Document Detail

Prior intense exercise reduces arterial carbon dioxide pressure in extreme obesity.
MedLine Citation:
PMID:  20926039     Owner:  NLM     Status:  MEDLINE    
PURPOSE: Unlike normal weight individuals, individuals with extreme obesity do not show a decrease in arterial carbon dioxide pressure (PaCO₂) from rest to peak exercise. This indicates that breathing is compromised. The objective of this study was to determine if prior high intensity exercise lowers PaCO₂ in comparison with a first bout, normalized for the same metabolic rate.
METHODS: Oxygen consumption during incremental, ramped exercise was matched to constant workload exercise (75% of peak power). Both protocols were to volitional exhaustion 39 ± 8 min apart. Eleven obese subjects (BMI = 47 ± 8 kg/m², aerobic capacity = 2.3 ± 0.6 L/min) were evaluated. Forty paired samples were obtained at the same metabolic rate between the two protocols.
RESULTS: The mean absolute difference and 95% CI were large for arterial oxygen pressure (PaO₂) = 9 (6, 11) mmHg and alveolar to arterial oxygen pressure difference (AaDO2) = 7 (5, 8) mmHg. The mean absolute difference for arterial oxyhemoglobin saturation (%SaO₂) = 0.5 (0.4, 0.7) %; PaCO2 = 4 (3, 4) mmHg; physiological dead space to tidal volume ratio (VD/VT) = 0.04 (0.03, 0.05); and alveolar ventilation (VA) = 3 (2, 4) L/min. The recovery period after the first bout of exercise reduced the PaCO₂ by 3 mmHg when matched for similar metabolic rates. Constant workload exercise predicted VA, %SaO2, V(D)/V(T), and PaCO₂, but not PaO₂ or AaDO₂ during incremental exercise at similar metabolic rates.
CONCLUSION: Given a sufficient chemical stimulus, obese subjects will attempt to breathe more, although this does not mean more VA, which removes CO₂.
Gerald S Zavorsky; Do Jun Kim; Lauren M Cass; Franco Carli
Related Documents :
6770529 - Alveolar pco2 during rest and exercise in divers and non-divers breathing o2 at 1 ata.
3121579 - Differential effects of oligomycin on carotid chemoreceptor responses to o2 and co2 in ...
3139619 - Ventilatory response to co2 and o2 near eupnea in awake dogs.
1314799 - Potassium and ventilation in exercise.
3924099 - Evidence for hco3- conductance pathways in nutrient membrane of bullfrog antrum.
1928869 - Sensation and control of breathing: a dynamic model.
2908309 - Xamoterol in patients with dilated cardiomyopathy: an increase in beta-receptors in lym...
2436139 - Intracellular ph in the rat mandibular salivary gland: the role of na-h and cl-hco3 ant...
6770529 - Alveolar pco2 during rest and exercise in divers and non-divers breathing o2 at 1 ata.
Publication Detail:
Type:  Clinical Trial; Journal Article; Research Support, Non-U.S. Gov't     Date:  2010-10-01
Journal Detail:
Title:  Clinical and investigative medicine. Médecine clinique et experimentale     Volume:  33     ISSN:  1488-2353     ISO Abbreviation:  Clin Invest Med     Publication Date:  2010  
Date Detail:
Created Date:  2010-10-07     Completed Date:  2011-01-21     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  7804071     Medline TA:  Clin Invest Med     Country:  Canada    
Other Details:
Languages:  eng     Pagination:  E321-34     Citation Subset:  IM    
Marywood University, Scranton, PA 18509, USA.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Blood Pressure / physiology
Carbon Dioxide / blood*
Exercise / physiology*
Obesity / blood*,  physiopathology*
Partial Pressure
Reg. No./Substance:
124-38-9/Carbon Dioxide

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  Effects of statin use on total oxidant and antoxidant capacity and ceruloplasmin activity.
Next Document:  Comparison of total oxidant/antioxidant status in unconjugated hyperbilirubinemia of newborn before ...