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

Triglycerides/high-density lipoprotein-cholesterol ratio outperforms traditional lipid indicators in predicting metabolic dysfunction-associated steatotic liver disease among U.S. adults

Objective

Triglycerides (TG), high-density lipoprotein cholesterol (HDL-c), and their ratio (TG/HDL-c) are key lipid markers associated with metabolic dysfunction. This study aims to investigate the association of TG, HDL-c, and TG/HDL-c ratio with metabolic dysfunction-associated steatotic liver disease (MASLD) and to assess whether TG/HDL-c ratio provides superior predictive ability for MASLD compared to TG or HDL-c alone.

Importance

Although previous research has explored the relationship between TG/HDL-c and MASLD, the applicability of these findings across different ethnicities and populations remains uncertain. Additionally, this study is based on NHANES data, which relies on self-reported measures and lacks longitudinal follow-up, limiting the ability to establish causal relationships. While we adjusted for multiple covariates, residual confounding cannot be ruled out. Therefore, further large-scale, prospective studies are needed to validate these associations and assess the long-term predictive value of TG/HDL-c ratio for MASLD.

Methods

A cross-sectional study utilizing the NHANES 2017-2020 database was conducted. We performed univariate and multivariate logistic regression analyses to examine the associations between TG, HDL-c, and the TG/HDL-c ratio with MASLD. Receiver Operating Characteristic (ROC) curve analysis was used to evaluate the predictive effectiveness. Sensitivity analysis was carried out using multiple imputation for missing data and subgroup stratification to validate the findings.

Results

TG, HDL-c, and TG/HDL-c ratio were significantly associated with MASLD (p < 0.05 for all). The TG/HDL-c ratio demonstrated the highest predictive value (AUC = 0.732, 95% CI: 0.683-0.781), compared to TG (AUC = 0.713, 95% CI: 0.664-0.762) and HDL-c (AUC = 0.313, 95% CI: 0.264-0.362). The weak predictive power of HDL-c alone may be attributed to its complex role in lipid metabolism and potential confounding by other metabolic factors.

Conclusion

Maintaining favorable levels of TG, HDL-c and TG/HDL-c ratio may lower MASLD risk. Using TG/HDL-c ratio could improve prediction models compared to individual TG or HDL-c markers.

PBMC transcriptome reveals an early metabolic risk profile in young rats with metabolically obese, normal-weight phenotype

Metabolically obese, normal-weight (MONW) phenotype is characterized by visceral adiposity and obesity-related complications despite the absence of excess body weight. Early identification of this phenotype is crucial to establish preventive strategies. We aim to validate the utility of peripheral blood mononuclear cells (PBMC) transcriptome to detect metabolic risk related to the MONW phenotype at early life stages (young adulthood). Male Wistar rats were pair-fed either standard (NW group) or a high-fat diet (MONW group) after weaning, until 3.5 months. Global gene expression was examined by microarray in PBMC, and specific genes of interest by RT-qPCR in PBMC and liver. Results were validated in adult 6-month-old MONW rats. Young MONW animals had similar weight to controls (NW group) but greater adiposity, including liver fat content, and insulin resistance signs. PBMC transcriptome distinguished clearly MONW from NW rats. Neurological pathways were affected in line with impaired cognition in these animals. Most top-regulated genes were related to inflammation, including the top-up and down-regulated genes, Hpgds and Slfn4. Expression of fatty liver-related genes like Mkrn1 and Nampt was also affected in PBMC of the young MONW group mirroring liver alteration. Slfn4 and Mkrn1 appeared as especially relevant biomarkers with altered expression also in PBMC of adult 6-month-old MONW rats. In conclusion, PBMC transcriptomic analysis emerges as a tool for identifying early biomarkers of obesity-related metabolic risk in young and apparently healthy (lean) subjects, pointing towards increased inflammation, liver fat deposition, and cognitive alterations.

Exploring Biomarkers in Nonalcoholic Fatty Liver Disease Among Individuals With Type 2 Diabetes Mellitus

Integrating biomarkers into a comprehensive strategy is crucial for precise patient management, especially considering the significant healthcare costs associated with diseases. Current studies emphasize the urgent need for a paradigm shift in conceptualizing nonalcoholic fatty liver disease (NAFLD), now renamed metabolic dysfunction-associated steatotic liver disease (MASLD). Biomarkers are emerging as indispensable tools for accurate diagnosis, risk stratification, and monitoring disease progression. This review classifies biomarkers into conventional and novel categories, such as lipids, insulin resistance, hepatic function, and cutting-edge imaging/omics, and evaluates their potential to transform the approach to MASLD among individuals with type 2 diabetes mellitus (T2D). It focuses on the critical role of biomarkers in early MASLD detection, enhancing predictive accuracy, and discerning responses to interventions (pharmacological or lifestyle modifications). Amid this discussion, the complexities of the relationship between T2D and MASLD are explored, considering factors like age, gender, genetics, ethnicity, and socioeconomic background. Biomarkers enhance the effectiveness of interventions and support global initiatives to reduce the burden of MASLD, thereby improving public health outcomes. This review recognizes the promising potential of biomarkers for diagnostic precision while candidly addressing the challenges in implementing these advancements in clinical practice. The transformative role of biomarkers emerges as a central theme, promising to reshape our understanding of disease trajectories, prognosis, and the customization of personalized therapeutic strategies for improved patient outcomes. From a future perspective, identifying early-stage biomarkers, understanding environmental impact through exposomes, and applying a multiomics approach may reveal additional insight into MASLD development.

