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Orbegozo D, Stringari G, Damazio R, De Backer D, Vincent JL, Creteur J. Altered Microvascular Reactivity During a Skin Thermal Challenge Is Associated With Organ Dysfunction and Slow Recovery After Cardiac Surgery. J Cardiothorac Vasc Anesth 2024:S1053-0770(24)00436-1. [PMID: 39034163 DOI: 10.1053/j.jvca.2024.06.045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2024] [Revised: 06/26/2024] [Accepted: 06/30/2024] [Indexed: 07/23/2024]
Abstract
OBJECTIVES To assess microvascular reactivity during a skin thermal challenge early post-cardiac surgery and its association with outcomes. DESIGN Noninvasive physiological study. SETTING Thirty-five-bed department of intensive care. PARTICIPANTS Patients admitted to the intensive care unit post-cardiac surgery. INTERVENTIONS Thermal challenge. MEASUREMENTS AND MAIN RESULTS A total of 46 patients were included; 14 needed vasoactive or ventilatory support for at least 48 hours (slow recovery), and 32 had a more rapid recovery. Skin blood flow (SBF) was measured on the anterior proximal forearm using skin laser Doppler. A thermal challenge was performed by abruptly increasing local skin temperature from 37°C to 43°C while monitoring SBF. The ratio between SBFs at 43°C and 37°C was calculated to measure microvascular reactivity. SBF at 37°C was not significantly different in patients with a slow recovery and those with a rapid recovery, but SBF after 9 minutes at 43°C was lower (48.5 [17.3-69.0] v 85.1 [45.2-125.7], p < 0.01), resulting in a lower SBF ratio (2.8 [1.5-4.7] v 4.8 [3.7-7.8], p < 0.01). Patients with lower SBF ratios were more likely to have dysfunction of at least one organ (assessed using the sequential organ dysfunction score) 48 hours post-cardiac surgery than those with higher ratios: 88% versus 40% versus 27% (p < 0.01), respectively, for the lowest, middle, and highest tertiles of SBF ratio. In multivariable analysis, a lower SBF ratio was an independent risk factor for slow recovery. CONCLUSIONS Early alterations in microvascular reactivity, evaluated by a skin thermal challenge, are correlated with organ dysfunction. These observations may help in the development of new, simple, noninvasive monitoring systems in postoperative patients.
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Affiliation(s)
- Diego Orbegozo
- Department of Intensive Care, Erasme University Hospital, Université Libre de Bruxelles, Brussels, Belgium
| | - Gianni Stringari
- Department of Intensive Care, Erasme University Hospital, Université Libre de Bruxelles, Brussels, Belgium
| | - Rafael Damazio
- Department of Intensive Care, Erasme University Hospital, Université Libre de Bruxelles, Brussels, Belgium
| | - Daniel De Backer
- Department of Intensive Care, Erasme University Hospital, Université Libre de Bruxelles, Brussels, Belgium
| | - Jean-Louis Vincent
- Department of Intensive Care, Erasme University Hospital, Université Libre de Bruxelles, Brussels, Belgium
| | - Jacques Creteur
- Department of Intensive Care, Erasme University Hospital, Université Libre de Bruxelles, Brussels, Belgium.
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Gordon RJFH, Worsley PR, Filingeri D. An evaluation of the effects of localised skin cooling on microvascular, inflammatory, structural, and perceptual responses to sustained mechanical loading of the sacrum: A study protocol. PLoS One 2024; 19:e0303342. [PMID: 38728306 PMCID: PMC11086830 DOI: 10.1371/journal.pone.0303342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Accepted: 04/22/2024] [Indexed: 05/12/2024] Open
Abstract
This study protocol aims to investigate how localised cooling influences the skin's microvascular, inflammatory, structural, and perceptual tolerance to sustained mechanical loading at the sacrum, evaluating factors such as morphology, physiology, and perceptual responses. The protocol will be tested on individuals of different age, sex, skin tone and clinical status, using a repeated-measure design with three participants cohorts: i) young healthy (n = 35); ii) older healthy (n = 35); iii) spinal cord injured (SCI, n = 35). Participants will complete three testing sessions during which their sacrum will be mechanically loaded (60 mmHg; 45 min) and unloaded (20 min) with a custom-built thermal probe, causing pressure-induced ischemia and post-occlusive reactive hyperaemia. Testing sessions will differ by the probe's temperature, which will be set to either 38°C (no cooling), 24°C (mild cooling), or 16°C (strong cooling). We will measure skin blood flow (via Laser Doppler Flowmetry; 40 Hz); pro- and anti-inflammatory biomarkers in skin sebum (Sebutape); structural skin properties (Optical Coherence Tomography); and ratings of thermal sensation, comfort, and acceptance (Likert Scales); throughout the loading and unloading phases. Changes in post-occlusive reactive hyperaemia will be considered as the primary outcome and data will be analysed for the independent and interactive effects of stimuli's temperature and of participant group on within- and between-subject mean differences (and 95% Confidence Intervals) in peak hyperaemia, by means of a 2-way mixed model ANOVA (or Friedman). Regression models will also be developed to assess the relationship between absolute cooling temperatures and peak hyperaemia. Secondary outcomes will be within- and between-subject mean changes in biomarkers' expression, skin structural and perceptual responses. This analysis will help identifying physiological and perceptual thresholds for the protective effects of cooling from mechanically induced damage underlying the development of pressure ulcers in individuals varying in age and clinical status.
