Dynamics of exhaled breath temperature (EBT) after a smoked cigarette

Abstract

Introduction: Exhaled breath temperature (EBT) has been more extensively studied during the last decade as a new inflammatory marker in different respiratory diseases (asthma, COPD, lung cancer). Still little is known about how major environmental factors (cigarette smoke) and lung function influence dynamics of EBT. Aim: The aim of this study was to assess the dynamics of EBT after a smoked cigarette in a group of current smokers without a respiratory disorder and its association with subject9s characteristics (age, smoking habit, lung function). Materials and methods: The study was done in a group (29-59 years of age) of current smokers (average smoking exposure 16 pack-years) of both sex without a diagnosis of respiratory disorder. Diagnostic workup: history, physical, baseline EBT and EBT 59, 159, 309, 459 and 609 after a smoked cigarette, lung function with bronchodilator test. EBT was measured as an average equilibrium EBT with baseline measurement at least 1 hour after the last cigarette. AUC for EBT was calculated using baseline EBT as reference. Results: An average EBT showed a maximum (an average increase of 0.6°C) value at 459 getting down to baseline values at 609 after a smoked cigarette. Two distinct patterns (increase and decrease in EBT after a cigarette) could be seen. AUC of EBT after a smoked cigarette was significantly associated with years of smoking, number of cigarettes smoked/day, % change in FEV 1 /FVC after a bronchodilator, and z-value of baseline MEF 25 (R 2 =0.56, p Conclusion: The results of our study showed that the dynamics of EBT after a smoked cigarette was dependent on both acute and chronic cigarette smoke exposure and small airways function.