title: Effect of temperature on cystic fibrosis lung disease and infections: a replicated cohort study.
abstract: BACKGROUND
  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.
  
  
  METHODS
  Multivariate 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).
  
  
  RESULTS
  In 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.
  
  
  CONCLUSIONS
  Ambient temperature is associated with prevalence of P. aeruginosa and lung function in four independent samples of CF patients from two continents.
authors: Eudowood Division of Pediatric Respiratory Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America. mcollac1@jhmi.edu
authors: Joseph M
authors: JM
authors: Collaco
authors: John
authors: J
authors: McGready
authors: Deanna M
authors: DM
authors: Green
authors: Kathleen M
authors: KM
authors: Naughton
authors: Christopher P
authors: CP
authors: Watson
authors: Timothy
authors: T
authors: Shields
authors: Scott C
authors: SC
authors: Bell
authors: Claire E
authors: CE
authors: Wainwright
authors: Garry R
authors: GR
authors: Cutting
mesh_terms: D001424:Bacterial Infections / Q000150:complications / Q000503:physiopathology*; D042602:Burkholderia cepacia complex / Q000302:isolation & purification; D015331:Cohort Studies; D003550:Cystic Fibrosis / Q000150:complications / Q000503:physiopathology*; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D016015:Logistic Models; D008168:Lung / Q000382:microbiology / Q000473:pathology / Q000503:physiopathology*; D008297:Male; D011550:Pseudomonas aeruginosa / Q000302:isolation & purification; D012042:Registries / Q000706:statistics & numerical data; D013696:Temperature