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Affiliation(s)
- Ralph J. F. H. Gordon
- ThermosenseLab, Skin Sensing Research Group, School of Health Science, University of Southampton, Southampton, United Kingdom
| | - Peter R. Worsley
- PressureLab, Skin Sensing Research Group, School of Health Science, University of Southampton, Southampton, United Kingdom
| | - Davide Filingeri
- ThermosenseLab, Skin Sensing Research Group, School of Health Science, University of Southampton, Southampton, United Kingdom
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Dubensky A, Ryzhkov I, Tsokolaeva Z, Lapin K, Kalabushev S, Varnakova L, Dolgikh V. Post-occlusive reactive hyperemia variables can be used to diagnose vascular dysfunction in hemorrhagic shock. Microvasc Res 2024; 152:104647. [PMID: 38092223 DOI: 10.1016/j.mvr.2023.104647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 11/24/2023] [Accepted: 12/08/2023] [Indexed: 02/03/2024]
Abstract
INTRODUCTION Laser doppler flowmetry (LDF) allows non-invasive assessment of microvascular functions. The combination of LDF with an occlusion functional test enables study of post-occlusive reactive hyperemia (PORH), providing additional information about vasomotor function, capillary blood flow reserve, and the overall reactivity of the microvascular system. AIM To identify early alterations of PORH variables in the skin of a rat in hemorrhagic shock (HS). MATERIAL AND METHODS Male Wistar rats (n = 14) weighing 400-450 g were anesthetized with a combination of tiletamine/zolazepam (20 mg/kg) and xylazine (5 mg/kg). The animals breathed on their own, and were placed on a heated platform in the supine position. A PE-50 catheter was inserted into the carotid artery to measure the mean arterial pressure (MAP). The optical probe of the Laser Doppler device was installed on the plantar surface of the hind limb of a rat; a pneumatic cuff was applied proximal to the same limb. The occlusion time was 3 min. The following physiological variables were measured at baseline and 30 min after blood loss: MAP, mmHg; mean cutaneous blood flow (M, PU); cutaneous vascular conductance (CVC = M/MAP); peak hyperemia (Mmax, PU) and maximum cutaneous vascular conductance (CVCmax) during PORH. In the HS group (n = 7), 30 % of the estimated blood volume was taken within 5 min. There was no blood loss in the group of sham-operated animals (Sham, n = 7). The results are presented as Me [25 %;75 %]. The U-Mann-Whitney criterion was used to evaluate intergroup differences. Differences were considered statistically significant at p < 0.05. RESULTS The groups did not differ at baseline. Blood loss led to a significant decrease in MAP (43 [31;46] vs. 94 [84;104] mmHg), M (11.5 [16.9;7.8] vs 16.7 [20.2;13.9]) and Mmax (18.1 [16.4;21.8] vs. 25.0 [23.0;26.2]) in the HS group compared to the Sham group, respectively. At the same time, both CVC (0.25 [0.23;0.30] vs. 0.16 [0.14;0.21]) and CVCmax (0.55 [0.38;0.49] vs 0.24 [0.23; 0.29]) increased after blood loss in the HS group compared to the Sham group. Arterial blood gas analysis revealed metabolic lactic acidosis in the HS group. CONCLUSION In this rat model of HS, alterations in cutaneous blood flow are manifested by a decrease in perfusion (M) and the intensity of PORH (Mmax) with a simultaneous increase in vascular conductance (CVC and CVCmax).
