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Bezruk D, Bahenský P, Marko D, Krajcigr M, Bahenský P, Novák-Nowická E, Mrkvička T. The Effect of Static Apnea Diving Training on the Physiological Parameters of People with a Sports Orientation and Sedentary Participants: A Pilot Study. Sports (Basel) 2024; 12:140. [PMID: 38921834 PMCID: PMC11209488 DOI: 10.3390/sports12060140] [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: 04/11/2024] [Revised: 05/17/2024] [Accepted: 05/18/2024] [Indexed: 06/27/2024] Open
Abstract
Diver training improves physical and mental fitness, which can also benefit other sports. This study investigates the effect of eight weeks of static apnea training on maximum apnea time, and on the physiological parameters of runners, swimmers, and sedentary participants, such as forced vital capacity (FVC), minimum heart rate (HR), and oxygen saturation (SpO2). The study followed 19 participants, including five runners, swimmers, sedentary participants, and four competitive divers for reference values. The minimum value of SpO2, HR, maximum duration of apnea, and FVC were measured. Apnea training occurred four times weekly, consisting of six apneas with 60 s breathing pauses. Apnea duration was gradually increased by 30 s. The measurement started with a 30 s apnea and ended with maximal apnea. There was a change in SpO2 decreased by 6.8%, maximum apnea length increased by 15.8%, HR decreased by 9.1%, and FVC increased by 12.4% for the groups (p < 0.05). There were intra-groups changes, but no significant inter-groups difference was observed. Eight weeks of apnea training improved the maximum duration of apnea, FVC values and reduced the minimum values of SpO2 and HR in all groups. No differences were noted between groups after training. This training may benefit cardiorespiratory parameters in the population.
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Affiliation(s)
- Dmitriy Bezruk
- Department of Sports Studies, Faculty of Education, University of South Bohemia in České Budějovice, 37005 České Budějovice, Czech Republic; (D.B.); (D.M.); (M.K.); (P.B.J.); (E.N.-N.)
| | - Petr Bahenský
- Department of Sports Studies, Faculty of Education, University of South Bohemia in České Budějovice, 37005 České Budějovice, Czech Republic; (D.B.); (D.M.); (M.K.); (P.B.J.); (E.N.-N.)
| | - David Marko
- Department of Sports Studies, Faculty of Education, University of South Bohemia in České Budějovice, 37005 České Budějovice, Czech Republic; (D.B.); (D.M.); (M.K.); (P.B.J.); (E.N.-N.)
| | - Miroslav Krajcigr
- Department of Sports Studies, Faculty of Education, University of South Bohemia in České Budějovice, 37005 České Budějovice, Czech Republic; (D.B.); (D.M.); (M.K.); (P.B.J.); (E.N.-N.)
| | - Petr Bahenský
- Department of Sports Studies, Faculty of Education, University of South Bohemia in České Budějovice, 37005 České Budějovice, Czech Republic; (D.B.); (D.M.); (M.K.); (P.B.J.); (E.N.-N.)
| | - Eva Novák-Nowická
- Department of Sports Studies, Faculty of Education, University of South Bohemia in České Budějovice, 37005 České Budějovice, Czech Republic; (D.B.); (D.M.); (M.K.); (P.B.J.); (E.N.-N.)
