Associations Of Long-term Exposure To Particulate Matter And NO₂ With Blood Pressure,and Acute Effects Of Exposure To PM_2.5 On Blood Pressure

BackgroundThe epidemiological evidence on relationships between exposure to particulate matter and hypertension and blood pressure were inconclusive,and the evidence from rural areas in developing countries was scarce.Objective?1?To investigate the associations of long-term exposure to particulate matter with an aerodynamic diameter?1?m?PM₁?,2.5?m(PM_2.5),10?m(PM₁₀)and nitrogen dioxide?NO₂?with hypertension and blood pressure,and effect modifiers in these associations,based on the Henan Rural Cohort Study.?2?To examine the effect of short-term exposure to PM_2.5 on blood pressure,heart rate and some blood parameters.Methods?1?We used baseline survey data of the Henan Rural Study,and participants'exposure to air pollutants was assessed by a satellite-based spatiotemporal model.The binary logistic regression model was used to examine the association between air pollution exposure and hypertension,and multivariable linear regression model was used to investigate the associations between exposure and systolic blood pressure?SBP?,diastolic blood pressure?DBP?,mean arterial pressure?MAP?and pulse pressure?PP?.Furthermore,the potential effect modification by sex,age,smoking,drinking,consumption of fruit and vegetables,high fat diet and physical activity was also examined.?2?The effect of short-term exposure to PM_2.5 on blood pressure,heart rate and some blood parameters were explored based on a self-controlled experiment.Individual exposure to PM_2.5 was obtained through a portable and intelligent air detector.Associations of PM_2.5 with blood pressure,heart rate and blood parameters were examined using mixed effect models.Results?1?A total of 39,207 participants were included in the study.Each 1?g/m³ increase in PM₁,PM_2.5,PM₁₀ and NO₂ were significantly associated with 4.3%?95%CI:3.3%,5.3%?,7.9%?95%CI:6.9%,9.0%?,3.7%?95%CI:3.3%,4.2%?and 5.0%?95%CI:4.3%,5.7%?increase in odds for hypertension,respectively.These four air pollutants were also associated with increased SBP,DBP,MAP and PP.For example,each 1?g/m³increase in the 3-year average PM₁ concentration was significantly associated with an increase of 0.401 mm Hg?95%CI,0.335,0.467?,0.328 mm Hg?95%CI,0.288,0.369?,0.353 mm Hg?95%CI,0.307,0.399?and 0.073 mm Hg?95%CI,0.030,0.116?in SBP,DBP,MAP and PP,respectively.Similar associations were explored for PM_2.5,PM₁₀and NO₂.Further stratified analyses showed that the associations of long-term exposure to four air pollutants with hypertension and blood pressure could be modified by sex,smoking status,drinking status,fruits and vegetables intake,high-fat diet and physical activity.?2?A total of 31 subjects were included in the study.A 10?g/m³ increase in PM_2.5concentration was significantly associated with an increase of 0.84bpm?95%CI:0.54,1.15?in heart rate.The lag effect of short-term exposure to PM_2.5on the heart rate was also observed.No significant associations were examined for between PM_2.5 and blood pressure.In addition,for each 10?g/m³ increase in PM_2.5,the average red blood cell volume decreased by 39.3%?95%CI:-54.11%,-19.90%?,and the average red blood cell hemoglobin concentration increased by 2.02g/L?95%CI:1.01,3.04?,the red blood cell volume distribution width-SD decreased by 43.08%?95%CI:-58.93%,-27.74%?,the red blood cell volume distribution width-CV decreased by 7.95%?95%CI:-14.09%,-1.61%?.The sodium ion concentration in the blood drops by 29%,while the potassium ion concentration increases by 6.9%.ConclusionsLong-term exposure to PM₁,PM_2.5,PM₁₀ and NO₂ was associated with increased blood pressure and hypertension prevalence among rural Chinese adults,and the associations were modified by sex and several behavioral factors?e.g.smoking,drinking and high-fat diet?.Short-term exposure to PM_2.5 was associated with increased heart rate and changes in some blood indicators such as average red blood cell volume and average red blood cell hemoglobin concentration.