Early Predictors of Cardiovascular Disease Risk in Nonalcoholic Fatty Liver Disease: Non-obese Versus Obese Patients

Cardiovascular disease and metabolic dysfunction-associated steatotic liver disease: pathophysiology and diagnostic aspects

Metabolic dysfunction-associated steatotic liver disease (MASLD) can be interpreted as the hepatic expression of metabolic syndrome, which is estimated to affect 30% of the adult population. Obesity, dyslipidaemia, arterial hypertension, and T2DM are considered significant risk factors of MASLD. The relationship is two-way with MASLD found in up to 75% of patients with T2DM. Importantly, MASLD is associated with increased risk of cardiovascular diseases (CVD) such as arrhythmia, atherosclerotic heart disease, heart failure, and CVD-associated mortality. In addition, MASLD patients present with a high prevalence of major adverse cardiac events, which calls for systematic surveillance of CVD in MASLD. This review focuses on the pathophysiology behind development of CVD in MASLD, the types of cardiovascular complications, morbidity and survival, and suggestions for evaluation of patients with MASLD.

Applying 1-hour postload plasma glucose diagnostic criteria reveals high Progressive Risks of potential MASLD

BACKGROUND

Recently, a 1-h PG value of ≥ 8.6 mmol/L, a more sensitive predictor of diabetes mellitus-related long-term cardiovascular complications than routine glucose markers, has been recommended as an additional diagnostic criterion for diabetes in the International Diabetes Federation Position Statement. However, its value in MASLD remains uncertain.

METHODS

Consecutive participants with imaging assessments of fatty liver and a 75-g oral glucose tolerance test, including 1154 participants with MASLD, 161 fulfilling the nonalcoholic fatty liver disease but not the MASLD diagnostic criteria (NAFLD-non-MASLD) and 1026 subjects with non-fatty liver, were retrospectively enrolled from June 2009 to May 2024.

RESULTS

Patients with MASLD or NAFLD-non-MASLD had higher 1-h PG levels than those with non-fatty liver (p < 0.001). In patients with MASLD or NAFLD-non-MASLD, 1-h PG ≥ 8.6 mmol/L was associated with the risk of moderate-to-severe steatosis (p < 0.001), ALT elevation (p < 0.001), advanced fibrosis (p = 0.03), and cardiovascular diseases (p < 0.001). Furthermore, NAFLD-non-MASLD patients with 1-h PG ≥ 8.6 mmol/L showed a higher prevalence of advanced fibrosis than MASLD patients with or without 1-h PG ≥ 8.6 mmol/L (p < 0.05).

CONCLUSIONS

NAFLD-non-MASLD patients with 1-h PG ≥ 8.6 mmol/L are still at high risk of poor clinical outcomes. These findings support including 1-h PG ≥ 8.6 mmol/L as a component of the metabolic dysfunction definition.

Long-term outcomes and risk modifiers of metabolic dysfunction-associated steatotic liver disease between lean and non-lean populations

One-third of adults across the globe exhibit metabolic dysfunction-associated steatotic liver disease (MASLD)-formerly known as nonalcoholic fatty liver disease (NAFLD). To date, MASLD is the fastest-growing etiology of chronic liver disease and hepatocellular carcinoma (HCC). Besides the population with obesity, MASLD can also be found in lean populations, accounting for 13% of the global population, especially Asians. Notably, individuals with lean MASLD face equal or higher overall mortality rates compared to their non-lean counterparts. Risk modifiers encompass advanced age, hepatic fibrosis, and type 2 diabetes mellitus (T2DM). Moreover, the population with lean MASLD is associated with an increased risk of HCC, while their non-lean counterparts are more prone to cardiovascular outcomes and T2DM. Existing evidence indicates a similar risk of liver-related events and extrahepatic cancer between the two groups. However, MASLD-related genetic variants, such as PNPLA3 and TM6SF2, did not significantly affect mortality between the two populations. Still, underreporting alcohol consumption and regional representation limits the study's comprehensiveness. Longitudinal studies and mechanistic explorations are needed to understand differences in lean versus non-lean MASLD populations. This review highlights the need for awareness and tailored interventions in managing MASLD, considering lean individuals' unique risks.

Noninvasive liver fibrosis markers are independently associated with carotid atherosclerosis risk in patients with nonalcoholic fatty liver disease

OBJECTIVE

Nonalcoholic fatty liver disease (NAFLD) is considered an independent risk factor for cardiovascular disease (CVD). The overall morbidity and mortality of CVD increase with higher fibrosis stage in NAFLD. Carotid atherosclerosis (CAS) is an important predictor of cardiovascular events. However, the relationship between liver fibrosis degree and the risk of CAS in NAFLD patients remains uncertain. We aimed to investigate the relationship between noninvasive liver fibrosis markers and CAS risk in patients with NAFLD.

