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Hemingway HW, Richey RE, Moore AM, Saul BM, Shokraeifard AM, Cope HL, Olivencia-Yurvati AH, Cunningham RL, Smith ML, Romero SA. Effect of acute heat exposure on the pressor response to a voluntary hypoxic apnea. J Appl Physiol (1985) 2023; 135:542-548. [PMID: 37439242 PMCID: PMC10538993 DOI: 10.1152/japplphysiol.00245.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 07/10/2023] [Accepted: 07/11/2023] [Indexed: 07/14/2023] Open
Abstract
The pressor response induced by a voluntary hypoxic apnea is mediated largely by increased sympathetic outflow. The neural control of blood pressure is altered in recovery from acute heat exposure, but its effect on the pressor response to a voluntary hypoxic apnea has never been explored. Therefore, we tested the hypothesis that prior heat exposure would attenuate the pressor response induced by a voluntary hypoxic apnea. Eleven healthy adults (five women) were exposed to whole body passive heating (water-perfused suit) sufficient to increase body core temperature by 1.2°C. Voluntary hypoxic apneas were performed at baseline and in recovery when body core temperature returned to ≤ 0.3°C of baseline. Participants breathed gas mixtures of varying [Formula: see text] (21%, 16%, and 12%; randomized) for 1 min followed by a 15-s end-expiratory apnea. The change in arterial oxygen saturation during each apnea did not differ from baseline to recovery (P = 0.6 for interaction), whereas the pressor response induced by a voluntary hypoxia apnea was reduced ([Formula: see text] 21%, baseline 17 ± 7 mmHg vs. recovery 14 ± 7 mmHg; [Formula: see text] 16%, baseline 24 ± 8 mmHg vs. recovery 18 ± 7 mmHg; [Formula: see text] 12%, baseline 28 ± 11 mmHg vs. recovery 24 ± 11 mmHg; P = 0.01 for main effect of time). These data suggest that prior heat exposure induces a cross-stressor effect such that the pressor response to a voluntary hypoxic apnea is attenuated.NEW & NOTEWORTHY The pressor response induced by a voluntary hypoxic apnea is mediated by increased sympathetic outflow. The neural control of blood pressure is altered in recovery from acute heat exposure, but its effect on the pressor response to a voluntary hypoxic apnea has never been explored. Our data suggest that prior heat exposure induces a cross-stressor effect such that the pressor response to a voluntary hypoxic apnea is attenuated.
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Affiliation(s)
- Holden W Hemingway
- Human Vascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas, United States
| | - Rauchelle E Richey
- Human Vascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas, United States
| | - Amy M Moore
- Human Vascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas, United States
| | - Benjamin M Saul
- Human Vascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas, United States
| | - Austin M Shokraeifard
- Human Vascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas, United States
| | - Heidi L Cope
- Human Vascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas, United States
| | - Albert H Olivencia-Yurvati
- Human Vascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas, United States
- Department of Surgery, University of North Texas Health Science Center, Fort Worth, Texas, United States
| | - Rebecca L Cunningham
- Department of Pharmaceutical Sciences, University of North Texas Health Science Center, Fort Worth, Texas, United States
| | - Michael L Smith
- Human Vascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas, United States
| | - Steven A Romero
- Human Vascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas, United States
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Meng Z, Chen Y, Yang T, Sun B, Luo C, Wei G, Xie X, Gu Y, Ding N, Zhang X, Xu J. New perspective on exploring the predictive factors of blood pressure reduction during CPAP treatment in people with severe OSA and hypertension: a prospective observational study. BMJ Open Respir Res 2023; 10:10/1/e001560. [PMID: 37169401 DOI: 10.1136/bmjresp-2022-001560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Accepted: 04/28/2023] [Indexed: 05/13/2023] Open
