How long-term air pollution and its metal constituents affect type 2 diabetes mellitus prevalence? Results from Wuhan Chronic Disease Cohort.

BACKGROUND: Epidemiological evidence linking type 2 diabetes mellitus (T2DM) with air pollution is discrepant and most are restricted to the influences of air-pollutant mass concentration. This study aims to explore the effects of long-term exposure to air pollution and its metal constituents on T2DM prevalence in China. METHODS: We used data on 10,253 adult residents from the baseline survey of Wuhan Chronic Disease Cohort in 2019. Ambient PM2.5, PM10 and NO2 exposure were estimated at residences based on Chinese Air Quality Reanalysis Dataset. Concentrations of 10 metal constituents were measured by 976 PM2.5 filter samples collected from four monitoring stations. Logistic regression models were employed to examine associations of T2DM prevalence with 3-year mean concentrations of each air pollutant and PM2.5 metal constituents prior to the baseline investigation. RESULTS: A total of 673 T2DM cases (6.6%) were identified. The 3-year mean exposures to PM2.5, PM10 and NO2 were 50.89 µg/m3, 82.86 µg/m3, and 39.79 µg/m3, respectively. And interquartile range (IQR) of 10 metals in PM2.5 varied from 0.03 ng/m3 to 78.30 ng/m3. For 1 µg/m3 increment in PM2.5, PM10 and NO2, the odds of T2DM increased by 7.2% (95%CI: 1.026, 1.136), 3.1% (95%CI: 1.013, 1.050), and 2.1% (95%CI: 1.005, 1.038) after adjusting for potential confounders. Cd and Sb in PM2.5 were significant risk factors to T2DM with odds ratios of 1.350 (95%CI: 1.089, 1.673) and 1.389 (95%CI: 1.164, 1.658) for per IQR increase, respectively. Stratification analyses indicated that males and those aged ≥45 years were more susceptive to long-term air pollution. CONCLUSIONS: Long-term exposure to PM2.5, PM10 and NO2 increased T2DM prevalence in a Wuhan population, especially for men and middle-aged and elderly people. Moreover, T2DM was significantly associated with Cd and Sb in PM2.5. Further research to validate these results and to clarify the underlying mechanisms is warranted.

Association of depressive symptoms with ambient PM2.5 in middle-aged and elderly Chinese adults: A cross-sectional study from the China health and Retirement Longitudinal Study wave 4.

Depressive symptoms have become a serious public health issue worldwide. Several studies showed that air pollution, especially fine particulate matter (PM2.5), may be a risk factor of mental disorders. However, existing studies reported inconsistent results and little evidence is available in developing countries, like China. To fill the gap, in this study, we explored the relationship between ambient PM2.5 exposure and depressive symptoms among middle-aged and elderly Chinese adults in the Chinese Health and Retirement Longitudinal Study (CHARLS). The social and demographic variables and depressive symptoms were obtained from the Wave4 of CHARLS in 2018. PM2.5 concentrations were obtained from the national urban air quality real-time release platform of China Environmental Monitoring Station. We applied generalized linear mixed models to determine the association between PM2.5 exposure and depressive symptoms. A total of 15,105 middle-aged and elderly adults from CHARLS Wave4 were included in the analyses. We found positive impact of ambient PM2.5 on depressive symptoms for the exposure windows of 30-day, 60-day, 120-day, 180-day, 1-year and 2-year. The most significant increase was observed for 180-day moving average. For every 10 µg/m3 increment in PM2.5 exposure, the incidence of depressive symptoms increased by 9% (OR = 1.09; 95%CI: 1.05, 1.14) after adjusting for age, sex and residence. In interaction analyses, we found PM2.5 had weaker effect on depressive symptoms among people who used to drink alcohol (OR = 1.05; 95%CI: 1.00, 1.10) and exercise (OR = 1.10; 95%CI: 1.02, 1.18). People living in western China (OR = 1.09; 95%CI: 1.03, 1.16) were more vulnerable than those living in eastern China (OR = 0.99; 95%CI: 0.94, 1.05). In conclusion, exposure to PM2.5 was significantly associated with depressive symptoms in middle-aged and elder Chinese adults, particularly for people who never drink, with lower physical activity levels, or lived in western China.