Background: Metabolic dysfunction-associated fatty liver disease (MASLD) affects nearly 20% of the Italian population, with an annual economic burden of € 7.94 billion on the National Health Service, largely due to advanced liver disease and metabolic comorbidities. Progressive liver fibrosis remains the strongest predictor of adverse outcomes. Early diagnosis is crucial, as fibrosis is potentially reversible in its early stages. Sedentary behavior (SB) is one of many modifiable risk factors for several chronic diseases; however, most evidence is based on self-reported data. This study investigates the association between objectively measured daily energy expenditure and liver stiffness in adults with MASLD. Methods: We conducted a cross-sectional analysis of 104 adults (18–65 years) with obesity and moderate-to-severe steatosis (CAP ≥ 248 dB/m) from the Obesity-AF study. Daily energy expenditure (METs/day) was assessed via 7-day wrist-worn actigraphy. Liver stiffness (LSM, kPa) was measured non-invasively using transient elastography (FibroScan^®). Results: Lower daily energy expenditure was independently associated with higher liver stiffness. Each 1-MET increase correlated with a −1.239 kPa reduction in LSM (95% CI: −2.012, −0.466; p = 0.002). Sedentary individuals (≤1.5 METs) exhibited significantly higher LSM (+0.73 kPa, p = 0.03) versus non-sedentary peers, even after full adjustment. Findings were robust across sensitivity analyses. Conclusions: Our study shows that SB, objectively measured by actigraphy, is independently associated with increased liver stiffness in patients with MASLD and obesity. Reducing sedentary time may represent a simple, low-cost, and scalable strategy to mitigate fibrosis progression. However, given the cross-sectional design and the specificity of our sample, longitudinal studies are needed to confirm the causal role of SB and to evaluate the effectiveness of targeted interventions in broader MASLD populations.

Background. Very low-calorie ketogenic diets (VLCKD) are an effective weight-loss strategy for obese individuals, reducing risks of liver conditions such as non-alcoholic steatohepatitis and fibrosis. Small extracellular vesicles (sEVs) are implicated in liver fibrosis by influencing hepatic cell phenotypes and contributing to liver damage. This study investigates sEVs derived from serum of 60 obese adults categorized into low fibrosis risk (LR) and intermediate/high fibrosis risk (IHR) groups based on FibroScan elastography (FIB E scores, limit value 8 kPa) and all participants underwent an 8-week VLCKD intervention. Methods. The study examines the impact of these sEVs on fibrosis markers, inflammation, and autophagy in a hepatocyte cell line (HEPA-RG) using bioinformatics, RNA sequencing, lipidomics, RT-PCR, and Western blotting before (T0) and after (T1) VLCKD. Results. sEVs from LR patients post-VLCKD reduced fibrosis related gene expression (e.g., ACTA2) and enhanced proteins associated with regeneration and inflammation (e.g., HDAC6). Conversely, sEVs from IHR patients increased fibrosis and inflammation related gene expression (PIK3CB, AKT1, ACTA2) in hepatocytes, raising concerns about VLCKD suitability for IHR patients. IHR sEVs also decreased expression of HDAC10, HDAC6, HDAC3, MMP19, and MMP2, while increasing modulation of p-AKT, α-SMA, and VIM. Conclusion. These findings underscore the critical role of sEVs in regulating inflammation, remodeling, and hepatic stress responses, particularly in IHR patients, and suggest sEVs could complement instrumental evaluations like FibroScan in fibrosis assessment.