Abstract
BACKGROUND The predictive factors of blood pressure (BP) response to continuous positive airway pressure (CPAP) in obstructive sleep apnoea (OSA) are still being explored. We aimed to assess the antihypertensive effect of CPAP considering the obstructive respiratory event-triggered BP surge profiles in 130 subjects with severe OSA and untreated hypertension. METHODS Nocturnal BP was monitored continuously and synchronised with polysomnography. Event-triggered BP surge profiles were studied: BP surge as the value of event-related systolic BP (SBP) elevation; BP index as the number of BP surge events of ≥10 mm Hg per hour. Patients were then divided into two groups according to the median BP index (high and low BP surge groups) and assigned to 4 weeks of CPAP. Changes in BPs and plasma biomarkers were compared. After the initial evaluation, patients with a better BP response in the high BP surge group were then followed up for the second evaluation at 24 months. RESULTS Overall, a modest decrease was observed in both office and asleep BPs at the 4-week follow-up; however, BPs dropped more markedly in patients in the high BP surge group than those in the low BP surge group, in both office SBP (5.3 mm Hg vs 2.2 mm Hg, p=0.003) and diastolic BP (4.0 mm Hg vs 1.2 mm Hg, p<0.001), especially the asleep SBP (9.0 mm Hg vs 2.1 mm Hg, p<0.001). For 30 cases in the high BP surge group, optimal BP control was achieved in 60.0% of patients and BP<140/90 mm Hg reached up to 83.3% after 24 months of CPAP. Linear regression revealed that BP index was significantly associated with BP decrease during CPAP treatment. CONCLUSIONS Our results suggested that high event-triggered BP surge was a sensitive predictor of BP response to CPAP in patients with severe OSA and untreated hypertension. TRIAL REGISTRATION NUMBER Clinical Trials.gov Identifier: NCT03246022; https://clinicaltrials.gov/ct2/show/NCT03246022?term=NCT+03246022&draw=2&rank=1.
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Affiliation(s)
- Zili Meng
- Department of Respiratory and Critical Care Medicine, The Affiliated Huaian No.1 People's Hospital of Nanjing Medical University, Huaian, China
| | - Ying Chen
- Department of Respiratory and Critical Care Medicine, The Affiliated Huaian No.1 People's Hospital of Nanjing Medical University, Huaian, China
| | - Ting Yang
- Department of Respiratory and Critical Care Medicine, The Affiliated Huaian No.1 People's Hospital of Nanjing Medical University, Huaian, China
| | - Bo Sun
- Department of Respiratory and Critical Care Medicine, The Affiliated Huaian No.1 People's Hospital of Nanjing Medical University, Huaian, China
| | - Chao Luo
- Department of Respiratory and Critical Care Medicine, The Affiliated Huaian No.1 People's Hospital of Nanjing Medical University, Huaian, China
| | - Guihong Wei
- Department of Respiratory and Critical Care Medicine, The Affiliated Huaian No.1 People's Hospital of Nanjing Medical University, Huaian, China
| | - Xiaochen Xie
- Department of Respiratory and Critical Care Medicine, The Affiliated Huaian No.1 People's Hospital of Nanjing Medical University, Huaian, China
| | - Yang Gu
- Department of Respiratory and Critical Care Medicine, The Affiliated Huaian No.1 People's Hospital of Nanjing Medical University, Huaian, China
| | - Ning Ding
- Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Xilong Zhang
- Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Jing Xu
- Department of Respiratory and Critical Care Medicine, The Affiliated Huaian No.1 People's Hospital of Nanjing Medical University, Huaian, China
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Greenlund IM, Bigalke JA, Tikkanen AL, Durocher JJ, Smoot CA, Carter JR. Evening Binge Alcohol Disrupts Cardiovagal Tone and Baroreflex Function During Polysomnographic Sleep. Sleep 2021; 44:6279273. [PMID: 34015116 DOI: 10.1093/sleep/zsab130] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 04/23/2021] [Indexed: 11/14/2022] Open
Abstract
