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Liu R, Wang X, Hoshi S, Zhang Y. High-speed measurement of retinal arterial blood flow in the living human eye with adaptive optics ophthalmoscopy. OPTICS LETTERS 2023; 48:1994-1997. [PMID: 37058625 PMCID: PMC11185870 DOI: 10.1364/ol.480896] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Accepted: 03/06/2023] [Indexed: 06/19/2023]
Abstract
We present a technique to measure the rapid blood velocity in large retinal vessels with high spatiotemporal resolution. Red blood cell motion traces in the vessels were non-invasively imaged using an adaptive optics near-confocal scanning ophthalmoscope at a frame rate of 200 fps. We developed software to measure blood velocity automatically. We demonstrated the ability to measure the spatiotemporal profiles of the pulsatile blood flow with a maximum velocity of 95-156 mm/s in retinal arterioles with a diameter >100 µm. High-speed and high-resolution imaging increased the dynamic range, enhanced sensitivity, and improved the accuracy when studying retinal hemodynamics.
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Affiliation(s)
- Ruixue Liu
- Doheny Eye Institute, 150 N Orange Grove Blvd, Pasadena, CA 91103
| | - Xiaolin Wang
- Doheny Eye Institute, 150 N Orange Grove Blvd, Pasadena, CA 91103
| | - Sujin Hoshi
- Doheny Eye Institute, 150 N Orange Grove Blvd, Pasadena, CA 91103
- Department of Ophthalmology, University of California - Los Angeles, 100 Stein Plaza Driveway, Los Angeles, CA 90024
- Department of Ophthalmology, University of Tsukuba, Ibaraki, Japan
| | - Yuhua Zhang
- Doheny Eye Institute, 150 N Orange Grove Blvd, Pasadena, CA 91103
- Department of Ophthalmology, University of California - Los Angeles, 100 Stein Plaza Driveway, Los Angeles, CA 90024
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2
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Muskat JC, Rayz VL, Goergen CJ, Babbs CF. Hemodynamic modeling of the circle of Willis reveals unanticipated functions during cardiovascular stress. J Appl Physiol (1985) 2021; 131:1020-1034. [PMID: 34264126 DOI: 10.1152/japplphysiol.00198.2021] [Citation(s) in RCA: 1] [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
The circle of Willis (CW) allows blood to be redistributed throughout the brain during local ischemia; however, it is unlikely that the anatomic persistence of the CW across mammalian species is driven by natural selection of individuals with resistance to cerebrovascular disease typically occurring in elderly humans. To determine the effects of communicating arteries (CoAs) in the CW on cerebral pulse wave propagation and blood flow velocity, we simulated young, active adult humans undergoing different states of cardiovascular stress (i.e., fear and aerobic exercise) using discrete transmission line segments with stress-adjusted cardiac output, peripheral resistance, and arterial compliance. Phase delays between vertebrobasilar and carotid pulses allowed bidirectional shunting through CoAs: both posteroanterior shunting before the peak of the pulse waveform and anteroposterior shunting after internal carotid pressure exceeded posterior cerebral pressure. Relative to an absent CW without intact CoAs, the complete CW blunted anterior pulse waveforms, although limited to 3% and 6% reductions in peak pressure and pulse pressure, respectively. Systolic rate of change in pressure (i.e., ∂P/∂t) was reduced 15%-24% in the anterior vasculature and increased 23%-41% in the posterior vasculature. Bidirectional shunting through posterior CoAs was amplified during cardiovascular stress and increased peak velocity by 25%, diastolic-to-systolic velocity range by 44%, and blood velocity acceleration by 134% in the vertebrobasilar arteries. This effect may facilitate stress-related increases in blood flow to the cerebellum (improving motor coordination) and reticular-activating system (enhancing attention and focus) via a nitric oxide-dependent mechanism, thereby improving survival in fight-or-flight situations.NEW & NOTEWORTHY Hemodynamic modeling reveals potential evolutionary benefits of the intact circle of Willis (CW) during fear and aerobic exercise. The CW equalizes pulse waveforms due to bidirectional shunting of blood flow through communicating arteries, which boosts vertebrobasilar blood flow velocity and acceleration. These phenomena may enhance perfusion of the brainstem and cerebellum via nitric oxide-mediated vasodilation, improving performance of the reticular-activating system and motor coordination in survival situations.