| | - Tomáš Mrkvička
- Department of Applied Mathematics and Informatics, Faculty of Economics, University of South Bohemia in České Budějovice, 37005 České Budějovice, Czech Republic;
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Magyar-Stang R, Pál H, Csányi B, Gaál A, Mihály Z, Czinege Z, Csipo T, Ungvari Z, Sótonyi P, Varga A, Horváth T, Bereczki D, Koller A, Debreczeni R. Assessment of cerebral autoregulatory function and inter-hemispheric blood flow in older adults with internal carotid artery stenosis using transcranial Doppler sonography-based measurement of transient hyperemic response after carotid artery compression. GeroScience 2023; 45:3333-3357. [PMID: 37599343 PMCID: PMC10643517 DOI: 10.1007/s11357-023-00896-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Accepted: 07/16/2023] [Indexed: 08/22/2023] Open
Abstract
Unhealthy vascular aging promotes atherogenesis, which may lead to significant internal carotid artery stenosis (CAS) in 5 to 7.5% of older adults. The pathogenic factors that promote accelerated vascular aging and CAS also affect the downstream portion of the cerebral microcirculation in these patients. Primary treatments of significant CAS are eversion endarterectomy or endarterectomy with patch plasty. Factors that determine adequate hemodynamic compensation and thereby the clinical consequences of CAS as well as medical and surgical complications of carotid reconstruction surgery likely involve the anatomy of the circle of Willis (CoW), the magnitude of compensatory inter-hemispheric blood flow, and the effectiveness of cerebral microcirculatory blood flow autoregulation. This study aimed to test two hypotheses based on this theory. First, we hypothesized that patients with symptomatic and asymptomatic CAS would exhibit differences in autoregulatory function and inter-hemispheric blood flow. Second, we predicted that anatomically compromised CoW would associate with impaired inter-hemispheric blood flow compensation. We enrolled older adults with symptomatic or asymptomatic internal CAS (>70% NASCET criteria; n = 46) and assessed CoW integrity by CT angiography. We evaluated transient hyperemic responses in the middle cerebral arteries (MCA) after common carotid artery compression (CCC; 10 s) by transcranial Doppler sonography (TCD). We compared parameters reflecting autoregulatory function (e.g., transient hyperemic response ratio [THRR], return to baseline time [RTB], changes of vascular resistance) and inter-hemispheric blood flow (residual blood flow velocity). Our findings revealed that CAS was associated with impaired cerebral vascular reactivity. However, we did not observe significant differences in autoregulatory function or inter-hemispheric blood flow between patients with symptomatic and asymptomatic CAS. Moreover, anatomically compromised CoW did not significantly affect these parameters. Notably, we observed an inverse correlation between RTB and THRR, and 49% of CAS patients exhibited a delayed THRR, which associated with decreased inter-hemispheric blood flow. Future studies should investigate how TCD-based evaluation of autoregulatory function and inter-hemispheric blood flow can be used to optimize surgical techniques and patient selection for internal carotid artery revascularization.
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Affiliation(s)
- Rita Magyar-Stang
- Department of Neurology, Semmelweis University, Budapest, Hungary.
- János Szentágothai Doctoral School of Neurosciences, Semmelweis University, Budapest, Hungary.
| | - Hanga Pál
- Department of Neurology, Semmelweis University, Budapest, Hungary
- János Szentágothai Doctoral School of Neurosciences, Semmelweis University, Budapest, Hungary
| | - Borbála Csányi
- Faculty of Medicine, Semmelweis University, Budapest, Hungary
| | - Anna Gaál
- Faculty of Medicine, Semmelweis University, Budapest, Hungary
| | - Zsuzsanna Mihály
- Department of Vascular and Endovascular Surgery, Semmelweis University, Budapest, Hungary
| | - Zsófia Czinege
- Department of Vascular and Endovascular Surgery, Semmelweis University, Budapest, Hungary
| | - Tamas Csipo
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Department of Neurosurgery, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 731042, USA
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Public Health, Semmelweis University, Budapest, Hungary
| | - Zoltan Ungvari
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Department of Neurosurgery, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 731042, USA
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Public Health, Semmelweis University, Budapest, Hungary
- Peggy and Charles Stephenson Cancer Center, Oklahoma City, OK, 73104, USA
- Department of Health Promotion Sciences, College of Public Health, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Péter Sótonyi
- Department of Vascular and Endovascular Surgery, Semmelweis University, Budapest, Hungary
| | - Andrea Varga
- Department of Diagnostic Radiology, Heart and Vascular Center, Semmelweis University, Budapest, Hungary
| | - Tamás Horváth
- Research Center for Sport Physiology, Hungarian University of Sports Science, Budapest, Hungary
| | - Dániel Bereczki
- Department of Neurology, Semmelweis University, Budapest, Hungary
| | - Akos Koller
- Research Center for Sport Physiology, Hungarian University of Sports Science, Budapest, Hungary
- Department of Morphology & Physiology, Faculty of Health Sciences, and Translational Medicine Institute, Faculty of Medicine, and ELKH-SE, Cerebrovascular and Neurocognitive Disorders Research Group, Semmelweis University, Budapest, Hungary
- Department of Physiology, New York Medical College, Valhalla, NY, USA
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Massini DA, Scaggion D, DE Oliveira TP, Macedo AG, Almeida TF, Pessôa Filho DM. Training methods for maximal static apnea performance: a systematic review and meta-analysis. J Sports Med Phys Fitness 2023; 63:77-85. [PMID: 35437303 DOI: 10.23736/s0022-4707.22.13621-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
INTRODUCTION Currently, there is an increase in people practicing freediving (FD) both in competition and leisure. As a sports practice, its modalities are grouped into static, dynamic, and constant weight apnea. The aim of this systematic review and meta-analysis (PROSPERO-CRD42021230322) was to identify the training methods used to improve the static apnea time (AT) performance. EVIDENCE ACQUISITION Ten training protocols were analyzed from eight studies published until March 09, 2022. The effect size (Hedge's g) and its confidence interval (CI<inf>95%</inf>) were calculated from the AT measured pre- and post-training. EVIDENCE SYNTHESIS Three different apnea training methods were verified, the breath-hold (BH) that uses BH exercises, physical training with strength and cardiorespiratory exercises, and cross training that combines BH exercises with physical training. These training methods were applied to 138 participants of both sexes with or without experience in apnea episode or diving practice. In general, the AT improvement showed a large effect after the interventions (g=1.30, CI<inf>95%</inf>=0.85-1.76, P<0.01). CONCLUSIONS All three methods were effective in improving static AT, however from the existing protocols is not possible to recommend an ideal to improve AT and therefore FD performance.
