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Flowmotion imaging analysis of spatiotemporal variations in skin microcirculatory perfusion. Microvasc Res 2023; 146:104456. [PMID: 36403668 DOI: 10.1016/j.mvr.2022.104456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 11/02/2022] [Accepted: 11/12/2022] [Indexed: 11/19/2022]
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Non-Invasive Assessment of Vascular Circulation Based on Flow Mediated Skin Fluorescence (FMSF). BIOLOGY 2023; 12:biology12030385. [PMID: 36979077 PMCID: PMC10044925 DOI: 10.3390/biology12030385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 02/24/2023] [Accepted: 02/25/2023] [Indexed: 03/02/2023]
Abstract
Flow Mediated Skin Fluorescence (FMSF) is a new non-invasive method for assessing vascular circulation and/or metabolic regulation. It enables assessment of both vasoconstriction and vasodilation. The method measures stimulation of the circulation in response to post-occlusive reactive hyperemia (PORH). It analyzes the dynamical changes in the emission of NADH fluorescence from skin tissue, providing the information on mitochondrial metabolic status and intracellular oxygen delivery through the circulatory system. Assessment of the vascular state using the FMSF technique is based on three parameters: reactive hyperemia response (RHR), hypoxia sensitivity (HS), and normoxia oscillatory index (NOI). The RHR and HS parameters determine the risk of vascular circulatory disorders and are the main diagnostic parameters. The NOI parameter is an auxiliary parameter for evaluating the state of microcirculation under stress of various origins (e.g., emotional stress, physical exhaustion, or post-infection stress). The clinical data show that the risk of vascular complications is limited among people whose RHR, log(HS), and NOI parameters are not significantly below the mean values determined by the FMSF technique, especially if they simultaneously meet the conditions RHR > 30% and log(HS) > 1.5 (HS > 30), and NOI > 60%.
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Rodrigues FTM, Ferreira APDL, Alves KFP, Marques TV, de Lima DF, de Lucena LC, Campos SL, Leite WS, Guerra RO, Rapin A, de Araújo MDGR, Taiar R. Whole-Body Vibration Associated with Strength Training on the Lower-Limb Blood Flow and Mobility in Older Adults with Type 2 Diabetes: A Study Protocol for a Randomized Controlled Trial. Diagnostics (Basel) 2022; 12:diagnostics12071550. [PMID: 35885456 PMCID: PMC9316832 DOI: 10.3390/diagnostics12071550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 06/18/2022] [Accepted: 06/22/2022] [Indexed: 11/16/2022] Open
Abstract
Vascular endothelium insults caused by high serum glucose levels affect the oxygen supply to tissues, via the microvascular endothelium, resulting in an increased perfusion heterogeneity. These insults may lead to the underuse of blood capillaries, while other vessels are overused and effectively overload their oxygen supply capacity, which eventually causes damages to distal parts of the peripheral nervous system. Therefore, the proprioceptive and exteroceptive feedback information will be gradually lost and contribute to a mobility reduction. This study aims to assess the efficacy of whole-body vibration (WBV) associated with strength training (ST) on lower-limb blood flow and mobility in older adults with type 2 diabetes (DM2). Methods and analyses: This is a protocol (1st version) for Pa single-blind, randomized, controlled clinical trial guided by the SPIRIT guidelines. Our sample will consist of 51 older adults with DM2 randomly allocated to three groups: low frequency WBV (16−26 Hz) associated to ST (G1), WBV sham (G2) and nonintervention control (G3). The study protocol is set for a 12-week (three times per week) schedule. Primary outcomes: skin temperature using infrared thermographic imaging (ITI); mean peripheral arterial blood flow velocity (MBF) by a handheld Doppler ultrasound (DU), and functional mobility by Timed Up and Go (TUG) test. Secondary outcomes: quasi-static posture using the DX100 BTS Smart optoelectronic system, and plantar pressure and body balance using the MPS stabilometric platform. Data will be collected and analyzed at baseline and post-intervention, considering p-value < 0.05 level of significance. The analyses will also be conducted with an intention-to-treat method and effect size. Dissemination: All results will be published in peer-reviewed journals as well as presented in conferences.
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Affiliation(s)
- François Talles Medeiros Rodrigues
- Laboratório de Cinesioterapia e Recursos Terapêuticos Manuais (LACIRTEM), Departamento de Fisioterapia, Universidade Federal de Pernambuco (UFPE), Recife 50670-901, PE, Brazil; (F.T.M.R.); (A.P.d.L.F.); (K.F.P.A.); (T.V.M.); (D.F.d.L.); (M.d.G.R.d.A.)
| | - Ana Paula de Lima Ferreira
- Laboratório de Cinesioterapia e Recursos Terapêuticos Manuais (LACIRTEM), Departamento de Fisioterapia, Universidade Federal de Pernambuco (UFPE), Recife 50670-901, PE, Brazil; (F.T.M.R.); (A.P.d.L.F.); (K.F.P.A.); (T.V.M.); (D.F.d.L.); (M.d.G.R.d.A.)
| | - Kennedy Freitas Pereira Alves
- Laboratório de Cinesioterapia e Recursos Terapêuticos Manuais (LACIRTEM), Departamento de Fisioterapia, Universidade Federal de Pernambuco (UFPE), Recife 50670-901, PE, Brazil; (F.T.M.R.); (A.P.d.L.F.); (K.F.P.A.); (T.V.M.); (D.F.d.L.); (M.d.G.R.d.A.)
| | - Thais Vitorino Marques
- Laboratório de Cinesioterapia e Recursos Terapêuticos Manuais (LACIRTEM), Departamento de Fisioterapia, Universidade Federal de Pernambuco (UFPE), Recife 50670-901, PE, Brazil; (F.T.M.R.); (A.P.d.L.F.); (K.F.P.A.); (T.V.M.); (D.F.d.L.); (M.d.G.R.d.A.)
