Impact of air pollution on cystic fibrosis pulmonary exacerbations: a case-crossover analysis.
BACKGROUND
Pulmonary exacerbations in cystic fibrosis (CF) contribute to the burden of disease, with a negative impact on quality of life, costs, and lung function. Our aim was to evaluate whether exacerbations, defi ned by antibiotic use, were triggered by daily fl uctuations in air pollution.


METHODS
In a case-crossover analysis, we evaluated 215 patients with CF and pollution data from January 1, 1998, to December 31, 2010. Exacerbation was defi ned as the start of IV or oral antibiotic use in a home or hospital setting. We calculated regional background levels of particulate matter with a diameter , 10 m m (PM 10 ), ozone, and nitrogen dioxide (NO 2 ) on the day of the event and on the 2 days prior to the event at each patient’s home address. We matched for day of the week and controlled for temperature on the day of the event and the 2 preceding days. In the month where antibiotic treatment was started, all days with the same temperature ( 2°C) as the event day served as control days, excluding 3 days before and after the start of treatment.


RESULTS
A total of 215 patients (male sex, 49%, mean age, 21 13 years) had 2,204 antibiotic treatments (1,107 IV and 1,097 oral). Over a period of 12 years, an increase in risk of antibiotic use was associated with increasing concentrations of PM 10 , NO 2 , and ozone on the event day and for NO 2 on the day before. A tendency toward signifi cance was seen the day before antibiotic use for PM 10 and ozone. Overall, a rise in OR was seen from 2 days before until the day of the start of antibiotics.


CONCLUSIONS
In patients with CF and exacerbations, ambient concentrations of ozone, PM 10 , and NO 2 play a role in triggering an exacerbation.
Department of Lung Disease, UZ Leuven, Leuven, Belgium. Electronic address: pieter.goeminne@student.kuleuven.be.
Pieter C
PC
Goeminne
Center for Environmental Sciences, UHasselt, Hasselt, KU Leuven, Leuven, Belgium.
Michał
M
Kiciński
Department of Paediatric Pulmonology, UZ Leuven, Leuven, Belgium.
François
F
Vermeulen
Belgian Interregional Environment Agency, Brussels, KU Leuven, Leuven, Belgium.
Frans
F
Fierens
Department of Paediatric Pulmonology, UZ Leuven, Leuven, Belgium.
Kris
K
De Boeck
Department of Public Health, Occupational and Environmental Medicine, KU Leuven, Leuven, Belgium.
Benoit
B
Nemery
Center for Environmental Sciences, UHasselt, Hasselt, KU Leuven, Leuven, Belgium; Department of Public Health, Occupational and Environmental Medicine, KU Leuven, Leuven, Belgium.
Tim S
TS
Nawrot
Department of Lung Disease, UZ Leuven, Leuven, Belgium.
Lieven J
LJ
Dupont
D061605:Administration, Intravenous; D000284:Administration, Oral; D000293:Adolescent; D000328:Adult; D000397:Air Pollution / Q000009:adverse effects*; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D002648:Child; D018592:Cross-Over Studies; D003550:Cystic Fibrosis / Q000150:complications* / Q000188:drug therapy*; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D009585:Nitrogen Dioxide / Q000009:adverse effects; D010126:Ozone / Q000009:adverse effects; D052638:Particulate Matter / Q000009:adverse effects; D012189:Retrospective Studies; D013696:Temperature; D055815:Young Adult
D000900:Anti-Bacterial Agents; D052638:Particulate Matter; D010126:Ozone; D009585:Nitrogen Dioxide