STUDY OBJECTIVES Binge alcohol consumption is associated with increased cardiovascular risk. The effects of evening binge alcohol consumption (i.e., 4-5 beverages within two hours) on the vagal components of HRV and cardiovagal baroreflex sensitivity (cvBRS) during sleep remain largely equivocal. The present study examined the effects of evening binge alcohol consumption on nocturnal cardiac vagal tone and baroreflex sensitivity during stage N2, slow wave (SWS), and rapid eye movement (REM) sleep. We hypothesized that evening binge drinking would reduce HRV and cvBRS in each sleep stage. METHODS Following a familiarization night within the laboratory, twenty-three participants were examined following a night of binge alcohol consumption and a fluid control (randomized, crossover design). A quality nocturnal beat-to-beat blood pressure signal was obtained in both conditions in 16 participants (7 men, 9 women; 25±1 years). RESULTS Binge drinking reduced both the high frequency (HF) and time-domain components (i.e., pNN50 and RMSSD) of HRV in stage N2 sleep, SWS, and REM. In addition, cvBRS up-up (vagal activation) was reduced following binge alcohol consumption in stage N2 (21±3 vs. 15±3 ms/mmHg, P=0.035) and REM (15[11-28] vs. 11[9-18] ms/mmHg, P=0.009). Binge alcohol consumption reduced cvBRS down-down (vagal withdrawal) in stage N2 (23±2 vs. 14±2 ms/mmHg, P<0.001), SWS (20[14-30] vs. 14[9-17] ms/mmHg, P=0.022), and REM (14[11-24] vs. 10[7-15] ms/mmHg, P=0.006). CONCLUSIONS Evening binge alcohol consumption disrupts cardiac vagal tone and baroreflex function during nearly all sleep stages. These findings provide mechanistic insight into the potential role of binge drinking and alcohol abuse on cardiovascular risk.
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Affiliation(s)
- Ian M Greenlund
- Department of Health & Human Development, Montana State University, Bozeman, Montana, United States.,Department of Psychology, Montana State University, Bozeman, Montana, United States.,Department of Kinesiology & Integrative Physiology, Michigan Technological University, Houghton, Michigan, United States
| | - Jeremy A Bigalke
- Department of Health & Human Development, Montana State University, Bozeman, Montana, United States.,Department of Psychology, Montana State University, Bozeman, Montana, United States.,Department of Kinesiology & Integrative Physiology, Michigan Technological University, Houghton, Michigan, United States
| | - Anne L Tikkanen
- Department of Health & Human Development, Montana State University, Bozeman, Montana, United States.,Department of Kinesiology & Integrative Physiology, Michigan Technological University, Houghton, Michigan, United States
| | - John J Durocher
- Department of Kinesiology & Integrative Physiology, Michigan Technological University, Houghton, Michigan, United States.,Department of Biological Sciences, Purdue University Northwest, Hammond, Indiana, United States
| | - Carl A Smoot
- Department of Health & Human Development, Montana State University, Bozeman, Montana, United States.,Department of Kinesiology & Integrative Physiology, Michigan Technological University, Houghton, Michigan, United States
| | - Jason R Carter
- Department of Health & Human Development, Montana State University, Bozeman, Montana, United States.,Department of Psychology, Montana State University, Bozeman, Montana, United States.,Department of Kinesiology & Integrative Physiology, Michigan Technological University, Houghton, Michigan, United States
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Smith JR, Sutterfield SL, Baumfalk DR, Didier KD, Hammer SM, Caldwell JT, Ade CJ. Left ventricular strain rate is reduced during voluntary apnea in healthy humans. J Appl Physiol (1985) 2017; 123:1730-1737. [PMID: 28912359 DOI: 10.1152/japplphysiol.00327.2017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