| | - Daniel Florentino de Lima
- Laboratório de Cinesioterapia e Recursos Terapêuticos Manuais (LACIRTEM), Departamento de Fisioterapia, Universidade Federal de Pernambuco (UFPE), Recife 50670-901, PE, Brazil; (F.T.M.R.); (A.P.d.L.F.); (K.F.P.A.); (T.V.M.); (D.F.d.L.); (M.d.G.R.d.A.)
| | | | - Shirley Lima Campos
- Laboratório Multiusuário de Inovação Instrumental e Desempenho Físico-Funcional (LInDEF), Departamento de Fisioterapia, Universidade Federal de Pernambuco (UFPE), Recife 50670-901, PE, Brazil; (S.L.C.); (W.S.L.)
| | - Wagner Souza Leite
- Laboratório Multiusuário de Inovação Instrumental e Desempenho Físico-Funcional (LInDEF), Departamento de Fisioterapia, Universidade Federal de Pernambuco (UFPE), Recife 50670-901, PE, Brazil; (S.L.C.); (W.S.L.)
| | - Ricardo Oliveira Guerra
- Grupo de Estudos em Epidemiologia e Fisioterapia Geriátrica (GEFEG), Departamento de Fisioterapia, Universidade Federal do Rio Grande do Norte (UFRN), Natal 59078-970, RN, Brazil;
| | - Amandine Rapin
- Faculté de Médecine, Université de Reims Champagne Ardennes, UR 3797 VieFra, 51097 Reims, France;
| | - Maria das Graças Rodrigues de Araújo
- Laboratório de Cinesioterapia e Recursos Terapêuticos Manuais (LACIRTEM), Departamento de Fisioterapia, Universidade Federal de Pernambuco (UFPE), Recife 50670-901, PE, Brazil; (F.T.M.R.); (A.P.d.L.F.); (K.F.P.A.); (T.V.M.); (D.F.d.L.); (M.d.G.R.d.A.)
| | - Redha Taiar
- MATériaux et Ingénierie Mécanique (MATIM), Université de Reims Champagne Ardenne, 51100 Reims, France
- Correspondence:
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Mayrovitz HN, Maqsood R, Tawakalzada AS. Do Magnetic Fields Have a Place in Treating Vascular Complications in Diabetes? Cureus 2022; 14:e24883. [PMID: 35698680 PMCID: PMC9184174 DOI: 10.7759/cureus.24883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 05/09/2022] [Indexed: 11/18/2022] Open
Abstract
The use of electromagnetic field therapy (EMFT) is a non-invasive, potential alternative or complementary choice in the treatment of wounds, chronic pain, neuropathy, and other medical conditions, including tissue repair and cell proliferation. Static magnetic fields (SMFs) have been reported to increase microcirculatory blood flow by mediating vasodilation via nitric oxide. Studies report that SMF exposure causes homeostatic, normalizing effects on the vascular tone that may have beneficial effects in situations where tissue perfusion is limited, such as may be present in diabetes. Pulsed electromagnetic fields (PEMFs) have also shown promise in treating diabetic wounds by improving wound healing rates and other attributes. Our purpose was to critically review prior applications of EMFT for relevancy and effectiveness in treating diabetic complications. The goal was to provide information to allow for informed decisions on the possible use of these modalities in the treatment of persons with diabetic complications. The focus was on the following major areas: wound healing, neuropathy, blood glucose control, blood flow, inflammation and oxidative stress.
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Okur Güney ZE, Cardone D, Sattel H, Ariens S, Witthöft M, Merla A, Kuppens P, Henningsen P. Interpersonal Emotion Dynamics in Couples With Somatic Symptom Disorder: Dyadic Coherence in Facial Temperature During Emotional Interactions. Psychosom Med 2022; 84:188-198. [PMID: 34654022 DOI: 10.1097/psy.0000000000001032] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE Disturbances in emotional processes are commonly reported in patients with a somatic symptom disorder (SSD). Although emotions usually occur in social interactions, little is known about interpersonal emotion dynamics of SSD patients during their actual emotional encounters. This study examined physiological coherence (linkage) between SSD patients and their partners, and in healthy couples during their emotional interactions. Secondarily, we explored group-level relationships between participants' and their partners' subjective affect. METHODS Twenty-nine romantic couples (16 healthy and 13 SSD patient-couples) underwent a dyadic conversation task with neutral and anger-eliciting topics followed by a guided relaxation. Partners' cutaneous facial temperature was recorded simultaneously by functional infrared thermal imaging. Immediately after each condition, participants reported on their pain intensity, self-affect, and perceived partner-affect. RESULTS Emotional conditions and having a partner with an SSD significantly affected coherence amplitude on the forehead (F(2,54) = 4.95, p = .011) and nose tip temperature (F(2,54) = 3.75, p = .030). From baseline to anger condition, coherence amplitude significantly increased in the patient-couples, whereas it decreased in the healthy couples. Correlation changes between partners' subjective affect comparably accompanied the changes in physiological coherence in healthy and patient-couples. CONCLUSIONS Inability to reduce emotional interdependence in sympathetic activity and subjective affect during a mutual conflict observed in SSD patient-couples seems to capture emotion co-dysregulation. Interventions should frame patients' emotional experiences as embodied and social. Functional infrared thermal imaging confirms to be an ecological and reliable method for examining autonomic changes in interpersonal contexts.Registration Page: https://osf.io/8eyjr.
