Effect of air pollutants on ambulatory blood pressure.

BACKGROUND AND METHODOLOGY: Air pollutants have a significant impact on public health. The aim of the study was to find out the relationship between ambulatory blood pressure measured by 24-h ambulatory blood pressure monitoring (ABPM) and the atmospheric pollutants that are measured regularly (PM10, PM2.5, NO2 and SO2). An observational study of temporal and geographic measurements of individual patients (case-time series design) was carried out in Primary Care Centres and Hypertension Units in the Barcelona metropolitan area. We included 2888 hypertensive patients≥18 years old, untreated, with a first valid ABPM performed between 2005 and 2014 and with at least one air pollution station within a radius of <3km. RESULTS AND CONCLUSIONS: The mean age was 54.3 (SD 14.6) years. 50.1% were women and 16.9% of the sample were smokers. Mean 24-h blood pressure (BP) was 128.0 (12.7)/77.4 (9.7) mmHg. After adjusting for mean ambient temperature and different risk factors, a significant association was found between ambulatory diastolic BP (DBP) and PM10 concentrations the day before ABPM. For each increase of 10µg/m3 of PM10, an increase of 1.37mmHg 24-h DBP and 1.48mmHg daytime DBP was observed. No relationship was found between PM2.5, NO2 and SO2 and ambulatory BP, nor between any pollutant and clinical BP. The concentration of PM10 the day before the ABPM is significantly associated with an increase in 24-h DBP and daytime DBP.