Dataset Information

Impact of the Method Used to Select Gas Exchange Data for Estimating the Resting Metabolic Rate, as Supplied by Breath-by-Breath Metabolic Carts.

ABSTRACT: The method used to select representative gas exchange data from large datasets influences the resting metabolic rate (RMR) returned. This study determines which of three methods yields the lowest RMR (as recommended for use in human energy balance studies), and in which method the greatest variance in RMR is explained by classical determinants of this variable. A total of 107 young and 74 middle-aged adults underwent a 30 min RMR examination using a breath-by-breath metabolic cart. Three gas exchange data selection methods were used: (i) steady state (SSt) for 3, 4, 5, or 10 min, (ii) a pre-defined time interval (TI), i.e., 6-10, 11-15, 16-20, 21-25, 26-30, 6-25, or 6-30 min, and (iii) "filtering", setting thresholds depending on the mean RMR value obtained. In both cohorts, the RMRs yielded by the SSt and filtering methods were significantly lower (p < 0.021) than those yielded by the TI method. No differences in RMR were seen under the different conditions of the SSt method, or of the filtering method. No differences were seen between the methods in terms of the variance in RMR explained by its classical determinants. In conclusion, the SSt and filtering methods return the lowest RMRs and intra-measurement coefficients of variation when using breath-by-breath metabolic carts.

SUBMITTER: Alcantara JMA

PROVIDER: S-EPMC7071290 | biostudies-literature | 2020 Feb

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Impact of the Method Used to Select Gas Exchange Data for Estimating the Resting Metabolic Rate, as Supplied by Breath-by-Breath Metabolic Carts.

Alcantara Juan M A JMA Sanchez-Delgado Guillermo G Amaro-Gahete Francisco J FJ Galgani Jose E JE Ruiz Jonatan R JR

Nutrients 20200214 2

The method used to select representative gas exchange data from large datasets influences the resting metabolic rate (RMR) returned. This study determines which of three methods yields the lowest RMR (as recommended for use in human energy balance studies), and in which method the greatest variance in RMR is explained by classical determinants of this variable. A total of 107 young and 74 middle-aged adults underwent a 30 min RMR examination using a breath-by-breath metabolic cart. Three gas exc ...[more]

PMID: 32075052

Similar Datasets

Project description:BackgroundThe origin of low frequency cerebral hemodynamic fluctuations (CHF) in the resting state remains unknown. Breath-by breath O2-CO2 exchange ratio (bER) has been reported to correlate with the cerebrovascular response to brief breath hold challenge at the frequency range of 0.008-0.03Hz in healthy adults. bER is defined as the ratio of the change in the partial pressure of oxygen (ΔPO2) to that of carbon dioxide (ΔPCO2) between end inspiration and end expiration. In this study, we aimed to investigate the contribution of respiratory gas exchange (RGE) metrics (bER, ΔPO2 and ΔPCO2) to low frequency CHF during spontaneous breathing.MethodsTwenty-two healthy adults were included. We used transcranial Doppler sonography to evaluate CHF by measuring the changes in cerebral blood flow velocity (ΔCBFv) in bilateral middle cerebral arteries. The regional CHF were mapped with blood oxygenation level dependent (ΔBOLD) signal changes using functional magnetic resonance imaging. Temporal features and frequency characteristics of RGE metrics during spontaneous breathing were examined, and the simultaneous measurements of RGE metrics and CHF (ΔCBFv and ΔBOLD) were studied for their correlation.ResultsWe found that the time courses of ΔPO2 and ΔPCO2 were interdependent but not redundant. The oscillations of RGE metrics were coherent with resting state CHF at the frequency range of 0.008-0.03Hz. Both bER and ΔPO2 were superior to ΔPCO2 in association with CHF while CHF could correlate more strongly with bER than with ΔPO2 in some brain regions. Brain regions with the strongest coupling between bER and ΔBOLD overlapped with many areas of default mode network including precuneus and posterior cingulate.ConclusionAlthough the physiological mechanisms underlying the strong correlation between bER and CHF are unclear, our findings suggest the contribution of bER to low frequency resting state CHF, providing a novel insight of brain-body interaction via CHF and oscillations of RGE metrics.

Project description:Background: HIV infection is associated with impaired gas transfer in the lung as indicated by a low diffusing capacity (DLCO). Mechanisms for reduced DLCO in the setting of HIV infection are not well understood. We hypothesized that HIV-associated gas exchange impairment is indicative of system-wide perturbations that could be reflected by alterations in peripheral blood gene expression. Methods: A total of 40 HIV-infected (HIV+) and uninfected (HIV-) men with preserved versus reduced DLCO were selected from a larger cohort study of lung function. All subjects were current smokers and those with acute illness, lung diseases other than COPD or asthma were excluded. Total RNA was extracted from peripheral blood leukocytes (PBLs) and hybridized to whole-genome microarrays. Gene set enrichment analysis (GSEA) was performed between HIV+ vs. HIV- subjects with preserved DLCO and those with impaired DLCO to identify differentially activated pathways. Results: Using pathway-based analyses we found that in subjects with preserved DLCO, HIV infection is associated with activation of processes involved in immunity, cell cycle, and apoptosis. When we applied a similar analysis to subjects with low DLCO, we identified a much broader repertoire of inflammatory and immune-related pathways in HIV+ patients relative to HIV- subjects, with up-regulation of multiple interleukin pathways, interferon signaling, Toll-like receptor signaling, and T cell/B cell receptor signaling. We confirmed elevated circulating levels of IL-6 in HIV+ patients with reduced DLCO relative to the other groups. Conclusions: Our findings reveal that PBLs of subjects with HIV infection and low DLCO are distinguished by widespread enrichment of immuno-inflammatory programs. Activation of these pathways may alter the biology of circulating leukocytes and play a role in the pathogenesis of HIV-associated pulmonary gas exchange impairment. Total RNA was isolated from peripheral blood leukocytes in four subject groups: 1. HIV-, low DLCO (N = 11); 2. HIV+, low DLCO (N = 10); 3. HIV-, preserved DLCO (N = 9); 4. HIV+, preserved DLCO (N = 9). Each sample was hybridized to an Affymetrix PrimeView Human Gene Expression microarray for a total of 39 experiments.

Dataset Information

Impact of the Method Used to Select Gas Exchange Data for Estimating the Resting Metabolic Rate, as Supplied by Breath-by-Breath Metabolic Carts.

Publications

Impact of the Method Used to Select Gas Exchange Data for Estimating the Resting Metabolic Rate, as Supplied by Breath-by-Breath Metabolic Carts.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets