Age patterns of nonalcoholic fatty liver disease incidence: heterogeneous associations with metabolic changes

Differential Exercise Requirements for Nonalcoholic Fatty Liver Disease Resolution Across Age Groups: A Longitudinal Study of Korean Military Officers

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is a global health concern, and despite its high prevalence, lifestyle modifications such as exercise play a pivotal role in resolving this condition. This study aims to identify factors associated with NAFLD resolution, with a focus on the role of exercise, in different age groups.

METHODS

Longitudinal data from Korean military officers, during the period 2019-2021, were obtained from the National Health Information Database. NAFLD was defined as a hepatic steatosis index ≥36, and NAFLD resolution was defined as individuals achieving hepatic steatosis index <36 in the subsequent year of diagnosis. Information on alcohol consumption, exercise frequency, and family history of diabetes was collected through self-reported questionnaires.

RESULTS

The analysis included a total of 163,728 individuals, with a mean age of 36.87, predominantly male (91.62%). The prevalence of NAFLD was 27.04%. Favorable factors for NAFLD resolution encompassed moderate-intensity exercise for more than 180 minutes per week, vigorous-intensity exercise for more than 90 minutes per week, female sex, age, and resistance exercise for more than 3 days per week. Hypertension, family history of diabetes, and smoking were identified as factors against NAFLD resolution. The exercise requirements for NAFLD resolution varied among age groups, with those <30 years old requiring more than 180 minutes per week of moderate- or vigorous-intensity exercise and those >50 years old needing only 90 minutes per week of such exercise.

CONCLUSION

The exercise requirements for NAFLD resolution exhibit age-related differences. Individualized guidance for NAFLD management should consider these variations and be tailored to specific age groups.

Ultrasound normalized local variance to assess metabolic dysfunction-associated steatotic liver disease

PURPOSE

Increased prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD) highlights a desire for screening with liver ultrasound normalized local variance (NLV). We aimed to assess variations in NLV values measured at different sampling depths and discuss common technical considerations in measuring liver NLV.

METHODS

We retrospectively measured liver NLVs at variable depths on ultrasound images pre-recorded in 116 participants who underwent liver magnetic resonance imaging-proton density fat fraction (MRI-PDFF) and ultrasound to screen for MASLD. Liver NLVs were measured and differences at variable depths were tested using one-way analysis of variance (ANOVA) and multiple paired comparisons using post hoc Tukey honestly significant difference (HSD), Scheffé, Bonferroni, and Holm multiple comparisons. Diagnostic performance of NLV values were analyzed by area under the receiver operating characteristic (AUROC) curve.

RESULTS

The NLV measured at a depth of 10 cm significantly differed from those measured near the liver capsule and at depths of 6 cm and 8 cm (p < 0.001) from the skin. There was no significant difference in NLV value in other paired groups (p > 0.05). The difference in the area under AUROCs for NLVs measured at variable depths was not significant (p > 0.05).

CONCLUSIONS

The best diagnostic performance of liver NLV was measured at depth of 8 cm from the skin, although NLV measured at variable depth showed similar diagnostic performance for assessing ≥ mild hepatic steatosis. The study results provide a reference that can be used in the development of standardized scanning protocols and technical considerations in measuring liver NLV.

Metabolic Dysfunction-Associated Steatotic Liver Disease in Patients with Inflammatory Bowel Diseases: A Pilot Study

BACKGROUND

Inflammatory bowel disease (IBD) is characterized by persistent inflammation and is often associated with metabolic dysfunction-associated steatotic liver disease (MASLD). IBD patients are at risk of developing MASLD due to shared risk factors such as gut dysbiosis and systemic inflammation. The new MASLD nomenclature emphasizes the link between liver steatosis and cardiometabolic comorbidities. However, the prevalence of MASLD in IBD patients remains poorly explored. The main aim of this cross-sectional study is to assess the prevalence of ultrasound (US) and the clinical features of MASLD in patients with IBDs.

MATERIALS AND METHODS

We conducted a retrospective study enrolling 272 Italian IBD patients attending Renato Dulbecco Teaching Hospital in a period between 1 January 2021 and 31 December 2023. MASLD was diagnosed based on the presence of liver steatosis with cardiometabolic risk factors, using established guidelines. Demographic, clinical, and laboratory data were collected and analyzed. Statistical significance was determined at a p-value < 0.05.

