Gender differences in liver fibrosis among patients younger than 50 years: A retrospective cohort study

MASLD: Prevalence, Mechanisms, and Sex-Based Therapies in Postmenopausal Women

Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most common chronic liver disease influenced by genetic, lifestyle, and environmental factors. While MASLD is more prevalent in men, women are at increased risk after menopause, highlighting the critical pathogenetic role of sex hormones. The complex interplay between estrogen deficiency, visceral fat accumulation, metabolic syndrome (MetS), and inflammation accelerates disease progression, increases cardiovascular (CV) risk, and triggers a cycle of worsening adiposity, metabolic dysfunction, and psychological problems, including eating disorders. Weight loss in postmenopausal women can significantly improve both metabolic and psychological outcomes, helping to prevent MASLD and related conditions. This review examines the prevalence of MASLD, its comorbidities (type 2 diabetes T2D, CV, mental disorders), pathogenetic mechanisms, and pharmacological treatment with GLP-1 receptor agonists (GLP1-RAs), with a focus on postmenopausal women. Given the use of GLP1-RAs in the treatment of obesity and T2D in MASLD patients, and the increase in MetS and MASLD after menopause, this review analyzes the potential of a stable GLP-1-estrogen conjugate as a therapeutic approach in this subgroup. By combining the synergistic effects of both hormones, this dual agonist has been shown to increase food intake and food reward suppression, resulting in greater weight loss and improved insulin sensitivity, glucose, and lipid metabolism. Therefore, we hypothesize that this pharmacotherapy may provide more targeted therapeutic benefits than either hormone alone by protecting the liver, β-cells, and overall metabolic health. As these effects are only supported by preclinical data, this review highlights the critical need for future research to evaluate and confirm the mechanisms and efficacy in clinical settings, particularly in postmenopausal women.

Limited use of FIB-4 index in patients under 65 years of age with type 2 diabetes mellitus

AIM

Screening for liver fibrosis holds significant importance in patients with type 2 diabetes mellitus (T2DM) due to their elevated risk of advanced hepatic fibrosis. However, it is recognized that the diagnostic performance of the Fibrosis-4 (FIB-4) index is relatively low in T2DM patients. Our study aims to explore the potential and limitations of utilizing FIB-4 as a screening tool in patients with T2DM.

METHODS

A retrospective biopsy cohort of 1906 patients with biopsy-proven metabolic dysfunction-associated steatotic liver disease from South Korea, Japan, and Taiwan. Diagnostic performance according to T2DM was again compared after propensity score matching on age, sex, and body mass index.

RESULTS

Patients with T2DM were significantly older than those without. The area under the receiver operating characteristic curve (AUROC) of FIB-4 for ruling out advanced fibrosis in non-T2DM patients was significantly higher than that of T2DM (0.821 vs. 0.761, p = 0.044). However, the AUROCs of FIB-4 according to the same age groups showed no significant difference between patients with T2DM and without (all p > 0.05). In the middle-aged group, the sensitivity of FIB-4 for ruling out advanced hepatic fibrosis was 77.1% for T2DM and did not differ with that of non-T2DM patients (73.0%) (p = 0.093). After propensity score matching of age, there was no statistically significant difference in the AUROCs of the T2DM and non-T2DM groups (0.860 vs. 0.761, p = 0.142).

CONCLUSION

Although the diagnostic performance of FIB-4 was found to be suboptimal in patients with T2DM, its limited use in individuals under 65 years of age with T2DM still holds value as a screening tool.

Ambient air pollution exposure is associated with liver fat and stiffness in Latino youth with a more pronounced effect in those with PNPLA3 genotype and more advanced liver disease

BACKGROUND

Exposure to ambient air pollutants has emerged as a risk for metabolic-dysfunction associated steatotic liver disease (MASLD).

OBJECTIVES

We sought to examine associations between short-term (prior month) and long-term (prior year) ambient air pollution exposure with hepatic fat fraction (HFF) and liver stiffness in Latino youth with obesity. A secondary aim was to investigate effect modification by patatin-like phospholipase domain-containing protein 3 (PNPLA3) genotype and liver disease severity.