MATERIALS AND METHODS

This study included 3,302 participants with NAFLD. Participants were divided into a CAS group and a non-CAS group based on carotid artery ultrasound results. They were then stratified into quartiles using various noninvasive liver fibrosis markers (fibrosis-4 (FIB-4), modified FIB-4 (mFIB-4), aminotransferase to platelet ratio index (APRI), aminotransferase to alanine aminotransferase ratio (AAR), AAR-to-platelet ratio index (AARPRI), and Forns index) to assess the associations between these markers and the risk of CAS.

RESULTS

In the NAFLD population, individuals with CAS exhibited elevated levels of blood pressure, glucose, lipids, and noninvasive liver fibrosis markers (p < 0.001). The higher quartiles of noninvasive liver fibrosis markers, including FIB-4, mFIB-4, AAR, AARPRI, and Forns index, were significantly associated with increased risks of CAS, even after adjusting for multiple CVD risk factors.

CONCLUSIONS

In individuals with NAFLD, increased noninvasive liver fibrosis markers were independently associated with elevated CAS risk, which may be beneficial in assessing the risk of CVD in individuals with NAFLD.

Perspective article: determinants and assessment of cardiovascular risk in steatotic liver disease owing to metabolic dysfunction-addressing the challenge

Metabolic dysfunction-associated steatotic liver disease (MASLD) stands as an independent risk factor for cardiovascular disease (CVD), which is the leading cause of mortality among MASLD patients. The diverse spectrum of cardio-nephro-metabolic and vascular manifestations inherent in MASLD highlights the complex profile of CVD risk associated with this condition. However, current approaches to assessing CVD risk in MASLD lack specificity, predominantly relying on traditional markers. Although it is widely accepted that patients with advanced fibrosis are more prone to CVD risk, recent evidence suggests that this isolated focus may overlook the remarkable phenotypic variability of this CVD risk across the entire MASLD population. Emerging data indicate a progressive escalation of CVD risk in parallel with the severity of MASLD, highlighting the need for precise disease staging to inform accurate risk assessment. To address this challenge, we propose a novel sequential approach to CVD risk assessment in MASLD. While traditional CVD risk factors remain essential, incorporating liver-specific parameters enhances risk stratification and guides targeted interventions to mitigate the substantial burden of cardiovascular disease in this vulnerable population. This approach involves initial screening using FIB-4 and NAFLD fibrosis score, followed by assessment of liver fibrosis with imaging-based non-invasive techniques in individuals at intermediate-high risk for advanced fibrosis and liver fat quantification in low-risk individuals. Future prospective investigations should focus on the simultaneous use of liver biomarkers and imaging modalities to evaluate, in a sex-specific manner, the efficacy of the proposed approach and to determine optimal thresholds of liver fibrosis and steatosis for optimal CVD risk assessment.

Machine Learning Approach for Cardiovascular Death Prediction among Nonalcoholic Steatohepatitis (NASH) Liver Transplant Recipients

Cardiovascular disease is the leading cause of mortality among nonalcoholic steatohepatitis (NASH) patients who undergo liver transplants. In the present study, machine learning algorithms were used to identify important risk factors for cardiovascular death and to develop a prediction model. The Standard Transplant Analysis and Research data were gathered from the Organ Procurement and Transplantation Network. After cleaning and preprocessing, the dataset comprised 10,871 patients and 92 features. Recursive feature elimination (RFE) and select from model (SFM) were applied to select relevant features from the dataset and avoid overfitting. Multiple machine learning algorithms, including logistic regression, random forest, decision tree, and XGBoost, were used with RFE and SFM. Additionally, prediction models were developed using a support vector machine, Gaussian naïve Bayes, K-nearest neighbors, random forest, and XGBoost algorithms. Finally, SHapley Additive exPlanations (SHAP) were used to increase interpretability. The findings showed that the best feature selection method was RFE with a random forest estimator, and the most critical features were recipient and donor blood type, body mass index, recipient and donor state of residence, serum creatinine, and year of transplantation. Furthermore, among all the outcomes, the XGBoost model had the highest performance, with an accuracy value of 0.6909 and an area under the curve value of 0.86. The findings also revealed a predictive relationship between features and cardiovascular death after liver transplant among NASH patients. These insights may assist clinical decision-makers in devising strategies to prevent cardiovascular complications in post-liver transplant NASH patients.

Phospholipid metabolism-related genotypes of PLA2R1 and CERS4 contribute to nonobese MASLD

BACKGROUND

Abnormal phospholipid metabolism is linked to metabolic dysfunction-associated steatotic liver disease (MASLD) development and progression. We aimed to clarify whether genetic variants of phospholipid metabolism modify these relationships.

