Gender and age specific differences in exhaled isoprene levels.

The analysis of volatile organic compounds (VOC) in the human breath has attracted a considerable amount of clinical and scientific interest during the last decade. In our study, we turned our attention to gender and age specific differences of exhaled volatile compounds, particularly on isoprene which is one of the most abundant organic molecules found in human exhaled air. A total of 126 test persons were enrolled in the study: 66 females and 60 males. Moreover, the participants were classified into six groups with regard to their age. In a standardized setting all of them had to exhale the endexpiratory breath into a sample bag. The volatile compounds at m/z values from 21 to 229 were analyzed by using proton-transfer-reaction-mass-spectrometry. Isoprene (at m/z 69) was found to be highly significantly (p<0.001) elevated in the exhaled air of male subjects. Furthermore, it could be shown that 19-29 years old subjects exhale significantly lower levels of isoprene than older adults (p=0.002). No significant differences between groups were detected for any other measured mass. In conclusion, the present study demonstrates gender and age specific differences of isoprene levels in the exhaled air. These findings may be of potential clinical relevance regarding the multifaceted roles of isoprene, representing both indicator and effector molecule.