TY - JOUR
T1 - Exaggerated respiratory chemosensitivity and association with Sa O2 level at 3568 m in obesity
AU - Ge, Ri Li
AU - Stone, J. A.
AU - Levine, B. D.
AU - Babb, T. G.
N1 - Funding Information:
The authors gratefully thank Paul Chase, Brenda Wyrick, Sarah Witkowski, Julie Zuckerman, Belinda Schwartz and all staffers of the hypobaric chamber for their contributions and support of this project. The US Wilderness Medicine Association, American Lung Association, and Natural Science Foundation of China (NSFC) supported this work.
Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 2005/3
Y1 - 2005/3
N2 - To investigate whether obesity is associated with alterations in respiratory chemosensitivity, we compared the ventilatory response to hypoxia (HVR) and hypercapnia (HCVR) in 9 obese men (BMI: 37.0 ± 4.3 kg m -2) and 10 lean men (BMI: 25.8 ± 4.8 kg m-2). HVR (ΔV̇E, L min-1 per ΔSaO2, %) was measured by a progressive isocapnic hypoxia technique, and HCVR (ΔV̇E/ΔPETCO2, L min-1 Torr-1) was measured by a progressive hypercapnic method. HCVR, was greater (p < 0.001) in the obese men (2.68 ± 0.78) than in the lean men (1.4 ± 0.45) as was HVR (p < 0.05) (1.26 ± 0.65 versus 0.71 ± 0.43, respectively). The difference (ΔSaO2%, 4.30 ± 3.69 and 10.54 ± 3.45 in the lean and obese men, respectively, p < 0.01) between daytime (86 ± 1 and 86 ± 1%) and nighttime SaO2 (81 ± 3 and 76 ± 4%) at a simulated altitude of 3658 m was significantly (p < 0.05) correlated with both HVR (r = 0.51) and HCVR (r = 0.48). These results suggest that chemosensitivity in mildly obese men is increased, not blunted. Furthermore, otherwise healthy, obese individuals have the potential for significant desaturation during sleep at high altitude possibly due to exaggerated sleep-disordered breathing.
AB - To investigate whether obesity is associated with alterations in respiratory chemosensitivity, we compared the ventilatory response to hypoxia (HVR) and hypercapnia (HCVR) in 9 obese men (BMI: 37.0 ± 4.3 kg m -2) and 10 lean men (BMI: 25.8 ± 4.8 kg m-2). HVR (ΔV̇E, L min-1 per ΔSaO2, %) was measured by a progressive isocapnic hypoxia technique, and HCVR (ΔV̇E/ΔPETCO2, L min-1 Torr-1) was measured by a progressive hypercapnic method. HCVR, was greater (p < 0.001) in the obese men (2.68 ± 0.78) than in the lean men (1.4 ± 0.45) as was HVR (p < 0.05) (1.26 ± 0.65 versus 0.71 ± 0.43, respectively). The difference (ΔSaO2%, 4.30 ± 3.69 and 10.54 ± 3.45 in the lean and obese men, respectively, p < 0.01) between daytime (86 ± 1 and 86 ± 1%) and nighttime SaO2 (81 ± 3 and 76 ± 4%) at a simulated altitude of 3658 m was significantly (p < 0.05) correlated with both HVR (r = 0.51) and HCVR (r = 0.48). These results suggest that chemosensitivity in mildly obese men is increased, not blunted. Furthermore, otherwise healthy, obese individuals have the potential for significant desaturation during sleep at high altitude possibly due to exaggerated sleep-disordered breathing.
KW - Chemoreflex
KW - Nocturnal hypoxia
KW - Obesity
KW - Ventilatory response
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U2 - 10.1016/j.resp.2004.11.009
DO - 10.1016/j.resp.2004.11.009
M3 - Article
C2 - 15733778
AN - SCOPUS:14344251788
SN - 1569-9048
VL - 146
SP - 47
EP - 54
JO - Respiratory Physiology and Neurobiology
JF - Respiratory Physiology and Neurobiology
IS - 1
ER -