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Affiliation(s)
- Zeynep Emine Okur Güney
- From the Department of Clinical Psychology, Psychotherapy and Experimental Psychopathology (Okur Güney, Witthöft), Johannes Gutenberg University of Mainz, Mainz; Department of Psychosomatic Medicine and Psychotherapy (Okur Güney, Sattel, Henningsen), Technical University of Munich, Munich, Germany; Department of Neurosciences, Imaging and Clinical Sciences (Cardone, Merla), University G. d'Annunzio of Chieti-Pescara, Pescara, Italy; and Faculty of Psychology and Educational Sciences, Quantitative Psychology and Individual Differences (Ariens, Kuppens), KU Leuven, Leuven, Belgium
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Diagnostic capabilities of different methods of laser doppler flowmetry spectral indexes assessment in patients with diabetic microangiopathy. BIOMEDICAL PHOTONICS 2021. [DOI: 10.24931/2413-9432-2021-10-2-18-24] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The article contains the results of a study of two different methods for calculating the spectral parameters of laser Doppler flowmetry in patients with diabetic microangiopathy caused by type 2 diabetes mellitus (main group) and those with excluded diabetes mellitus (control group). Spectral indices were calculated using either average or maximum amplitudes of the frequency ranges. When comparing the contribution of respiratory and pulse fluxmotions using average amplitudes, there were significant (p < 0.05) differences between the main and control groups. On the contrary, when using the maximum amplitudes, no significant differences were noted (p > 0.05). Also, significant correlations were found between the contributions of respiratory and pulse fluxmotions and the estimated glomerular filtration rate in the main group, using both calculation methods. These studies indicate the feasibility of using a technique based on the analysis of average amplitudes to increase the specificity of laser Doppler flowmetry as a method for diagnosing diabetic microangiopathy.
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Stanisic D, Jeremic N, Majumder S, Pushpakumar S, George A, Singh M, Tyagi SC. High Fat Diet Dysbiotic Mechanism of Decreased Gingival Blood Flow. Front Physiol 2021; 12:625780. [PMID: 33746772 PMCID: PMC7965981 DOI: 10.3389/fphys.2021.625780] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 02/09/2021] [Indexed: 01/14/2023] Open
Abstract
The gut microbiome has a very important role in human health and its influence on the development of numerous diseases is well known. In this study, we investigated the effect of high fat diet (HFD) on the onset of dysbiosis, gingival blood flow decreases, and the periodontal matrix remodeling. We established a dysbiosis model (HFD group) and probiotic model by Lactobacillus rhamnosus GG (LGG) treatment for 12weeks. Fecal samples were collected 24h before mice sacrificing, while short chain fatty acids (SCFA) analysis, DNA extraction, and sequencing for metagenomic analysis were performed afterwards. After sacrificing the animals, we collected periodontal tissues and conducted comprehensive morphological and genetic analyses. While HFD reduced Bacteroidetes, SCFA, and gingival blood flow, this type of diet increased Firmicutes, lipopolysaccharide (LPS) binding protein, TLR4, pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6), matrix metalloproteinases (MMP-2 and MMP-9) expression, and also altered markers of bone resorption (OPG and RANKL). However, LGG treatment mitigated these effects. Thus, it was observed that HFD increased molecular remodeling via inflammation, matrix degradation, and functional remodeling and consequently cause reduced gingival blood flow. All of these changes may lead to the alveolar bone loss and the development of periodontal disease.
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Affiliation(s)
- Dragana Stanisic
- Department of Dentistry, Faculty of Medical Sciences, University of Kragujevac, Kragujevac, Serbia
- Department of Physiology, School of Medicine, University of Louisville, Louisville, KY, United States
| | - Nevena Jeremic
- Department of Physiology, School of Medicine, University of Louisville, Louisville, KY, United States
- Department of Pharmacy, Faculty of Medical Sciences, University of Kragujevac, Kragujevac, Serbia
| | - Suravi Majumder
- Department of Physiology, School of Medicine, University of Louisville, Louisville, KY, United States
| | - Sathnur Pushpakumar
- Department of Physiology, School of Medicine, University of Louisville, Louisville, KY, United States
| | - Akash George
- Department of Physiology, School of Medicine, University of Louisville, Louisville, KY, United States
| | - Mahavir Singh
- Department of Physiology, School of Medicine, University of Louisville, Louisville, KY, United States
| | - Suresh C. Tyagi
- Department of Physiology, School of Medicine, University of Louisville, Louisville, KY, United States
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Clough GF, Chipperfield AJ, Thanaj M, Scorletti E, Calder PC, Byrne CD. Dysregulated Neurovascular Control Underlies Declining Microvascular Functionality in People With Non-alcoholic Fatty Liver Disease (NAFLD) at Risk of Liver Fibrosis. Front Physiol 2020; 11:551. [PMID: 32581841 PMCID: PMC7283580 DOI: 10.3389/fphys.2020.00551] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Accepted: 04/30/2020] [Indexed: 11/30/2022] Open
Abstract
Background/Aims Increasing evidence shows that non-alcoholic fatty liver disease (NAFLD) is associated with dysregulation of microvascular perfusion independently of established cardio-metabolic risk factors. We investigated whether hepatic manifestations of NAFLD such as liver fibrosis and liver fat are associated with microvascular hemodynamics through dysregulation of neurovascular control. Methods Microvascular dilator (post-occlusive reactive hyperemia) and sympathetically mediated constrictor (deep inspiratory breath-hold) responses were measured at the forearm and finger, respectively, using laser Doppler fluximetry. Non-linear complexity-based analysis was used to assess the information content and variability of the resting blood flux (BF) signals, attributable to oscillatory flow-motion activity, and over multiple sampling frequencies. Results Measurements were made in 189 adults (113 men) with NAFLD, with (n = 65) and without (n = 124) type 2 diabetes mellitus (T2DM), age = 50.9 ± 11.7 years (mean ± SD). Microvascular dilator and constrictor capacity were both negatively associated with age (r = −0.178, p = 0.014, and r = −0.201, p = 0.007, respectively) and enhanced liver fibrosis (ELF) score (r = −0.155, p = 0.038 and r = −0.418, p < 0.0001, respectively). There was no association with measures of liver fat, obesity or T2DM. Lempel-Ziv complexity (LZC) and sample entropy (SE) of the BF signal measured at the two skin sites were associated negatively with age (p < 0.01 and p < 0.001) and positively with ELF score (p < 0.05 and p < 0.0001). In individuals with an ELF score ≥7.8 the influence of both neurogenic and respiratory flow-motion activity on LZC was up-rated (p < 0.0001). Conclusion Altered microvascular network functionality occurs in adults with NAFLD suggesting a mechanistic role for dysregulated neurovascular control in individuals at risk of severe liver fibrosis.