Socioeconomic status and health disparities drive differences in accelerometer-derived physical activity in fatty liver disease and significant fibrosis

BACKGROUND AND AIMS

The cornerstone of clinical management of patients with nonalcoholic fatty liver disease (NAFLD) are lifestyle changes such as increasing physical activity (PA) aimed at improving cardiometabolic risk. To inform NAFLD prevention and treatment guidelines we aimed to: (i) quantify the role of PA on lowering the risk for NAFLD and fibrosis; (ii) characterize NAFLD and fibrosis association with PA in the context of socioeconomic environment.

METHODS

A sample of 2648 participants from the NHANES 2003-2006 was selected to develop survey weighted multivariable logistic regression models for predicting NAFLD and significant fibrosis, diagnosed non-invasively via fatty liver index (FLI) and fibrosis-4 (FIB-4) index. The PA measures were obtained from a hip-worn accelerometer.

RESULTS

The predictive model for NAFLD showed AUC of 0.687 and a decrease of 43% in NAFLD risk with moderate vigorous PA (MVPA) (OR = 0.569, p < 0.001). The predictive model for fibrosis had AUC of 0.755 and there was a 48% and a 70% decrease in significant fibrosis risk with MVPA (OR = 0.518, p = 0.022) and total log activity count (TLAC) (OR = 0.296, p = 0.017), respectively. Participants with NAFLD and NAFLD with fibrosis engage in declining PA. Despite having jobs with higher level of PA and participating in more moderate-to-vigorous PA, a larger proportion of Hispanics participants had NAFLD and significant fibrosis.

CONCLUSIONS

These findings demonstrate the role of PA as a protective factor against the presence of NAFLD and significant fibrosis. Protective levels of PA in NAFLD differ by races.

[Application of TG/HDL-C Combined with Liver Function Indexes to Predict Metabolic-Associated Fatty Liver Disease]

Objective

To study the application of triglycerides to high-density lipoprotein cholesterol ratio (TG/HDL-C) combined with liver function indexes to predict metabolic-associated fatty liver disease (MAFLD).

Methods

A total of 2971 outpatients diagnosed with MAFLD and 2794 healthy controls were enrolled, and their relevant data were collected. Two-sample Mann-Whitney U test and binary logistic regression analysis were conducted to study the relationship between TG/HDL-C and MAFLD and to construct combined diagnosis models of MAFLD. The area under the curve (AUC) of receiver operating characteristic (ROC) was used to pick out the optimal model.

Results

The TG/HDL-C of MAFLD patients was significantly higher than that of healthy controls. In multivariate analysis, after adjusting for body mass index, systolic blood pressure, diastolic blood pressure, fasting blood glucose, triglycerides, high-density lipoprotein cholesterol, uric acid and creatinine, the odds ratio of TG/HDL-C was 2.356 (95% confidence interval [CI]: 1.028-5.400). Therefore, TG/HDL-C was an independent risk factor for MAFLD. ROC curve analysis showed that the AUC of using TG/HDL-C to predict MAFLD was 0.795 (95% CI: 0.784-0.807), and when the cut-off value was 1.09, the sensitivity was 0.679 and the specificity was 0.755. The AUC of the diagnosis model established by a combined use of TG/HDL-C, alanine aminotransferase (ALT), aspartate aminotransferase (AST), and albumin (ALB) was 0.890 (95% CI: 0.882-0.898), and when the cut-off value was 0.47, the sensitivity and specificity were 0.792 and 0.839, respectively.

Conclusion

TG/HDL-C is an independent risk factor for MAFLD. TG/HDL-C can well predict MAFLD when it is used in combination with ALT, AST, and ALB.

NAFLD and Physical Exercise: Ready, Steady, Go!

Along with the increase in obesity and type 2 diabetes, the non-alcoholic fatty liver disease (NAFLD) incidence is escalating, thus becoming a leading cause of liver cirrhosis and a significant burden of liver-related outcomes. Since there is no pharmacotherapy available to address the NAFLD, the most effective solutions seem to be lifestyle changes centered on physical activity. Exercise could mediate its beneficial effects directly on the liver and indirectly via extrahepatic pathways, forming a dose-response relationship with NAFLD in terms of prevalence and disease severity. Health-enhancing physical activity (HEPA) levels are mainly needed to exert beneficial effects in obese subjects, while even a small amount of exercise can be beneficial for lean individuals to prevent NAFLD. This mini-review addresses three major points regarding physical activity and NAFLD: prevention, treatment, and extrahepatic benefits, offering recommendations on type and intensity of exercise in liver disease.