METHODS

Data was analyzed from 113 Latino youth (age 11-19) with obesity in Southern California. Individual exposure to particulate matter with aerodynamic diameter ≤ 2.5μm (PM2.5), ≤ 10μm (PM10), nitrogen dioxide (NO2), 8-hour maximum ozone (8hrMax-O3), 24-hr O3, and redox-weighted oxidative capacity (Oxwt) were estimated using residential address histories and United States Environmental Protection Agency air quality observations. HFF and liver stiffness were measured using magnetic resonance imaging. Linear models were used to determine associations between short-term and long-term exposure to air pollutants with HFF and liver stiffness. Modification by PNPLA3 and liver disease severity was then examined.

RESULTS

Short-term exposure to 8hrMax-O3 was positively associated with HFF. Relationships between air pollution exposure and HFF were not impacted by PNPLA3 genotype or liver disease severity. Long-term exposure to 8hrMax-O3 and Oxwt were positively associated with liver stiffness. Associations between air pollution exposure and liver stiffness depended on PNPLA3 genotype, such that individuals with GG genotypes exhibited stronger, more positive relationships between short-term exposure to PM10, 8hrMax-O3, 24-hr O3, and Oxwt and liver stiffness than individuals with CC/CG genotypes. In addition, relationships between short-term exposure to NO2 and liver stiffness were stronger in those with severe liver disease.

DISCUSSION

Air pollution exposure may be a risk factor for liver disease among Latino youth with obesity, particularly in those with other preexisting risks for liver damage.

Gender Differences in Liver Steatosis and Fibrosis in Overweight and Obese Patients with Metabolic Dysfunction-Associated Steatotic Liver Disease before and after 8 Weeks of Very Low-Calorie Ketogenic Diet

Obesity and metabolic syndrome are linked to steatotic liver disease (SLD), the most common form of chronic liver disease. Lifestyle modifications and dieting are strategies that can prevent metabolic dysfunction-associated steatotic liver disease (MASLD). The very low-calorie ketogenic diet (VLCKD) is a helpful treatment for MASLD and has been recommended for people affected by obesity; we evaluated the effect of gender on steatosis and fibrosis in a cohort of 112 overweight or obese patients undergoing an eight-week treatment with a VLCKD. Differences between the genders in terms of anthropometric measures, body composition, and metabolic indicators were examined before, during, and after the nutritional intervention. At baseline, there were significant differences between men and women in terms of anthropometric parameters, blood pressure, Homeostatic Model Assessment for Insulin Resistance (HOMA-IR), fasting insulin, hepatic markers, and lipid profile. Men had considerably higher levels of liver steatosis (measured by CAP) and liver stiffness (measured by E) under basal conditions than women. After the VLCKD, there were reductions in both genders of controlled attenuation parameter (CAP), body weight, body mass index (BMI), waist circumference, systolic and diastolic blood pressure, insulin resistance, fat mass (FM), free fat mass (FFM), and fasting blood glucose, insulin, glycated hemoglobin (HbA1c), triglycerides, total cholesterol, low-density lipoprotein (LDL) cholesterol, alanine transaminase (ALT), gamma-glutamyl transferase (γGT), and uric acid levels. Only in men, liver stiffness, aspartate aminotransferase (AST), creatinine, and C-reactive protein (CRP) levels significantly decreased. Moreover, men had significantly greater levels of liver steatosis: the male gender featured an increase of 23.96 points of the Fibroscan CAP. Men exhibited higher levels of steatosis and fibrosis than women, and these differences persist despite VLCKD. These gender-specific variations in steatosis and fibrosis levels could be caused by hormonal and metabolic factors, suggesting that different therapeutic strategies might be required depending on the gender.

Increased type-I interferon level is associated with liver damage and fibrosis in primary sclerosing cholangitis

BACKGROUND

The level of type-I interferons (IFNs) in primary sclerosing cholangitis (PSC) was investigated to evaluate its association with disease activity and progression.