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Affiliation(s)
- Geraldine F Clough
- Human Development and Health, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| | - Andrew J Chipperfield
- Faculty of Engineering and Physical Sciences, University of Southampton, Southampton, United Kingdom
| | - Marjola Thanaj
- Faculty of Engineering and Physical Sciences, University of Southampton, Southampton, United Kingdom
| | - Eleonora Scorletti
- Human Development and Health, Faculty of Medicine, University of Southampton, Southampton, United Kingdom.,National Institute for Health Research Southampton Biomedical Research Centre, University of Southampton, University Hospital Southampton National Health Service Foundation Trust, Southampton, United Kingdom.,Department of Gastroenterology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Philip C Calder
- Human Development and Health, Faculty of Medicine, University of Southampton, Southampton, United Kingdom.,National Institute for Health Research Southampton Biomedical Research Centre, University of Southampton, University Hospital Southampton National Health Service Foundation Trust, Southampton, United Kingdom
| | - Christopher D Byrne
- Human Development and Health, Faculty of Medicine, University of Southampton, Southampton, United Kingdom.,National Institute for Health Research Southampton Biomedical Research Centre, University of Southampton, University Hospital Southampton National Health Service Foundation Trust, Southampton, United Kingdom
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Katarzynska J, Cholewinski T, Sieron L, Marcinek A, Gebicki J. Flowmotion Monitored by Flow Mediated Skin Fluorescence (FMSF): A Tool for Characterization of Microcirculatory Status. Front Physiol 2020; 11:702. [PMID: 32636761 PMCID: PMC7317028 DOI: 10.3389/fphys.2020.00702] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 05/28/2020] [Indexed: 01/20/2023] Open
Abstract
Oscillations in the microcirculation, known as flowmotion, are a well-recognized characteristic of cutaneous blood flow. Since flowmotion reflects the microcirculatory status of the vascular system, which is very often impaired in many diseases and disorders, a quantitative assessment of skin flowmotion could potentially be used to screen for early symptoms of such conditions. In this study, skin flowmotion was monitored using the Flow Mediated Skin Fluorescence (FMSF) technique. The flowmotion parameter was used for quantitative assessment of basal flowmotion both at rest (FM) and during reperfusion [FM(R)] following the post-occlusive reactive hyperemia (PORH). The study population was composed of healthy volunteers between the ages of 30 and 72 (n = 75). The FM parameter showed an inverse dependence relative to age, while the FM(R) parameter was inversely correlated to blood pressure. The FM(R) parameter reflects the strong effect of hypoxia on flowmotion, which is mainly due to increased myogenic activity in the vessels. The FMSF technique appears to be uniquely suited for the analysis of basal flowmotion and the hypoxia response, and may be used for the characterization of microcirculatory status.
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Affiliation(s)
| | | | | | - Andrzej Marcinek
- Angionica Ltd., Lodz, Poland
- Institute of Applied Radiation Chemistry, Lodz University of Technology, Lodz, Poland
| | - Jerzy Gebicki
- Angionica Ltd., Lodz, Poland
- Institute of Applied Radiation Chemistry, Lodz University of Technology, Lodz, Poland
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Thanaj M, Chipperfield AJ, Clough GF. Attractor Reconstruction Analysis for Blood Flow Signals. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2020; 2019:2281-2284. [PMID: 31946355 DOI: 10.1109/embc.2019.8856856] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Attractor reconstruction analysis has been previously used to determine changes in the shape and variability of fairly periodic signals such as arterial blood pressure signals and electroencephalogram signals, providing a two-dimensional attractor with features like density and symmetry. Since BF signals are fairly periodic and quasi-stationary, we set out to investigate whether attractor reconstruction method could be applied in signals derived from the microvascular perfusion. We describe the basis and the implementation of attractor reconstruction analysis of the microvascular blood flux (BF) signals recorded from the skin of 15 healthy male volunteers, age 29.2 ± 8.1y (mean ± SD). The efficacy of attractor reconstruction analysis (ARA) as a potential method of identifying changes in the microvascular function is evaluated in two haemodynamic steady states, at 33°C, and during warming at 43°C to generate a local thermal hyperaemia (LTH). Our findings show a significant drop of the maximal density derived from the ARA, during increased flow and that there was good discrimination of the blood flow signals between the two haemodynamic steady states, having good classification accuracy (80%). This study shows that ARA of BF signals can identify different microvascular functional states and thus has a potential for the clinical assessment and diagnosis of pathophysiological condition.
