Changes in urine headspace composition as an effect of strenuous walking

Area of Science:

• Metabolomics
• Biomarker Discovery
• Exercise Physiology

Background:

• Strenuous physical activity, such as endurance walking, significantly impacts human metabolism.
• Monitoring metabolic changes in athletes and participants of mass sporting events is crucial for health and performance.
• Existing methods for metabolic monitoring may not be suitable for real-time or large-scale application.

Purpose of the Study:

• To investigate the utility of proton transfer reaction mass spectrometry (PTR-MS) for identifying urinary metabolic biomarkers associated with strenuous walking.
• To differentiate metabolic profiles before and after exercise across different participant groups (controls, type-1 diabetes, type-2 diabetes).
• To assess the potential of urinary biomarkers for monitoring exercise-induced metabolic alterations in mass participation events.

Main Methods:

• Collection of urine, breath, and blood samples from 51 participants during the International Four Days Marches event.
• Application of proton transfer reaction mass spectrometry (PTR-MS) for analyzing volatile organic compounds in samples.
• Utilisation of multivariate and univariate statistical analyses to identify significant metabolic changes and biomarkers.

Main Results:

• Multivariate analysis successfully discriminated between pre- and post-exercise metabolic states for all participant groups across multiple days.
• Twelve molecular ions were identified as significant contributors to this discrimination.
• Acetic acid in urine was confirmed as a significant biomarker, showing increased levels post-exercise.
• Urinary acetone analysis revealed time-averaged metabolic effects over the 4-day event, contrasting with immediate breath acetone measurements.

Conclusions:

• PTR-MS analysis of urine can effectively detect and monitor metabolic alterations induced by strenuous walking.
• Acetic acid is a promising urinary biomarker for assessing exercise-related metabolic changes.
• Urinary metabolic profiling offers a valuable tool for monitoring participants in large-scale exercise events, providing insights into metabolic responses over time.