Air Pollution and Autonomic and Vascular Dysfunction in Patients With Cardiovascular Disease: Interactions of Systemic Inflammation, Overweight, and Gender

• Published in: American journal of epidemiology 2012-07, Vol.176 (2), p.117-126
• Main Authors: WEI HUANG, TONG ZHU, XIAOCHUAN PAN, MIN HU, LU, Shou-En, YONG LIN, TONG WANG, YUANHANG ZHANG, XIAOYAN TANG
• Format: Article
• Language: English
• Subjects: Aged; Air Pollutants - analysis; Air pollution; Air Pollution - analysis; Autonomic Nervous System Diseases - epidemiology; Biological and medical sciences; Blood Pressure Monitoring, Ambulatory; Body mass index; Carbon Monoxide - analysis; Cardiovascular disease; Cardiovascular Diseases - diagnosis; Cardiovascular Diseases - epidemiology; Causality; China - epidemiology; Comorbidity; Environment. Living conditions; Environmental Exposure - statistics & numerical data; Epidemiology; Female; Follow-Up Studies; General aspects; Heart rate; Humans; Inflammation - epidemiology; Longitudinal Studies; Male; Medical sciences; Metabolic diseases; Miscellaneous; Models, Statistical; Nitrogen Dioxide - analysis; Obesity; Original Contributions; Overweight - epidemiology; Ozone - analysis; Particulate Matter - analysis; Public health. Hygiene; Public health. Hygiene-occupational medicine; Risk Factors; Sex Distribution; Sulfur Dioxide - analysis; Vascular Diseases - epidemiology
• ISSN: 0002-9262; 1476-6256
• DOI: 10.1093/aje/kwr511

The authors conducted a 2-year follow-up of 40 cardiovascular disease patients (mean age = 65.6 years (standard deviation, 5.8)) who underwent repeated measurements of cardiovascular response before and during the 2008 Beijing Olympics (Beijing, China), when air pollution was strictly controlled. Ambient levels of particulate matter with an aerodynamic diameter less than 2.5 µm (PM(2.5)), black carbon, nitrogen dioxide, sulfur dioxide, ozone, and carbon monoxide were measured continuously, with validation of concurrent real-time measurements of personal exposure to PM(2.5) and carbon monoxide. Linear mixed-effects models were used with adjustment for individual risk factors, time-varying factors, and meteorologic effects. Significant heart rate variability reduction and blood pressure elevation were observed in association with exposure to air pollution. Specifically, interquartile-range increases of 51.8 µg/m(3), 2.02 µg/m(3), and 13.7 ppb in prior 4-hour exposure to PM(2.5), black carbon, and nitrogen dioxide were associated with significant reductions in the standard deviation of the normal-to-normal intervals of 4.2% (95% confidence interval (CI): 1.9, 6.4), 4.2% (95% CI: 1.8, 6.6), and 3.9% (95% CI: 2.2, 5.7), respectively. Greater heart rate variability declines were observed among subjects with C-reactive protein values above the 90th percentile, subjects with a body mass index greater than 25, and females. The authors conclude that autonomic and vascular dysfunction may be one of the mechanisms through which air pollution exposure can increase cardiovascular disease risk, especially among persons with systemic inflammation and overweight.