METHODS

Bioactive type-I IFNs were evaluated in a murine model of PSC and human patients' sera using a cell-based reporter assay and ELISA techniques. In total, 57 healthy participants, 71 PSC, and 38 patients with primary biliary cholangitis were enrolled in this study.

RESULTS

Bioactive type-I IFNs were elevated in the liver and serum of multidrug resistance protein 2-deficient animals and showed a correlation with the presence of CD45+ immune cells and serum alanine transaminase levels. Concordantly, bioactive type-I IFNs were elevated in the sera of patients with PSC as compared to healthy controls (sensitivity of 84.51%, specificity of 63.16%, and AUROC value of 0.8267). Bioactive IFNs highly correlated with alkaline phosphatase (r=0.4179, p<0.001), alanine transaminase (r=0.4704, p<0.0001), and gamma-glutamyl transpeptidase activities (r=0.6629, p<0.0001) but not with serum bilirubin. In addition, patients with PSC with advanced fibrosis demonstrated significantly higher type-I IFN values. Among the type-I IFN subtypes IFNα, β and IFNω could be detected in patients with PSC with IFNω showing the highest concentration among the subtypes and being the most abundant among patients with PSC.

CONCLUSIONS

The selectively elevated bioactive type-I IFNs specifically the dominating IFNω could suggest a novel inflammatory pathway that might also have a hitherto unrecognized role in the pathomechanism of PSC.

Mechanisms of the TGF-β1/Smad3-signaling pathway in gender differences in alcoholic liver fibrosis

The TGF-β1/Smad3-signaling pathway and gender differences were investigated in alcoholic liver fibrosis. Mice were divided into female normal, female model, male normal, and male model groups. Liver injury and fibrosis were assessed using histopathology and serology. Western blotting was performed to analyze the expression of relevant factors. HSC-T6 cells were divided into estradiol + saline, estradiol + ethanol, testosterone + saline, and testosterone + ethanol groups, and similar assessments were conducted in vitro. Compared with the female model group, the male model group exhibited significantly increased GPT, GOT, TNF-α, IL-6, and testosterone levels, fibrosis rate, and TGF-β1, Smad3, and PCNA expression, and significantly decreased estradiol levels and Caspase-3 expression. The apoptosis rate was higher in the estradiol + ethanol group than in the testosterone + ethanol group, although the testosterone + ethanol group exhibited significantly increased TNF-α, IL-6, Collagen-I, α-SMA, TGF-β1, Smad3, and PCNA expression, and significantly decreased Caspase-3 expression. Alcoholic liver fibrosis showed significant gender differences associated with the TGF-β1/Smad3-signaling pathway.

Association of weight-adjusted-waist index with non-alcoholic fatty liver disease and liver fibrosis: a cross-sectional study based on NHANES

AIM

The purpose of this study was to explore the association of weight-adjusted-waist index (WWI) with non-alcoholic fatty liver disease (NAFLD) and liver fibrosis.

METHODS

A cross-sectional study including 6587 participants was conducted in the National Health and Nutrition Examination Survey (NHANES). Multiple linear regression was used to validate the association of WWI with NAFLD and liver fibrosis, and smoothed curve fitting and threshold effect models were used to validate non-linear relationships. Subgroup analyses were used to verify the stability of the relationship between the independent and dependent variables in different populations.

RESULTS

There was a positive association of WWI with NAFLD and liver fibrosis. In the model adjusted for all covariates, the effect values of WWI with NAFLD and liver fibrosis were (OR = 3.44, 95% CI: 3.09-3.82) and (OR = 2.40, 95% CI: 2.05-2.79), respectively. This positive correlation became more significant as WWI increased when WWI was presented in quartiles (P for trend < 0.01). Smoothed curve fitting and threshold effects analysis suggested a non-linear correlation between WWI and NAFLD (LLR < 0.01), with the positive correlation between WWI and NAFLD becoming more significant when WWI was less than 11.44 [5.93 (95% CI: 5.04-6.98)]. However, there was a linear correlation between WWI and liver fibrosis (LLR = 0.291). When subgroup analyses were performed by indicators such as age, race and gender, we found that the positive association between WWI and the dependent variables (NAFLD and liver fibrosis) was more pronounced in white male participants aged < 40 years.

