TY - JOUR T1 - OSA-related respiratory events and desaturation severity are associated with the cardiac response JF - ERJ Open Research JO - erjor DO - 10.1183/23120541.00121-2022 SP - 00121-2022 AU - Salla Hietakoste AU - Tuomas Karhu AU - Saara Sillanmäki AU - Raquel Bailón AU - Thomas Penzel AU - Juha Töyräs AU - Timo Leppänen AU - Sami Myllymaa AU - Samu Kainulainen Y1 - 2022/01/01 UR - http://openres.ersjournals.com/content/early/2022/06/30/23120541.00121-2022.abstract N2 - Obstructive sleep apnea (OSA) causes e.g. intermittent blood oxygen desaturations increasing the sympathetic tone. Yet, the effect of desaturations on heart rate variability (HRV), a simple, non-invasive method for assessing sympathovagal balance, has not been comprehensively studied. We aimed to study whether the desaturation severity affects the immediate HRV. We retrospectively analysed the electrocardiography (ECG) signals in 5-minute segments (N=39 132), recorded during clinical polysomnography, of 642 suspected OSA patients. HRV parameters were calculated for each segment. The segments were pooled into severity groups based on the desaturation severity (DesSev, the integrated area under the blood oxygen saturation curve) and the respiratory event rate within the segment (Ev). Covariate-adjusted regression analyses were performed to investigate the possible confounding effects of e.g., comorbidities. With increasing Ev, the normalized high-frequency band power (HFNU) decreased from 0.517 to 0.364 (p<0.01), the normalized low-frequency band power (LFNU) increased from 0.483 to 0.636 (p<0.01), and the mean RR interval decreased from 915 to 869 ms (p<0.01). Similarly, with increasing DesSev, the HFNU decreased from 0.499 to 0.364 (p<0.01), the LFNU increased from 0.501 to 0.636 (p<0.01), and the mean RR interval decreased from 952 to 854 ms (p<0.01). DesSev-related findings were confirmed by considering the confounding factors in the regression analyses. In conclusion, the short-term HRV response differs based on the desaturation severity and the respiratory event rate in suspected OSA patients. Therefore, a more detailed analysis of the HRV and desaturation characteristics could enhance the OSA severity estimation.FootnotesThis manuscript has recently been accepted for publication in the ERJ Open Research. It is published here in its accepted form prior to copyediting and typesetting by our production team. After these production processes are complete and the authors have approved the resulting proofs, the article will move to the latest issue of the ERJOR online. Please open or download the PDF to view this article.Conflicts of interest: Dr. Hietakoste reports grants from The Research Committee of the Kuopio University Hospital Catchment Area, grants from Research Foundation of the Pulmonary Diseases, grants from Foundation of the Finnish Anti-Tuberculosis Association, grants from Instrumentarium Science Foundation, during the conduct of the study.Conflicts of interest: Dr. Karhu reports grants from The Research Committee of the Kuopio University Hospital Catchment Area for the State Research Funding, grants from Instrumentarium Science Foundation, grants from Tampere Tuberculosis Foundation, during the conduct of the study.Conflicts of interest: Dr. Sillanmäki reports grants from Kuopio University Hospital Catchment Area; State Research Funding (no 5041798), during the conduct of the study; personal fees from Finnish Society of Cardiology, personal fees from Finnish Society of Nuclear Medicine, personal fees from Finnish Society of Clinical Physiology, personal fees from Onni and Hilja Tuovinen Foundation, personal fees from Paavo Nurmi Foundation , personal fees from Scandinavian Society of Clinical Physiology, outside the submitted work.Conflicts of interest: Dr. Bailón reports other from Aragon Government and European Social Fund (EU), during the conduct of the study.Conflicts of interest: Dr. Penzel reports grants from Cidelec, grants and personal fees from Löwenstein Medical, grants from Novartis, other from Bayer, personal fees from Neuwirth, personal fees from National Sleep Foundation, personal fees from Cerebra, other from MyCardio, personal fees from Jazz Pharma, from null, outside the submitted work; and Shareholder of Advanced Sleep Research, The Siestagroup GmbH, and Nukute. .Dr. Penzel reports grants from Cidelec, grants and personal fees from Löwenstein Medical, grants from Novartis, other from Bayer, personal fees from Neuwirth, personal fees from National Sleep Foundation, personal fees from Cerebra, other from MyCardio, personal fees from Jazz Pharma, grants from European Union, outside the submitted work; and Shareholder of Advanced Sleep Research, The Siestagroup GmbH, and Nukute. .Conflicts of interest: Dr. Töyräs reports grants from Business Finland, grants from National Health and Medical Research Council, Australia, grants from European Commission, Horizon 2020, during the conduct of the study.Conflicts of interest: Dr. Leppänen reports grants from European Union's Horizon 2020 research and innovation programme under grant agreement no. 965417, grants from NordForsk (NordSleep project 90458) via Business Finland (5133/31/2018) , grants from Academy of Finland (323536), grants from Research Committee of the Kuopio University Hospital Catchment Area for the State Research Funding (5041767 and 5041794), personal fees from Turku University Hospital, Turku, Finland, during the conduct of the study.Conflicts of interest: Dr. Myllymaa reports grants from The Research Committee of the Kuopio University Hospital Catchment Area for the State Research Funding (project numbers 5041770, 5041797), grants from Research Foundation of the Pulmonary Diseases, grants from Foundation of the Finnish Anti-Tuberculosis Association, during the conduct of the study.Conflicts of interest: Dr. Kainulainen reports grants from Maud Kuistila Memorial Foundation, grants from Finnish Cultural Foundation - Central fund, grants from Tampere Tuberculosis Foundation, grants from Kuopio University Hospital, other from Regional Fund of Northern Savo, during the conduct of the study. 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