Current status, trends, and predictions in the burden of silicosis in 204 countries and territories from 1990 to 2019

Silica aggravates pulmonary fibrosis through disrupting lung microbiota and amino acid metabolites

Silicosis, recognized as a severe global public health issue, is an irreversible pulmonary fibrosis caused by the long-term inhalation of silica particles. Given the intricate pathogenesis of silicosis, there is no effective intervention measure, which poses a severe threat to public health. Our previous study reported that dysbiosis of lung microbiota is associated with the development of pulmonary fibrosis, potentially involving the lipopolysaccharides/toll-like receptor 4 pathway. Similarly, the process of pulmonary fibrosis is accompanied by alterations in metabolic pathways. This study employed a combined approach of 16S rDNA sequencing and metabolomic analysis to investigate further the role of lung microbiota in silicosis delving deeper into the potential pathogenesis of silicosis. Silica exposure can lead to dysbiosis of the lung microbiota and the occurrence of pulmonary fibrosis, which was alleviated by a combination antibiotic intervention. Additionally, significant metabolic disturbances were found in silicosis, involving 85 differential metabolites among the three groups, which are mainly focused on amino acid metabolic pathways. The changed lung metabolites showed a substantial correlation with lung microbiota. The relative abundance of Pseudomonas negatively correlated with L-Aspartic acid, L-Glutamic acid, and L-Threonine levels. These results indicate that dysbiosis in pulmonary microbiota exacerbates silica-induced fibrosis through impacts on amino acid metabolism, providing new insights into the potential mechanisms and interventions of silicosis.

Occupational Exposure to Silica Dust and Silicosis Risk in Chinese Noncoal Mines: Qualitative and Quantitative Risk Assessment

BACKGROUND

Despite increasing awareness, silica dust-induced silicosis still contributes to the huge disease burden in China. Worryingly, recent silica dust exposure levels and silicosis risk in Chinese noncoal mines remain unclear.

OBJECTIVE

We aimed to determine recent silica dust exposure levels and assess the risk of silicosis in Chinese noncoal mines.

METHODS

Between May and December 2020, we conducted a retrospective cohort study on 3 noncoal mines and 1 public hospital to establish, using multivariable Cox regression analyses, prediction formulas of the silicosis cumulative hazard ratio (H) and incidence (I) and a cross-sectional study on 155 noncoal mines in 10 Chinese provinces to determine the prevalence of silica dust exposure (PDE), free silica content, and total dust and respirable dust concentrations. The qualitative risk of silicosis was assessed using the International Mining and Metals Commission's risk-rating table and the occupational hazard risk index; the quantitative risk was assessed using prediction formulas.

RESULTS

Kaplan-Meier survival analysis revealed significant differences in the silicosis probability between silica dust-exposed male and female miners (log-rank test χ21=7.52, P=.01). A total of 126 noncoal mines, with 29,835 miners and 4623 dust samples, were included; 13,037 (43.7%) miners were exposed to silica dust, of which 12,952 (99.3%) were male. The median PDE, free silica content, total dust concentration, and respirable dust concentration were 61.6%, 27.6%, 1.30 mg/m3, and 0.58 mg/m3, respectively, indicating that miners in nonmetal, nonferrous metal, small, and open-pit mines suffer high-level exposure to silica dust. Comprehensive qualitative risk assessment showed noncoal miners had a medium risk of silicosis, and the risks caused by total silica dust and respirable silica dust exposure were high and medium, respectively. When predicting H and I over the next 10, 20, and 30 years, we assumed that the miner gender was male. Under exposure to current total silica dust concentrations, median I10, I20, and I30 would be 6.8%, 25.1%, and 49.9%, respectively. Under exposure to current respirable silica dust concentrations, median I10, I20, and I30 would be 6.8%, 27.7%, and 57.4%, respectively. These findings showed that miners in nonmetal, nonferrous metal, small, and open-pit mines have a higher I and higher qualitative silicosis risk.

CONCLUSIONS

Chinese noncoal miners, especially those in nonmetal, nonferrous metal, small, and open-pit mines, still suffer high-level exposure to silica dust and a medium-level risk of silicosis. Data of both total silica dust and respirable silica dust are vital for occupational health risk assessment in order to devise effective control measures to reduce noncoal mine silica dust levels, improve miners' working environment, and reduce the risk of silicosis.

Disease burden and related risk factors of esophageal cancer in China and globally from 1990 to 2021, with forecast to 2035: An analysis and comparison

INTRODUCTION

In this study we estimate the burden of esophageal cancer (EC) in China and globally from 1990 to 2021, with a forecast to 2035, using Global Burden of Disease (GBD) data. We also analyze the related risk factors to investigate burden trends.

METHODS

Mortality, disability-adjusted life years (DALYs), crude rates, and age-standardized rates of EC were analyzed in China and globally from 1990 to 2035, utilizing GBD open data as a secondary dataset analysis of GBD data. Temporal change trends of EC risk factors were analyzed from 1990 to 2021. Joinpoint regression determined average annual percentage change (AAPC) of age-standardized rates. Descriptive analysis compared mortality and DALYs by age groups. Bayesian age-period-cohort (BAPC) predicted age-standardized mortality and DALYs rates for the next 14 years.

