TY - JOUR
T1 - The validity and reliability of a novel isotope ratio infrared spectrometer to quantify 13C enrichment of expired breath samples in exercise
AU - Sutehall, Shaun
AU - Muniz-Pardos, Borja
AU - Smajgl, Danijela
AU - Mandic, Magda
AU - Jeglinski, Cedric
AU - Bosch, Andrew
AU - Galloway, Stuart D.
AU - Pitsiladis, Yannis
N1 - The Sub2 project is affiliated to a nontrading company (Athlome Limited, UK) that is minor (<1.1%) shareholder of Maurten AB. S.S. is a PhD student funded partly by the Sub2 project and Maurten AB. S.S. and S.G. have received one travel grant each. This research is funded partly from a research grant from the Sub2 project and Maurten AB. Support from Thermo Fisher Scientific, Bremen, Germany, was in the form of equipment loan and analysis without any cost to the project. No funding was received from Thermo Fisher Scientific.
PY - 2021/5
Y1 - 2021/5
N2 - The traditional method to measure 13CO2 enrichment in breath involves isotope ratio mass spectrometry (IRMS), which has several limitations such as cost, extensive training, and large space requirements. Here, we present the validity and reliability data of an isotope ratio infrared spectrometer (IRIS)-based method developed to combat these limitations. Eight healthy male runners performed 105 min of continuous running on a motorized treadmill while ingesting various carbohydrate beverages enriched with 13C and expired breath samples were obtained every 15 min in triplicates. A total of 213 breath samples were analyzed using both methods, whereas 212 samples were repeated using IRIS to determine test-retest reliability. Bland–Altman analysis was performed to determine systematic and proportional bias, and intraclass correlation coefficient (ICC) and coefficient of variation (CV) to assess level of agreement and magnitude of error. The IRIS method demonstrated a small but significant systematic bias to overestimate δ13CO2 (0.18‰; P < 0.05) compared with IRMS, without any proportional bias or heteroscedasticity and a small CV (0.5%). There was a small systematic bias during the test-retest of the IRIS method (−0.07‰; P < 0.05), no proportional bias, an excellent ICC (1.00), and small CV (0.4%). The use of the Delta Ray IRIS to determine 13C enrichment in expired breath samples captured during exercise has excellent validity and reliability when compared with the gold standard IRMS.
AB - The traditional method to measure 13CO2 enrichment in breath involves isotope ratio mass spectrometry (IRMS), which has several limitations such as cost, extensive training, and large space requirements. Here, we present the validity and reliability data of an isotope ratio infrared spectrometer (IRIS)-based method developed to combat these limitations. Eight healthy male runners performed 105 min of continuous running on a motorized treadmill while ingesting various carbohydrate beverages enriched with 13C and expired breath samples were obtained every 15 min in triplicates. A total of 213 breath samples were analyzed using both methods, whereas 212 samples were repeated using IRIS to determine test-retest reliability. Bland–Altman analysis was performed to determine systematic and proportional bias, and intraclass correlation coefficient (ICC) and coefficient of variation (CV) to assess level of agreement and magnitude of error. The IRIS method demonstrated a small but significant systematic bias to overestimate δ13CO2 (0.18‰; P < 0.05) compared with IRMS, without any proportional bias or heteroscedasticity and a small CV (0.5%). There was a small systematic bias during the test-retest of the IRIS method (−0.07‰; P < 0.05), no proportional bias, an excellent ICC (1.00), and small CV (0.4%). The use of the Delta Ray IRIS to determine 13C enrichment in expired breath samples captured during exercise has excellent validity and reliability when compared with the gold standard IRMS.
KW - exercise
KW - expired breath 13C enrichment
KW - isotope ratio infrared spectrometry
KW - isotope ratio mass spectrometry
U2 - 10.1152/japplphysiol.00805.2020
DO - 10.1152/japplphysiol.00805.2020
M3 - Journal article
SN - 8750-7587
VL - 130
SP - 1421
EP - 1426
JO - Journal of Applied Physiology
JF - Journal of Applied Physiology
IS - 5
ER -