Author(s): TEIXEIRA, E., SILVA, G., RUFO, J., Institution: FACULTY OF SPORT - UNIVERSITY OF PORTO, Country: PORTUGAL, Abstract-ID: 1414

INTRODUCTION:
Cardiorespiratory fitness (CRF) is a fundamental exercise-related factor and a well-established vital sign (1). Maximal oxygen consumption (VO2max), the CRF gold-standard assessment, is cumbersome and imposes significant participant stress, limiting testing frequency. Expedient and safer CRF assessment methods are imperative to exercise and health professionals. Recent studies analysing the exhaled breath (breathomics) volatile organic compounds (VOCs), which differ depending on health status (2), may pose such an alternative. Breathomics is conducted through the analysis of exhaled VOCs with electronic nose systems (eNose), which are capable of discerning distinct compound profiles, holding predictive value for CRF assessment. This study investigated the use of breathomics to identify individuals with directly measured peak VO2max (VO2) above or below the age- and gender-specific estimated oxygen consumption (eVO2) (3).
METHODS:
Breathomics of sixty-five participants (age: 34.8±11.5 years, 86% males) were performed by collecting the individuals’ VOCs while fasting for at least 3 hours, following a 2-minute preliminary breathing procedure through an A2 filter. VOCs were collected in Tedlar bags and analyzed by Cyranose 320 eNose. Then, participants performed a VO2max test (Quark, COSMED), cycling nearly 15 minutes during progressive intensity levels until exhaustion, to determine VO2. Participants were dichotomized based on their eVO2 for analytical purposes.
RESULTS:
Recursive partitioning regression identified twenty participants with a distinct breathomics profile (DBP) defined by eNose sensors S4 and S26. Post-hoc analysis showed a significantly higher proportion of individuals who did not meet eVO2 criteria when having the DBP (66.6%, p<0.001). In addition, a t-student test revealed significant differences in mean VO2 values between groups, being lower in individuals with the DBP (40.8±6.0 vs 46.8±11.1, p=0.027). Logistic regression showed a significant association between having the DBP and failing the eVO2 criteria, even when adjusted for exercise volume and the number of fasting hours (OR 95%, CI = 17.5 [4.2, 97.3], p<0.001). This model identified individuals who failed to meet the eVO2 criteria with a sensitivity of 75% and a specificity of 95% (AUC = 0.87).
CONCLUSION:
Individuals with DBP were, on average, 17.5 times more likely to have VO2 values lower than eVO2. Further analysis of the breathomics profile using mass spectrometry methods is needed to identify the specific discriminant VOCs. While further research is warranted, breathomics holds promise for predicting VO2 outcomes, potentially fostering continuous CRF monitoring both in exercise and health-related scenarios.
References:
1-Circulation, 2016, 134(24), e653–e699. https://doi.org/10.1161/CIR.0000000000000461
2-Allergy, 2015, 71(2), 175–188. https://doi.org/10.1111/all.12793
3-European journal of preventive cardiology, 2020, 25(7), 742–750. https://doi.org/10.1177/2047487318763958