RESULTS

Of the 272 IBD patients, 6% had non-alcoholic fatty liver disease (NAFLD), while 18% had MASLD. Patients with IBD-MASLD were significantly older, had higher body mass index, waist circumference, and triglyceride levels, and were more likely to have type 2 diabetes mellitus and hypertension compared to those with IBD-NAFLD. IBD-MASLD patients also showed higher disease activity scores and required more frequent surgical interventions. Bivariate logistic regression revealed triglyceride levels as a significant predictor of MASLD in IBD patients.

CONCLUSIONS

MASLD is more prevalent in IBD patients, highlighting the importance of early detection of liver steatosis in this at-risk population. The association between MASLD and cardiometabolic risk factors underscores the need for a multidisciplinary approach to manage these patients effectively. Further studies in larger cohorts are necessary to confirm these findings and explore the pathophysiological mechanisms involved.

Impact of Korean Military Service on the Prevalence of Steatotic Liver Disease: A Longitudinal Study of Pre-enlistment and In-Service Health Check-Ups

Background/Aims

Young Korean men are obligated to serve in the military for 18 to 21 months. We investigated the effects of military service on steatotic liver disease (SLD) and other metabolic parameters.

Methods

Pre-enlistment health check-up performed from 2019 to 2022 and in-service health check-up performed from 2020 to 2022 were merged as paired data. SLD was defined as a hepatic steatosis index of 36 or higher. Hypertension (HTN) and hypertriglyceridemia were also included in the analysis.

Results

A total of 503,136 paired cases were included in the analysis. Comparing pre-enlistment and in-service health check-ups, the prevalence of SLD (22.2% vs 17.6%, p<0.001), HTN (7.6% vs 4.3%, p<0.001), and hypertriglyceridemia (8.1% vs 2.9%, p<0.001) decreased during military service. In terms of body mass index, the proportion of underweight (8.2% vs 1.4%, p<0.001) and severely obese (6.1% vs 4.9%, p<0.001) individuals decreased over time. Regarding factors associated with SLD development and resolution, age was positively associated with SLD development (odds ratio, 1.146; p<0.001) and a health check-up interval of <450 days was a protective factor for SLD development (odds ratio, 0.746; p<0.001). Those serving in the marines were less likely to develop SLD, whereas those serving in the navy were more likely to develop SLD. Serving in the army or the navy was negatively associated with SLD resolution, whereas serving in the air force was positively associated with SLD resolution.

Conclusions

The prevalence of SLD, HTN, and hypertriglyceridemia decreased substantially during Korean military service.

Impact of diet intervention on visceral adipose tissue and hepatic fat in patients with obesity or type 2 diabetes: a randomized trial

This study aimed to assess the effects of a diet intervention on visceral and hepatic fat in patients with obesity or type 2 diabetes (T2D). Participants with obesity or T2D were randomized to a diet intervention or their usual diet. The intervention comprised a "3G rice" regimen combined with a low-salt, high-fiber diet. The primary outcomes were changes in visceral adipose tissue (VAT) area and hepatic fat over 12 weeks assessed by magnetic resonance imaging. Eighty-six patients were randomized. Their mean age was 47.5 ± 11.0 years, and 82.3% were female. Eighty-one (94.2%) had obesity, and 16 (18.6%) had T2D. Baseline metrics were body weight 76.3 ± 16.1 kg, BMI 29.6 ± 4.6, VAT 12 629 ± 5819 mm2, and hepatic fat 7.9% ± 7.2%. At the 12-week follow-up, the diet group had greater VAT and hepatic fat reductions than controls (- 1468 ± 1468 vs. - 179 ± 1576 mm2, P = 0.001; and - 2.6% ± 3.4% vs. 0.4% ± 2.2%, P < 0.001). Adjusted differences remained significant for VAT (- 1093 mm2, P < 0.001) and hepatic fat (- 2.5%, P < 0.001). In conclusion, the 12-week diet intervention decreased VAT, hepatic fat, body weight, and BMI compared to a usual diet.

Machine Learning Identifies Metabolic Dysfunction-Associated Steatotic Liver Disease in Patients With Diabetes Mellitus

CONTEXT

The presence of metabolic dysfunction-associated steatotic liver disease (MASLD) in patients with diabetes mellitus (DM) is associated with a high risk of cardiovascular disease, but is often underdiagnosed.

OBJECTIVE

To develop machine learning (ML) models for risk assessment of MASLD occurrence in patients with DM.

METHODS

Feature selection determined the discriminative parameters, utilized to classify DM patients as those with and without MASLD. The performance of the multiple logistic regression model was quantified by sensitivity, specificity, and percentage of correctly classified patients, and receiver operating characteristic (ROC) curve analysis. Decision curve analysis (DCA) assessed the model's net benefit for alternative treatments.

