Year: 2011
Type: article
Study design: Observational Study
Abstract: Cigarette smoking results both in acute and chronic changes of inflammatory cells and mediators. In clinical studies investigating the chronic effects of smoking, it is therefore important to ascertain that study participants have refrained from smoking prior to sampling. We investigated whether carbon monoxide in exhaled breath (CObreath), a well established method used for separating smokers from non-smokers, could be used to distinguish between recent smokers and smokers that had refrained from smoking during the past 8 hours. CObreath decline was measured on nonsmokers (n = 7) and non symptomatic smokers (n = 6) hourly during one day. In addition, CObreath was measured on nonsmokers (n = 29), smokers with normal lung function (n = 38) and smoking patients with chronic obstructive pulmonary disease (COPD), (n = 19), all participating in a clinical study, at at least three different occasions. In both study groups, CObreath was significantly higher in smokers than in nonsmokers (p < 0.01). Neither initial CObreath levels nor the decline pattern differed when comparing smokers with or without chronic airway obstruction. Women had a significantly (p < 0.05) lower CObreath compared to men at 9 hours past smoking. The decline was described as a monoexponential decay (r2 = 0.7) with a half-life of 4.5 hours. A generic cut-off value of 12 ppm could be used to discriminate recent smokers from smokers that had refrained from smoking for 8 hours or more with a specificity of 94% and a sensitivity of 90%. We propose this model to be used in clinical studies where time since smoking has an impact on the outcome.
Source: The Clinical Respiratory Journal
Institutions: Karolinska Institutet, Karolinska University Hospital
Language: English
Subfield: Physiology
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
OpenAlex ID: W1596196151