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Affiliation(s)
- Aleksey Dubensky
- Federal Research and Clinical Center of Intensive Care Medicine and Rehabilitology, Moscow, Russia
| | - Ivan Ryzhkov
- Federal Research and Clinical Center of Intensive Care Medicine and Rehabilitology, Moscow, Russia.
| | - Zoya Tsokolaeva
- Federal Research and Clinical Center of Intensive Care Medicine and Rehabilitology, Moscow, Russia
| | - Konstantin Lapin
- Federal Research and Clinical Center of Intensive Care Medicine and Rehabilitology, Moscow, Russia.
| | - Sergey Kalabushev
- Federal Research and Clinical Center of Intensive Care Medicine and Rehabilitology, Moscow, Russia.
| | - Lidia Varnakova
- Federal Research and Clinical Center of Intensive Care Medicine and Rehabilitology, Moscow, Russia.
| | - Vladimir Dolgikh
- Federal Research and Clinical Center of Intensive Care Medicine and Rehabilitology, Moscow, Russia
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Marynissen H, Janssen C, Bamps D, de Hoon J. Vascular read-out for TRP channel functionality on distal peripheral nerve endings in healthy men. Microvasc Res 2024; 152:104654. [PMID: 38215901 DOI: 10.1016/j.mvr.2024.104654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 12/23/2023] [Accepted: 01/04/2024] [Indexed: 01/14/2024]
Abstract
BACKGROUND Quantification of the vasodilation after topical application of capsaicin or cinnamaldehyde is often implemented to indirectly assess Transient Receptor Potential (TRP) Vanilloid 1 (TRPV1) or Ankyrin 1 (TRPA1) functionality respectively. This method has been well-established on the human forearm. However, to enable TRP functionality assessments in distal peripheral neuropathy, the vascular response upon TRP activation on dorsal finger skin was characterized. METHODS Two doses of cinnamaldehyde (3 % and 10 % v/v) and capsaicin (300 μg and 1000 μg) were topically applied (20 μL) on the skin of the mid three proximal phalanges in 17 healthy men. The dose-response, and inter-hand and inter-period reproducibility of the dermal blood flow (DBF) increase was assessed using Laser Speckle Contrast Imaging (LSCI) during 60 min post-application. Linear mixed models explored dose-driven differences, whereas the intra-class correlation coefficient (ICC) estimated the reproducibility of the vascular response. RESULTS Both doses of cinnamaldehyde and capsaicin induced a robust, dose-dependent increase in DBF. The vascular response to cinnamaldehyde 10 % on finger skin, expressed as area under the curve, correlated well over time (ICC = 0.66) and excellently between hands (ICC = 0.87). Similarly, the response to capsaicin 1000 μg correlated moderately over time (ICC = 0.50) and well between hands (ICC = 0.73). CONCLUSION The vascular response upon topical cinnamaldehyde and capsaicin application on finger skin is an alternative approach for measurements on forearm skin. Thereby, it is a promising vascular read-out to investigate the pathophysiology, and TRP involvement in particular, of specific peripheral neuropathic pain syndromes.
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Affiliation(s)
- Heleen Marynissen
- Center for Clinical Pharmacology, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium.
| | - Charlien Janssen
- Center for Clinical Pharmacology, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium
| | - Dorien Bamps
- Center for Clinical Pharmacology, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium
| | - Jan de Hoon
- Center for Clinical Pharmacology, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium
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Rodrigues LM, Caetano J, Andrade SF, Rocha C, Alves JD, Ferreira HA. Studying Erythromelalgia Using Doppler Flowmetry Perfusion Signals and Wavelet Analysis-An Exploratory Study. Biomedicines 2023; 11:3327. [PMID: 38137548 PMCID: PMC10741181 DOI: 10.3390/biomedicines11123327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 12/09/2023] [Accepted: 12/15/2023] [Indexed: 12/24/2023] Open
Abstract
Erythromelalgia (EM) is a rare disease, which is still poorly characterized. In the present paper, we compared the hand perfusion of one female EM patient, under challenges, with a healthy control group. Using a laser Doppler flowmeter (LDF) with an integrated thermal probe, measurements were taken in both hands at rest (Phase I) and after two separate challenges-post-occlusive hyperemia (PORH) in one arm (A) and reduction of skin temperature (cooling) with ice in one hand (B) (Phase II). The final measurement periods corresponded to recovery (Phases III and IV). The control group involved ten healthy women (27.3 ± 7.9 years old). A second set of measurements was taken in the EM patient one month after beginning a new therapeutic approach with beta-blockers (6.25 mg carvedilol twice daily). Z-scores of the patient's LDF and temperature fluctuations compared to the control group were assessed using the Wavelet transform (WT) analysis. Here, fluctuations with |Z| > 1.96 were considered significantly different from healthy values, whereas positive or negative Z values indicated higher or lower deviations from the control mean values. Cooling elicited more measurable changes in LDF and temperature fluctuations, especially in higher frequency components (cardiac, respiratory, and myogenic), whereas PORH notably evoked changes in lower frequency components (myogenic, autonomic, and endothelial). No significant Z-score deviations were observed in the second measurement, which might signify a stabilization of the patient's distal perfusion following the new therapeutic approach. This analysis involving one EM patient, while clearly exploratory, has shown significant deviations in WT-derived physiological components' values in comparison with the healthy group, confirming the interest in using cold temperature as a challenger. The apparent agreement achieved with the clinical evaluation opens the possibility of expanding this approach to other patients and pathologies in vascular medicine.