CONCLUSIONS

Among adults in the United States, WWI was positively associated with the prevalence of NAFLD and liver fibrosis. Participants with a WWI less than 11.44 should be cautious about the possibility of an increased risk of NAFLD development due to a higher WWI. Meanwhile, white males younger than 40 years of age should be more cautious about the higher risk of NAFLD and liver fibrosis that might be associated with an increased WWI.

Metformin alleviates liver fibrosis in mice by enriching Lactobacillus sp. MF-1 in the gut microbiota

BACKGROUND

Liver fibrosis is associated with gut dysbiosis. Metformin administration has emerged as a promising method for the treatment of organ fibrosis. We aimed to investigate whether metformin ameliorates liver fibrosis by enhancing the gut microbiota in mice with carbon tetrachloride (CCl₄)-induced liver fibrosis and the underlying mechanism.

MATERIALS AND METHODS

A liver fibrosis mouse model was established, and the therapeutic effects of metformin were observed. We administered antibiotic treatment and performed fecal microbiota transplantation (FMT), and 16S rRNA-based microbiome analysis to evaluate the effects of the gut microbiome on metformin-treated liver fibrosis. We isolated the bacterial strain preferably enriched by metformin and assessed its antifibrotic effects.

RESULTS

Metformin treatment repaired the gut integrity of the CCl₄-treated mice. It reduced the number of bacteria in colon tissues and reduced the portal vein lipopolysaccharide (LPS) levels. The FMT performed on the metformin-treated CCl₄ mice alleviated their liver fibrosis and reduced their portal vein LPS levels. The markedly changed gut microbiota was screened out from the feces and named Lactobacillus sp. MF-1 (L. sp. MF-1). In the CCl₄-treated mice, daily gavage of L. sp. MF-1 maintained gut integrity, inhibited bacterial translocation, and reduced liver fibrosis. Mechanistically, metformin or L. sp. MF-1 inhibited the apoptosis of intestinal epithelial cells and restored CD3⁺ intestinal intraepithelial lymphocytes in the ileum and CD4⁺Foxp3⁺ lamina propria lymphocytes in the colon.

CONCLUSIONS

Metformin and its enriched L. sp. MF-1 can reinforce the intestinal barrier to alleviate liver fibrosis by restoring immune function.

Perspectives of nonalcoholic fatty liver disease research: a personal point of view

Rational government of patient fluxes from primary care to hepatology clinic is a priority of nonalcoholic fatty liver disease (NAFLD) research. Estimating pre-test probability of disease, risk of fibrosis progression, and exclusion of competing causes of liver disease must be addressed. Here we propose a novel taxonomic classification of NAFLD based on hepatic, pathogenic and systemic features of disease in the individual patient. The variable course of disease in any given patient remains a clinical enigma. Therefore, future studies will have to better characterize the role of genetic polymorphisms, family and personal history, diet, alcohol, physical activity and drugs as modifiers of the course of disease and clues to the early diagnosis of hepatocellular carcinoma. A better understanding of these, together with a taxonomic diagnosis, may prompt a more accurate personalization of care. For example, understanding the putative role of psycho-depression in NAFLD promises to revolutionize disease management in a proportion of cases. Similarly, sex differences in outcome and response to treatment are insufficiently characterized. More studies are awaited regarding those forms of NAFLD which occur secondary to endocrine derangements. The intersections between NAFLD and the lung must better be defined. These include the bi-directional associations of NAFLD and chronic obstructive pulmonary disease and sleep apnoea syndrome, as well as the totally unexplored chapter of NAFLD and coronavirus disease 2019 (COVID-19). Finally, the therapeutic roles of intermittent fasting and anticoagulation must be assessed. In conclusion, over the last 20 years, NAFLD has taught us a lot regarding the pathogenic importance of insulin resistance, the limitations of correcting this in the treatment of NAFLD, the root causes of diabetes and the metabolic syndrome, sex differences in disease and the role of nuclear receptors. However, the overwhelming COVID-19 pandemic is now expected to reset the priorities of public health.