METHODS

This case-control study consecutively recruited 600 patients who underwent MRI-based proton density fat fraction examination (240 participants with serum metabonomics analysis, 128 biopsy-proven cases) as 3 groups: healthy control, nonobese MASLD, and obese MASLD, (n = 200 cases each). Ten variants of phospholipid metabolism-related genes [phospholipase A2 Group VII rs1805018, rs76863441, rs1421378, and rs1051931; phospholipase A2 receptor 1 (PLA2R1) rs35771982, rs3828323, and rs3749117; paraoxonase-1 rs662 and rs854560; and ceramide synthase 4 (CERS4) rs17160348)] were genotyped using SNaPshot.

RESULTS

The T-allele of CERS4 rs17160348 was associated with a higher risk of both obese and nonobese MASLD (OR: 1.95, 95% CI: 1.20-3.15; OR: 1.76, 95% CI: 1.08-2.86, respectively). PLA2R1 rs35771982-allele is a risk factor for nonobese MASLD (OR: 1.66, 95% CI: 1.11-1.24), moderate-to-severe steatosis (OR: 3.24, 95% CI: 1.96-6.22), and steatohepatitis (OR: 2.61, 95% CI: 1.15-3.87), while the paraoxonase-1 rs854560 T-allele (OR: 0.50, 95% CI: 0.26-0.97) and PLA2R1 rs3749117 C-allele (OR: 1.70, 95% CI: 1.14-2.52) are closely related to obese MASLD. After adjusting for sphingomyelin level, the effect of the PLA2R1 rs35771982CC allele on MASLD was attenuated. Furthermore, similar effects on the association between the CERS4 rs17160348 C allele and MASLD were observed for phosphatidylcholine, phosphatidic acid, sphingomyelin, and phosphatidylinositol.

CONCLUSIONS

The mutations in PLA2R1 rs35771982 and CERS4 rs17160348 presented detrimental impact on the risk of occurrence and disease severity in nonobese MASLD through altered phospholipid metabolism.

Cardiometabolic and Metabolic Profiles of Lean/Normal, Overweight and Obese Patients with Nonalcoholic Fatty Liver Disease

Purpose

Disagreements about the risk of non-obese, non-alcoholic fatty liver disease for cardiometabolic outcomes occurred widely. This study aims to characterize the cardiometabolic and metabolic profile of lean/normal, overweight and obese patients with nonalcoholic fatty liver disease on a big sample.

Patients and methods

Appeared healthy adults who participated in health examinations during the year of 2019-2022 were screened for fatty liver diagnosis. BMI classified fatty livers as lean, overweight and obese. Eleven cardiometabolic metrics (SBP: systolic blood pressure; DBP: diastolic blood pressure; TC: total cholesterol; TG: triglycerides; HDL: high-density lipoprotein cholesterol; LDL: low-density lipoprotein cholesterol) and metabolic metrics (GLU: blood glucose; GHB: glycated haemoglobin; UA: uric acid; AST: aspartate aminotransferase; ALT: alanine aminotransferase) were included, described and compared among BMI categories.

Results

There were 56,496 fatty livers diagnosed by ultrasound in this study. In total, the lean fatty liver had lowest mean SBP, DBP, GLU, TG, UA, AST, and ALT but highest TC and HDL among BMI categories (all p < 0.001). The number of abnormal metrics in total was 2.5, 2.9 and 3.4 in lean, overweight, and obesity, respectively (p < 0.001, p_trend < 0.001). Visualized data showed that lean fatty liver was similar but milder in all metabolic metrics than overweight and obesity at the young ages. However, lean fatty liver had higher coefficients of age and risk of metabolic abnormality regression (p <0.001 for SBP, DBP, GLU, GHB, TC).

Conclusion

The lean type of fatty livers at a younger age has a relatively favourable cardiometabolic and metabolic profile compared to overweight and obese fatty livers. Due to the possible catch-up effect of metabolic dysfunctions in young lean fatty liver, lean fatty liver may have the same health outcomes as overweight/obesity fatty liver in long term. The evaluation and intervention may be critical for young lean fatty liver management to slowdown the rapid progress of metabolic dysfunction.

Assessment of left atrial function by two-dimensional speckle tracking echocardiography in patients with metabolic-associated fatty liver disease

BACKGROUND

Metabolic-associated fatty liver disease (MAFLD) and cardiovascular diseases have mutual risk factors that contribute to pathogenic processes, increasing mortality and morbidity. This study aimed to evaluate variations in left ventricular (LV) structure and diastolic function among different subtypes and severity degrees of MAFLD patients, allowing early identification, intervention, and prevention of severe cardiac outcomes in high-risk populations.

RESULTS

The cross-sectional study included 142 MAFLD patients and 142 non-MAFLD participants as a control group. All participants underwent abdominal ultrasound, transient elastography, transthoracic echocardiography, tissue Doppler, and strain imaging. The results showed a significant impairment in the diastolic left ventricular function, as assessed with tissue Doppler, and the left atrial (LA) function, as evaluated with strain imaging, in the MAFLD group. Additionally, the left atrial stiffness was significantly higher in the MAFLD group.