RESULTS

The ASMR and ASDR fluctuations in EC were significant in China, showing an overall downward trend. Globally, although there was also a downward trend, the fluctuations were relatively mild. The number of deaths and DALYs related to EC in China and globally showed a significant upward trend. Age-specific burden trends in China for EC indicated that the age group with the peak number of EC deaths shifted to the 70-74 years age group in 2021, while DALYs peaked in the 65-69 years age group. The crude mortality rate (CMR) peaked consistently in 1990 and 2021, both within the 90-94 years age range, while the crude DALY rate (CDR) shifted to the 85-89 years age group. Overall, the burden of EC deaths and DALYs in the population aged <40 years was relatively low, increasing rapidly after the age of 40 years, reaching a peak and gradually declining, and reaching a lower level after the age of 85 years. The predictive results of the BAPC model indicated that over the next 14 years, both ASMR and ASDR for EC in China and globally would show a slight overall increase. The GBD 2021 study identified smoking, high alcohol use, chewing tobacco, and diet low in vegetables as the main risk factors affecting EC mortality rate and DALYs. Among these, smoking and alcohol use were the most significant risk factors, with a higher impact on EC in China compared to the global level. From 1990 to 2021, the overall changes in ASMR and ASDR indicate a decreasing trend in the impact of these four risk factors on EC mortality rate and DALYs.

CONCLUSIONS

The burden of EC is expected to steadily increase in China and globally until 2035, posing a significant challenge. Targeted prevention and control policies, such as calling on people to quit smoking and reduce alcohol use, may help curb this upward trend.

Investigation of the mechanism of silica-induced pulmonary fibrosis: The role of lung microbiota dysbiosis and the LPS/TLR4 signaling pathway

The widespread manufacture of silica and its extensive use, and potential release of silica into the environment pose a serious human health hazard. Silicosis, a severe global public health issue, is caused by exposure to silica, leading to persistent inflammation and fibrosis of the lungs. The underlying pathogenic mechanisms of silicosis remain elusive. Lung microbiota dysbiosis is associated with the development of inflammation and fibrosis. However, limited information is currently available regarding the role of lung microbiota in silicosis. The study therefore is designed to conduct a comprehensive analysis of the role of lung microbiota dysbiosis and establish a basis for future investigations into the potential mechanisms underlying silicosis. Here, the pathological and biochemical parameters were used to systematically assessed the degree of inflammation and fibrosis following silica exposure and treatment with combined antibiotics. The underlying mechanisms were studied via integrative multi-omics analyses of the transcriptome and microbiome. Analysis of 16S ribosomal DNA revealed dysbiosis of the microbial community in silicosis, characterized by a predominance of gram-negative bacteria. Exposure to silica has been shown to trigger lung inflammation and fibrosis, leading to an increased concentration of lipopolysaccharides in the bronchoalveolar lavage fluid. Furthermore, Toll-like receptor 4 was identified as a key molecule in the lung microbiota dysbiosis associated with silica-induced lung fibrosis. All of these outcomes can be partially controlled through combined antibiotic administration. The study findings demonstrate that the dysbiosis of lung microbiota enhances silica-induced fibrosis associated with the lipopolysaccharides/Toll-like receptor 4 pathway and provided a promising target for therapeutic intervention of silicosis.

The burden of low back pain in adolescents and young adults

BACKGROUND

Low back pain is highly prevalent and the main cause of years lived with disability, but data on the burden and trends of low back pain (LBP) in adolescents and young adults (AYAs) are sparse.

OBJECTIVE

To assess trends in the burden of LBP among AYAs aged 15-39 years at the global, regional and national levels from 1990 to 2019.

METHODS

Data from the Global Burden of Disease (GBD) 2019 were used to analyze incidence, prevalence and Disability-adjusted life year (DALY) due to LBP at global, regional, and national levels. Joinpoint regression analysis calculated the average annual percentage changes (AAPC). Then analyse the association between incidence, prevalence and DALYs and socioeconomic development using the GBD Socio-demographic Index (SDI). Finally, projections were made until 2030 and calculated in Nordpred.

RESULTS

The incidence, prevalence and DALYs rates (95%UI) were 2252.78 (1809.47-2784.79), 5473.43 (4488.62-6528.15) and 627.66 (419.71-866.97) in 2019, respectively. From 1990 to 2019, the incidence, prevalence, and DALYs rates AAPC (95%CI) were -0.49 (-0.56 to -0.42), -0.58 (-0.65 to -0.51) and -0.57 (-0.64 to -0.5), respectively. Incidence, prevalence, and DALYs rates in South Asia, East Asia, High-income North America, Western Europe, and Australasia decreased with SDI. Incidence, prevalence, and DALYs rates in Central Asia, Central Europe, and Eastern Europe decreased and then increased with SDI. At the national level, the incidence, prevalence, and DALYs rates are high in the United States and low in India and China. From the 2020 to 2030, most regions is predicted to decline.

CONCLUSION

LBP in AYAs is a major global public problem with a high burden. There are large differences in incidence, prevalence and DALYs across SDIs, regions and countries. there is still a need to focus on LBP in AYAs and tailor interventions to reduce the future burden of this condition.