Uric acid may serve as the sixth cardiometabolic criterion for defining MASLD

Gender difference in the association between serum uric acid and metabolic dysfunction-associated steatotic liver disease in patients with newly diagnosed type 2 diabetes

PURPOSE

To investigate the relationship between serum uric acid (SUA) levels and metabolic dysfunction-associated steatotic liver disease (MASLD) in newly diagnosed type 2 diabetic patients.

METHODS

We performed this retrospective research among 1087 inpatients with new-onset type 2 diabetes millitus (T2DM). Data were analyzed according to gender. Then, the populations were stratified according to their body mass index (BMI) levels in men and women, respectively. The physical and biochemical indicators were measured and recorded. The relationship between SUA and MASLD was estimated using logistic regression analysis, and the unadjusted and adjusted odds ratios (ORs) were calculated.

RESULTS

After adjusting for age, BMI, and other components of the metabolic syndrome, SUA was independently associated with MASLD only in men, but not in women. In addition, for men, the SUA levels were independently associated with MASLD in both non-overweight/obesity and overweight/obesity group. However, for women, the SUA levels were independently related to MASLD in non-overweight/obesity group. There was no association between SUA and MASLD in women with overweight/obesity.

CONCLUSION

In newly diagnosed type 2 diabetic patients, elevated SUA is an independent predictor for the risk of MASLD in males. In females, the relationship between SUA and MASLD may depend on BMI, with significance only in non-overweight/obese individuals.

A Comprehensive Review of Metabolic Dysfunction-Associated Steatotic Liver Disease: Its Mechanistic Development Focusing on Methylglyoxal and Counterbalancing Treatment Strategies

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a multifactorial disorder characterized by excessive lipid accumulation in the liver which dysregulates the organ's function. The key contributor to MASLD development is insulin resistance (IR) which affects many organs (including adipose tissue, skeletal muscles, and the liver), whereas the molecular background is associated with oxidative, nitrosative, and carbonyl stress. Among molecules responsible for carbonyl stress effects, methylglyoxal (MGO) seems to play a major pathological function. MGO-a by-product of glycolysis, fructolysis, and lipolysis (from glycerol and fatty acids-derived ketone bodies)-is implicated in hyperglycemia, hyperlipidemia, obesity, type 2 diabetes, hypertension, and cardiovascular diseases. Its causative effect in the stimulation of prooxidative and proinflammatory pathways has been well documented. Since metabolic dysregulation leading to these pathologies promotes MASLD, the role of MGO in MASLD is addressed in this review. Potential MGO participation in the mechanism of MASLD development is discussed in regard to its role in different signaling routes leading to pathological events accelerating the disorder. Moreover, treatment strategies including approved and potential therapies in MASLD are overviewed and discussed in this review. Among them, medications aimed at attenuating MGO-induced pathological processes are addressed.

High-Intensity Interval Training Reduces Liver Enzyme Levels and Improves MASLD-Related Biomarkers in Overweight/Obese Girls

BACKGROUND/OBJECTIVES

Despite the abundant body of evidence linking high-intensity interval training (HIIT) to cardiometabolic markers, little is known about how HIIT affects liver enzymes, particularly in obese adolescents. This study aimed to investigate the effects of HIIT on metabolic dysfunction-associated steatotic liver disease (MASLD)-related biomarkers in overweight/obese adolescent girls.

METHODS

Thirty-three overweight/obese adolescent girls (age, 17.0 ± 1.15 yr.; body mass index, 33.3 ± 4.77 kg/m2) were randomly assigned to HIIT (n = 17) or control (n = 16) groups. The HIIT group participated in a nine-week HIIT program (three times weekly) without caloric restriction. Maximal aerobic speed, body composition indexes, blood pressure, MASLD-related biomarkers [liver enzymes (alanine aminotransferase (ALT) and aspartate aminotransferase (AST)), plasma lipids, uric acid, platelet count, and homeostasis model assessment index for insulin-resistance (HOMA-IR)] were examined at baseline and after the intervention.

RESULTS

Significant "time × group" interactions were found for body composition indexes, systolic blood pressure, maximal aerobic speed, liver enzymes ALT and AST, plasma lipids, glucose, and HOMA-IR. The HIIT program resulted in an increase in maximal aerobic speed (p = 0.035) and a decrease in body composition and plasma lipids (p < 0.01), systolic blood pressure (p = 0.011), ALT (p = 0.013), AST (p = 0.012), and HOMA-IR (p = 0.01), but no significant changes in uric acid and platelet count. None of these markers changed in the control group.

CONCLUSIONS

HIIT resulted in an improvement in MASLD-related biomarkers. HIIT could be an effective exercise therapy to prevent and reverse MASLD in adolescents with obesity.

