Empirical Analysis Of The Effects Of Air Pollution On Type 2 Diabetes Mellitus

Background Type 2 diabetes mellitus(T2DM)is one of the major chronic metabolic diseases influencing human health across China and even the whole world.Recent years,researchers are beginning to concern about the adverse effect of environmental factors,especially air pollutant exposures,on the health of human.Whereas,whether air pollutant is a new risk factor for T2DM and whether air pollutant is associated with the epidemic of T2DM has not been concluded yet.Evidence from low-and middle-income countries are also limited.It has important practical significance to conduct an empirical analysis to explore the effects of air pollution on T2DM,which can help to reduce the domestic and international disease burden of T2DM and to reduce life quality losses.Objective The objective of the research was to evaluate the concentrations of air pollutants in different administrative regions of China using survey data from large-scale of population,to assess the epidemic situation of T2DM in China,and then to explore the potential relationship between long-term air pollutant exposures and prevalence and/or incidence risk of T2DM as well as the diabetic traditional risk factors.There is the hope that results of this research can provide scientific guidance and population data support for the development and revisions of China's air pollution prevention policies,and can help improving the existing diabetes management model.Methods Firstly,literature analysis method was used to summarize studies globally which focus on the relationships between air pollutant exposures and prevalence and/or incident risks of T2DM.Research advantages and limitations were also discussed in this part.Secondly,on the consideration of the characteristics of China's development and the health needs of Chinese,we optimized the study path by establishing a satellite-based spatio-temporal model which can evaluate individual's air pollutant exposure concentrations accurately in different administrative regions and in different periods.The air pollutant concentration level retrieved from the spatio-temporal model was considered as a direct measurement index to evaluate the effect of air pollution prevention policies in different administrative regions.Meanwhile,experimental analysis was performed based on Chineses.Briefly,the baseline survey data from the China Health and Retirement Longitudinal Study(CHARLS)in 2011 were used to investigate the major air pollutants'concentrations and the prevalence of T2DM in different administrative regions of China.Relationships of long-term air pollutant exposures and T2DM prevalent among subjects in CHARLS 2011 was also evaluated through the empirical analysis.Then the non-diabetic population from CHARLS baseline survey in 2011 were selected and followed for 5 years.The relationship between long-term air pollutant exposures and incidence of T2DM was assessed.Finally,Henan province,one of the most air polluted region in China,was selected as the research site,to investigate the prevalence and risk factors of T2DM of population through an empirical analysis.The relationship of long-term exposure to high levels of air pollutant and T2DM was then calculated simultaneous to assess the hazard effects of air pollutants.Results(1)Globally,a 10?g/m³ increase in PM_2.5,PM₁₀,and NO₂exposure were significantly associated with higher prevalence of T2DM(PM_2.5:OR=1.09,95%CIs:1.05,1.13;PM₁₀:OR=1.12,95%CIs:1.06,1.19;NO₂:OR=1.05,95%CIs:1.03,1.08),and higher T2DM incidence(per 10?g/m³ increase in concentration of PM_2.5:HR=1.10,95%CIs:1.04,1.16;PM₁₀:HR=1.06,95%CIs:0.98,1.13;NO₂:HR=1.02,95%CIs:0.97,1.06).Different associations between long-term exposure to air pollutants and risks of T2DM were identified in different geographic areas.(2)There were significant differences in the exposure concentrations of air pollutants among different administrative regions between 2009 and 2011.Higher concentration of air pollutants was found associated with higher prevalence of T2DM.Generally,the air pollution level in the Central China was the highest,followed by the North China,East China,Northwest China,Northeast China,South China and Southwest China.While the prevalence of T2DM in Central China was the highest(19.5%)and followed by North China(17.2%),Northeast China(17.1%),Southwest China (15.9%),Northwest China(15.2%),East China(15.1%),and in South China was lowest(13.4%).Quantitative analysis results showed that long-term exposure to air pollutant was associated with increased T2DM prevalent in China.A 10?g/m³ increase in PM₁₀ and PM_2.5 was positively related to a 2.4%(OR=1.024,95% CIs:1.001,1.048)and 4.9%(OR=1.049,95%CIs:1.006,1.093)increase in odds of T2DM.Positive associations were also observed between PM₁,NO₂ and T2DM prevalent,though the results were not statistically significant.Moreover,interaction effects between air pollutants and traditional diabetes risk factors including age, gender,physical activity intensity,chronic disease drug use and current residence type was not identified.