The role of mathematical modeling in VOC analysis using isoprene as a prototypic example

TL;DR

This paper discusses the development and application of a mathematical model to understand the exhalation kinetics of isoprene, a VOC linked to human physiology, especially during exercise, to support its potential as a biomarker.

Contribution

The paper provides an overview of a mathematical model for isoprene exhalation, supporting the hypothesis of a peripheral source and advancing understanding of its biochemical origins.

Findings

Model supports peripheral source of isoprene

Exhalation kinetics vary with exercise

Provides insights into isoprene formation processes

Abstract

Isoprene is one of the most abundant endogenous volatile organic compounds (VOCs) contained in human breath and is considered to be a potentially useful biomarker for diagnostic and monitoring purposes. However, neither the exact biochemical origin of isoprene nor its physiological role are understood in sufficient depth, thus hindering the validation of breath isoprene tests in clinical routine. Exhaled isoprene concentrations are reported to change under different clinical and physiological conditions, especially in response to enhanced cardiovascular and respiratory activity. Investigating isoprene exhalation kinetics under dynamical exercise helps to gather the relevant experimental information for understanding the gas exchange phenomena associated with this important VOC. A first model for isoprene in exhaled breath has been developed by our research group. In the present paper, we aim at giving a concise overview of this model and describe its role in providing supportive evidence for a peripheral (extrahepatic) source of isoprene. In this sense, the results presented here may enable a new perspective on the biochemical processes governing isoprene formation in the human body.