RESULTS

We studied 2000 patients with DM (mean age 58.85 ± 17.37 years; 48% women). Eight parameters: age, body mass index, type of DM, alanine aminotransferase, aspartate aminotransferase, platelet count, hyperuricaemia, and treatment with metformin were identified as discriminative. The experiments for 1735 patients show that 744/991 (75.08%) and 586/744 (78.76%) patients with/without MASLD were correctly identified (sensitivity/specificity: 0.75/0.79). The area under ROC (AUC) was 0.84 (95% CI, 0.82-0.86), while DCA showed a higher clinical utility of the model, ranging from 30% to 84% threshold probability. Results for 265 test patients confirm the model's generalizability (sensitivity/specificity: 0.80/0.74; AUC: 0.81 [95% CI, 0.76-0.87]), whereas unsupervised clustering identified high-risk patients.

CONCLUSION

A ML approach demonstrated high performance in identifying MASLD in patients with DM. This approach may facilitate better risk stratification and cardiovascular risk prevention strategies for high-risk patients with DM at risk of MASLD.

Is MASLD lost in translation in mice?

Lack of preclinical model translation is often blamed for failed drug development. Here we discuss mouse models within the context of human steatotic liver disease (SLD). Variables such as aging and non-food hepatic stressors are often ignored but could explain challenges in reproducing the human disease in a laboratory.

From NAFLD to NASH: Understanding the spectrum of non-alcoholic liver diseases and their consequences

Non-alcoholic fatty liver disease (NAFLD) has become one of the most frequent chronic liver diseases worldwide in recent decades. Metabolic diseases like excessive blood glucose, central obesity, dyslipidemia, hypertension, and liver function abnormalities cause NAFLD. NAFLD significantly increases the likelihood of liver cancer, heart disease, and mortality, making it a leading cause of liver transplants. Non-alcoholic steatohepatitis (NASH) is a more advanced form of the disease that causes scarring and inflammation of the liver over time and can ultimately result in cirrhosis and hepatocellular carcinoma. In this review, we briefly discuss NAFLD's pathogenic mechanisms, their progression into NASH and afterward to NASH-related cirrhosis. It also covers disease epidemiology, metabolic mechanisms, glucose and lipid metabolism in the liver, macrophage dysfunction, bile acid toxicity, and liver stellate cell stimulation. Additionally, we consider the contribution of intestinal microbiota, genetics, epigenetics, and ecological factors to fibrosis progression and hepatocellular carcinoma risk in NAFLD and NASH patients.

Proanthocyanidins-Based Synbiotics as a Novel Strategy for Nonalcoholic Fatty Liver Disease (NAFLD) Risk Reduction

Nonalcoholic fatty liver disease (NAFLD), the most common liver disease worldwide, is a spectrum of liver abnormalities ranging from steatosis to nonalcoholic steatohepatitis (NASH) characterized by excessive lipid accumulation. The prevalence of NAFLD is predicted to increase rapidly, demanding novel approaches to reduce the global NAFLD burden. Flavonoids, the most abundant dietary polyphenols, can reduce the risk of NAFLD. The majority of dietary flavonoids are proanthocyanidins (PACs), which are oligomers and polymers of the flavonoid sub-group flavan-3-ols. The efficacy of PAC in reducing the NAFLD risk can be significantly hindered by low bioavailability. The development of synbiotics by combining PAC with probiotics may increase effectiveness against NAFLD by biotransforming PAC into bioavailable metabolites. PAC and probiotic bacteria are capable of mitigating steatosis primarily through suppressing de novo lipogenesis and promoting fatty acid β-oxidation. PAC and probiotic bacteria can reduce the progression of steatosis to NASH mainly through ameliorating hepatic damage and inflammation induced by hepatic oxidative stress, endoplasmic reticulum stress, and gut microbiota dysbiosis. Synbiotics of PAC are superior in reducing the risk of NAFLD compared to independent administration of PAC and probiotics. The development of PAC-based synbiotics can be a novel strategy to mitigate the increasing incidence of NAFLD.

Circulating microRNA expression and nonalcoholic fatty liver disease in adolescents with severe obesity

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is one of the most common chronic liver diseases in children and adolescents. NAFLD ranges in severity from isolated hepatic steatosis to nonalcoholic steatohepatitis (NASH), wherein hepatocellular inflammation and/or fibrosis coexist with steatosis. Circulating microRNA (miRNA) levels have been suggested to be altered in NAFLD, but the extent to which miRNA are related to NAFLD features remains unknown. This analysis tested the hypothesis that plasma miRNAs are significantly associated with histological features of NAFLD in adolescents.