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Affiliation(s)
- Luis Monteiro Rodrigues
- CBIOS—Research Center for Biosciences and Health Technologies, Universidade Lusófona Lisboa, 1700-097 Lisbon, Portugal; (J.C.); (S.F.A.); (C.R.)
| | - Joana Caetano
- CBIOS—Research Center for Biosciences and Health Technologies, Universidade Lusófona Lisboa, 1700-097 Lisbon, Portugal; (J.C.); (S.F.A.); (C.R.)
- Immuno-Mediated Systemic Diseases, Medicina IV, Hospital Fernando Fonseca, 2720-276 Amadora, Portugal;
- Nova Medical School, Nova University of Lisboa, 1169-056 Lisboa, Portugal
| | - Sergio Faloni Andrade
- CBIOS—Research Center for Biosciences and Health Technologies, Universidade Lusófona Lisboa, 1700-097 Lisbon, Portugal; (J.C.); (S.F.A.); (C.R.)
| | - Clemente Rocha
- CBIOS—Research Center for Biosciences and Health Technologies, Universidade Lusófona Lisboa, 1700-097 Lisbon, Portugal; (J.C.); (S.F.A.); (C.R.)
| | - José Delgado Alves
- Immuno-Mediated Systemic Diseases, Medicina IV, Hospital Fernando Fonseca, 2720-276 Amadora, Portugal;
- Nova Medical School, Nova University of Lisboa, 1169-056 Lisboa, Portugal
| | - Hugo Alexandre Ferreira
- Faculty of Sciences, Institute of Biophysics and Biomedical Engineering, University of Lisbon, Campo Grande, 1749-019 Lisboa, Portugal;
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Kranen SH, Oliveira RS, Bond B, Williams CA, Barker AR. The utility of the reperfusion rate of tissue oxygen saturation as a measure of vascular endothelial function in adolescents: reliability, validity and sensitivity. Front Physiol 2023; 14:1163474. [PMID: 37781222 PMCID: PMC10533909 DOI: 10.3389/fphys.2023.1163474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Accepted: 08/17/2023] [Indexed: 10/03/2023] Open
Abstract
Introduction: The near-infrared spectroscopy (NIRS)-derived reperfusion rate of tissue oxygen saturation (slope 2 StO2) may provide a surrogate measure of vascular function, however, this has yet to be examined in a paediatric population. This study investigated in adolescents: 1) the between-day reliability of NIRS-derived measurements; 2) the relationship between slope 2 StO2 and macro- (flow-mediated dilation, FMD) and microvascular (peak reactive hyperaemia, PRH) function; and 3) the effect of high-intensity interval exercise (HIIE) on slope 2 StO2, FMD, and PRH. Methods: Nineteen boys (13.3 ± 0.5 y) visited the laboratory on two occasions, separated by ∼ 1 week. On visit 1, participants underwent simultaneous assessment of brachial artery FMD and slope 2 StO2 and PRH on the internal face of the forearm. On visit 2, participants completed a bout of HIIE with slope 2 StO2, FMD and PRH measured pre-, immediately post- and 1.5 h post-exercise. Results: Slope 2 StO2 showed no mean bias (p = 0.18) and an intraclass correlation coefficient of 0.67 (p = 0.003) between visits. No significant correlation between slope 2 StO2 and FMD or PRH was observed on visit 1 (r = -0.04, p = 0.89 and r = -0.30, p = 0.23, respectively) or visit 2 pre-exercise (r = -0.28, p = 0.25 and r = -0.31, p = 0.20, respectively). Compared to pre-exercise, FMD decreased immediately post-exercise (p < 0.001) and then increased 1.5 h post-exercise (p < 0.001). No significant change was detected for slope 2 StO2 (p = 0.30) or PRH (p = 0.55) following HIIE. Conclusion: In adolescents, slope 2 StO2 can be measured reliably, however, it is not correlated with FMD or PRH and does not follow the acute time course of changes in FMD post-exercise. Hence, the use of slope 2 StO2 as a surrogate measure of vascular function in youth must be refuted.