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Affiliation(s)
- Danilo A Massini
- Post-Graduate Program in Human Development and Technology from São Paulo State University (UNESP), Rio Claro, Brazil.,University Center of São Paulo State (UNICEP), Rio Claro, Brazil.,São Paulo State University (UNESP), Bauru, Brazil
| | - Danilo Scaggion
- University Center of São Paulo State (UNICEP), Rio Claro, Brazil
| | - Thiago P DE Oliveira
- Post-Graduate Program in Human Development and Technology from São Paulo State University (UNESP), Rio Claro, Brazil
| | - Anderson G Macedo
- Post-Graduate Program in Human Development and Technology from São Paulo State University (UNESP), Rio Claro, Brazil.,São Paulo State University (UNESP), Bauru, Brazil
| | - Tiago F Almeida
- São Paulo State University (UNESP), Bauru, Brazil - .,CIPER, Faculty of Human Kinetics, University of Lisbon, Lisbon, Portugal
| | - Dalton M Pessôa Filho
- Post-Graduate Program in Human Development and Technology from São Paulo State University (UNESP), Rio Claro, Brazil.,São Paulo State University (UNESP), Bauru, Brazil
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Lemaître F, Billaut F, Joulia F. Editorial: Physiology and Physiopathology of Breath-Holding Activity. Front Physiol 2022; 13:858371. [PMID: 35250647 PMCID: PMC8893164 DOI: 10.3389/fphys.2022.858371] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Accepted: 01/21/2022] [Indexed: 11/16/2022] Open
Affiliation(s)
- Frédéric Lemaître
- CETAPS EA 3832, Faculty of Sports Sciences, University of Rouen, Rouen, France
- CRIOBE UAR 3278, CNRS-EPHE-UPVD, Papetoai, French Polynesia
- *Correspondence: Frédéric Lemaître
| | | | - Fabrice Joulia
- C2VN, INRAE 1260, INSERM 1263, Aix Marseille Université, Marseille, France
- UFRSTAPS, Université de Toulon, Toulon, France
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Wang X, Cui L, Ji X. Cognitive impairment caused by hypoxia: from clinical evidences to molecular mechanisms. Metab Brain Dis 2022; 37:51-66. [PMID: 34618295 DOI: 10.1007/s11011-021-00796-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 07/09/2021] [Indexed: 12/23/2022]
Abstract
Hypoxia is a state of reduced oxygen supply and excessive oxygen consumption. According to the duration of hypoxic period, it can be classified as acute and chronic hypoxia. Both acute and chronic hypoxia could induce abundant neurological deficits. Although there have been significant advances in the pathophysiological injuries, few studies have focused on the cognitive dysfunction. In this review, we focused on the clinical evidences and molecular mechanisms of cognitive impairment under acute and chronic hypoxia. Hypoxia can impair several cognitive domains such as attention, learning and memory, procession speed and executive function, which are similar in acute and chronic hypoxia. The severity of cognitive deficit correlates with the duration and degree of hypoxia. Recovery can be achieved after acute hypoxia, while sequelae or even dementia can be observed after chronic hypoxia, perhaps due to the different molecular mechanisms. Cardiopulmonary compensatory response, glycolysis, oxidative stress, calcium overload, adenosine, mitochondrial disruption, inflammation and excitotoxicity contribute to the molecular mechanisms of cognitive deficit after acute hypoxia. During the chronic stage of hypoxia, different adaptive responses, impaired neurovascular coupling, apoptosis, transcription factors-mediated inflammation, as well as Aβ accumulation and tau phosphorylation account for the neurocognitive deficit. Moreover, brain structural changes with hippocampus and cortex atrophy, ventricle enlargement, senile plaque and neurofibrillary tangle deposition can be observed under chronic hypoxia rather than acute hypoxia.