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Affiliation(s)
- J C Muskat
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana
| | - V L Rayz
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana.,School of Mechanical Engineering, Purdue University, West Lafayette, Indiana
| | - C J Goergen
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana
| | - C F Babbs
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana
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3
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Elmetwally MA, Samy A, Eldesouky A, Lenis YY, Eldomany W. Uterine blood flow, fetal heart rate, gestational length, and fetal birth weight variability in response to maternal temperament in the goat. Anim Sci J 2021; 92:e13563. [PMID: 34013649 DOI: 10.1111/asj.13563] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 02/22/2021] [Accepted: 03/23/2021] [Indexed: 11/26/2022]
Abstract
This prospective study was designed to investigate the effects of maternal temperament on uterine blood flow, fetal heart rate, gestational length, and fetal birth weight in a goat experimental model. Based on the arena test, behavioral testing related to fear-eliciting stimulus, goats were divided into nervous (n = 13) and calm (n = 11) groups. After mating, the perfusion of maternal uterine arteries (UTAs) and its related Doppler parameters, blood flow volume (BFV), time-averaged mean velocity (TAMEANV), acceleration (Acce), and resistance impedance (S/D), were evaluated biweekly from week two until the end of pregnancy. Fetal heart rate (FHR) was investigated during the pregnancy in addition to the gestation length (GL) and fetal birth weight (FBW). The UTA-BFV and TAMEANV, as well as Acce and S/D, were influenced by maternal temperament (p < .05). The FHR showed no significant changes between experimental animals of different temperaments (p = .81). Both GL and FBW were increased in calm rather than nervous goats (p < .05). These results indicated that the maternal nervous (temperament) have negative impacts on uterine artery Doppler indices, fetal growth, and gestational length in a goat experimental model.
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Affiliation(s)
- Mohammed A Elmetwally
- Department of Theriogenology, Mansoura University, Mansoura, Egypt.,Institute of Reproductive Biology, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Alaa Samy
- Department of Surgery, Anesthesiology and Radiology, Faculty of Veterinary Medicine, Mansoura University, Mansoura, Egypt
| | - Ashraf Eldesouky
- Department of Theriogenology, Mansoura University, Mansoura, Egypt
| | - Yasser Y Lenis
- Division of Animal Science, University of Missouri, Columbia, Missouri, USA.,OHVRI, Health and Veterinary Innovative Research and Development, School of Veterinary Medicine, Faculty of Agrarian Science, Antioquia University, Medellín, Colombia.,Departamento de Ciencia Animal, Facultad de Ciencias Agropecuarias, Universidad Nacional de Colombia, Palmira, Colombia
| | - Wael Eldomany
- Department of Theriogenology, Mansoura University, Mansoura, Egypt
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Stoner L, Stone K, Zieff G, Blackwell J, Diana J, Credeur DP, Paterson C, Fryer S. Endothelium function dependence of acute changes in pulse wave velocity and flow-mediated slowing. Vasc Med 2020; 25:419-426. [PMID: 32490736 PMCID: PMC7575299 DOI: 10.1177/1358863x20926588] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Flow-mediated slowing (FMS), defined as the minimum pulse wave velocity (PWVmin) during reactive hyperemia, is potentially a simple, user-objective test for examining endothelial function. The purpose of the current study was to determine the effects of a known endothelial dysfunction protocol on arm PWV and PWVmin. Complete data were successfully collected in 22 out of 23 healthy adults (23.8 years [SD 4.1], 16 F, 22.8 kg/m2 [SD 2.8]). Local endothelial dysfunction was induced by increasing retrograde shear stress in the upper arm, through inflation of a distal (forearm) tourniquet to 75 mmHg, for 30 min. Pre- and post-endothelial dysfunction, PWV was measured followed by simultaneous assessment of PWVmin and flow-mediated dilation (FMD). PWV was measured between the upper arm and wrist using an oscillometric device, and brachial FMD using ultrasound. FMD (%) and PWVmin (m/s) were calculated as the maximum increase in diameter and minimum PWV during reactive hyperemia, respectively. Endothelial dysfunction resulted in a large effect size (ES) decrease in FMD (∆ = -3.10%; 95% CI: -4.15, -2.05; ES = -1.3), and a moderate increase in PWV (∆ = 0.38 m/s; 95% CI: 0.07, 0.69; ES = 0.5) and PWVmin (∆ = 0.16 m/s; 95% CI: 0.05, 0.28; ES = 0.6). There was a large intra-individual (pre- vs post-endothelial dysfunction) association between FMD and PWVmin (r = -0.61; 95% CI: -0.82, -0.24). In conclusion, acute change in PWV and PWVmin are at least partially driven by changes in endothelial function.