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Chipperfield AJ, Thanaj M, Clough GF. Multiscale, multidomain analysis of microvascular flow dynamics. Exp Physiol 2019; 105:1452-1458. [PMID: 31875329 DOI: 10.1113/ep087874] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 12/23/2019] [Indexed: 12/17/2022]
Abstract
NEW FINDINGS What is the topic of this review? We describe a range of techniques in the time, frequency and information domains and their application alone and together for the analysis of blood flux signals acquired using laser Doppler fluximetry. What advances does it highlight? This review highlights the idea of using quantitative measures in different domains and scales to gain a better mechanistic understanding of the complex behaviours in the microcirculation. ABSTRACT To date, time- and frequency-domain metrics of signals acquired through laser Doppler fluximetry have been unable to provide consistent and robust measures of the changes that occur in the microcirculation in healthy individuals at rest or in response to a provocation, or in patient cohorts. Recent studies have shown that in many disease states, such as metabolic and cardiovascular disease, there appears to be a reduction in the adaptive capabilities of the microvascular network and a consequent reduction in physiological information content. Here, we introduce non-linear measures for assessing the information content of fluximetry signals and demonstrate how they can yield deeper understanding of network behaviour. In addition, we show how these methods may be adapted to accommodate the multiple time scales modulating blood flow and how they can be used in combination with time- and frequency-domain metrics to discriminate more effectively between the different mechanistic influences on network properties.
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Affiliation(s)
- A J Chipperfield
- Faculty of Engineering and Physical Sciences, University of Southampton, Southampton, UK
| | - M Thanaj
- Faculty of Engineering and Physical Sciences, University of Southampton, Southampton, UK
| | - G F Clough
- Faculty of Medicine, University of Southampton, Southampton, UK
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Enhanced flow-motion complexity of skin microvascular perfusion in Sherpas and lowlanders during ascent to high altitude. Sci Rep 2019; 9:14391. [PMID: 31591502 PMCID: PMC6779732 DOI: 10.1038/s41598-019-50774-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Accepted: 09/13/2019] [Indexed: 12/17/2022] Open
Abstract
An increased and more effective microvascular perfusion is postulated to play a key role in the physiological adaptation of Sherpa highlanders to the hypobaric hypoxia encountered at high altitude. To investigate this, we used Lempel-Ziv complexity (LZC) analysis to explore the spatiotemporal dynamics of the variability of the skin microvascular blood flux (BF) signals measured at the forearm and finger, in 32 lowlanders (LL) and 46 Sherpa highlanders (SH) during the Xtreme Everest 2 expedition. Measurements were made at baseline (BL) (LL: London 35 m; SH: Kathmandu 1300 m) and at Everest base camp (LL and SH: EBC 5,300 m). We found that BF signal content increased with ascent to EBC in both SH and LL. At both altitudes, LZC of the BF signals was significantly higher in SH, and was related to local slow-wave flow-motion activity over multiple spatial and temporal scales. In SH, BF LZC was also positively associated with LZC of the simultaneously measured tissue oxygenation signals. These data provide robust mechanistic information of microvascular network functionality and flexibility during hypoxic exposure on ascent to high altitude. They demonstrate the importance of a sustained heterogeneity of network perfusion, associated with local vaso-control mechanisms, to effective tissue oxygenation during hypobaric hypoxia.
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Al-Tamimi H, Al-Dawood A, Awaishesh S, Abdalla T. Resveratrol mitigates hypercholesterolemia exacerbated hyperthermia in chronically heat-stressed rats. Vet World 2019; 12:337-344. [PMID: 31040579 PMCID: PMC6460863 DOI: 10.14202/vetworld.2019.337-344] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Accepted: 01/17/2019] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND AND AIM Hypercholesterolemia (HC) is the major leading cause of cardiovascular disease worldwide. Such atherogenic aberration deeply impacts blood circulation. Resveratrol (R) is a polyphenol that has received attention as a hypolipidemic, antioxidant, and vascular agility advocate. Efficient blood redistribution is a key element in mammalian thermoregulation. We hypothesized that R treatment may aid in mitigating hyperthermic responses under both acute and chronic heat stress (HS) conditions in HC male rats. MATERIALS AND METHODS All rats were initially fitted with miniaturized thermologgers to measure core body temperature (Tcore). With a 2 × 2 factorial arrangement, four groups were randomly allotted, in which half of the animals ingested an HC diet (C+), while the other half ingested a control (C-) diet, throughout the whole study duration of 35 days. Seven rats from each dietary treatment, however, received R (R+; 13 mg/kg BW/day), while the rest received normal saline (R-) for 5 continuous days. All animals were maintained at thermoneutrality (TN; ambient temperature; Ta=23.15±0.04°C) for a period of 30 continuous days (days 0-29). On day 29, an acute HS (HS; Ta=35.86±0.37°C; for 9 nocturnal h) was imposed. Then, from day 29, a chronic HS protocol (Ta=32.28±1.00°C) was maintained until the past day of the trial (day 34), after which blood samples were drawn for analyses of platelet (PL) count, total antioxidant activity (TAO), total cholesterol (TC), triglycerides (TGs), and lipid peroxidation (LP). RESULTS Switching animals from TN to HS resulted in abrupt rises in Tcore. The HC diet induced a significant (p<0.01) hyperlipidemia over the control of diet-consuming rats. Interestingly, the hyperthermic response to acute HS was highly pronounced in the rats consuming the C- diet, while the C+ diet exacerbated the chronic HS-induced hyperthermia. Despite failure to improve TAO in the C+ diet, R+ treatment caused a marked (p<0.05) decline in nighttime - hyperthermia in C+ rats, likely by enhancing blood flow to extremities (for heat dissipation) as delineated by drastic downregulations of C+ related rises in PL, TC, TG, and LP (HC diet by R+ interaction; p<0.03). CONCLUSION The hyperthermic response in C- groups was attributed to higher amount of feed intake than those consuming the C+ diet. Yet, the R+ improvement of thermoregulation in the C+ group was likely related to enhancement of vascular hemodynamics. Resveratrol intake mitigated chronic HS-evoked hyperthermia in rats. Such an approach is worthy to follow-up in other mammals and humans.