CONCLUSION

The use of strain imaging facilitated the detection of subtle impairments of the left atrial reservoir, contraction, conduit function, and left ventricular diastolic function in MAFLD patients.

Update in lean metabolic dysfunction-associated steatotic liver disease

BACKGROUND

A new nomenclature consensus has emerged for liver diseases that were previously known as non-alcoholic fatty liver disease (NAFLD) and metabolic dysfunction-associated fatty liver disease (MAFLD). They are now defined as metabolic dysfunction-associated steatotic liver disease (MASLD), which includes cardiometabolic criteria in adults. This condition, extensively studied in obese or overweight patients, constitutes around 30% of the population, with a steady increase worldwide. Lean patients account for approximately 10%-15% of the MASLD population. However, the pathogenesis is complex and is not well understood.

AIM

To systematically review the literature on the diagnosis, pathogenesis, characteristics, and prognosis in lean MASLD patients and provide an interpretation of these new criteria.

METHODS

We conducted a comprehensive database search on PubMed and Google Scholar between January 2012 and September 2023, specifically focusing on lean NAFLD, MAFLD, or MASLD patients. We include original articles with patients aged 18 years or older, with a lean body mass index categorized according to the World Health Organization criteria, using a cutoff of 25 kg/m2 for the general population and 23 kg/m2 for the Asian population.

RESULTS

We include 85 studies in our analysis. Our findings revealed that, for lean NAFLD patients, the prevalence rate varied widely, ranging from 3.8% to 34.1%. The precise pathogenesis mechanism remained elusive, with associations found in genetic variants, epigenetic modifications, and adaptative metabolic response. Common risk factors included metabolic syndrome, hypertension, and type 2 diabetes mellitus, but their prevalence varied based on the comparison group involving lean patients. Regarding non-invasive tools, Fibrosis-4 index outperformed the NAFLD fibrosis score in lean patients. Lifestyle modifications aided in reducing hepatic steatosis and improving cardiometabolic profiles, with some medications showing efficacy to a lesser extent. However, lean NAFLD patients exhibited a worse prognosis compared to the obese or overweight counterpart.

CONCLUSION

MASLD is a complex disease comprising epigenetic, genetic, and metabolic factors in its pathogenesis. Results vary across populations, gender, and age. Limited data exists on clinical practice guidelines for lean patients. Future studies employing this new nomenclature can contribute to standardizing and generalizing results among lean patients with steatotic liver disease.

Systematic review with meta-analysis: Steatosis severity and subclinical atherosclerosis in metabolic dysfunction-associated steatotic liver disease

BACKGROUND

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a prevalent liver condition recognised as an independent risk factor for cardiovascular disease (CVD). However, there is ongoing debate regarding the effective strategy for cardiovascular risk assessment in MASLD.

AIM

To investigate the relationship between liver imaging, specifically focusing on the severity of steatosis and subclinical atherosclerosis.

METHODS

We conducted a thorough search across four databases, from 1950 to April 2023, to identify eligible studies employing imaging to explore the relationship between different degrees of steatosis and subclinical atherosclerosis among MASLD. Additionally, we conducted a quality assessment using the Newcastle Ottawa Scale, performed a meta-analysis employing the DerSimonian-Liard random-effects model, and conducted subgroup analyses for validation.

RESULTS

In total, 19 studies, encompassing 147,411 middle-aged individuals without previous CVD (74.94% male; mean age 45.53 years [SD 10.69]; mean BMI 24.3 kg/m2 [SD 3.35]), were included. The pooled odds ratio for subclinical atherosclerosis was 1.27 (95% CI: 1.13-1.41, I2  = 76.68%) in mild steatosis and significantly increased to 1.68 (95% CI: 1.41-2.00, I2  = 89.02%) in moderate to severe steatosis. Sensitivity analysis, focusing on high-quality studies, consistently supported this finding and the results remained robust across subgroup analyses. Furthermore, meta-regression revealed that a higher mean AST and ALT, alongside a lower mean HDL, were significant moderators of this association.

CONCLUSIONS

Even mild steatosis is associated with CVD risk, and steatosis severity further intensifies this association. These findings suggest that liver fat quantification enhances CVD risk stratification in patients with MASLD.

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.

Metabolomics to identify fingerprints of carotid atherosclerosis in nonobese metabolic dysfunction-associated fatty liver disease

BACKGROUND/AIMS

Nonobese metabolic dysfunction-associated fatty liver disease (MAFLD) is paradoxically associated with improved metabolic and pathological features at diagnosis but similar cardiovascular diseases (CVD) prognosis to obese MAFLD. We aimed to utilize the metabolomics to identify the potential metabolite profiles accounting for this phenomenon.

METHODS

This prospective multicenter cross-sectional study was conducted in China enrolling derivation and validation cohorts. Liquid chromatography coupled with mass spectrometry and gas chromatography-mass spectrometry were applied to perform a metabolomics measurement.