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Affiliation(s)
- Lee Stoner
- Department of Exercise and Sport Science, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Keeron Stone
- School of Sport and Exercise, University of Gloucestershire, Gloucester, UK
| | - Gabriel Zieff
- Department of Exercise and Sport Science, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Jade Blackwell
- Department of Exercise and Sport Science, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Jake Diana
- Department of Exercise and Sport Science, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Daniel P Credeur
- School of Kinesiology and Nutrition, University of Southern Mississippi, Hattiesburg, MS, USA
| | - Craig Paterson
- School of Sport and Exercise, University of Gloucestershire, Gloucester, UK
| | - Simon Fryer
- School of Sport and Exercise, University of Gloucestershire, Gloucester, UK
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5
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Pappelis K, Choritz L, Jansonius NM. Microcirculatory model predicts blood flow and autoregulation range in the human retina: in vivo investigation with laser speckle flowgraphy. Am J Physiol Heart Circ Physiol 2020; 319:H1253-H1273. [PMID: 32986964 DOI: 10.1152/ajpheart.00404.2020] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
In this study, we mathematically predict retinal vascular resistance (RVR) and retinal blood flow (RBF), we test predictions using laser speckle flowgraphy (LSFG), we estimate the range of vascular autoregulation, and we examine the relationship of RBF with the retinal nerve fiber layer (RNFL) and ganglion cell complex (GCC). Fundus, optical coherence tomography (OCT), and OCT-angiography images, systolic/diastolic blood pressure (SBP/DBP), and intraocular pressure (IOP) measurements were obtained from 36 human subjects. We modeled two circulation markers (RVR and RBF) and estimated individualized lower/higher autoregulation limits (LARL/HARL), using retinal vessel calibers, fractal dimension, perfusion pressure, and population-based hematocrit values. Quantitative LSFG waveforms were extracted from vessels of the same eyes, before and during IOP elevation. LSFG metrics explained most variance in RVR (R2 = 0.77/P = 6.9·10-9) and RBF (R2 = 0.65/P = 1.0·10-6), suggesting that the markers strongly reflect blood flow physiology. Higher RBF was associated with thicker RNFL (P = 4.0·10-4) and GCC (P = 0.003), thus also verifying agreement with structural measurements. LARL was at SBP/DBP of 105/65 mmHg for the average subject without arterial hypertension and at 115/75 mmHg for the average hypertensive subject. Moreover, during IOP elevation, changes in RBF were more pronounced than changes in RVR. These observations physiologically imply that healthy subjects are already close to LARL, thus prone to hypoperfusion. In conclusion, we modeled two clinical markers and described a novel method to predict individualized autoregulation limits. These findings could improve understanding of retinal perfusion and pave the way for personalized intervention decisions, when treating patients with coexisting ophthalmic and cardiovascular pathologies.NEW & NOTEWORTHY We describe and test a new approach to quantify retinal blood flow, based on standard clinical examinations and imaging techniques, linked together with a physiological model. We use these findings to generate individualized estimates of the autoregulation range. We provide evidence that healthy subjects are closer to the lower autoregulation limit than thought before. This suggests that some retinas are less prepared to withstand hypoperfusion, even after small intraocular pressure rises or blood pressure drops.
