Association of metabolic signatures of air pollution with MASLD: Observational and Mendelian randomization study

Developing and validating a predictive model for all-cause mortality in patients with metabolic dysfunction-associated steatotic liver disease

OBJECTIVE

This study aimed to construct a scientific, accurate, and readily applicable clinical all-cause mortality prediction model for patients with metabolic dysfunction-associated steatotic liver disease (MASLD) to enhance the efficiency of disease management and improve patient prognosis.

METHODS

This study was a retrospective cohort study based on the National Health and Nutrition Examination Survey database. The 17,861 participants diagnosed with MASLD were randomly assigned to either a training cohort (n = 12,503) or a validation cohort (n = 5358). Potential predictors were subjected to LASSO regression analysis, and independent risk factors were subsequently identified through multivariate Cox regression analysis. An all-cause mortality prediction model was constructed based on the significant predictors, and a nomogram was generated to illustrate the survival probability of patients at various time points. The model's performance was evaluated using receiver operating characteristic (ROC), calibration, and decision curve analysis (DCA) curves.

RESULTS

A multiple Cox regression analysis identified several independent predictors significantly influencing all-cause mortality in patients with MASLD. These included gender, age, smoking status, hypertension, red blood cell count, albumin, glutamyl transpeptidase, glycosylated hemoglobin, and creatinine. The constructed predictive model demonstrated high accuracy in the training and validation cohorts, with AUC values approaching 0.85 at 3, 5, and 10 years, respectively. Calibration and DCA curves were employed to verify the stability and generalizability of the model.

CONCLUSIONS

We successfully constructed and validated an all-cause mortality prediction model for MASLD patients. This model provides a powerful tool for clinical risk assessment and treatment decision-making.

The Dark Triad of Particulate Matter, Oxidative Stress and Coronary Artery Disease: What About the Antioxidant Therapeutic Potential

Particulate matter (PM) is a complex mixture of particles with different adverse effects on health, especially on the cardiovascular (CV) risk and disease (e.g., increased risk of total and CV mortality, ischemic heart disease, heart failure, stroke, hypertension, dyslipidemia and type 2 diabetes). Since oxidative stress (OS) and inflammation are the main key mechanisms by which PM exerted its biological effects on health, several oxidative and inflammatory-related biomarkers have been measured and associated with PM; abnormalities in these parameters in relation to PM highlight the key role of this relationship in terms of adverse health effects, including CV conditions. Antioxidant strategies might prevent/reverse, almost partly, CV effects related to PM exposure, by addressing OS and inflammation, although the clinical gain of these interventional tools is not yet clearly demonstrated. This review aims to summarize PM source and composition, discussing OS and inflammatory events associated with environmental PM exposure as key mechanistic determinants of CV risk and acute event precipitation. Moreover, the modifying potential of antioxidants, especially in subjects more susceptible to the adverse effects of air pollution and/or more highly exposed, will be discussed as a promising research area beyond conventional strategies actually available to prevent the harmful effects of PM (e.g., reduction of pollution sources and population exposure, assessment of air quality standards) in order to better face this dark triad composed of PM, OS and CV disease.

Air Pollution Associated With Mortality Among Chronic Hepatitis B Patients Treated With Nucleotide/Nucleoside Analogues

BACKGROUND AND AIMS

Air pollution is associated with advanced liver fibrosis in patients with chronic liver diseases, including chronic hepatitis B (CHB). This study aimed to investigate the association between air pollution and mortality in patients with CHB treated with nucleotide/nucleoside analogues.

METHODS

We enrolled 697 patients with CHB treated with nucleotide/nucleoside analogues and analysed the incidence and risk factors for mortality. Daily air pollutant concentrations were estimated from the year before enrolment.

RESULTS

All-cause mortality showed an annual incidence of 1.1/100 person-years after a follow-up period of 3798.1 person-years. Factors with the strongest association with all-cause mortality were liver cirrhosis (hazard ratio [HR]/95% confidence interval [CI]: 3.95/1.69-9.23; p = 0.02), age ([HR]/CI: 1.07/1.03-1.17, p < 0.001) and pre-treatment gamma-glutamyl transferase (GGT) levels (HR/CI: 1.004/1.001-1.006, p = 0.004). Among patients with cirrhosis, the factors associated with all-cause mortality were age (HR/CI: 1.08/1.04-1.12, p < 0.001), pre-treatment GGT levels (HR/CI: 1.004/1.001-1.008, p = 0.01), platelet count (HR/CI: 0.988/0.977-0.998, p = 0.02) and NOx concentration (per unit increment, ppb) (1.045/1.001-1.091; p = 0.046). The best NOx cut-off value for predicting all-cause mortality in patients with cirrhosis was 25.5 ppb (AUROC 0.63; p = 0.03). NOx levels > 25.5 ppb were associated with a higher incidence of mortality in patients with cirrhosis (HR/CI:2.49/1.03-6.02; p = 0.04).

CONCLUSIONS

Air pollution influences all-cause mortality in patients with CHB receiving nucleotide/nucleoside analogue therapy. Long-term NOx exposure may increase liver-related mortality in patients with chronic hepatitis B and cirrhosis receiving nucleotide/nucleoside analogue treatment.