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Affiliation(s)
- Xiaoyin Wang
- Department of Neurology, Xuanwu Hospital of Capital Medical University, Beijing, China
- Beijing Institute for Brain Disorders, Capital Medical University, Beijing, China
| | - Lili Cui
- Department of Neurology, Xuanwu Hospital of Capital Medical University, Beijing, China
| | - Xunming Ji
- Beijing Institute for Brain Disorders, Capital Medical University, Beijing, China.
- Department of Neurosurgery, Xuanwu Hospital of Capital Medical University, No 45, Changchun Street, Beijing, 100053, Xicheng District, China.
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Kohshi K, Denoble PJ, Tamaki H, Morimatsu Y, Ishitake T, Lemaître F. Decompression Illness in Repetitive Breath-Hold Diving: Why Ischemic Lesions Involve the Brain? Front Physiol 2021; 12:711850. [PMID: 34539434 PMCID: PMC8446421 DOI: 10.3389/fphys.2021.711850] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Accepted: 07/28/2021] [Indexed: 12/03/2022] Open
Abstract
Nitrogen (N2) accumulation in the blood and tissues can occur due to breath-hold (BH) diving. Post-dive venous gas emboli have been documented in commercial BH divers (Ama) after repetitive dives with short surface intervals. Hence, BH diving can theoretically cause decompression illness (DCI). “Taravana,” the diving syndrome described in Polynesian pearl divers by Cross in the 1960s, is likely DCI. It manifests mainly with cerebral involvements, especially stroke-like brain attacks with the spinal cord spared. Neuroradiological studies on Ama divers showed symptomatic and asymptomatic ischemic lesions in the cerebral cortex, subcortex, basal ganglia, brainstem, and cerebellum. These lesions localized in the external watershed areas and deep perforating arteries are compatible with cerebral arterial gas embolism. The underlying mechanisms remain to be elucidated. We consider that the most plausible mechanisms are arterialized venous gas bubbles passing through the lungs, bubbles mixed with thrombi occlude cerebral arteries and then expand from N2 influx from the occluded arteries and the brain. The first aid normobaric oxygen appears beneficial. DCI prevention strategy includes avoiding long-lasting repetitive dives for more than several hours, prolonging the surface intervals. This article provides an overview of clinical manifestations of DCI following repetitive BH dives and discusses possible mechanisms based on clinical and neuroimaging studies.
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Affiliation(s)
- Kiyotaka Kohshi
- Division of Neurosurgery, Nishinihon Hospital, Kumamoto, Japan.,Department of Environmental Medicine, Kurume University School of Medicine, Kurume, Japan
| | | | - Hideki Tamaki
- Department of Environmental Medicine, Kurume University School of Medicine, Kurume, Japan.,Division of Surgery and General Medicine, Tamaki Hospital, Hagi, Japan
| | - Yoshitaka Morimatsu
- Department of Environmental Medicine, Kurume University School of Medicine, Kurume, Japan
| | - Tatsuya Ishitake
- Department of Environmental Medicine, Kurume University School of Medicine, Kurume, Japan
| | - Frédéric Lemaître
- Faculty of Sport Sciences, University of Rouen, Mont-Saint-Aignan, France.,CRIOBE USR 3278, CNRS-EPHE-UPVD, PSL, Moorea, France
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7
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Tetzlaff K, Lemaitre F, Burgstahler C, Luetkens JA, Eichhorn L. Going to Extremes of Lung Physiology-Deep Breath-Hold Diving. Front Physiol 2021; 12:710429. [PMID: 34305657 PMCID: PMC8299524 DOI: 10.3389/fphys.2021.710429] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2021] [Accepted: 06/16/2021] [Indexed: 01/03/2023] Open
Abstract
Breath-hold diving involves environmental challenges, such as water immersion, hydrostatic pressure, and asphyxia, that put the respiratory system under stress. While training and inherent individual factors may increase tolerance to these challenges, the limits of human respiratory physiology will be reached quickly during deep breath-hold dives. Nonetheless, world records in deep breath-hold diving of more than 214 m of seawater have considerably exceeded predictions from human physiology. Investigations of elite breath-hold divers and their achievements revised our understanding of possible physiological adaptations in humans and revealed techniques such as glossopharyngeal breathing as being essential to achieve extremes in breath-hold diving performance. These techniques allow elite athletes to increase total lung capacity and minimize residual volume, thereby reducing thoracic squeeze. However, the inability of human lungs to collapse early during descent enables respiratory gas exchange to continue at greater depths, forcing nitrogen (N2) out of the alveolar space to dissolve in body tissues. This will increase risk of N2 narcosis and decompression stress. Clinical cases of stroke-like syndromes after single deep breath-hold dives point to possible mechanisms of decompression stress, caused by N2 entering the vasculature upon ascent from these deep dives. Mechanisms of neurological injury and inert gas narcosis during deep breath-hold dives are still incompletely understood. This review addresses possible hypotheses and elucidates factors that may contribute to pathophysiology of deep freediving accidents. Awareness of the unique challenges to pulmonary physiology at depth is paramount to assess medical risks of deep breath-hold diving.
