Long-term effects of PM2.5 components on hypertension: A national analysis in China

Background: Evidence is less about the associations between fine particulate matter (PM2.5) components and hypertension. We aimed to examine the long-term effects of PM2.5 components on prevalence of hypertension, diastolic blood pressure (DBP) and systolic blood pressure (SBP).Methods: We included participants between March 1, and July 31, 2021, from 13 provinces in China. Geocoded residential address was used for exposure assignment. Mixed-effect regression was used to assess 3-year average concentrations of PM2.5 and its components (black carbon, organic matter, nitrate, ammonium, and sulfate) on prevalence of hypertension, DBP and SBP with covariate-adjusted. SHapley Additive exPlanation was used to compare the contribution of PM2.5 components to hypertension, DBP, and SBP. Sex and age subgroup were also analyzed.Results: We enrolled a total of 113,159 participants aged >= 18 years. Long-term exposure to PM2.5 and its com-ponents (black carbon, organic matter, nitrate, ammonium, and sulfate) had associations with prevalence of hypertension, with the Odds Ratios and 95% confidence interval (CI) of 1.06 (95%CI: 1.03-1.09), 1.07 (95%CI: 1.04-1.09), 1.07 (95%CI: 1.04-1.10), 1.05 (95%CI: 1.01-1.08), 1.03 (95%CI: 1.00-1.06), and 1.03 (95%CI: 1.00-1.04), respectively. Effects of that except for black carbon on DBP with per interquartile upticks of con-centration were 0.23 (95%CI: 0.11-0.35), 0.17 (95%CI: 0.04-0.29), 0.35 (95%CI: 0.21-0.48), 0.40 (95%CI: 0.28-0.52), and 0.25 (95%CI: 0.13-0.26), respectively. Ammonium was associated with SBP, corresponding to an increase of 0.18 (95%CI: 0.01-0.35). Males had higher risks of DBP (Z = 2.54-6.08, P < 0.001). Older people were substantially more affected by PM2.5 and its components. Nitrate showed the highest contribution to hy-pertension, DBP and SBP compared with other components.Conclusions: Long-term exposure to PM2.5 and its components had adverse consequences on prevalence of hy-pertension, DBP and SBP, especially for males and older people. Nitrate contributed the highest to hypertension, DBP and SBP. Findings may have implications for pollution and hypertension control.