AIM

To investigate the relationship between plasma miRNA expression and NAFLD features among adolescents with NAFLD.

METHODS

This study included 81 adolescents diagnosed with NAFLD and 54 adolescents without NAFLD from the Teen-Longitudinal Assessment of Bariatric Surgery study. Intra-operative core liver biopsies were collected from participants and used to characterize histological features of NAFLD. Plasma samples were collected during surgery for miRNA profiling. A total of 843 plasma miRNAs were profiled using the HTG EdgeSeq platform. We examined associations of plasma miRNAs and NAFLD features using logistic regression after adjusting for age, sex, race, and other key covariates. Ingenuity Pathways Analysis was used to identify biological functions of miRNAs that were associated with multiple histological features of NAFLD.

RESULTS

We identified 16 upregulated plasma miRNAs, including miR-193a-5p and miR-193b-5p, and 22 downregulated plasma miRNAs, including miR-1282 and miR-6734-5p, in adolescents with NAFLD. Moreover, 52, 16, 15, and 9 plasma miRNAs were associated with NASH, fibrosis, ballooning degeneration, and lobular inflammation, respectively. Collectively, 16 miRNAs were associated with two or more histological features of NAFLD. Among those miRNAs, miR-411-5p was downregulated in NASH, ballooning, and fibrosis, while miR-122-5p, miR-1343-5p, miR-193a-5p, miR-193b-5p, and miR-7845-5p were consistently and positively associated with all histological features of NAFLD. Pathway analysis revealed that most common pathways of miRNAs associated with multiple NAFLD features have been associated with tumor progression, while we also identified linkages between miR-122-5p and hepatitis C virus and between miR-199b-5p and chronic hepatitis B.

CONCLUSION

Plasma miRNAs were associated with NAFLD features in adolescent with severe obesity. Larger studies with more heterogeneous NAFLD phenotypes are needed to evaluate miRNAs as potential biomarkers of NAFLD.

New-Onset Age of Nonalcoholic Fatty Liver Disease and Cancer Risk

Importance

The onset age of nonalcoholic fatty liver disease (NAFLD) is decreasing, and whether earlier ages of NAFLD onset are associated with increased cancer risk is currently unclear.

Objective

To explore the association between NAFLD new-onset age and cancer risk.

Design, Setting, and Participants

This cohort study was conducted among 179 328 participants included in the Kailuan Cohort Study between 2006 and 2021. In total, 46 100 incident NAFLD cases were identified. For each case, a participant matched by age (older or younger by 1 year) and sex was randomly selected to create a new matched study cohort. Data were analyzed from December 2022 through April 2023.

Exposure

Onset of NAFLD.

Main Outcomes and Measures

The association between the onset age of NAFLD and the risk of different cancer types was evaluated using weighted Cox regression models. Population-attributable fractions (PAFs) were used to quantify the association of NAFLD with cancer risk at different ages.

Results

Among 63 696 participants (mean [SD] age, 51.37 [12.43] years; ‭10 932 females [17.2%] and ‭52 764 males [82.8%]), 31 848 individuals had NAFLD and 31 848 individuals were in the control group. During a median (IQR) follow-up of 10.16 (7.89-11.67) years, 2415 patients were diagnosed with cancer. Compared with the matched group, patients aged less than 45 years at NAFLD onset exhibited a higher risk of cancer (average hazard ratio [AHR], 1.52; 95% CI, 1.09-2.12), and as the onset age of NAFLD increased, the cancer risk decreased (ages 45-54 years: AHR, 1.50; 95% CI, 1.15-1.97; ages 55-64 years: AHR, 1.13; 95% CI, 0.97-1.33; ages >65 years: AHR, 0.75; 95% CI, 0.45-1.27; P for interaction < .001). Among patients aged less than 45 years at NAFLD onset, cancers were mainly digestive system and lung cancers, with AHR values of 2.00 (95% CI, 1.08-3.47) and 2.14 (95% CI, 1.05-4.36), respectively. PAFs also showed that in patients aged less than 45 years at NAFLD onset, 17.83% (95% CI, 4.92%-29.86%) of cancer risk was attributable to NAFLD.‬‬‬‬.

Conclusions and Relevance

This study found that NAFLD was associated with increased cancer risk and there was an interaction with onset age, such that the younger the onset age of NAFLD, the greater the cancer risk.

