Short-Term Effects of Air Pollution in a Cohort of Patients With Chronic Obstructive Pulmonary Disease

• Published in: Epidemiology (Cambridge, Mass.) Mass.), 2012-11, Vol.23 (6), p.861-869
• Main Authors: Faustini, Annunziata, Stafoggia, Massimo, Cappai, Giovanna, Forastiere, Francesco
• Format: Article
• Language: English
• Subjects: Adult; Age Distribution; Aged; Aged, 80 and over; Air pollutants; Air pollution; Air Pollution - adverse effects; Air Pollution - analysis; Air Pollution - statistics & numerical data; Biological and medical sciences; Cardiovascular Diseases - epidemiology; Cause of Death; Chronic obstructive pulmonary disease; Chronic obstructive pulmonary disease, asthma; Cohort Studies; Comorbidity; Death; Disease models; Environment. Living conditions; Environmental Monitoring - statistics & numerical data; Epidemiology; Female; Humans; International Statistical Classification of Diseases; Italy - epidemiology; Male; Medical sciences; Middle Aged; Miscellaneous; Mortality; Nitrogen Dioxide - analysis; Ozone - analysis; Particulate matter; Pneumology; Public health. Hygiene; Public health. Hygiene-occupational medicine; Pulmonary Disease, Chronic Obstructive - mortality; Respiratory diseases; Risk Factors; Sex Distribution; Survival Rate
• ISSN: 1044-3983; 1531-5487
• DOI: 10.1097/EDE.0b013e31826767c2

Background: Although damage to the respiratory system from air pollutants has been recognized, research on susceptibility to air pollution in patients with chronic obstructive respiratory disease (COPD) has produced contradictory results. We studied the short-term effects of particulate matter (PM₁₀, PM₂.₄, nitrogen dioxide (NO₂), and ozone (O₃) on cardiac and respiratory mortality in a COPD cohort. We assessed age, sex, and previous diseases as effect modifiers. Methods: Using hospital data (1998-2009) and pharmaceutical data (2005-2009), we enrolled 145,681 COPD subjects, aged 35+ years and residents of Rome, and followed them from 2005 to 2009. A comparison group of people without COPD (1,710,557 subjects) was also studied. We analyzed deaths due to all natural causes (International Classification of Diseases -Ninth Revision codes 1-799). Statistical analyses were carried out using Poisson regression and a case-crossover approach. Results: PM₁₀ , PM ₂.₄, and NO₂ (0-to 5-day lag) were associated with daily mortality, with stronger effects in people with COPD. The mortality associated with PM₁₀ (per interquartile range [IQR] = 16μg/m³) was five times more in COPD patients (3.5% [95% confidence interval = -0.1% to 7.2%]) than in other subjects (0.7% [-0.8% to 2.2%]). Effects on respiratory mortality among COPD subjects were particularly elevated from PM₂.₂ (IQR = 11 μg/m³) (11.6% [2.0% to 22.2%]) and NO₂ (IQR = 24 μg/m³) (19.6% [3.5% to 38.2%]). Older age, male sex, preexisting heart conduction disorders, and cerebrovascular diseases were associated with stronger effects in COPD subjects. Conclusions: COPD patients are more susceptible to air pollutants, especially PM₁₀ and NO₂. These results suggest a need for more protective air pollution standards for susceptible groups.