Association between ambient fine particulate matter with blood pressure levels among Iranian individuals admitted for cardiac and respiratory diseases: Data from CAPACITY study

The relation between air pollution and cardiovascular diseases (CVDs) risk factors, especially blood pressure (BP) levels, has been less frequently assessed. The aim of this study was evaluating the association between air pollutants of less than 2.5 µm [particulate matter (PM2.5)] and BP indices among individuals admitted with CVDs and pulmonary diseases.

This cross-sectional study was in context of air pollution associated with hospitalization and mortality of CVDs and respiratory diseases (CAPACITY) study. Data of 792 Iranian patients referring to two hospitals in Isfahan, Iran, for cardiovascular or respiratory problems from March 2011 to March 2012 were used for analysis. BP indices including systolic BP (SBP), diastolic BP (DBP), and mean arterial pressure (MAP) were obtained from patients’ medical forms and mean PM2.5 concentrations during 24 hours prior to admission of each patient were obtained from Isfahan Department of Environment (DOE).

Mean ± standard deviation (SD) of participants’ age were 62.5 ± 15.9 years. All BP indices on admission were significantly higher in women compared with men. Adjustment of all potential confounders including age, sex, temperature, wind speed, and dew point revealed that increasing one quartile in PM2.5 concentrations had been associated with 1.98 mmHg raising in SBP at the time of admission [95% confidence interval (CI) = 0.41-3.54, P = 0.010]. Women with cardiac diseases had higher all BP indices with increased PM2.5 concentration [SBP: β: 4.30, 95% CI = 0.90-7.70, P = 0.010; DBP: β: 1.89, 95% CI = 0.09-3.69, P = 0.040; MAP: β: 3.09, 95% CI = 0.68-5.51, P= 0.010, respectively).

Our findings suggest that increasing PM2.5 concentration has been positively associated with raising SBP in total population and all BP indices among women with cardiac problems at admission time. Several comprehensive studies are required for confirming these relations.