Effect of Temperature on Cystic Fibrosis Lung Disease and Infections: A Replicated Cohort Study

Joseph M Collaco,Deanna M Green,Timothy Shields,Christopher P Watson,John Mcgready,Kathleen M Naughton,Claire E Wainwright,Scott C Bell,James L Kreindler

doi:10.1371/journal.pone.0027784

Abstract

BackgroundProgressive lung disease accounts for the majority of morbidity and mortality observed in cystic fibrosis (CF). Beyond secondhand smoke exposure and socio-economic status, the effect of specific environmental factors on CF lung function is largely unknown.MethodsMultivariate regression was used to assess correlation between specific environmental factors, the presence of pulmonary pathogens, and variation in lung function using subjects enrolled in the U.S. CF Twin and Sibling Study (CFTSS: n = 1378). Significant associations were tested for replication in the U.S. CF Foundation Patient Registry (CFF: n = 16439), the Australian CF Data Registry (ACFDR: n = 1801), and prospectively ascertained subjects from Australia/New Zealand (ACFBAL: n = 167).ResultsIn CFTSS subjects, the presence of Pseudomonas aeruginosa (OR = 1.06 per °F; p<0.001) was associated with warmer annual ambient temperatures. This finding was independently replicated in the CFF (1.02; p<0.001), ACFDR (1.05; p = 0.002), and ACFBAL (1.09; p = 0.003) subjects. Warmer temperatures (−0.34 points per °F; p = 0.005) and public insurance (−6.43 points; p<0.001) were associated with lower lung function in the CFTSS subjects. These findings were replicated in the CFF subjects (temperature: −0.31; p<0.001; insurance: −9.11; p<0.001) and similar in the ACFDR subjects (temperature: −0.23; p = 0.057). The association between temperature and lung function was minimally influenced by P. aeruginosa. Similarly, the association between temperature and P. aeruginosa was largely independent of lung function.ConclusionsAmbient temperature is associated with prevalence of P. aeruginosa and lung function in four independent samples of CF patients from two continents.

Highlights

Cystic fibrosis (CF) is an autosomal recessive disorder caused by mutations in the CFTR gene
Australian Cystic Fibrosis Bronchoalveolar Lavage Trial (ACFBAL): Anonymized data was provided for 168 infants diagnosed with cystic fibrosis (CF) in Australia and New Zealand between 6/10/99 and 1/18/05 who were prospectively followed for microbial acquisition until 5 years of age
Given the importance of bacterial infection in CF lung function decline [23,24], we tested whether selected environmental factors were associated with specific organisms using multivariate logistic regression

Summary

Introduction

Cystic fibrosis (CF) is an autosomal recessive disorder caused by mutations in the CFTR gene. Progressive obstructive lung disease and recurrent respiratory infections account for the majority of morbidity and mortality associated with CF. Prior CF studies have demonstrated associations between lung function and local environmental factors, including secondhand smoke exposure [6,7,8,9,10], air pollution [11], household income [12,13,14], maternal education [13], and insurance status [13,15,16,17]. Progressive lung disease accounts for the majority of morbidity and mortality observed in cystic fibrosis (CF). Beyond secondhand smoke exposure and socio-economic status, the effect of specific environmental factors on CF lung function is largely unknown

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