Hepatic Involvement across the Metabolic Syndrome Spectrum: Non-Invasive Assessment and Risk Prediction Using Machine Learning

Metabolic-dysfunction-associated steatotic liver disease (MASLD) and metabolic syndrome (MetS) are inextricably linked conditions, both of which are experiencing an upward trend in prevalence, thereby exerting a substantial clinical and economic burden. The presence of MetS should prompt the search for metabolic-associated liver disease. Liver fibrosis is the main predictor of liver-related morbidity and mortality. Non-invasive tests (NIT) such as the Fibrosis-4 index (FIB4), aspartate aminotransferase-to-platelet ratio index (APRI), aspartate aminotransferase-to-alanine aminotransferase ratio (AAR), hepatic steatosis index (HIS), transient elastography (TE), and combined scores (AGILE3+, AGILE4) facilitate the detection of liver fibrosis or steatosis. Our study enrolled 217 patients with suspected MASLD, 109 of whom were diagnosed with MetS. We implemented clinical and biological evaluations complemented by transient elastography (TE) to discern the most robust predictors for liver disease manifestation patterns. Patients with MetS had significantly higher values of FIB4, APRI, HSI, liver stiffness, and steatosis parameters measured by TE, as well as AGILE3+ and AGILE4 scores. Machine-learning algorithms enhanced our evaluation. A two-step cluster algorithm yielded three clusters with reliable model quality. Cluster 1 contained patients without significant fibrosis or steatosis, while clusters 2 and 3 showed a higher prevalence of significant liver fibrosis or at least moderate steatosis as measured by TE. A decision tree algorithm identified age, BMI, liver enzyme levels, and metabolic syndrome characteristics as significant factors in predicting cluster membership with an overall accuracy of 89.4%. Combining NITs improves the accuracy of detecting patterns of liver involvement in patients with suspected MASLD.

Maternal Obesity Programs the Premature Aging of Rat Offspring Liver Mitochondrial Electron Transport Chain Genes in a Sex-Dependent Manner

We investigated whether maternal obesity affects the hepatic mitochondrial electron transport chain (ETC), sirtuins, and antioxidant enzymes in young (110 postnatal days (PND)) and old (650PND) male and female offspring in a sex- and age-related manner. Female Wistar rats ate a control (C) or high-fat (MO) diet from weaning, through pregnancy and lactation. After weaning, the offspring ate the C diet and were euthanized at 110 and 650PND. The livers were collected for RNA-seq and immunohistochemistry. Male offspring livers had more differentially expressed genes (DEGs) down-regulated by both MO and natural aging than females. C-650PND vs. C-110PND and MO-110PND vs. C-110PND comparisons revealed 1477 DEGs in common for males (premature aging by MO) and 35 DEGs for females. Analysis to identify KEGG pathways enriched from genes in common showed changes in 511 and 3 KEGG pathways in the male and female livers, respectively. Mitochondrial function pathways showed ETC-related gene down-regulation. All ETC complexes, sirtuin2, sirtuin3, sod-1, and catalase, exhibited gene down-regulation and decreased protein expression at young and old ages in MO males vs. C males; meanwhile, MO females down-regulated only at 650PND. Conclusions: MO accelerates the age-associated down-regulation of ETC pathway gene expression in male offspring livers, thereby causing sex-dependent oxidative stress, premature aging, and metabolic dysfunction.

Weigh change across adulthood is related to the presence of NAFLD: results from NHANES III

BACKGROUND

Obesity is a widely recognized driving factor of Non-alcoholic fatty liver disease (NAFLD), it remains unclear whether historical weight status was associated with the presence of NAFLD. The study aimed to explore the relationship between weight change across adulthood and the presence of NAFLD.

METHODS

Data from the National Health and Nutrition Examination Survey III included 6586 participants. Weight change was assessed according to body mass index (BMI) at baseline, at 25 years old, and 10 years before baseline. Obesity was defined as BMI ≥ 30 kg/m². NAFLD was assessed by hepatic ultrasonography.

RESULTS

The prevalence of NAFLD was highest among stable obese participants (48.1%), and the lowest among stable non-obese participants (18.9%). Among non-obese participants, those who get obese in early adulthood had a higher risk for the presence of NAFLD than those who were never obese (odds ratio [OR], 1.82; 95% confidence interval [CI] 1.17-2.92). Among obese participants, those who become obese in middle-late adulthood had a lower risk of NAFLD (OR, 0.79; 95% CI 0.65-0.96) than those with stable obesity. A weight gain of more than 12 kg and 4 kg since early and middle-late adulthood respectively were associated with increased risks of NAFLD.

CONCLUSION

Among current nonobese individuals, those with a history of obesity in their early adulthood had a higher risk of NAFLD than those never obese. Among the currently obese population, those who became obese after mid-adulthood have a significantly lower risk of NAFLD compared with those who were stable obese.