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Affiliation(s)
- Konstantinos Pappelis
- Department of Ophthalmology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.,Research School of Behavioural and Cognitive Neurosciences, Graduate School of Medical Sciences, University of Groningen, Groningen, The Netherlands
| | - Lars Choritz
- University Eye Clinic, Otto von Guericke University Magdeburg, Magdeburg, Germany
| | - Nomdo M Jansonius
- Department of Ophthalmology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.,Research School of Behavioural and Cognitive Neurosciences, Graduate School of Medical Sciences, University of Groningen, Groningen, The Netherlands
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6
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Impact of catheterization on shear-mediated arterial dilation in healthy young men. Eur J Appl Physiol 2020; 120:2525-2532. [PMID: 32857185 PMCID: PMC7557491 DOI: 10.1007/s00421-020-04473-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 08/10/2020] [Indexed: 01/24/2023]
Abstract
Purpose Animal studies have shown that endothelial denudation abolishes vasodilation in response to increased shear stress. Interestingly, shear-mediated dilation has been reported to be reduced, but not abolished, in coronary artery disease (CAD) patients following catheterization. However, it is not known whether this resulted from a priori endothelial dysfunction in this diseased population. In this study, we evaluated shear-mediated dilation following catheterization in healthy young men. Methods Twenty-six (age: 24.4 ± 3.8 years, BMI: 24.3 ± 2.8 kg m−2, VO2peak: 50.5 ± 8.8 ml/kg/min) healthy males underwent unilateral transradial catheterization. Shear-mediated dilation of both radial arteries was measured using flow-mediated dilation (FMD) pre-, and 7 days post-catheterization. Results FMD was reduced in the catheterized arm [9.3 ± 4.1% to 4.3 ± 4.1% (P < 0.001)] post-catheterization, whereas no change was observed in the control arm [8.4 ± 3.8% to 7.3 ± 3.8% (P = 0.168)]. FMD was completely abolished in the catheterized arm in five participants. Baseline diameter (P = 0.001) and peak diameter during FMD (P = 0.035) were increased in the catheterized arm 7 days post-catheterization (baseline: 2.3 ± 0.3 to 2.6 ± 0.2 mm, P < 0.001, peak: 2.5 ± 0.3 to 2.7 ± 0.3 mm, P = 0.001), with no change in the control arm (baseline: 2.3 ± 0.3 to 2.3 ± 0.3 mm, P = 0.288, peak: 2.5 ± 0.3 to 2.5 ± 0.3 mm, P = 0.608). Conclusion This is the first study in young healthy individuals with intact a priori endothelial function to provide evidence of impaired shear-mediated dilation following catheterization. When combined with earlier studies in CAD patients, our data suggest the catheterization impairs artery function in humans.
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Meza D, Musmacker B, Steadman E, Stransky T, Rubenstein DA, Yin W. Endothelial Cell Biomechanical Responses are Dependent on Both Fluid Shear Stress and Tensile Strain. Cell Mol Bioeng 2019; 12:311-325. [PMID: 31719917 DOI: 10.1007/s12195-019-00585-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 06/28/2019] [Indexed: 12/15/2022] Open
Abstract
Introduction The goal of this study was to investigate how concurrent shear stress and tensile strain affect endothelial cell biomechanical responses. Methods Human coronary artery endothelial cells were exposed to concurrent pulsatile shear stress and cyclic tensile strain in a programmable shearing and stretching device. Three shear stress-tensile strain conditions were used: (1) pulsatile shear stress at 1 Pa and cyclic tensile strain at 7%, simulating normal stress/strain conditions in a healthy coronary artery; (2) shear stress at 3.7 Pa and tensile strain at 3%, simulating pathological stress/strain conditions near a stenosis; (3) shear stress at 0.7 Pa and tensile strain at 5%, simulating pathological stress/strain conditions in a recirculation zone. Cell morphology was quantified using immunofluorescence microscopy. Cell surface PECAM-1 phosphorylation, ICAM-1 expression, ERK1/2 and NF-κB activation were measured using ELISA or Western blot. Results Simultaneous stimulation from pulsatile shear stress and cyclic tensile strain induced a significant increase in cell area, compared to that induced by shear stress or tensile strain alone. The combined stimulation caused significant increases in PECAM-1 phosphorylation. The combined stimulation also significantly enhanced EC surface ICAM-1 expression (compared to that under shear stress alone) and transcriptional factor NF-κB activation (compared to that under control conditions). Conclusion Pulsatile shear stress and cyclic tensile strain could induce increased but not synergistic effect on endothelial cell morphology or activation. The combined mechanical stimulation can be relayed from cell membrane to nucleus. Therefore, to better understand how mechanical conditions affect endothelial cell mechanotransduction and cardiovascular disease development, both shear stress and tensile strain need to be considered.