(3)There remain significant differences in air pollution levels among different administrative regions in China between 2011 and 2015.On the whole,the air pollution levels in the Central China was still the highest,followed by the North China,East China,Northwest China,Northeast China,South China and Southwest China.Among 3510 individuals,128 were diagnosed as new cases of T2DM in 2015,and the incidence of T2DM was 3.6%.Incidence differences among different administrative regions were also identified.The T2DM incidence in the Northwest China was the highest(4.9%),and followed by the East China(4.1%),North China(3.6%),Northeast China(3.5%),Central China(3.4%),South China(2.8%)and the Southwest China(2.8%).Quantitative analysis results showed that long-term exposure to air pollutants remains associated with increased T2DM incident among Chinese populations those with the similar age,and lifestyle.A 10?g/m³ increase in PM₁₀,PM_2.5,PM₁ and NO₂ was related to a 8.4%(RR=1.084,95%CIs:1.003,1.173),16.3%(RR=1.163,95%CIs:1.013,1.340),14.8%(RR=1.148,95%CIs:0.984,1.342)and 30.4%(RR=1.304,95%CIs:1.048,1.620)increase in incidence of T2DM in Chinese populations,respectively.(4)During the survey period(2015-2017),the mean concentrations of PM_2.5,PM₁and NO₂ in rural region of Henan was 73.4?g/m³,57.4?g/m³,and 39.9?g/m3,respectively.Quantitative analysis results showed that long-term exposure to higher exposure concentrations of PM_2.5,PM₁ and NO₂ were positively related to the increased odds of T2DM,as well as higher fasting blood glucose levels in Chinese rural populations.A 1?g/m³ increase of PM_2.5,PM₁ and NO₂ was positively related to a 6.8%(OR=1.068,95%CIs:1.052,1.084),4.0%(OR=1.040,95%CIs:1.026,1.054)and 5.0%(OR=1.050,95%CIs:1.039,1.061)increase in odds of T2DM in the final adjusted model.Besides,a 1?g/m³increase of PM_2.5,PM₁ and NO₂ was related to a0.036 mmol/L(95%CIs:0.030,0.042),0.020 mmol/L(95%CIs:0.014,0.026)and 0.030 mmol/L(95%CIs:0.026,0.034)mmol/L higher fasting blood glucose levels.There is an interaction effect between PM_2.5,PM₁ and NO₂ and traditional diabetes risk factors,such as age and gender,among individuals those living in a highly polluted environment.Men and the elderly were more sensitive to the adverse effects of air pollutants.Conclusions and Suggestions In the research,based on the empirical analysis of large-scale population,it was found that concentration levels of main air pollutants are significantly different among different administrative regions of China,suggesting that the process of implementing environmental regulation policies in different administrative regions may be affected by other factors.For example,in central China where the level of air pollutants is the highest with the highest T2DM prevalence from2009 to 2011.Moreover,we found air pollutants,including PM₁₀,PM_2.5,PM₁ and NO₂ are all risk factors of T2DM and are associated with epidemic of diabetes.Long-term exposure to high levels of air pollutants was associated with increased risks of T2DM.In order to improve the health level of Chinese population and to control the epidemic and development of diabetes,we propose the following suggestions:Firstly,local governments should strictly implement the air pollution prevention and control policies and other relevant regulations introduced by national departments.Secondly,government should take targeted measures to control and reduce residents'air pollutants exposure concentrations generally.Thirdly,more attention should be paid to the susceptibility of middle-aged and elderly people.Fourthly,government and medical institutions need to further improve the diabetes prevention and management model.In addition to traditional risk factors of T2DM,air pollutants protection deserves more attention,to improve the overall population health level and to enhance T2DM patients'self-management ability.Finally,health education activities should be encouraged and promoted,which promote a healthy and green life style,then help to build a harmonious and healthy social and cultural environment.