RESULTS

The study involved 120 MAFLD patients and 60 non-MAFLD controls in the derivation cohort. Controls were divided into two groups according to the presence of carotid atherosclerosis (CAS). The MAFLD group was further divided into nonobese MAFLD with/without CAS groups and obese MAFLD with/without CAS groups. Fifty-six metabolites were statistically significant for discriminating the six groups. Among the top 10 metabolites related to CAS in nonobese MAFLD, only phosphatidylethanolamine (PE 20:2/16:0), phosphatidylglycerol (PG 18:0/20:4) and de novo lipogenesis (16:0/18:2n-6) achieved significant areas under the ROC curve (AUCs, 0.67, p = 0.03; 0.79, p = 0.02; 0.63, p = 0.03, respectively). The combination of these three metabolites and liver stiffness achieved a significantly higher AUC (0.92, p < 0.01). In obese MAFLD patients, cystine was found to be significant with an AUC of 0.69 (p = 0.015), followed by sphingomyelin (SM 16:1/18:1) (0.71, p = 0.004) and de novo lipogenesis (16:0/18:2n-6) (0.73, p = 0.004). The combination of these three metabolites, liver fat content and age attained a significantly higher AUC of 0.91 (p < 0.001). The AUCs of these metabolites remained highly significant in the independent validation cohorts involving 200 MAFLD patients and 90 controls.

CONCLUSIONS

Diagnostic models combining different metabolites according to BMI categories could raise the accuracy of identifying subclinical CAS. Trial registration The study protocol was approved by the local ethics committee and all the participants have provided written informed consent (Approval number: [2014] No. 112, registered at the Chinese Clinical Trial Registry, ChiCTR-ChiCTR2000034197).

Discrepancies between Nonalcoholic and Metabolic-associated Fatty Liver Disease by Multiple Steatosis Assessment

BACKGROUND AND AIMS

The redefinition of metabolic-associated fatty liver disease (MAFLD) from nonalcoholic fatty liver disease (NAFLD) has caused a revolution in clinical practice, and the characteristics of patients with steatosis but not MAFLD remain unclear. The aims were to compare the diagnosis rate of MAFLD in NAFLD using different steatosis methods and explore the features of non-MAFLD-NAFLD and MAFLD-non-NAFLD.

METHODS

A cross-sectional study enrolling consecutive individuals was conducted at three medical centers in southern China from January 2015 to September 2020. Steatosis was evaluated by liver biopsy or magnetic resonance imaging-based proton density fat fraction (MRI-PDFF), ultrasound, controlled attenuation parameter (CAP), and fatty liver index (FLI). Fibrosis was assessed by the NAFLD fibrosis score, transient elastography, or shear wave elastography.

RESULTS

The study enrolled 14,985 Chinese adults. The agreement of MAFLD and NAFLD diagnoses were 83% for FLI, 95% for ultrasound, 94% for both CAP and MRI-PDFF, and 95% for liver biopsy. The body mass index, blood pressure and lipid levels among non-MAFLD-NAFLD patients were similar metabolic parameters (p>0.05 for all), but not the alanine aminotransferase and the proportion of patients with insulin resistance, which were significantly higher in non-MAFLD-NAFLD with significant fibrosis.

CONCLUSIONS

The new MAFLD definition ruled out 5-17% of NAFLD cases. NAFLD and MAFLD-NAFLD involved more severe metabolic abnormalities than MAFLD and MAFLD-non-NAFLD. Non-MAFLD-NAFLD patients with significant fibrosis had more severe liver injury and increased glycemic dysregulation within the normal range. Attention should be paid to its progression.

Recent advances in lean NAFLD

As the predominant type of chronic liver disease, the growing prevalence of nonalcoholic fatty liver disease (NAFLD) has become a concern worldwide. Although obesity plays the most pivotal role in NAFLD, approximately 10-20% of individuals with NAFLD who are not overweight or obese (BMI < 25 kg/m2, or BMI < 23 kg/m2 in Asians) have "lean NAFLD." Lean individuals with NAFLD have a lower prevalence of diabetes, hypertension, hypertriglyceridemia, central obesity, and metabolic syndrome than nonlean individuals with NAFLD, but higher fibrosis scores and rates of cardiovascular morbidity and all-cause mortality in advanced stages. The pathophysiological mechanisms of lean NAFLD remain poorly understood. Studies have shown that lean NAFLD is more correlated with factors such as environmental, genetic susceptibility, and epigenetic regulation. This review will examine the way in which the research progress and characteristic of lean NAFLD, and explore the function of epigenetic modification to provide the basis for the clinical treatment and diagnosis of lean NAFLD.