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Affiliation(s)
- Daphne Meza
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794 USA
| | - Bryan Musmacker
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794 USA
| | - Elisabeth Steadman
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794 USA
| | - Thomas Stransky
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794 USA
| | - David A Rubenstein
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794 USA
| | - Wei Yin
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794 USA
- Stony Brook University, Bioengineering Building, Room 109, Stony Brook, NY 11794 USA
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Stoner L, Stone K, Zieff G, Hanson ED, Credeur D, Faulkner J, Kucharska-Newton A, Fryer S. The impact of upper-limb position on estimated central blood pressure waveforms. J Hum Hypertens 2019; 33:444-453. [PMID: 30804459 DOI: 10.1038/s41371-019-0179-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Revised: 01/25/2019] [Accepted: 02/08/2019] [Indexed: 11/09/2022]
Abstract
Pulse wave analysis (PWA) utilizes arm blood pressure (BP) waveforms to estimate aortic waveforms. The accuracy of central BP waveform estimation may be influenced by assessment site local haemodynamics. This study investigated whether local haemodynamic changes, induced via arm tilting ±30° relative to heart level, affect estimated central systolic BP (cSBP) and arterial wave reflection (central augmentation index, cAIx; aortic backward pressure wave, Pb). In 20 healthy adults (26.7 years [SD 5.2], 10 F) brachial BP waveforms were simultaneously recorded on experimental and control arms. The experimental arm was randomly repositioned three times (heart level, -30° heart level, +30° heart level), while the control arm remained fixed at heart level. For the experimental arm, arm repositioning resulted in a large (partial eta-squared > 0.14) effect size (ES) change in SBP (ES = 0.75, P < 0.001), cSBP (ES = 0.81, P < 0.001), and cAIx (ES = 0.75, P = 0.002), but not Pb (ES = 0.06, P = 0.38). In the control arm, cAIx (ES = 0.22, P = 0.013) but not SBP or cSBP significantly changed. Change in experimental arm cSBP was partially explained by brachial systolic blood velocity (P = 0.026) and mean diameter (P = 0.012), while change in cAIx was associated with brachial retrograde blood velocity (P = 0.020) and beta stiffness (P = 0.038). In conclusion, manipulation of assessment site local haemodynamics, including the blood velocity profile and local arterial stiffness, had a large effect on estimated cSBP and cAIx, but not on Pb. These findings do not invalidate PWA devices but do suggest that the accuracy of the estimated aortic pressure waveform is dependent on stable peripheral haemodynamics.
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Affiliation(s)
- Lee Stoner
- Department of Exercise and Sport Science, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.
| | - Keeron Stone
- School of Sport and Exercise, University of Gloucestershire, Gloucester, UK
| | - Gabriel Zieff
- Department of Exercise and Sport Science, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - EriK D Hanson
- Department of Exercise and Sport Science, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Daniel Credeur
- School of Kinesiology, University of Southern Mississippi, Hattiesburg, MS, USA
| | - James Faulkner
- Department of Sport & Exercise, University of Winchester, Winchester, UK
| | - Anna Kucharska-Newton
- Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Simon Fryer
- School of Sport and Exercise, University of Gloucestershire, Gloucester, UK
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Siegel SR, Fryer SM. Rock Climbing for Promoting Physical Activity in Youth. Am J Lifestyle Med 2017; 11:243-251. [PMID: 30202339 PMCID: PMC6125082 DOI: 10.1177/1559827615592345] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Revised: 05/13/2015] [Accepted: 06/01/2015] [Indexed: 11/16/2022] Open
Abstract
Prevalence of overweight and obesity in youth has steadily increased over the last decade, although it appears to have currently stabilized. Physical inactivity is a major contributor to this obesity epidemic, and more than half of American youth do not meet physical activity recommendations. Rock climbing and bouldering require both aerobic and anaerobic fitness, with the metabolic cost comparable to moderate to vigorous physical activity in adults. Minimal data on youth climbers exist, yet climbing is extremely popular with youth, and thus the sport may be a viable option for decreasing the prevalence of obesity. Available data show that rock climbing can provide youth with muscular strength and endurance building exercise, and possibly improve flexibility. In addition, rock climbing has the potential to provide youth with moderate levels of physical activity according to recommended guidelines. Nine peer reviewed articles are included in this review, as these are the articles specifically associated with youth climbing and health-related fitness. Due to limited research in this area, no articles were excluded if they were related to health-related fitness and youth and rock climbing/bouldering. This review aims to systematically address the impact of rock climbing and bouldering on health-related fitness in youth.
