Study On The Effect Of PM2.5 On Hypertension In The Middle-aged And Elderly People In China

ObjectiveHypertension is one of the most common chronic diseases,and it has a high prevalence both globally and in mainland China.Meanwhile it continues to rise.At the same time,high blood pressure has brought a great burden of diseases.In 2011,the burden of chronic diseases in China accounted for 68.6%of the country’s total burden of disease,a large part of which was due to hypertension and its complications.Hypertension also showed an increasing prevalence with age.However,people with different genders and smoking status also showed significantly different prevalence rates.More importantly,based on the mainland of China,the prevalence of hypertension showed a clear spatial distribution pattern.Further more,in the study of risk factors of hypertension,the air problem had become a research hotspot in recent years,especially in the impact of PM2.5 on hypertension.This study aimed to explore the spatial distribution characteristics of hypertension prevalence in mainland China,the impact of PM2.5 on hypertension,and the differences among different genders and different smoking populations from the perspective of spatial research.Further,it provided targeted measures for the prevention and control of hypertension in different regions and effectively reduced the prevalence of hypertension.MethodsBasing on China Health and Retirement Longitudinal Study(CHARLS),we obtained data on the prevalence of hypertension among people over 45 years old in 31 provinces in Chinese mainland.Meanwhile through the "Environmental Status Bulletin",the daily average concentration of PM2.5 in each province was obtained.A spatial database was established by combining epidemiological data and PM2.5 data with spatial information.Then the prevalence of hypertension was calculated for each region for disease mapping,and the spatial distribution of prevalence of hypertension was initially explored.Further,the Spatial Bayesian Model,such as the convolution model(BYM)and the Shared Component Model(SCM)were used to study the risk of hypertension in each region.Finally,the PM2.5 average daily observations were added to the model as covariates to explore the effect of PM2.5 on the prevalence of hypertension in the population and the differences among the different populations.ResultsA total of 20,927 people were included in the study,males accounted for 47.45%,and the prevalence of hypertension was 32.74%.The prevalence for males and females were 32.92%and 32.58%,respectively.The provinces with the highest prevalence of hypertension were Heilongjiang,Qinghai and Shandong,respectively,and their prevalence exceeded 40%.The prevalence in Fujian,Guangdong and Chongqing were relatively low,both lower than 27%.According to the smoothing results of the Bayesian model,the elderly in most regions in the northeastern part of mainland China had a higher risk of hypertension,and the risk in the eastern region,especially in the southeast region,was lower;in most regions of the central region,the risk was lower than baseline risk;while the risk of hypertension in the western region was above average,especially in the northwestern provinces.Among them,Heilongjiang,Beijing-Tianjin-Hebei and Shandong provinces were at higher risks and their relative odds ratio(OR)exceeded 1.29.Followed by the Inner Mongolia,Liaoning,Shanxi and Jiangsu,the ORs of these provinces were greater than 1.17.The risks of provinces such as Fujian,Jiangxi,Guangdong and Guangxi were significantly lower than the baseline risk,and the OR of they were less than 0.91.In terms of men,the overall characteristics of distribution were similar to those of the entire population.Specifically,the risk of hypertension in Heilongjiang,Beijing and Tianjin were relatively high,and the ORs were over 1.6.Followed by Inner Mongolia,Hebei,Shandong and Qinghai,the OR also exceeded 1.4.The relative risks of the two provinces in Fujian and Guangdong were significantly lower than the baseline risk,and their ORs were all less than 0.9.For women’s smooth results,the spatial characteristics of the risk were approximately the same as those of men.Like men,Heilongjiang,Beijing,and Tianjin had the highest risk of disease,and their ORs were over 1.6.The Fujian,Guangdong,and Jiangxi provinces had the lowest risk of disease,with OR less than 0.9.Further,it was confirmed from the spatial level that PM2.5 was a risk factor of hypertension and the OR median posterior was 1.015.From the perspective of gender,PM2.5 had a slightly greater impact on women than men,and the OR median posterior were 1.033 and 1.013,respectively.This study further explored the differences in PM2.5 between different smoking populations.The impact of PM2.5 on non-smokers was greater than that of smokers,and the OR median posterior were 1.020 and 1.002,respectively.ConclusionsThis study was based on the 2015 survey data of the CHARLS and used the BYM and SCM to describe the risk of hypertension in middle-aged and elderly people in various provinces of mainland China.The results showed that the risk of hypertension was highest in the eastern region,followed by the west and lowest in the middle.Based on the spatial Bayesian model,PM2.5 was a risk factor for hypertension.At the same time,PM2.5 has a higher impact on hypertension for males than that for females,and that for non-smoking population was greater than that for smoking population.It was worth mentioning that PM2.5 in the central region had the greatest impact on hypertension.Therefore,air pollution,especially of PM2.5,would be the focus of attention in the prevention and control of future hypertension in this region.