Vitamin D Status Presents Different Relationships with Severity in Metabolic-Associated Fatty Liver Disease Patients with or without Hepatitis B Infection

Whether the associations between serum vitamin D (VitD) and metabolic-associated fatty liver disease (MAFLD) vary with chronic hepatitis B (CHB) infection has not been well established. This study aims to investigate the relationships between serum VitD and metabolism, liver fat content (LFC) and fibrosis among MAFLD patients with and without CHB. Consecutive subjects (healthy controls: 360, CHB: 684, MAFLD: 521, CHB with MAFLD: 206) were prospectively enrolled between January 2015 and December 2021. Anthropometric, laboratory, imaging, and histological evaluations were conducted, with LFC measured via magnetic resonance imaging-based proton density fat fraction (MRI-PDFF). Serum VitD levels were lower in MAFLD patients than in healthy controls and patients with CHB alone or overlapping with MAFLD (24.4 ± 8.1 vs. 29.0 ± 9.5 vs. 27.4 ± 9.6 vs. 26.8 ± 8.4 ng/mL respectively; p < 0.001 in one-way ANOVA test). After adjusting for confounding factors, including season, hypersensitive C-reactive protein, insulin resistance, liver stiffness measurements, sun exposure, exercise and dietary intake, multivariate linear regression analysis revealed that VitD remained significantly negatively correlated with LFC in MAFLD patients (β = −0.38, p < 0.001), but not in CHB with MAFLD patients. Moreover, quantile regression models also demonstrated that lower VitD tertiles were inversely associated with the risk of insulin resistance and moderate−severe steatosis in the MAFLD group (p for trend <0.05) but not in the MAFLD with CHB group. VitD deficiency was associated with the severity of metabolic abnormalities and steatosis independent of lifestyle factors in MAFLD-alone subjects but not in MAFLD with CHB subjects.

Association between the atherogenic index of plasma and new-onset non-alcoholic fatty liver disease in non-obese participants

INTRODUCTION

Non-alcoholic fatty liver disease (NAFLD) in the non-obese population accounts for a large proportion of NAFLD. Atherogenic index of plasma (AIP, defined as the logarithm of the triglyceride/high-density lipoprotein cholesterol ratio.) can provide a stronger reflection of dyslipidemia and studies on the longitudinal association between AIP and NAFLD were limited in non-obese participants, especially in different BMI groups.

METHODS

We performed a post-hoc analysis of data obtained from the Dryad data repository (Dryad is a nonprofit open database of medicine.) and explored the predictive value of AIP on the risk of NAFLD among non-obese participants.

RESULTS

This study included 16173 participants with AIP, of which 2322(14.4%) non-obese participants developed into individuals with NAFLD with the 5-year follow-up examination. The difference between AIP quartiles in the cumulative estimation of new-onset NAFLD was significant, and with increased AIP, the cumulative new-onset NAFLD gradually increased. Participants in higher AIP quartiles had a significantly increased risk of NAFLD. In the fully adjusted model 3, hazard ratios of the new-onset NAFLD for subjects in Q2, Q3, and Q4 of AIP were 2.00 (1.59, 2.53), 2.61 (2.09, 3.72), and 4.49 (3.62, 5.57) respectively. Meanwhile, the trend test for the association between AIP quartiles and the new-onset NAFLD presented that AIP quartile was positively and strongly associated with the new-onset NAFLD (adjusted hazard ratio (95%CI) in Model 3: 1.59 (1.51, 1.67), P<0.001). We found that AIP was also positively and strongly associated with new-onset NAFLD in different sex groups and different age groups in female patients. Moreover, the predictive ability of AIP was no significant difference in different sex groups and different age groups in female patients. In the subgroup analysis, we found that in the low BMI population, the predictive effect of AIP for new-onset NAFLD was expanded by 2-3 times for each quality increase of AIP.

CONCLUSION

This study found that AIP was a strong independent risk factor for new-onset NAFLD among non-obese individuals especially in the low BMI participants, and screening for AIP in this population can be used to prevent future NAFLD.

Metabolic-Associated Fatty Liver Disease (MAFLD), Diabetes, and Cardiovascular Disease: Associations with Fructose Metabolism and Gut Microbiota

Non-alcoholic fatty liver disease (NAFLD) is an increasingly common condition associated with type 2 diabetes (T2DM) and cardiovascular disease (CVD). Since systemic metabolic dysfunction underlies NAFLD, the current nomenclature has been revised, and the term metabolic-associated fatty liver disease (MAFLD) has been proposed. The new definition emphasizes the bidirectional relationships and increases awareness in looking for fatty liver disease among patients with T2DM and CVD or its risk factors, as well as looking for these diseases among patients with NAFLD. The most recommended treatment method of NAFLD is lifestyle changes, including dietary fructose limitation, although other treatment methods of NAFLD have recently emerged and are being studied. Given the focus on the liver-gut axis targeting, bacteria may also be a future aim of NAFLD treatment given the microbiome signatures discriminating healthy individuals from those with NAFLD. In this review article, we will provide an overview of the associations of fructose consumption, gut microbiota, diabetes, and CVD in patients with NAFLD.

