PM2.5 exposure linked to elevated BP
28 Oct 2024
People with long-term exposure to PM2.5 and its chemical constituents appear to be at greater risk for elevated blood pressure (BP), suggests a study.
This cross-sectional study included 36,792 adults, which represented 25 counties of southeast China. The investigators used quantile regression models to explore the relationship of PM2.5 and its chemical constituents (ie, ammonium [NH4+], nitrate [NO3−], sulfate [SO42−], black carbon [BC], organic matter [OM]) with systolic BP (SBP), diastolic BP (DBP), and mean artery pressure (MAP).
Finally, the investigators used a weighted quantile sum (WQS) index to assess the relative importance of each chemical constituent to the joint effect on BP.
The adverse effects of each interquartile range (IQR) increase in PM2.5, NH4+, NO3−, SO42−, and BC on BP were pronounced among participants with elevated BP, particularly when SBP rose above 133 mm Hg and DBP 82 mm Hg.
Each IQR increase in all PM2.5 chemical constituents correlated with increased SBP (β, 0.90, 95 percent confidence interval [CI], 0.75‒1.05), DBP (β, 0.44, 95 percent CI, 0.34‒0.53), and MAP (β, 0.57, 95 percent CI, 0.45‒0.69), with NH4+ (for SBP: weight, 99.43 percent; for DBP: 12.78 percent; for MAP: 60.73 percent) and BC (for DBP: 87.06 percent; for MAP: 39.07 percent) primarily influencing these effects.
Notably, the joint effect of PM2.5 chemical constituents on the risks for increased SBP and DBP showed an upward trend from the 70th quantile (SBP exceeded 133 mm Hg, DBP exceeded 82 mm Hg.
“Long-term exposure to PM2.5 and its chemical constituents was associated with increased risk for elevated BP, with NH4+ and BC being the main contributors, and such associations were significantly stronger at the 70th to 90th quantiles,” according to the investigators.