Association between solid fuel combustion and diabetes mellitus: a systematic review and meta-analysis

Effects of air pollutants exposure on frailty risk: A systematic review and meta-analysis

Air pollutants have been investigated to be associated with many health issues. Recently, increasing epidemiological studies have suggested the association between air pollution exposure and risk of frailty with inconsistent findings. This systematic review and meta-analysis was to summarize and evaluate effects of exposure to various air pollutants on risk of frailty. PubMed, Embase, Scopus and Web of Science were systematically searched for relevant studies published before May 11, 2024. Studies that explored the potential relationship between exposure to air pollutants (PM2.5, PM10, O3, NOx, solid fuel, secondhand tobacco, and air quality) and risk of frailty were included. The quality of cross-sectional and cohort studies was evaluated using an eight-item assessment instrument for epidemiological studies and Newcastle-Ottawa Scale, respectively. A total of 9,929 papers were retrieved, of which 20 met the inclusion criteria. Meta-analysis indicated that PM2.5 exposure was significantly associated with frailty assessed by the frailty index [OR (95% CI): 1.24 (1,11-1.38) per 10 μg/m3 increment]. Moreover, solid fuel exposures were significantly associated with an increased risk of frailty assessed by the frailty phenotype [OR (95% CI): 1.91 (1.09-3.34)] or the frailty index [OR (95% CI): 1.25 (1.11-1.41)]. Exposure to PM2.5 and solid fuel increases the risk of frailty. Environmental protection policies and public health measures should be developed to reduce PM2.5 concentrations. Effective measures, such as improving stoves and using clean fuels, should be taken to reduce indoor air pollution levels.

Effects of indoor air pollution from household solid fuel use on the risk of gastrointestinal and liver diseases in middle aged and elderly adults

Solid fuels are widely used in China and increase the concentrations of indoor air pollutants. Nevertheless, there is limited longitudinal evidence linking solid fuel use and Gastrointestinal (GI) and liver diseases. This study aimed to prospectively investigate the association between household solid fuel use and the risk of GI and liver diseases in middle aged and elderly adults. This work was based on the China Health and Retirement Longitudinal Study (CHARLS). Longitudinal data incorporate with cross-sectional data were analyzed. Compared with individuals using clean fuel for cooking, solid fuel users were observed to have higher risk of GI diseases (OR in 2011, 2013, 2015, 2018 wave separately: 1.37, 95 % CI: 1.24-1.50, P < 0.001; 1.24, 95 % CI: 1.11-1.39, P < 0.001; 1.18, 95 % CI: 1.06-1.33, P < 0.001; 1.23, 95 % CI: 1.04-1.45, P < 0.05). The associations between solid fuel use and liver diseases were not significant in most of the groups. Participants transforming from solid to clean cooking fuels had lower risk of GI and liver diseases than persistent solid fuel users. Moreover, biomass cooking fuel users were at a significant higher risk of both liver and GI diseases compared with clean fuel users. Overall, household solid fuel use, especially for cooking, was related to higher risk of GI and liver diseases, while switching from solid to clean fuels could reduce this risk. Using biomass for cooking was identified to be more associated with the increasing risk of GI and liver diseases than cooking with coal.

The role of liver enzymes in the association between ozone exposure and diabetes risk: a cross-sectional study of Zhuang adults in China

Background: Growing evidence has demonstrated the role of ambient air pollutants in driving diabetes incidence. However, epidemiological evidence linking ozone (O3) exposure to diabetes risk has been scarcely studied in Zhuang adults in China. We aimed to investigate the associations of long-term exposure to O3 with diabetes prevalence and fasting plasma glucose (FPG) and estimate the mediating role of liver enzymes in Zhuang adults. Methods: We recruited 13 843 ethnic minority adults during 2018-2019 based on a cross-sectional study covering nine districts/counties in Guangxi. Generalized linear mixed models were implemented to estimate the relationships between O3 exposure and diabetes prevalence and FPG. Mediation effect models were constructed to investigate the roles of liver enzymes in the associations of O3 exposure with diabetes prevalence and FPG. Subgroup analyses were conducted to identify potential effect modifications. Results: Long-term exposure to O3 was positively associated with diabetes prevalence and FPG levels in Zhuang adults, with an excess risk of 7.32% (95% confidence interval [CI]: 2.56%, 12.30%) and an increase of 0.047 mmol L-1 (95% CI: 0.032, 0.063) for diabetes prevalence and FPG levels, respectively, for each interquartile range (IQR, 1.18 μg m-3) increment in O3 concentrations. Alanine aminotransferase (ALT) significantly mediated 8.10% and 29.89% of the associations of O3 with FPG and diabetes prevalence, respectively, and the corresponding mediation proportions of alkaline phosphatase (ALP) were 8.48% and 30.00%. Greater adverse effects were observed in females, obese subjects, people with a low education level, rural residents, non-clean fuel users, and people with a history of stroke and hypertension in the associations of O3 exposure with diabetes prevalence and/or FPG levels (all P values for interaction < 0.05). Conclusion: Long-term exposure to O3 is related to an increased risk of diabetes, which is partially mediated by liver enzymes in Chinese Zhuang adults. Promoting clean air policies and reducing exposure to environmental pollutants should be a priority for public health policies geared toward preventing diabetes.