During an apneic event, sympathetic nerve activity increases resulting in subsequent increases in left ventricular (LV) afterload and myocardial work. It is unknown how cardiac mechanics are acutely impacted by the increased myocardial work during an apneic event. Ten healthy individuals (23 ± 3 yr) performed multiple voluntary end-expiratory apnea (VEEA) maneuvers exposed to room air, while a subset ( n = 7) completed multiple VEEA exposed to hyperoxic air (100% [Formula: see text]). Beat-by-beat blood pressure, heart rate, and stroke volume were measured continuously. Effective arterial elastance (EA) was calculated as an index of cardiac afterload, and myocardial work was calculated as the rate pressure product (RPP). Tissue Doppler echocardiography was used to measure LV tissue velocities, deformation via strain, and strain rate (SR). Systolic blood pressure (Δ18 ± 13 mmHg, P < 0.01), EA (Δ0.13 ± 0.10 mmHg/ml, P < 0.01), and RPP (Δ9 ± 10 beats/min × mmHg 10-2, P < 0.01) significantly increased with room air VEEA. This occurred in parallel with decreases in peak longitudinal systolic (Δ-0.62 ± 0.41 cm/s, P < 0.01) and early LV filling (Δ-2.81 ± 1.99 cm/s, P < 0.01) myocardial velocities. Longitudinal SR (Δ-0.30 ± 0.32 1/s, P = 0.01) was significantly decreased during room air VEEA. VEEA with hyperoxia did not alter ( P > 0.18) EA or RPP and attenuated the systolic blood pressure response compared with room air. Myocardial velocities and LV strain rate response to VEEA were unchanged ( P = 0.30) with hyperoxia. Consistent with our hypotheses, VEEA-induced increases in EA and myocardial work impact LV mechanics, which may depend, in part, on stimulation of peripheral chemoreceptors. NEW & NOTEWORTHY Transient increases in arterial blood pressure and systemic vascular resistance occur during sleep apnea events and may contribute to the associated daytime hypertension and risk of overt cardiovascular disease. To date, the link between this apnea pressor response and acute changes in left ventricular function remains poorly understood. We demonstrate that in parallel to increases in cardiac afterload a depressed left ventricular systolic function occurs at end apnea.
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Affiliation(s)
- Joshua R Smith
- Department of Kinesiology, Kansas State University , Manhattan, Kansas
| | | | - Dryden R Baumfalk
- Department of Kinesiology, Kansas State University , Manhattan, Kansas
| | - Kaylin D Didier
- Department of Kinesiology, Kansas State University , Manhattan, Kansas
| | - Shane M Hammer
- Department of Kinesiology, Kansas State University , Manhattan, Kansas
| | - Jacob T Caldwell
- Department of Kinesiology, Kansas State University , Manhattan, Kansas
| | - Carl J Ade
- Department of Kinesiology, Kansas State University , Manhattan, Kansas
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Ghiasi F, Amra B, Sebghatollahi V, Azimian F. Association of irritable bowel syndrome and sleep apnea in patients referred to sleep laboratory. JOURNAL OF RESEARCH IN MEDICAL SCIENCES 2017; 22:72. [PMID: 28717369 PMCID: PMC5508502 DOI: 10.4103/jrms.jrms_523_16] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/25/2016] [Revised: 11/09/2016] [Accepted: 03/11/2017] [Indexed: 12/13/2022]
Abstract
Background: Irritable bowel syndrome (IBS) is assumed as one of the most frequent gastrointestinal disorders, which decreases the patient's quality of life. IBS pathogenesis, however, is not clearly defined. It seems that sleep apnea induces or escalates IBS clinical symptoms. This study aims at evaluating of IBS prevalence in patients, who are afflicted or are not afflicted with sleep apnea. Materials and Methods: This was a case–control study, which was implemented in a sleep laboratory located in Isfahan, Iran. We recruited 200 patients being more than 15 years from 2014 to 2015. Based on the apnea–hypopnea index (AHI), we recruited 100 patients in each of two groups: negative sleep apnea (NSA) (AHI ≤4) and positive sleep apnea (PSA) (AHI >4). IBS was diagnosed through a Rome III diagnostic questionnaire. Results: Overall, the prevalence of IBS among patients referred to sleep laboratory was 17.6%. Indeed, IBS prevalence in NSA and PSA groups were 8.2% and 27.1%, respectively. Furthermore, odds ratio of IBS in PSA group versus NSA was 3.92 (95% confidence interval = 1.58–9.77, P = 0.003). Our results showed that the prevalence of IBS did not differ significantly between various severity of sleep apnea (P = 0.452). Conclusion: This study showed that there was a positive association between sleep apnea and IBS.