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Affiliation(s)
- Kay Tetzlaff
- Department of Sports Medicine, University Hospital of Tübingen, Tübingen, Germany
| | - Frederic Lemaitre
- Faculte des Sciences du Sport et de l'Education Physique, Universite de Rouen, Rouen, France
| | - Christof Burgstahler
- Department of Sports Medicine, University Hospital of Tübingen, Tübingen, Germany
| | | | - Lars Eichhorn
- Department of Anesthesiology and Intensive Care Medicine, University Hospital Bonn, Bonn, Germany
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Physiology, pathophysiology and (mal)adaptations to chronic apnoeic training: a state-of-the-art review. Eur J Appl Physiol 2021; 121:1543-1566. [PMID: 33791844 PMCID: PMC8144079 DOI: 10.1007/s00421-021-04664-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 03/04/2021] [Indexed: 02/08/2023]
Abstract
Breath-hold diving is an activity that humans have engaged in since antiquity to forage for resources, provide sustenance and to support military campaigns. In modern times, breath-hold diving continues to gain popularity and recognition as both a competitive and recreational sport. The continued progression of world records is somewhat remarkable, particularly given the extreme hypoxaemic and hypercapnic conditions, and hydrostatic pressures these athletes endure. However, there is abundant literature to suggest a large inter-individual variation in the apnoeic capabilities that is thus far not fully understood. In this review, we explore developments in apnoea physiology and delineate the traits and mechanisms that potentially underpin this variation. In addition, we sought to highlight the physiological (mal)adaptations associated with consistent breath-hold training. Breath-hold divers (BHDs) are evidenced to exhibit a more pronounced diving-response than non-divers, while elite BHDs (EBHDs) also display beneficial adaptations in both blood and skeletal muscle. Importantly, these physiological characteristics are documented to be primarily influenced by training-induced stimuli. BHDs are exposed to unique physiological and environmental stressors, and as such possess an ability to withstand acute cerebrovascular and neuronal strains. Whether these characteristics are also a result of training-induced adaptations or genetic predisposition is less certain. Although the long-term effects of regular breath-hold diving activity are yet to be holistically established, preliminary evidence has posed considerations for cognitive, neurological, renal and bone health in BHDs. These areas should be explored further in longitudinal studies to more confidently ascertain the long-term health implications of extreme breath-holding activity.
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Tsukamoto H, Ishibashi A, Marley CJ, Shinohara Y, Ando S, Bailey DM, Hashimoto T, Ogoh S. Plasma brain-derived neurotrophic factor and dynamic cerebral autoregulation in acute response to glycemic control following breakfast in young men. Am J Physiol Regul Integr Comp Physiol 2021; 320:R69-R79. [PMID: 33112655 DOI: 10.1152/ajpregu.00059.2020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 10/20/2020] [Accepted: 10/20/2020] [Indexed: 11/22/2022]
Abstract
We examined the acute impact of both low- and high-glycemic index (GI) breakfasts on plasma brain-derived neurotrophic factor (BDNF) and dynamic cerebral autoregulation (dCA) compared with breakfast omission. Ten healthy men (age 24 ± 1 yr) performed three trials in a randomized crossover order; omission and Low-GI (GI = 40) and High-GI (GI = 71) breakfast conditions. Middle cerebral artery velocity (transcranial Doppler ultrasonography) and arterial pressure (finger photoplethysmography) were continuously measured for 5 min before and 120 min following breakfast consumption to determine dCA using transfer function analysis. After these measurements of dCA, venous blood samples for the assessment of plasma BDNF were obtained. Moreover, blood glucose was measured before breakfast and every 30 min thereafter. The area under the curve of 2 h postprandial blood glucose in the High-GI trial was higher than the Low-GI trial (P < 0.01). The GI of the breakfast did not affect BDNF. In addition, both very-low (VLF) and low-frequency (LF) transfer function phase or gains were not changed during the omission trial. In contrast, LF gain (High-GI P < 0.05) and normalized gain (Low-GI P < 0.05) were decreased by both GI trials, while a decrease in VLF phase was observed in only the High-GI trial (P < 0.05). These findings indicate that breakfast consumption augmented dCA in the LF range but High-GI breakfast attenuated cerebral blood flow regulation against slow change (i.e., the VLF range) in arterial pressure. Thus we propose that breakfast and glycemic control may be an important strategy to optimize cerebrovascular health.