The global burden and biomarkers of cardiovascular disease attributable to ambient particulate matter pollution

BACKGROUND

Understanding the evolving patterns of cardiovascular disease (CVD) burden attributable to ambient particulate matter pollution (APMP) is essential. Furthermore, research on the underlying mechanisms has mostly been limited to laboratory and animal models, with few large-scale population-based studies.

METHODS

Using data from the Global Burden of Disease Study (GBD) 2021, we analyzed disability-adjusted life years and mortality for CVD attributable to APMP (measured as particulate matter [PM]2.5) from 1990 to 2021. We examined shifts in burden between APMP and household air pollution (HAP), regional disparities by socio-demographic index (SDI), and predicted trends using a Bayesian age-period-cohort model. Additionally, we used UK Biobank (UKB) data (metabolomics: 230,000 + participants; proteomics: 50,000 +) to identify biomarkers mediating the association between PM2.5 exposure and CVD outcomes, and further analyzed their biological roles. Metabolic and proteomic signatures were constructed using regression and elastic net models, with predictive performance assessed via time-dependent receiver operating characteristic analysis. Life expectancy was evaluated using flexible parametric survival models. Subgroup analysis was conducted by age, sex, lifestyle, socioeconomic status, and genetic susceptibility.

RESULTS

In 2021, the global CVD absolute burden attributable to APMP was more than double that of 1990, with significant regional disparities. The burden shifted from HAP to APMP, with 15% of CVD cases globally attributed to APMP. The CVD burden attributable to APMP increased with age and is projected to rise through 2030. In the UKB, approximately 30 metabolites, including albumin, mediated the association between PM2.5 exposure and CVD outcomes, primarily involving lipid and fatty acids metabolism. Over 60 proteins, including growth differentiation factor-15 and trefoil factor 2, mediated the association with CVD outcomes, enriched in cytokine-receptor interaction and leukocyte migration pathways. Metabolic and proteomic signatures outperformed PM2.5 alone in predicting 1-, 5-, and 10-year CVD outcomes. Participants in the lowest decile of PM2.5 exposure, metabolic, and proteomic signatures had longer life expectancy than those in the highest decile.

CONCLUSION

The CVD burden attributable to APMP remains a critical public health concern. This study presents a novel approach for identifying and managing susceptible populations through metabolomic and proteomic perspectives.

Environmental Pollutants, Occupational Exposures, and Liver Disease

Environmental pollutants significantly impact liver disease development, progression, and outcomes. This review examines the complex relationship between environmental exposures and liver pathology, from malignant conditions like hepatocellular carcinoma to steatotic and cholestatic liver diseases. Key environmental factors include air pollutants, volatile organic compounds, persistent organic pollutants, heavy metals, and per- and polyfluoroalkyl substances. These compounds can act through multiple mechanisms, including endocrine disruption, metabolic perturbation, oxidative stress, and direct hepatotoxicity. The impact of these exposures is often modified by factors such as sex, diet, and genetic predisposition. Recent research has revealed that even low-level exposures to certain chemicals can significantly affect liver health, particularly when combined with other risk factors. The emergence of exposomics as a research tool promises to enhance our understanding of how environmental factors influence liver disease. Importantly, exposure effects can vary by demographic and socioeconomic factors, highlighting environmental justice concerns. Implementation of this knowledge in clinical practice requires new diagnostic approaches, healthcare system adaptations, and increased awareness among medical professionals. In conclusion, this review provides a comprehensive examination of current evidence linking environmental exposures to liver disease and discusses implications for clinical practice and public health policy.

The socioeconomic and environmental determinants of metabolic dysfunction-associated steatotic liver disease: understanding inequalities in prevalence and outcomes

Metabolism-associated steatotic liver disease (MASLD) is the most prevalent chronic liver condition worldwide and affects nearly 30% of the global population. While traditionally associated with metabolic risk factors, such as obesity and insulin resistance, increasing attention is being directed toward socioeconomic and environmental determinants that contribute to disparities in MASLD prevalence and outcomes. Low-income populations often experience higher rates of MASLD owing to limited access to healthcare, poor diet quality, and reduced opportunities for physical activity. Conversely, high-income countries are witnessing a paradoxical rise in MASLD cases, driven by sedentary lifestyles and excessive consumption of ultra-processed foods. This review examined the effects of socioeconomic status, education, healthcare access, and environmental exposure on the epidemiology of MASLD. The findings revealed that individuals from lower socioeconomic backgrounds and migrant populations experience a disproportionately higher burden of MASLD due to systemic healthcare barriers, dietary transitions, and occupational exposure. Children and adolescents face increasing susceptibility owing to rising obesity rates, and geographic disparities highlight Europe as the most affected region, followed by Asia and North America. Given the growing public health impact of MASLD, addressing both socioeconomic and environmental determinants is essential. Future efforts should prioritize policy-driven interventions, including equitable healthcare access, lifestyle modifications, and research into novel therapeutic approaches to mitigate the disease burden and improve patient outcomes.