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Affiliation(s)
- Hosam Al-Tamimi
- Department of Animal Science, Faculty of Agriculture, Jordan University of Science and Technology, Irbid, 22110, Jordan
| | - Amani Al-Dawood
- Department of Applied Biology, Faculty of Sciences, Tafila Technical University, Tafila, 66110, Jordan
| | - Saddam Awaishesh
- Department of Nutrition and Food Processing, Faculty of Agriculture, Al-Balqa Applied University, Al-Salt, 19117, Jordan
| | - Tony Abdalla
- Department of Animal Science, Faculty of Agriculture, Jordan University of Science and Technology, Irbid, 22110, Jordan
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Chipperfield AJ, Thanaj M, Scorletti E, Byrne CD, Clough GF. Multi-domain analysis of microvascular flow motion dynamics in NAFLD. Microcirculation 2019; 26:e12538. [PMID: 30803094 DOI: 10.1111/micc.12538] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 01/22/2019] [Accepted: 02/20/2019] [Indexed: 12/21/2022]
Abstract
OBJECTIVE To determine whether analysis of microvascular network perfusion using complexity-based methods can discriminate between groups of individuals at an increased risk of developing CVD. METHODS Data were obtained from laser Doppler recordings of skin blood flux at the forearm in 50 participants with non-alcoholic fatty liver disease grouped for absence (n = 28) or presence (n = 14) of type 2 diabetes and use of calcium channel blocker medication (n = 8). Power spectral density was evaluated and Lempel-Ziv complexity determined to quantify signal information content at single and multiple time-scales to account for the different processes modulating network perfusion. RESULTS Complexity was associated with dilatory capacity and respiration and negatively with baseline blood flux and cardiac band power. The relationship between the modulators of flowmotion and complexity of blood flux is shown to change with time-scale improving discrimination between groups. Multiscale Lempel-Ziv achieved best classification accuracy of 86.1%. CONCLUSIONS Time and frequency domain measures alone are insufficient to discriminate between groups. As cardiovascular disease risk increases, the degree of complexity of the blood flux signal reduces, indicative of a reduced temporal activity and heterogeneous distribution of blood flow within the microvascular network sampled. Complexity-based methods, particularly multiscale variants, are shown to have good discriminatory capabilities.
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Affiliation(s)
- Andrew J Chipperfield
- Faculty of Engineering and Physical Sciences, University of Southampton, Southampton, UK
| | - Marjola Thanaj
- Faculty of Engineering and Physical Sciences, University of Southampton, Southampton, UK
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15
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Thanaj M, Chipperfield AJ, Clough GF. Multiscale Analysis of Microvascular Blood Flow and Oxygenation. IFMBE PROCEEDINGS 2019. [DOI: 10.1007/978-981-10-9038-7_36] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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16
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Frisbee JC, Lewis MT, Wiseman RW. Skeletal muscle performance in metabolic disease: Microvascular or mitochondrial limitation or both? Microcirculation 2018; 26:e12517. [PMID: 30471168 DOI: 10.1111/micc.12517] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Accepted: 11/14/2018] [Indexed: 12/20/2022]
Abstract
One of the clearly established health outcomes associated with chronic metabolic diseases (eg, type II diabetes mellitus) is that the ability of skeletal muscle to maintain contractile performance during periods of elevated metabolic demand is compromised as compared to the fatigue-resistance of muscle under normal, healthy conditions. While there has been extensive effort dedicated to determining the major factors that contribute to the compromised performance of skeletal muscle with chronic metabolic disease, the extent to which this poor outcome reflects a dysfunctional state of the microcirculation, where the delivery and distribution of metabolic substrates can be impaired, versus derangements to normal metabolic processes and mitochondrial function, versus a combination of the two, represents an area of considerable unknown. The purpose of this manuscript is to present some of the current concepts for dysfunction to both the microcirculation of skeletal muscle as well as to mitochondrial metabolism under these conditions, such that these diverse issues can be merged into an integrated framework for future investigation. Based on an interpretation of the current literature, it may be hypothesized that the primary site of dysfunction with earlier stages of metabolic disease may lie at the level of the vasculature, rather than at the level of the mitochondria.