The VLCKD is a diet recognized to promote rapid fat mobilization and reduce inflammation, hepatic steatosis, and liver fibrosis. Extracellular vesicles (EVs) mediate cell-to-cell communication. The aim of the study is to investigate the role of circulating EVs in cell proliferation, ketone bodies, and ROS production in patients on an 8-week VLCKD regimen. Participants were classified as responders (R) or non-responders (NR) to VLCKD treatment based on their fibroscan results. In vitro experiments with the hepatic cell lines HEPA-RG (normal hepatocytes) and LX-2 (stellate cells) were conducted to investigate the effects of circulating EVs on cell viability, ROS production, and ketone body presence. The findings reveal a notable reduction in cell viability in both cell lines when treated with exosomes (EXOs). In contrast, treatment with microvesicles (MVs) did not appear to affect cell viability, which remained unchanged. Additionally, the levels of ketone bodies measured in urine were not consistently correlated with the reduction of fibrosis in responders (R). Similarly, an increase in ketone bodies was observed in non-responders (NR), which was also not aligned with the expected reduction in fibrosis. This inconsistency stands in stark contrast to the levels of Reactive Oxygen Species (ROS), which exhibited a clear and consistent pattern in accordance with the dietary intervention. Finally, in this preliminary study, ROS has been identified as a potential diet adherence marker for VLCKD patients; the ROS levels reliably follow the progression of the fibrosis response, providing a more accurate reflection of the therapeutic effects.

Background: Metabolic dysfunction-associated steatotic liver disease (MASLD) is strongly correlated with the severity of obesity, and the extent of liver fibrosis is associated with a higher risk of liver-related complications, cardiovascular events, and overall mortality. Leptin circulating levels are directly correlated with the amount of adipose tissue. Aims: In the present study, we investigated the association between circulating leptin levels and liver steatosis and fibrosis. Methods: Eighty-six patients (41.7 ± 12.6 yrs, 35 men, 41%), naïve to medications, who attended the Nutrition Center for the Research and Care of Obesity and Metabolic Diseases at the National Institute of Gastroenterology “Saverio de Bellis” for weight management, were cross-sectionally evaluated. Demographic, anthropometric, clinical, and laboratory data were collected and analyzed. All patients underwent liver ultrasonographic assessment by FibroScan to diagnose liver steatosis (controlled attenuation parameter, CAP > 275 dBm) and fibrosis (liver stiffness measurement, LSM > 8.2 kPa). Results: Sixty-three individuals (73.3%) had liver steatosis, and 17 (19.8%) had liver fibrosis. The mean leptin levels were 22.3 ± 14.1 ng/mL, while the BMI and waist circumference were 36.7 ± 7.2 kg/m² and 114.5 ± 16.4 cm, respectively. CAP values exhibited no correlation with leptin (r = 0.09, p = 0.436), while a significant connection was seen between leptin and LSM (β = 0.065; p = 0.038). Specifically, for each unit increase in leptin, LSM values were varied by +0.065 units (p = 0.038). This association was independent of gender, age, insulin resistance, adiponectin, RBP4, and visfatin. This is the first study showing these results by using FibroScan assessment in patients naïve to medications. Conclusions: Circulating leptin concentrations are independently correlated with hepatic fibrosis in individuals with a BMI ≥ 25 kg/m². These findings indicate a function for leptin in promoting liver fibrosis; however, longitudinal studies are required to elucidate the causal nature of this interaction.

Background: Metabolic dysfunction-associated steatotic liver disease (MASLD) is linked to metabolic syndrome, type 2 diabetes, and obesity. This study investigates the relationship between physical capacity, assessed by the Global Physical Capacity Score (GPCS), and MASLD-related parameters, including hepatic steatosis (CAP score), insulin resistance (HOMA-IR), and body mass index (BMI). Methods: A cross-sectional analysis was performed on 204 individuals with MASLD (mean age: 50 years; 57.6% males). Participants underwent physical tests to determine their GPCS. Hepatic steatosis was assessed using FibroScan® (Echosens, Paris, France), and metabolic markers were collected from fasting blood samples. Statistical analyses included linear and logistic regression models adjusted for potential confounders. Results: A higher GPCS was inversely associated with CAP (β = −5.30; p < 0.05), HOMA-IR (β = −0.28; p < 0.001), and BMI (β = −0.96; p < 0.001). Logistic regression analysis confirmed a lower risk of severe hepatic steatosis (OR = 0.44; p < 0.05), obesity (OR = 0.39; p < 0.05), and insulin resistance (OR = 0.32; p < 0.001) in individuals with higher GPCS values. Conclusions: The GPCS may indicate MASLD severity and reflect metabolic and hepatic health. Our findings support the promotion of physical activity and suggest a potential role for GPCS in risk stratification and personalized interventions for patients with MASLD.