Apolipoproteins and liver parameters optimize cardiovascular disease risk-stratification in nonalcoholic fatty liver disease

BACKGROUND

Advanced Non-alcoholic fatty liver disease (NAFLD) is associated with increased risk of cardiovascular disease (CVD).

AIM

We determine whether combinations of ultrasound graphic steatosis grades, fibrosis scores and apolipoprotein levels add value to CVD risk prediction in NAFLD patients.

METHODS

The retrospective cohort study enrolled 10,453 individuals (3519 NAFLD; 6934 non NAFLD) from 2004 to 2018. Hepatic ultrasound measurements, lipid and apolipoprotein profiles, Fibrosis-4 and the NAFLD fibrosis scores (NFS) were assessed. The primary outcome included both clinical and subclinical CVD.

RESULTS

During 116-month follow-up period, there were 957 clinical and 752 subclinical CVD events. NAFLD patients had a higher incidence of CVD than non NAFLD patients as the steatosis degree, NFS, and FIB4 scores increased (25.1% vs 11.9%, Log Rank: p < 0.001). For the lipid and apolipoprotein profiles excluding triglyceride or ApoE, subjects with varied steatosis severity in the upper two tertiles had different risk of CVD (p for interaction < 0.001). A nomogram model combination of Framingham Risk Score (FRS), NFS and apolipoprotein profiles presented a higher AUC than FRS in a time-dependent ROC curve (0.816 vs 0.752, p < 0.001).

CONCLUSION

The novel risk score considering ultrasonography-defined steatosis grades, non-invasive liver fibrosis scores and apolipoprotein profiles accurately predicted the 10-year risk of CVD.

Risk of Cardiovascular Disease in Individuals With Nonobese Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is independently associated with obesity and cardiovascular disease (CVD). CVD is the primary cause of mortality in the predominantly obese population of adults with NAFLD. NAFLD is increasingly seen in individuals who are lean and overweight (i.e., nonobese), but it is unclear whether their risk of CVD is comparable to those with NAFLD and obesity. Using a prospective cohort of patients with NAFLD, we compared the prevalence and incidence of CVD in individuals with and without obesity. NAFLD was diagnosed by biopsy or imaging after excluding other chronic liver disease etiologies. Logistic regression was used to compare the odds of baseline CVD by obesity status. Cox proportional hazards regression was used to evaluate obesity as a predictor of incident CVD and to identify predictors of CVD in subjects with and without obesity. At baseline, adults with obesity had a higher prevalence of CVD compared to those without obesity (12.0% vs. 5.0%, P = 0.02). During follow-up, however, obesity did not predict incident CVD (hazard ratio [HR], 1.24; 95% confidence interval [CI], 0.69-2.22) or other metabolic diseases. Findings were consistent when considering body mass index as a continuous variable and after excluding subjects who were overweight. Age (adjusted HR [aHR], 1.05; 95% CI, 1.03-1.08), smoking (aHR, 4.61; 95% CI, 1.89-11.22), and decreased low-density lipoprotein levels (aHR, 0.98; 95% CI, 0.96-1.00) independently predicted incident CVD in the entire cohort, in subjects with obesity, and in those without obesity, respectively. Conclusion: Individuals with overweight or lean NAFLD are not protected from incident CVD compared to those with NAFLD and obesity, although CVD predictors appear to vary between these groups. Patients without obesity also should undergo rigorous risk stratification and treatment.

Nonalcoholic Fatty Liver Disease and Cardiovascular Disease: Overlapping Mechanisms

Nonalcoholic fatty liver disease (NAFLD) denotes a condition with excess fat in the liver. The prevalence of NAFLD is increasing, averaging > 25% of the Western population. In 25% of the patients, NAFLD progresses to its more severe form: nonalcoholic steatohepatitis and >25% of these progress to cirrhosis following activation of inflammatory and fibrotic processes. NAFLD is associated with obesity, type 2 diabetes, and the metabolic syndrome and represents a considerable and increasing health burden. In the near future, NAFLD cirrhosis is expected to be the most common cause for liver transplantation. NAFLD patients have an increased risk of developing cardiovascular disease as well as liver-related morbidity. In addition, hepatic steatosis itself appears to represent an independent cardiovascular risk factor. In the present review, we provide an overview of the overlapping mechanisms and prevalence of NAFLD and cardiovascular disease.

Association between the severity of liver fibrosis and cardiovascular outcomes in patients with type 2 diabetes

BACKGROUND AND AIM

Cardiovascular disease (CVD) is the principal cause of death in patients with type 2 diabetes (T2D). In this study, we assessed whether liver fibrosis predicted the risk of CVD in patients with T2D.

METHODS

A total of 1481 patients who had commenced oral antidiabetic drugs to treat newly diagnosed T2D between 2006 and 2010 were recruited. The fibrosis-4 index (FIB-4), non-alcoholic fatty liver disease fibrosis score (NFS), and BARD score were used to assess fibrotic burden at the time of T2D diagnosis.

