Short-Term Associations Between Ambient Air Pollution and Outpatient and Emergency Visits for Hypertension: A...

Despite growing evidence that short-term ambient air pollution increases hypertension risk, data from China's border regions are limited; this study quantifies the association between daily pollutant concentrations and daily emergency and outpatient visits for hypertension in Baise, a southern border city.

We collected hypertension case data from two tertiary hospitals in Baise City (1 Jan 2020-30 Dec 2022) and concurrent local air pollutant and meteorological data, and used a distributed lag non-linear model (DLNM) to assess pollutant effects on outpatient and emergency visits, with subgroup analyses by sex, age, and season.

Every 10 μg/m³ increase in PM_2.5 (lag06), PM₁₀ (lag06), NO₂ (lag06), and every 100 μg/m³ increase in CO (lag04), the risk of hypertension outpatient/emergency department visits increased by 3.2%, 2.8%, 14.8%, and 3.0%, respectively. Exposure-response curves were approximately linear without a clear threshold. There was no statistically significant effect modification by sex or age, whereas associations were stronger in the cold season than in the warm season.

Short-term exposure to pollutants such as PM_2.5, PM₁₀, NO₂, and CO is significantly associated with increased outpatient and emergency visits for hypertension, exhibiting a lag effect. During cold seasons, sensitivity to environmental pollutants among hypertensive patients markedly increases.