Coarse Particulate Matter (PM _2.5–10 ) Affects Heart Rate Variability, Blood Lipids, and Circulating Eosinophils in Adults with Asthma

Abstract

IntroductionWe investigated whether markers of airway and systemic inflammation, as well as heart rate variability (HRV) in asthmatics, change in response to fluctuations in ambient particulate matter (PM) in the coarse [PM with aerodynamic diameter 2.5–10 μm (PM2.5–10)] and fine (PM2.5) size range.MethodsTwelve adult asthmatics, living within a 30-mile radius of an atmospheric monitoring site in Chapel Hill, North Carolina, were followed over a 12-week period. Daily PM2.5–10 and PM2.5 concentrations were measured separately for each 24-hr period. Each subject had nine clinic visits, at which spirometric measures and peripheral blood samples for analysis of lipids, inflammatory cells, and coagulation-associated proteins were obtained. We also assessed HRV [SDNN24HR (standard deviation of all normal-to-normal intervals in a 24-hr recording), ASDNN5 (mean of the standard deviation in all 5-min segments of a 24-hr recording)] with four consecutive 24-hr ambulatory electrocardiogram measurements. Linear mixed models with a spatial covariance matrix structure and a 1-day lag were used to assess potential associations between PM levels and cardiopulmonary end points.ResultsFor a 1-μg/m3 increase in coarse PM, SDNN24HR, and ASDNN5 decreased 3.36% (p = 0.02), and 0.77%, (p = 0.05) respectively. With a 1-μg/m3 increase in coarse PM, circulating eosinophils increased 0.16% (p = 0.01), triglycerides increased 4.8% (p = 0.02), and very low-density lipoprotein increased 1.15% (p = 0.01). No significant associations were found with fine PM, and none with lung function.ConclusionThese data suggest that small temporal increases in ambient coarse PM are sufficient to affect important cardiopulmonary and lipid parameters in adults with asthma. Coarse PM may have underappreciated health effects in susceptible populations.

Particulate Matter Air Pollution and Cardiovascular Disease

“…This could help explain some of the previously negative study findings. 116 Similarly, coarse particulates between 0.25 and 1.0 m in diameter may affect the cardiovascular system, 221,264,265 and although the available data related to hard events and cardiovascular mortality have suggested a relationship, 265,266 recent findings have been less consistent. 104 In the most recent time-series analysis of 112 US cities, coarse PM was independently associated with elevated all-cause, stroke, and pulmonary, but not cardiovascular, mortality after controlling for PM 2.5 .…”

Exposure to Concentrated Coarse Air Pollution Particles Causes Mild Cardiopulmonary Effects in Healthy Young Adults

“…A panel study of 12 adult asthmatics residing in Chapel Hill, North Carolina, reported associations between HRV, blood lipids, and circulating eosinophils and coarse, but not fine, PM (Yeatts et al 2007).…”

Impact of Climate Change and Air Pollution on Dyslipidemia and the Components of Metabolic Syndrome

“…A study among asthmatic patients showed that with a 1-microg/m3 increase in coarse PM, triglycerides increased 4.8% (p = 0.02), and very low-density lipoprotein increased 1.15% (p = 0.01). This study suggested that small temporal increases in ambient coarse PM are sufficient to affect lipid profile in adults with asthma (Yeatts et al, 2007). Hypercholesterolemia may potentiate diesel exhaust-related endothelial gene regulation.…”