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Affiliation(s)
- Shannon R. Siegel
- Shannon R. Siegel, PhD, Department of Kinesiology, University of San Francisco, 2130 Fulton Street, San Francisco, CA 94117; e-mail:
| | - Simon M. Fryer
- Department of Kinesiology, University of San Francisco, San Francisco, CA (SRS)
- University of Gloucestershire, Gloucester, United Kingdom (SMF)
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Mitranun W, Deerochanawong C, Tanaka H, Suksom D. Continuous vs interval training on glycemic control and macro- and microvascular reactivity in type 2 diabetic patients. Scand J Med Sci Sports 2013; 24:e69-76. [DOI: 10.1111/sms.12112] [Citation(s) in RCA: 184] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/26/2013] [Indexed: 12/29/2022]
Affiliation(s)
- W. Mitranun
- Faculty of Sports Science; Chulalongkorn University; Bangkok Thailand
| | - C. Deerochanawong
- Rajvithi Hospital; Bangkok Thailand
- Rangsit Medical School; Bangkok Thailand
| | - H. Tanaka
- Department of Kinesiology and Health Education; The University of Texas at Austin; Austin Texas USA
| | - D. Suksom
- Faculty of Sports Science; Chulalongkorn University; Bangkok Thailand
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Tarro Genta F, Eleuteri E, Temporelli PL, Comazzi F, Tidu M, Bouslenko Z, Bertolin F, Vigorito C, Giannuzzi P, Giallauria F. Flow-mediated dilation normalization predicts outcome in chronic heart failure patients. J Card Fail 2013; 19:260-7. [PMID: 23582092 DOI: 10.1016/j.cardfail.2013.01.014] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2012] [Revised: 01/28/2013] [Accepted: 01/29/2013] [Indexed: 11/18/2022]
Abstract
BACKGROUND Reduced flow-mediated dilation (FMD) is a known prognostic marker in heart failure (HF), but may be influenced by the brachial artery (BA) diameter. Aiming to adjust for this influence, we normalized FMD (nFMD) by the peak shear rate (PSR) and tested its prognostic power in HF patients. METHODS AND RESULTS BA diameter, FMD, difference in hyperemic versus rest brachial flow velocity (FVD), PSR (FVD/BA), and nFMD (FMD/PSR × 1000) were assessed in 71 HF patients. At follow-up (mean 512 days), 19 HF (27%) reached the combined endpoint (4 heart transplantations [HTs], 1 left ventricle assist device implantation [LVAD], and 14 cardiac deaths [CDs]). With multivariate Cox regression analysis, New York Heart Association functional class ≥III (hazard ratio [HR] 9.36, 95% confidence interval [CI] 2.11-41.4; P = .003), digoxin use (HR 6.36, 95% CI 2.18-18.6; P = .0010), FMD (HR 0.703, 95% CI 0.547-0.904; P = .006), PSR (HR 1.01, 95% CI 1.005-1.022; P = .001), FVD (HR 1.04, 95% CI 1.00-1.06; P = .02), and nFMD (HR 0.535, 95% CI 0.39-0.74; P = .0001) were predictors of unfavorable outcome. Receiver operating characteristic curve for nFMD showed that patients with nFMD >5 seconds had significantly better event-free survival than patients with nFMD ≤5 seconds (log-rank test: P < .0001). CONCLUSIONS nFMD is a strong independent predictor of CD, HT, and LVAD in HF with left ventricular ejection fraction <40%. Patients with nFMD >5 seconds have a better prognosis than those with lower values.
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Affiliation(s)
- Franco Tarro Genta
- Division of Cardiology, Fondazione Salvatore Maugeri, Istituto di Ricovero e Cura a Carattere Scientifico, Turin, Italy.
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