Longer term exposure to secondhand smoke and health outcomes in COPD: impact of urine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol.
BACKGROUND
Secondhand smoke (SHS) contains respiratory irritants and has the potential to adversely affect adults with chronic obstructive pulmonary disease (COPD), but few studies have evaluated the impact of SHS on COPD.


METHODS
We used data from 72 nonsmoking participants in a cohort study of COPD. Urine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) was measured as an indicator of longer term SHS exposure, whereas urine cotinine was assessed as a measure of more recent exposure. The impact of SHS exposure on COPD-related health status was examined using multivariate linear regression (controlling for age, sex, race, educational attainment, and smoking history). Health status was measured using a validated COPD severity score, reported dyspnea, a standard health status measure (Short Form-12), and activity restriction.


RESULTS
The urine NNAL-to-creatinine ratio (per interquartile increment) was associated with greater COPD severity (mean score increase 1.7 points; 95% CI 0.6-2.8; p = .0003). Higher urine NNAL was also related to greater dyspnea, poorer physical health status, and more restricted activity (p < or = .05 in all cases). When considered simultaneously, longer term exposure (NNAL) had a greater negative impact on COPD status than shorter term exposure (cotinine).


CONCLUSIONS
Urine NNAL can be used to estimate longer term SHS exposure and negatively affects a number of health outcomes among adults with COPD. Screening for and prevention of SHS exposure among persons with COPD may be beneficial.
Eisner
Mark D
MD
Department of Medicine, University of California, San Francisco, 350 Parnassus Avenue, Suite 609, San Francisco, CA 94117, USA. mark.eisner@ucsf.edu
Jacob
Peyton
P
Benowitz
Neal L
NL
Balmes
John
J
Blanc
Paul D
PD
D000368:Aged; D015331:Cohort Studies; D005260:Female; D006304:Health Status; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009602:Nitrosamines / Q000652:urine*; D029424:Pulmonary Disease, Chronic Obstructive / Q000503:physiopathology / Q000652:urine*; D011725:Pyridines / Q000652:urine*; D053719:Tandem Mass Spectrometry; D014028:Tobacco Smoke Pollution
D009602:Nitrosamines; D011725:Pyridines; D014028:Tobacco Smoke Pollution; C099565:4-(methylnitrosamino)-1-(3-pyridyl)-1-butan-1-ol