In Patients With Coronary Heart Disease
Jeremy P. Langrish, Xi Li, Shengfeng Wang, Matthew MY. Lee, Gareth D. Barnes, Mark R. Miller, Flemming R. Cassee, Nicholas A. Boon, Ken Donaldson, Jing Li, Liming Li, Nicholas L. Mills, David E. Newby, Lixin Jiang
http://ehp03.niehs.nih.gov/article/info ... hp.1103898
Background. Air pollution exposure increases cardiovascular morbidity and mortality, and is a major global public health concern.
Objectives. To investigate the benefits of reducing personal exposure to urban air pollution in patients with coronary heart disease.
Methods. In an open randomised crossover trial, 98 patients with coronary heart disease walked on a pre-defined route in central Beijing, China on two occasions, once while using a highly efficient facemask and once while not using the mask. Symptoms, exercise, personal air pollution exposure, blood pressure, heart rate and 12-lead electrocardiography were monitored throughout the 24-hour study period.
Results. Ambient air pollutants were dominated by fine and ultrafine particles that were present at high levels (74 µg/m3 for particulate matter <2.5 µm). Consistent with traffic-derived sources, this particulate matter contained organic carbon and polycyclic aromatic hydrocarbons, and was highly oxidising generating large amounts of free radicals. The facemask was well tolerated, and use was associated with decreased self-reported symptoms and reduced maximal ST segment depression (-142 vs. -156 µV, P=0.046) over the 24-hour period. When the mask was used, mean arterial pressure was lower (93±10 vs. 96±10 mmHg; P=0.025) and heart rate variability increased (HF-power 54 vs 40 ms2, P=0.005; HFn 23.5 vs 20.5 ms, P=0.001; RMSSD 16.7 vs 14.8 ms, P=0.007) during the prescribed walk, but mask use did not appear to influence heart rate or energy expenditure.
Conclusions. Reducing personal exposure to air pollution using a highly efficient facemask appeared to reduce symptoms and improve a range of cardiovascular health measures in patients with coronary heart disease. Such interventions to reduce personal exposure to particulate air pollution have the potential to reduce the incidence of cardiovascular events in this highly susceptible population.
Citation: Langrish JP, Li X, Wang S, Lee MM, Barnes GD, Miller MR, et al. 2012. Reducing Personal Exposure To Particulate Air Pollution Improves Cardiovascular Health In Patients With Coronary Heart Disease. Environ Health Perspect :-. http://dx.doi.org/10.1289/ehp.1103898
Received: 05 May 2011; Accepted: 03 January 2012; Online: 03 January 2012