The effects of metals and mixture exposure on lung function and the potential mediating effects of oxidative stress

Is type 2 diabetes a link between lung function and metabolic dysfunction-associated steatotic liver disease? Insights from population studies and Mendelian randomization

AIM

This study aimed to investigate the relationship between lung function and metabolic dysfunction-associated steatotic liver disease (MASLD), and the potential mediating role of type 2 diabetes.

METHODS

Data from the 2007 to 2012 National Health and Nutrition Examination Survey were used. Logistic regression analysis was employed to assess the association between lung function parameters [forced vital capacity (FVC), forced expiratory volume in 1 s (FEV 1 ), FEV 1 /FVC] and MASLD prevalence while exploring type 2 diabetes mediation. Further analyses included linkage disequilibrium score regression, Mendelian randomization, and meta-analysis to examine the causal relationship between lung function and MASLD, considering type 2 diabetes mediation.

RESULTS

The results showed that higher FVC and FEV 1 levels were associated with decreased MASLD risk, with type 2 diabetes partially mediating this relationship. Genetic analyses supported a causal link between lung function and MASLD, with type 2 diabetes acting as an intermediary. However, no significant association was found between FEV 1 /FVC and MASLD.

CONCLUSION

The study identified a causal relationship between lung function and MASLD, with type 2 diabetes playing a partial mediating role.

Cross-sectional associations between multiple plasma heavy metals and lung function among elderly Chinese

Environmental exposure to heavy metals may adversely affect lung function particularly in the elderly. However, limited data are available directly evaluating the relationship of heavy metal exposures with lung function in Chinese elderly. We aimed to investigate the associations between plasma metals and lung function among Chinese elderly residents. We conducted a cross-sectional study of 308 elderly residents in an industrial area and a non-industrial area in northwest China and estimated the single and combined effects of plasma metals and their interactions with lung functions (forced vital capacity [FVC], forced expiratory volume in 1 s [FEV1], and FEV1/FVC). We analyzed 12 plasma metals and identified 4 metals by lasso regression and BKMR model for further analysis. Bayesian kernel machine regression (BKMR) and quantile-g computation (QG-comp) models estimated four metals that had greater importance in lung function indicators, namely strontium (Sr), chromium (Cr), cobalt (Co) and nickel (Ni). Subgroup analyses were performed based on the resident areas. Both BKMR and QG-comp models showed metal mixtures was positively associated with FEV1/FVC (0.046 [0.017,0.075]) among all participants but of negative association with FVC, and similar results were found among participants in non-industrial area. The subgroup analysis by region showed higher heavy metal levels in industrial areas than non-industrial area. Sr concentrations were lower in non-industrial area, but they had a negative effect on FVC. In conclusion, plasma Sr, Cr, Co, and Ni levels are significant associated with lung function particularly with restrictive ventilatory dysfunction among the Chinese elderly population.

Landscape fire smoke airway exposure impairs respiratory and cardiac function and worsens experimental asthma

BACKGROUND

Millions of people are exposed to landscape fire smoke (LFS) globally, and inhalation of LFS particulate matter (PM) is associated with poor respiratory and cardiovascular outcomes. However, how LFS affects respiratory and cardiovascular function is less well understood.

OBJECTIVE

We aimed to characterize the pathophysiologic effects of representative LFS airway exposure on respiratory and cardiac function and on asthma outcomes.

METHODS

LFS was generated using a customized combustion chamber. In 8-week-old female BALB/c mice, low (25 μg/m3, 24-hour equivalent) or moderate (100 μg/m3, 24-hour equivalent) concentrations of LFS PM (10 μm and below [PM10]) were administered daily for 3 (short-term) and 14 (long-term) days in the presence and absence of experimental asthma. Lung inflammation, gene expression, structural changes, and lung function were assessed. In 8-week-old male C57BL/6 mice, low concentrations of LFS PM10 were administered for 3 days. Cardiac function and gene expression were assessed.

RESULTS

Short- and long-term LFS PM10 airway exposure increased airway hyperresponsiveness and induced steroid insensitivity in experimental asthma, independent of significant changes in airway inflammation. Long-term LFS PM10 airway exposure also decreased gas diffusion. Short-term LFS PM10 airway exposure decreased cardiac function and expression of gene changes relating to oxidative stress and cardiovascular pathologies.

CONCLUSIONS

We characterized significant detrimental effects of physiologically relevant concentrations and durations of LFS PM10 airway exposure on lung and heart function. Our study provides a platform for assessment of mechanisms that underpin LFS PM10 airway exposure on respiratory and cardiovascular disease outcomes.

Association of blood cadmium concentration with chronic obstructive pulmonary disease progression: a prospective cohort study

BACKGROUND

Prior studies in patients with chronic obstructive pulmonary disease (COPD) had indicated a potential correlation between cadmium (Cd) exposure and reduction in lung function. Nevertheless, the influence of Cd exposure on the progression of COPD remained unknown. Exploring the relationship between Cd exposure and the progression of COPD was the aim of this investigation.

METHODS

Stable COPD patients were enrolled. Blood samples were collected and lung function was evaluated. Regular professional follow-ups were conducted through telephone communications, outpatient services, and patients' hospitalization records.

RESULTS

Each additional unit of blood Cd was associated with upward trend in acute exacerbation, hospitalization, longer hospital stay, and death within 2 years. Even after adjusting for potential confounding factors, each 1 unit rise in blood Cd still correlated with a rise in the frequencies of acute exacerbation, longer hospital stay, and death. Moreover, COPD patients with less smoking amount, lower lung function and without comorbidities were more vulnerable to Cd-induced disease deterioration.

CONCLUSION

Patients with COPD who have higher blood Cd concentration are susceptible to worse disease progression.