Abstract We examined whether exposure to intermittent hypoxia (IH) during wakefulness impacted on the apnea/hypopnea index (AHI) during sleep in individuals with sleep apnea. Participants were exposed to twelve 4-min episodes of hypoxia in the presence of sustained mild hypercapnia each day for 10 days. A control group was exposed to sustained mild hypercapnia for a similar duration. The intermittent hypoxia protocol was completed in the evening on day 1 and 10 and was followed by a sleep study. During all sleep studies, the change in esophageal pressure (ΔPes) from the beginning to the end of an apnea and the tidal volume immediately following apneic events were used to measure respiratory drive. Following exposure to IH on day 1 and 10 , the AHI increased above baseline measures ( day 1 : 1.95 ± 0.42 fraction of baseline, P ≤ 0.01, vs. day 10 : 1.53 ± 0.24 fraction of baseline, P < 0.06). The indexes were correlated to the hypoxic ventilatory response (HVR) measured during the IH protocol but were not correlated to the magnitude of ventilatory long-term facilitation (vLTF). Likewise, ΔPes and tidal volume measures were greater on day 1 and 10 compared with baseline (ΔPes: −8.37 ± 0.84 vs. −5.90 ± 1.30 cmH 2 0, P ≤ 0.04; tidal volume: 1,193.36 ± 101.85 vs. 1,015.14 ± 119.83 ml, P ≤ 0.01). This was not the case in the control group. Interestingly, the AHI on day 10 (0.78 ± 0.13 fraction of baseline, P ≤ 0.01) was significantly less than measures obtained during baseline and day 1 in the mild hypercapnia control group. We conclude that enhancement of the HVR initiated by exposure to IH may lead to increases in the AHI during sleep and that initiation of vLTF did not appear to impact on breathing stability. Lastly, our results suggest that repeated daily exposure to mild sustained hypercapnia may lead to a decrease in breathing events. progressive augmentation ventilatory long-term facilitation apnea/hypopnea index apnea duration esophageal pressure « Previous | Next Article » Table of Contents This Article Published online before print November 2011 , doi: 10.​1152/​japplphysiol.​00702.​2011 Journal of Applied Physiology February 2012 vol. 112 no. 3 367-377 » Abstract Free Full Text Free to you Full Text (PDF) Free to you All Versions of this Article: japplphysiol.00702.2011v1 112/3/367 most recent Classifications Article Services Email this article to a friend Alert me when this article is cited Alert me if a correction is posted Alert me when eletters are published Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Download to citation manager Responses Submit a response No responses published Citing Articles Load citing article information Citing articles via Web of Science Google Scholar Articles by Yokhana, S. S. Articles by Mateika, J. H. PubMed PubMed citation Articles by Yokhana, S. S. Articles by Mateika, J. H. Related Content Load related web page information Current Issue February 2012, 112 (3) Alert me to new issues of Journal of Applied Physiology About the Journal Information for Authors Submit a Manuscript Ethical Policies AuthorChoice PubMed Central Policy Reprints and Permissions Advertising Press Copyright © 2012 the American Physiological Society Print ISSN: 8750-7587 Online ISSN: 1522-1601 var gaJsHost = (("https:" == document.location.protocol) ? "https://ssl." : "http://www."); document.write(unescape("%3Cscript src='" + gaJsHost + "google-analytics.com/ga.js' type='text/javascript'%3E%3C/script%3E")); var pageTracker = _gat._getTracker("UA-2924550-1"); pageTracker._trackPageview();

/lp/the-american-physiological-society/impact-of-repeated-daily-exposure-to-intermittent-hypoxia-and-mild-JjW3yJsXP0