RESULTS

During the follow-up period (median 88.1 [interquartile range 36.6-113.6] months), 242 (16.3%) patients developed CVD. CVD occurred frequently in older patients and was associated with hypertension; metabolic syndrome; obesity; smoking; administration of statin, which is an antihyperlipidemic drug; lower platelet counts; lower alanine aminotransferase, total cholesterol, and HbA1c levels; higher C-peptide and homeostatic model assessment of insulin resistance levels; and higher FIB-4, NFS, and BARD score (all P < 0.05). FIB-4 (hazard ratio [HR] = 1.163), NFS (HR = 1.322), BARD score (HR = 1.564), metabolic syndrome (HR = 1.556), smoking (HR = 2.829), and statin use (HR = 0.603) independently predicted the risk of CVD (all P < 0.05). The cumulative incidence of CVD was significantly different among groups stratified by liver fibrotic burden (all P < 0.05, log-rank test). Competing risk analysis showed a significant association between the severity of liver fibrosis and CVD development (all P < 0.001, Gray's test).

CONCLUSIONS

The severity of liver fibrosis independently predicted CVD in patients with T2D. Thus, assessment of liver fibrosis might allow physicians to optimize the timing of appropriate cardiovascular interventions in such patients.

Association between nonalcoholic fatty liver and increased low-level albuminuria in postmenopausal women in China: A cross-sectional study

BACKGROUND

Several studies have suggested that nonalcoholic fatty liver disease (NAFLD) is associated with cardiovascular disease (CVD). The excretion of low-level albuminuria (LLA) elevates as the prevalence of CVD increases. However, few studies have explored the association between NAFLD and LLA.

METHODS

This cross-sectional study included 31 147 Chinese adults (7664 men and 23 483 women). The "normal" level of albuminuria as determined by the urinary albumin to creatinine ratio (UACR) was below 30 mg/g. LLA was defined as a higher level within the "normal" albuminuria range (5.54 mg/g < LLA≤29.9 mg/g). The participants with NAFLD were defined as having a fatty liver index (FLI) ≥ 60. The FLI was calculated using the Bedogni equation.

RESULTS

A positive association was found between UACR and FLI through multivariate linear regression analyses (nonstandardized β ± SE: .047 ± 0.004, P <.001). The logistic regression analyses revealed that NAFLD had adjusted odds ratios (ORs) showing a significant relationship with LLA in models 1 to 4 (all subjects: OR, 1.207; 95% CI, 1.098-1.326; women: OR, 1.43; 95% CI, 1.26-1.63; all P <.001); however, we did not find significant adjusted ORs among the men. In the stratified analyses, the relationship between NAFLD and LLA was significant among postmenopausal women with a body mass index ≥24 but <28 kg/m² , fasting plasma glucose ≥5.6 but <7.0 mmol/L, or postprandial plasma glucose ≥7.8 but <11.1 mmol/L and those aged below 60 years without moderate-intensity exercise.

CONCLUSIONS

A noteworthy association between NAFLD and LLA was found among postmenopausal women who had borderline blood glucose values, were overweight, and did not engage in moderate-intensity physical activity.

Nonalcoholic fatty liver disease in lean subjects: Prognosis, outcomes and management

Nonalcoholic fatty liver disease (NAFLD) accounts for most cases of chronic liver disease worldwide, with an estimated global prevalence of approximately 25% and ranges from simple steatosis to nonalcoholic steatohepatitis and cirrhosis. NAFLD is strongly connected to metabolic syndrome, and for many years, fatty liver was considered to be an exclusive feature of obese patients. However, recent studies have highlighted the presence of NAFLD in non-obese subjects, with or without increased visceral fat or even in lean subjects without increased waist circumference. "Lean NAFLD" is a relatively new concept and there is significant scientific interest in understanding the differences in pathophysiology, prognosis and management compared with NAFLD in overweight/obese patients. In the present editorial, we discuss the clinical and metabolic profiles and outcomes of lean NAFLD compared with both obese NAFLD and lean healthy individuals from Asian and Western countries. Moreover, we shed light to the challenging topic of management of NAFLD in lean subjects since there are no specific guidelines for this population. Finally, we discuss open questions and issues to be addressed in the future in order to categorize NAFLD patients into lean and non-lean cohorts.

Relationship between non-alcoholic fatty liver disease and cardiovascular disease

With the in-depth study of non-alcoholic fatty liver disease (NAFLD), it has been found in recent years that NAFLD is closely related to cardiovascular disease (CVD). It has been proved that NAFLD is not only an important risk factor for CVD, but it is also an important mechanism of atherosclerosis, coronary heart disease, and hypertension in young people. This article reviews the recent progress in the understanding of the relationship between NAFLD and CVD, with an aim to improve the knowledge of CVD physicians on liver disease and provide reference for prevention and treatment of these conditions.