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Affiliation(s)
- Jefferson C Frisbee
- Department of Medical Biophysics, University of Western Ontario, London, Ontario, Canada
| | - Matthew T Lewis
- Department of Physiology, Michigan State University, East Lansing, Michigan
| | - Robert W Wiseman
- Department of Physiology, Michigan State University, East Lansing, Michigan.,Department of Radiology, Michigan State University, East Lansing, Michigan
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17
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Thanaj M, Chipperfield AJ, Clough GF. Analysis of microvascular blood flow and oxygenation: Discrimination between two haemodynamic steady states using nonlinear measures and multiscale analysis. Comput Biol Med 2018; 102:157-167. [DOI: 10.1016/j.compbiomed.2018.09.026] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 09/07/2018] [Accepted: 09/24/2018] [Indexed: 11/16/2022]
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18
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Davies T, Gilbert-Kawai E, Wythe S, Meale P, Mythen M, Levett D, Mitchell K, Grocott M, Clough G, Martin D. Sustained vasomotor control of skin microcirculation in Sherpas versus altitude-naive lowlanders: Experimental evidence from Xtreme Everest 2. Exp Physiol 2018; 103:1494-1504. [PMID: 30182473 DOI: 10.1113/ep087236] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 08/21/2018] [Indexed: 12/20/2022]
Abstract
NEW FINDINGS What is the central question of this study? Do Sherpa highlanders, when exposed to graded hypobaric hypoxia, exhibit enhanced vasomotor and neurovascular control to maintain microcirculatory flux, and thus tissue oxygenation, when compared with altitude-naive lowlanders? What is the main finding and its importance? Sherpas, when exposed to hypobaric hypoxia at high altitude, demonstrated superior preservation of their peripheral microcirculatory perfusion, a greater oxygen unloading rate and sustained microvascular reactivity with enhanced vasomotion, when compared with altitude-naive lowlanders. These differences have not been reported previously and may improve our understanding of the multifactorial responses to sustained environmental hypoxia. ABSTRACT Enhanced oxygen delivery, consequent to an increased microvascular perfusion, has been postulated to play a key role in the physiological adaptation of Tibetan highlanders to the hypobaric hypoxia encountered at high altitude. We tested the hypothesis that Sherpas, when exposed to graded hypobaric hypoxia, demonstrate enhanced vasomotor and neurovascular control to maintain microcirculatory flux, and thus tissue oxygenation, when compared with altitude-naive lowlanders. Eighty-three lowlanders [39 men and 44 women, 38.8 (13.1) years old; mean (SD)] and 61 Sherpas [28 men and 33 women, 27.9 (6.9) years old] were studied on ascent to Everest Base Camp over 11 days. Skin blood flux and tissue oxygen saturation were measured simultaneously using combined laser Doppler fluximetry and white light spectroscopy at baseline, 3500 and 5300 m. In both cohorts, ascent resulted in a decline in the sympathetically mediated microvascular constrictor response (P < 0.001), which was more marked in lowlanders than in Sherpas (P < 0.001). The microvascular dilator response evaluated by postocclusive reactive hyperaemia was significantly greater in Sherpas than in lowlanders at all sites (P < 0.002). Spectral analysis of the blood flux signals revealed enhanced myogenic (vasomotion) activity in Sherpas, which was unaffected by ascent to 5300 m. Although skin tissue oxygenation was lower in Sherpas than in lowlanders, the oxygen unloading rate was faster, and deoxyhaemoglobin levels higher, at all altitudes. Together, these data suggest that Sherpas, when exposed to hypobaric hypoxia, demonstrated superior preservation of peripheral microcirculatory perfusion compared with altitude-naive lowlanders. The physiological differences in local microvasculature vasomotor and neurovascular control may play a key role in Sherpa adaptation to high-altitude hypobaric hypoxia by sustaining local perfusion and tissue oxygenation.
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Affiliation(s)
- Thomas Davies
- University College London Centre for Altitude Space and Extreme Environment Medicine, UCLH NIHR Biomedical Research Centre, Institute of Sport and Exercise Health, London, UK
| | - Edward Gilbert-Kawai
- University College London Centre for Altitude Space and Extreme Environment Medicine, UCLH NIHR Biomedical Research Centre, Institute of Sport and Exercise Health, London, UK
| | - Stephen Wythe
- University College London Centre for Altitude Space and Extreme Environment Medicine, UCLH NIHR Biomedical Research Centre, Institute of Sport and Exercise Health, London, UK
| | - Paula Meale
- University College London Centre for Altitude Space and Extreme Environment Medicine, UCLH NIHR Biomedical Research Centre, Institute of Sport and Exercise Health, London, UK
| | - Monty Mythen
- University College London Centre for Altitude Space and Extreme Environment Medicine, UCLH NIHR Biomedical Research Centre, Institute of Sport and Exercise Health, London, UK
| | - Denny Levett
- University College London Centre for Altitude Space and Extreme Environment Medicine, UCLH NIHR Biomedical Research Centre, Institute of Sport and Exercise Health, London, UK.,Faculty of Medicine (CES) and Institute for Life Science, University of Southampton, Southampton, UK.,NIHR Southampton Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust, Southampton, UK.,Centre for Human Integrative Physiology, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Kay Mitchell
- University College London Centre for Altitude Space and Extreme Environment Medicine, UCLH NIHR Biomedical Research Centre, Institute of Sport and Exercise Health, London, UK
| | - Michael Grocott
- University College London Centre for Altitude Space and Extreme Environment Medicine, UCLH NIHR Biomedical Research Centre, Institute of Sport and Exercise Health, London, UK.,Faculty of Medicine (CES) and Institute for Life Science, University of Southampton, Southampton, UK.,NIHR Southampton Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust, Southampton, UK.,Centre for Human Integrative Physiology, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Geraldine Clough
- Institute of Developmental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Daniel Martin
- University College London Centre for Altitude Space and Extreme Environment Medicine, UCLH NIHR Biomedical Research Centre, Institute of Sport and Exercise Health, London, UK.,Critical Care Unit, Royal Free Hospital, London, UK
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- University College London Centre for Altitude Space and Extreme Environment Medicine, UCLH NIHR Biomedical Research Centre, Institute of Sport and Exercise Health, London, UK
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Lemaster KA, Frisbee SJ, Dubois L, Tzemos N, Wu F, Lewis MT, Wiseman RW, Frisbee JC. Chronic atorvastatin and exercise can partially reverse established skeletal muscle microvasculopathy in metabolic syndrome. Am J Physiol Heart Circ Physiol 2018; 315:H855-H870. [PMID: 29932769 DOI: 10.1152/ajpheart.00193.2018] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
It has long been known that chronic metabolic disease is associated with a parallel increase in the risk for developing peripheral vascular disease. Although more clinically relevant, our understanding about reversing established vasculopathy is limited compared with our understanding of the mechanisms and development of impaired vascular structure/function under these conditions. Using the 13-wk-old obese Zucker rat (OZR) model of metabolic syndrome, where microvascular dysfunction is sufficiently established to contribute to impaired skeletal muscle function, we imposed a 7-wk intervention of chronic atorvastatin treatment, chronic treadmill exercise, or both. By 20 wk of age, untreated OZRs manifested a diverse vasculopathy that was a central contributor to poor muscle performance, perfusion, and impaired O2 exchange. Atorvastatin or exercise, with the combination being most effective, improved skeletal muscle vascular metabolite profiles (i.e., nitric oxide, PGI2, and thromboxane A2 bioavailability), reactivity, and perfusion distribution at both individual bifurcations and within the entire microvascular network versus responses in untreated OZRs. However, improvements to microvascular structure (i.e., wall mechanics and microvascular density) were less robust. The combination of the above improvements to vascular function with interventions resulted in an improved muscle performance and O2 transport and exchange versus untreated OZRs, especially at moderate metabolic rates (3-Hz twitch contraction). These results suggest that specific interventions can improve specific indexes of function from established vasculopathy, but either this process was incomplete after 7-wk duration or measures of vascular structure are either resistant to reversal or require better-targeted interventions. NEW & NOTEWORTHY We used atorvastatin and/or chronic exercise to reverse established microvasculopathy in skeletal muscle of rats with metabolic syndrome. With established vasculopathy, atorvastatin and exercise had moderate abilities to reverse dysfunction, and the combined application of both was more effective at restoring function. However, increased vascular wall stiffness and reduced microvessel density were more resistant to reversal. Listen to this article's corresponding podcast at https://ajpheart.podbean.com/e/reversal-of-microvascular-dysfunction/ .