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Affiliation(s)
- Hayato Tsukamoto
- Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, Pontypridd, United Kingdom
- Faculty of Sport and Health Science, Ritsumeikan University, Shiga, Japan
| | - Aya Ishibashi
- Japan Institute of Sports Science, Tokyo, Japan
- Department of Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Christopher J Marley
- Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, Pontypridd, United Kingdom
| | - Yasushi Shinohara
- Faculty of Sport and Health Science, Ritsumeikan University, Shiga, Japan
| | - Soichi Ando
- Graduate School of Informatics and Engineering, The University of Electro-Communications, Tokyo, Japan
| | - Damian M Bailey
- Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, Pontypridd, United Kingdom
| | - Takeshi Hashimoto
- Faculty of Sport and Health Science, Ritsumeikan University, Shiga, Japan
| | - Shigehiko Ogoh
- Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, Pontypridd, United Kingdom
- Department of Biomedical Engineering, Toyo University, Saitama, Japan
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10
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Moir ME, Klassen SA, Zamir M, Shoemaker JK. Rapid changes in vascular compliance contribute to cerebrovascular adjustments during transient reductions in blood pressure in young, healthy adults. J Appl Physiol (1985) 2020; 129:27-35. [PMID: 32463732 DOI: 10.1152/japplphysiol.00272.2020] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Characterization of dynamic cerebral autoregulation has focused primarily on adjustments in cerebrovascular resistance in response to blood pressure (BP) alterations. However, the role of vascular compliance in dynamic autoregulatory processes remains elusive. The present study examined changes in cerebrovascular compliance and resistance during standing-induced transient BP reductions in nine young, healthy adults (3 women). Brachial artery BP (Finometer) and middle cerebral artery blood velocity (BV; Multigon) waveforms were collected. Beginning 20 beats before standing and continuing 40 beats after standing, individual BP and BV waveforms of every second heartbeat were extracted and input into a four-element modified Windkessel model to calculate indexes of cerebrovascular resistance (Ri) and compliance (Ci). Standing elicited a transient reduction in mean BP of 20 ± 9 mmHg. In all participants, a large increase in Ci (165 ± 84%; P < 0.001 vs. seated baseline) occurred 2 ± 2 beats following standing. Reductions in Ri occurred 11 ± 3 beats after standing (Ci vs. Ri delay: P < 0.001). The increase in Ci contributed to maintained systolic BV before the decrease in Ri. The present results demonstrate rapid, large but transient increases in Ci that precede reductions in Ri, in response to standing-induced reductions in BP. Therefore, Ci represents a discreet component of cerebrovascular responses during acute decreases in BP and, consequently, dynamic autoregulation.NEW & NOTEWORTHY Historically, dynamic cerebral autoregulation has been characterized by adjustments in cerebrovascular resistance following systematic changes in blood pressure. However, with the use of Windkessel modeling approaches, this study revealed rapid and large increases in cerebrovascular compliance that preceded reductions in cerebrovascular resistance following standing-induced blood pressure reductions. Importantly, the rapid cerebrovascular compliance response contributed to preservation of systolic blood velocity during the transient hypotensive phase. These results broaden our understanding of dynamic cerebral autoregulation.
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Affiliation(s)
- M Erin Moir
- School of Kinesiology, University of Western Ontario, London, Ontario, Canada
| | - Stephen A Klassen
- School of Kinesiology, University of Western Ontario, London, Ontario, Canada
| | - Mair Zamir
- Department of Applied Mathematics, University of Western Ontario, London, Ontario, Canada.,Department of Medical Biophysics, University of Western Ontario, London, Ontario, Canada
| | - J Kevin Shoemaker
- School of Kinesiology, University of Western Ontario, London, Ontario, Canada.,Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario, Canada
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