Serum uric acid and mortality in metabolic dysfunction-associated steatotic liver disease: Subgroup differences

BACKGROUND AND AIMS

This study aims to investigate the association between serum uric acid (SUA) and both the risk and long-term mortality of dysfunction-associated steatotic liver disease (MASLD), and to explore differences between the pure MASLD and metabolic and alcohol related/associated liver disease (MetALD) subgroups.

METHODS AND RESULTS

We included 11,675 participants from the Third National Health and Nutrition Examination Survey, with matched mortality data up to 2019. Logistic regression and Cox proportional hazards regression evaluated the relationship between SUA and both the risk and mortality of MASLD. Non-linear correlations and threshold effects were explored using restricted cubic splines and a two-piecewise Cox proportional hazards model. We found that SUA was positively associated with the risk of MASLD [odds ratio (OR): 1.19, 95 % confidence interval (CI) 1.12-1.27]. For pure MASLD, SUA showed a positive association with all-cause mortality [<4.7 mg/dL: hazard ratio (HR): 1.34, 95 % CI 1.04-1.73; ≥4.7 mg/dL: HR: 1.08, 95 % CI 1.02-1.15] and cardiovascular mortality (HR: 1.12, 95 % CI 1.02-1.22). For MetALD, there was an inverse J-shaped relationship (threshold: 6.6 mg/dL) between SUA and all-cause mortality. Below the threshold, SUA was negatively correlated with all-cause mortality (HR: 0.42, 95 % CI 0.19-0.93), but no association was found above it (HR: 0.81, 95 % CI 0.54-1.21). Additionally, no association was observed between SUA and cardiovascular mortality.

CONCLUSIONS

SUA serves as an independent predictor of the risk and all-cause mortality of MASLD. The relationship between SUA and both all-cause and cardiovascular mortality differs between the pure MASLD and MetALD subgroups.

Gut microbiota-NLRP3 inflammasome crosstalk in metabolic dysfunction-associated steatotic liver disease

Nonalcoholic fatty liver disease (NAFLD) is a chronic liver disease associated with metabolic dysfunction, ranging from hepatic steatosis with or without mild inflammation to nonalcoholic steatohepatitis, which can rapidly progress to liver fibrosis and even liver cancer. In 2023, after several rounds of Delphi surveys, a new consensus recommended renaming NAFLD as metabolic dysfunction-associated steatotic liver disease (MASLD). Ninety-nine percent of NAFLD patients meet the new MASLD criteria related to metabolic cardiovascular risk factors under the "multiple parallel hits" of lipotoxicity, insulin resistance (IR), a proinflammatory diet, and an intestinal microbiota disorder, and previous research on NAFLD remains valid. The NLRP3 inflammasome, a well-known member of the pattern recognition receptor (PRR) family, can be activated by danger signals transmitted by pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs), as well as cytokines involved in immune and inflammatory responses. The activation of the NLRP3 inflammasome pathway by MASLD triggers the production of the inflammatory cytokines IL-1β and IL-18. In MASLD, while changes in the composition and metabolites of the intestinal microbiota occur, the disrupted intestinal microbiota can also generate the inflammatory cytokines IL-1β and IL-18 by damaging the intestinal barrier, negatively regulating the liver on the gut-liver axis, and further aggravating MASLD. Therefore, modulating the gut-microbiota-liver axis through the NLRP3 inflammasome may emerge as a novel therapeutic approach for MASLD patients. In this article, we review the evidence regarding the functions of the NLRP3 inflammasome and the intestinal microbiota in MASLD, as well as their interactions in this disease.

From Hypothalamic Obesity to Metabolic Dysfunction-Associated Steatotic Liver Disease: Physiology Meets the Clinics via Metabolomics

Metabolic health is tightly regulated by neuro-hormonal control, and systemic metabolic dysfunction may arise from altered function of the hypothalamic-anterior pituitary axis (HAPA). Ancient experimental observations of hypothalamic obesity (HO) and liver cirrhosis occurring among animals subjected to hypothalamic injury can now be explained using the more recent concepts of lipotoxicity and metabolic dysfunction-associated steatotic liver disease (MASLD). Lipotoxicity, the range of abnormalities resulting from the harmful effects of fatty acids accumulated in organs outside of adipose tissue, is the common pathogenic factor underlying closely related conditions like hypothalamic syndrome, HO, and MASLD. The hormonal deficits and the array of metabolic and metabolomic disturbances that occur in cases of HO are discussed, along with the cellular and molecular mechanisms that lead, within the MASLD spectrum, from uncomplicated steatotic liver disease to steatohepatitis and cirrhosis. Emphasis is placed on knowledge gaps and how they can be addressed through novel studies. Future investigations should adopt precision medicine approaches by precisely defining the hormonal imbalances and metabolic dysfunctions involved in each individual patient with HO, thus paving the way for tailored management of MASLD that develops in the context of altered HAPA.