAFLD/NASH; however, a significant number of lean individuals may develop these diseases. Little attention has been paid to the causes and mechanisms contributing to NAFLD development in normal-weight individuals. One of the main causes of NAFLD in normal-weight individuals is the accumulation of visceral and muscular fat and its interaction with the liver. Myosteatosis (triglyceride accumulation in the muscle) induces a loss of muscle by reducing blood flow and insulin diffusion, contributing to NAFLD. Normal-weight patients with NAFLD exhibit higher serum markers of liver damage and C-reactive protein levels, as well as more pronounced insulin resistance, compared to healthy controls. Notably, increased levels of C-reactive protein and insulin resistance are strongly correlated with the risk of developing NAFLD/NASH. Gut dysbiosis has also been associated with NAFLD/NASH progression in normal-weight individuals. More investigation is required to elucidate the mechanisms leading to NAFLD in normal-weight individuals.

Nonalcoholic Fatty Liver Disease in Asia, Africa, and Middle East Region

Non-alcoholic fatty liver disease (NAFLD) is one of the most common causes of chronic liver disease worldwide. The global prevalence of the disease varies according to the geographical region. Despite having distinct models for the western patterns of NAFLD, Africa, Asia, and the Middle East regions exhibited varying prevalence rates of NAFLD. The disease burden is anticipated to significantly increase in these areas. Furthermore, with an increase in NAFLD risk factors in these regions, the disease burden is expected to rise even more. Policies at the regional and international levels are required to address such growing burden of NAFLD consequences.

Special Population: Lean Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is strongly associated with obesity but around 10% to 20% of patients with NAFLD have normal body mass index, a condition referred to as lean or nonobese NAFLD. Although lean patients more often have milder liver disease, a proportion may nonetheless develop steatohepatitis and advanced liver fibrosis. Both genetic and environmental factors contribute to the development of NAFLD. Noninvasive tests have similarly good accuracy as initial assessments for lean NAFLD. Future studies should determine the most appropriate treatment in this special population.

Nonalcoholic Fatty Liver Disease in Lean/Nonobese and Obese Individuals: A Comprehensive Review on Prevalence, Pathogenesis, Clinical Outcomes, and Treatment

Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease worldwide, with an estimated prevalence of 25% globally. NAFLD is closely associated with metabolic syndrome, which are both becoming increasingly more common with increasing rates of insulin resistance, dyslipidemia, and hypertension. Although NAFLD is strongly associated with obesity, lean or nonobese NAFLD is a relatively new phenotype and occurs in patients without increased waist circumference and with or without visceral fat. Currently, there is limited literature comparing and illustrating the differences between lean/nonobese and obese NAFLD patients with regard to risk factors, pathophysiology, and clinical outcomes. In this review, we aim to define and further delineate different phenotypes of NAFLD and present a comprehensive review on the prevalence, incidence, risk factors, genetic predisposition, and pathophysiology. Furthermore, we discuss and compare the clinical outcomes, such as insulin resistance, dyslipidemia, hypertension, coronary artery disease, mortality, and progression to nonalcoholic steatohepatitis, among lean/nonobese and obese NAFLD patients. Finally, we summarize the most up to date current management of NAFLD, including lifestyle interventions, pharmacologic therapies, and surgical options.