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Affiliation(s)
- Farzin Ghiasi
- Department of Pulmonology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Babak Amra
- Department of Pulmonology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Vahid Sebghatollahi
- Department of Gastroenterology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Fatemeh Azimian
- Department of Internal Medicine, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
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Jouett NP, Moralez G, Raven PB, Smith ML. Losartan reduces the immediate and sustained increases in muscle sympathetic nerve activity after hyperacute intermittent hypoxia. J Appl Physiol (1985) 2017; 122:884-892. [DOI: 10.1152/japplphysiol.00683.2016] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Revised: 12/21/2016] [Accepted: 01/08/2017] [Indexed: 11/22/2022] Open
Abstract
Obstructive sleep apnea (OSA) is characterized by intermittent hypoxemia, which produces elevations in sympathetic nerve activity (SNA) and associated hypertension in experimental models that persist beyond the initial exposure. We tested the hypotheses that angiotensin receptor blockade in humans using losartan attenuates the immediate and immediately persistent increases in 1) SNA discharge and 2) mean arterial pressure (MAP) after hyperacute intermittent hypoxia training (IHT) using a randomized, placebo-controlled, repeated-measures experimental design. We measured ECG and photoplethysmographic arterial pressure in nine healthy human subjects, while muscle SNA (MSNA) was recorded in seven subjects using microneurography. Subjects were exposed to a series of hypoxic apneas in which they inhaled two to three breaths of nitrogen, followed by a 20-s apnea and 40 s of room air breathing every minute for 20 min. Hyperacute IHT produced substantial and persistent elevations in MSNA burst frequency (baseline: 15.3 ± 1.8, IHT: 24 ± 1.5, post-IHT 20.0 ± 1.3 bursts/min, all P < 0.01) and MAP (baseline: 89.2 ± 3.3, IHT: 92.62 ± 3.1, post-IHT: 93.83 ± 3.1 mmHg, all P < 0.02). Losartan attenuated the immediate and sustained increases in MSNA (baseline: 17.3 ± 2.5, IHT: 18.6 ± 2.2, post-IHT 20.0 ± 1.3 bursts/min, all P < 0.001) and MAP (baseline: 81.9 ± 2.6, IHT: 81.1 ± 2.8, post-IHT: 81.3 ± 3.0 mmHg, all P > 0.70). This investigation confirms the role of angiotensin II type 1a receptors in the immediate and persistent sympathoexcitatory and pressor responses to IHT. NEW & NOTEWORTHY This study demonstrates for the first time in humans that losartan, an angiotensin receptor blocker (ARB), abrogates the acute and immediately persistent increases in muscle sympathetic nerve activity and arterial pressure in response to acute intermittent hypoxia. This investigation, along with others, provides important beginning translational evidence for using ARBs in treatment of the intermittent hypoxia observed in obstructive sleep apnea patients.
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Affiliation(s)
- Noah P. Jouett
- Institute for Cardiovascular and Metabolic Disease, University of North Texas Health Science Center, Fort Worth, Texas; and
| | - Gilbert Moralez
- Institute for Environmental and Exercise Medicine, Texas Health Presbyterian Hospital, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Peter B. Raven
- Institute for Cardiovascular and Metabolic Disease, University of North Texas Health Science Center, Fort Worth, Texas; and
| | - Michael L. Smith
- Institute for Cardiovascular and Metabolic Disease, University of North Texas Health Science Center, Fort Worth, Texas; and
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Uzun S. Comment on: 'Retina nerve fiber layer and choroidal thickness changes in obstructive sleep apnea syndrome' by Ozge et al. Postgrad Med J 2016; 92:364. [PMID: 27053516 DOI: 10.1136/postgradmedj-2016-134097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Affiliation(s)
- Salih Uzun
- Department of Ophthalmology, Etimesgut Military Hospital, Ankara, Turkey
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