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Affiliation(s)
- Kent A Lemaster
- Department of Medical Biophysics, University of Western Ontario , London, Ontario , Canada
| | - Stephanie J Frisbee
- Department of Pathology and Laboratory Medicine, University of Western Ontario , London, Ontario , Canada
| | - Luc Dubois
- Division of Vascular Surgery, University of Western Ontario , London, Ontario , Canada
| | - Nikolaos Tzemos
- Division of Cardiology, University of Western Ontario , London, Ontario , Canada
| | - Fan Wu
- DMPK, Nonclinical Development, Celgene Corporation, Summit, New Jersey
| | - Matthew T Lewis
- Department of Physiology, Michigan State University , East Lansing, Michigan
| | - Robert W Wiseman
- Department of Physiology, Michigan State University , East Lansing, Michigan
| | - Jefferson C Frisbee
- Department of Medical Biophysics, University of Western Ontario , London, Ontario , Canada
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Abstract
Cardiovascular disease (CVD) is the leading cause of mortality in people with type 2 diabetes mellitus (T2DM), yet a significant proportion of the disease burden cannot be accounted for by conventional cardiovascular risk factors. Hypertension occurs in majority of people with T2DM, which is substantially more frequent than would be anticipated based on general population samples. The impact of hypertension is considerably higher in people with diabetes than it is in the general population, suggesting either an increased sensitivity to its effect or a confounding underlying aetiopathogenic mechanism of hypertension associated with CVD within diabetes. In this contribution, we aim to review the changes observed in the vascular tree in people with T2DM compared to the general population, the effects of established anti-diabetes drugs on microvascular outcomes, and explore the hypotheses to account for common causalities of the increased prevalence of CVD and hypertension in people with T2DM.
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Affiliation(s)
- W David Strain
- Diabetes and Vascular Medicine Research Centre, NIHR Exeter Clinical Research Facility and Institute of Biomedical and Clinical Science, University of Exeter Medical School, Royal Devon & Exeter NHS Foundation Trust, Barrack Road, Exeter, EX2 5AX, UK.
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21
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Breslin JW. Cellular cross talk, inflammatory signals, and enhanced microvascular permeability. Microcirculation 2018; 24. [PMID: 28295872 DOI: 10.1111/micc.12368] [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] [Received: 03/07/2017] [Accepted: 03/08/2017] [Indexed: 01/24/2023]
Abstract
Microvascular leakage remains a significant clinical problem for which there is no specific therapeutic available. This Special Topics issue of the journal Microcirculation features reviews pertaining to the cellular and molecular mechanisms that control the integrity of the microvascular barrier. (Meegan et al., Microcirculation, 2017) summarize recent research findings about how neutrophil extracellular traps and how these can cause injury to the microvascular barrier.( Zhang et al. Microcirculation, 2017) highlight the microvascular response to advanced glycation end-products that are formed as part of the pathophysiology of diabetes mellitus. These ongoing investigations are helping to clarify the mechanisms by which endothelial cells receive information and integrate it to generate cellular responses that fine-tune barrier function. Better understanding of these mechanisms is needed for the rational development of therapeutic strategies to reduce excessive microvascular leakage.
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Affiliation(s)
- Jerome W Breslin
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
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22
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Frisbee JC. Obesity, insulin resistance, and microvascular adaptation. Microcirculation 2018; 24. [PMID: 27987530 DOI: 10.1111/micc.12346] [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] [Received: 12/12/2016] [Accepted: 12/13/2016] [Indexed: 11/27/2022]
Abstract
Two of the primary risk factors for the progressive evolution of cardiovascular disease are obesity and impaired glycemic control-including both insulin resistance and overt type 2 diabetes mellitus, leading to increased research emphasis on these conditions, their mechanistic bases, and their health outcomes. This Special Topics Issue of the journal Microcirculation summarizes a symposium at the recent Joint Meeting of the American Physiological Society and the Physiological Society, held in Dublin, Ireland, on July 30, 2016. This symposium, "Adaptive outcomes of microvascular networks to obesity and type 2 diabetes mellitus/insulin resistance," presented four lectures, each of which addressed the larger issue from a different perspective.
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Affiliation(s)
- Jefferson C Frisbee
- Department of Medical Biophysics, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, Canada
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23
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Kuliga KZ, Gush R, Clough GF, Chipperfield AJ. Time-dependent Behavior of Microvascular Blood Flow and Oxygenation: a Predictor of Functional Outcomes. IEEE Trans Biomed Eng 2017; 65:1049-1056. [DOI: 10.1109/tbme.2017.2737328] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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