Metabolomic stability of exercise-induced sweat

Area of Science:

• Biochemistry
• Physiology
• Analytical Chemistry

Background:

• Growing interest in using excreted sweat for biomarker discovery.
• Need for validated sample collection and handling protocols for large-scale studies.

Purpose of the Study:

• To assess the stability of amino acids in excreted sweat under different temperature conditions.
• To determine the feasibility of sweat sample handling for up to 90 minutes for biomarker discovery.

Main Methods:

• Quantification of twelve amino acids in exercise-induced sweat.
• Incubation of sweat samples at room temperature and 37°C for up to 90 minutes.
• Application of untargeted metabolomics to evaluate global metabolic changes.

Main Results:

• Amino acid quantities showed significant variation across individuals and storage conditions (e.g., alanine, arginine, threonine, p < 0.05).
• Less than 10% of amino acid measurements changed by more than 10% from baseline within 90 minutes.
• Over 88% of all metabolomic data points remained within established limits, irrespective of temperature or ionization mode.

Conclusions:

• Excreted sweat metabolites, particularly amino acids, are relatively stable for up to 90 minutes at room temperature and 37°C.
• These findings support the viability of sweat collection and sample handling for up to 90 minutes with minimal metabolite alteration.
• The study validates sweat as a promising biofluid for large-scale biomarker discovery initiatives.