Study of 5 Volatile Organic Compounds in Exhaled Breath in Chronic Obstructive Pulmonary Disease

INTRODUCTION

A major risk factor for chronic obstructive pulmonary disease (COPD) is tobacco smoke, which generates oxidative stress in airways, resulting in the production of volatile organic compounds (VOC). The purpose of this study was to identify VOCs in exhaled breath and to determine their possible use as disease biomarkers.

METHOD

Exhaled breath from 100 healthy volunteers, divided into 3groups (never smokers, former smokers and active smokers) and exhaled breath from 57 COPD patients were analyzed. Samples were collected using BioVOC^® devices and transferred to universal desorption tubes. Compounds were analyzed by thermal desorption, gas chromatography and mass spectrometry. VOCs analyzed were linear aldehydesand carboxylic acids.

RESULTS

The COPD group and healthy controls (never smokers and former smokers) showed statistically significant differences in hexanal concentrations, and never smokers and the COPD group showed statistically significant differences in nonanal concentrations.

CONCLUSIONS

Hexanal discriminates between COPD patients and healthy non-smoking controls. Nonanal discriminates between smokers and former smokers (with and without COPD) and never smokers.

Volatile organic compounds in exhaled breath in a healthy population: effect of tobacco smoking

INTRODUCTION

Tobacco smoke is a source of free radicals and reactive oxygen and nitrogen species, which are the main causes of oxidative stress. The analysis of volatile organic compounds (VOC) in exhaled breath is an indirect method of measuring the level of oxidative stress that occurs in the airways caused by tobacco consumption. The aim of this study was to determine whether smoking influences the production of VOC, in a clinically healthy population.

METHODS

Exhaled breath from 89 healthy volunteers, divided into three groups (non-smokers, ex-smokers and smokers) was analysed. Samples were collected using Bio-VOC® devices and transferred to universal desorption tubes. Chemical compounds were analysed by thermal desorption, gas chromatography and mass spectrometry. We analysed hexanal, heptanal, octanal, nonanal, nonanoic acid and propanoic acid, all identified by retention time and mass spectra referenced in the NIST 08 mass spectral library; confirmation was carried out using reference standards of the pure chemical compound.

RESULTS

These VOC were found in very low concentrations. Only nonanal showed significant quantitative and qualitative statistical differences among the study groups. Nonanal concentration is dependent on smoking, but is independent of the amount of tobacco consumed, age and gender.

CONCLUSIONS

Nonanal in exhaled breath is associated with tobacco consumption, current or previous. Nonanal is a sub-product of the destruction of the cell membrane, and its finding may be indicative of cell damage in smokers. This result appears in many farmers who smoke.