Short-Term Exposure to Air Pollution Increases Mortality From Hypertension and its Multiorgan Complications: A Case Crossover Study of 2.1 Million Deaths in China.
Short-term air pollution exposure is a known trigger for cardiovascular events, yet how this risk varies across different progression stages of hypertensive patients remains unclear.
This study sought to quantify the mortality risk and burden due to hypertensive diseases of different progression stages in association with air pollution.
We conducted a nationwide, individual-level, time-stratified, case-crossover study including >2.1 million hypertension-related deaths across mainland China (2013-2019). Daily concentrations of fine particulate matter (PM2.5), inhalable particulate (PM10), NO2, and O3 were estimated using high-resolution spatiotemporal models (1 × 1 km). Conditional logistic regression was used to quantify the associations.
We observed a clear, stepwise risk gradient. For PM2.5, the mortality risk per interquartile range increase rose from 1.39% (95% CI: 0.55%-2.24%) in uncomplicated primary hypertension to 2.62% (95% CI: 2.20%-3.05%) in hypertensive heart disease and 3.03% (95% CI: 1.53%-4.56%) in hypertensive kidney disease, reaching 5.01% (95% CI: 1.96%-8.16%) in hypertensive heart and kidney disease with concurrent cardiorenal failure at lag 02 days (average of lag 0-2 days). This high-risk phenotype also had the highest attributable fraction, with 4.20% (95% CI: 3.55%-4.85%) of deaths attributable to PM2.5. Furthermore, NO2 consistently showed the strongest associations among 4 air pollutants. We observed that the exposure-response curves for all 4 pollutants demonstrated approximately linear relationships with hypertension mortality, with no apparent evidence of a threshold. Hypertensive patients of female sex, age ≥65 years, northern residence, lower educational attainment, and no spousal support, and patients during the cold season were more vulnerable.
Air pollution acts as an acute stressor superimposed on hypertensive patients, creating a mortality risk gradient determined by the severity of comorbidity. These findings highlight the need for targeted risk stratification, identifying patients with concurrent cardiorenal failure as a priority group for precision-based environmental health advisories and targeted clinical management.
This study sought to quantify the mortality risk and burden due to hypertensive diseases of different progression stages in association with air pollution.
We conducted a nationwide, individual-level, time-stratified, case-crossover study including >2.1 million hypertension-related deaths across mainland China (2013-2019). Daily concentrations of fine particulate matter (PM2.5), inhalable particulate (PM10), NO2, and O3 were estimated using high-resolution spatiotemporal models (1 × 1 km). Conditional logistic regression was used to quantify the associations.
We observed a clear, stepwise risk gradient. For PM2.5, the mortality risk per interquartile range increase rose from 1.39% (95% CI: 0.55%-2.24%) in uncomplicated primary hypertension to 2.62% (95% CI: 2.20%-3.05%) in hypertensive heart disease and 3.03% (95% CI: 1.53%-4.56%) in hypertensive kidney disease, reaching 5.01% (95% CI: 1.96%-8.16%) in hypertensive heart and kidney disease with concurrent cardiorenal failure at lag 02 days (average of lag 0-2 days). This high-risk phenotype also had the highest attributable fraction, with 4.20% (95% CI: 3.55%-4.85%) of deaths attributable to PM2.5. Furthermore, NO2 consistently showed the strongest associations among 4 air pollutants. We observed that the exposure-response curves for all 4 pollutants demonstrated approximately linear relationships with hypertension mortality, with no apparent evidence of a threshold. Hypertensive patients of female sex, age ≥65 years, northern residence, lower educational attainment, and no spousal support, and patients during the cold season were more vulnerable.
Air pollution acts as an acute stressor superimposed on hypertensive patients, creating a mortality risk gradient determined by the severity of comorbidity. These findings highlight the need for targeted risk stratification, identifying patients with concurrent cardiorenal failure as a priority group for precision-based environmental health advisories and targeted clinical management.