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Affiliation(s)
- Sascha H. Kranen
- Children’s Health and Exercise Research Centre, Public Health and Sports Sciences, University of Exeter Medical School, Faculty of Health and Life Sciences, University of Exeter, Exeter, United Kingdom
| | - Ricardo S. Oliveira
- Children’s Health and Exercise Research Centre, Public Health and Sports Sciences, University of Exeter Medical School, Faculty of Health and Life Sciences, University of Exeter, Exeter, United Kingdom
- Department of Physical Education, Federal University of Rio Grande do Norte, Natal, Brazil
| | - Bert Bond
- Children’s Health and Exercise Research Centre, Public Health and Sports Sciences, University of Exeter Medical School, Faculty of Health and Life Sciences, University of Exeter, Exeter, United Kingdom
| | - Craig A. Williams
- Children’s Health and Exercise Research Centre, Public Health and Sports Sciences, University of Exeter Medical School, Faculty of Health and Life Sciences, University of Exeter, Exeter, United Kingdom
| | - Alan R. Barker
- Children’s Health and Exercise Research Centre, Public Health and Sports Sciences, University of Exeter Medical School, Faculty of Health and Life Sciences, University of Exeter, Exeter, United Kingdom
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Eglin CM, Wright J, Maley MJ, Hollis S, Massey H, Montgomery H, Tipton MJ. The peripheral vascular responses in non-freezing cold injury and matched controls. Exp Physiol 2023; 108:420-437. [PMID: 36807667 PMCID: PMC10103892 DOI: 10.1113/ep090721] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Accepted: 01/20/2023] [Indexed: 02/22/2023]
Abstract
NEW FINDINGS What is the central question of this study? Does non-freezing cold injury (NFCI) alter normal peripheral vascular function? What is the main finding and its importance? Individuals with NFCI were more cold sensitive (rewarmed more slowly and felt more discomfort) than controls. Vascular tests indicated that extremity endothelial function was preserved with NFCI and that sympathetic vasoconstrictor response might be reduced. The pathophysiology underpinning the cold sensitivity associated with NFCI thus remains to be identified. ABSTRACT The impact of non-freezing cold injury (NFCI) on peripheral vascular function was investigated. Individuals with NFCI (NFCI group) and closely matched controls with either similar (COLD group) or limited (CON group) previous cold exposure were compared (n = 16). Peripheral cutaneous vascular responses to deep inspiration (DI), occlusion (PORH), local cutaneous heating (LH) and iontophoresis of acetylcholine and sodium nitroprusside were investigated. The responses to a cold sensitivity test (CST) involving immersion of a foot in 15°C water for 2 min followed by spontaneous rewarming, and a foot cooling protocol (footplate cooled from 34°C to 15°C), were also examined. The vasoconstrictor response to DI was lower in NFCI compared to CON (toe: 73 (28)% vs. 91 (17)%; P = 0.003). The responses to PORH, LH and iontophoresis were not reduced compared to either COLD or CON. During the CST, toe skin temperature rewarmed more slowly in NFCI than COLD or CON (10 min: 27.4 (2.3)°C vs. 30.7 (3.7)°C and 31.7 (3.9)°C, P < 0.05, respectively); however, no differences were observed during the footplate cooling. NFCI were more cold-intolerant (P < 0.0001) and reported colder and more uncomfortable feet during the CST and footplate cooling than COLD and CON (P < 0.05). NFCI showed a decreased sensitivity to sympathetic vasoconstrictor activation than CON and greater cold sensitivity (CST) compared to COLD and CON. None of the other vascular function tests indicated endothelial dysfunction. However, NFCI perceived their extremities to be colder and more uncomfortable/painful than the controls.
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Affiliation(s)
- Clare M. Eglin
- Extreme Environments Laboratory, School of Sport, Health and Exercise ScienceUniversity of PortsmouthPortsmouthUK
| | - Jennifer Wright
- Extreme Environments Laboratory, School of Sport, Health and Exercise ScienceUniversity of PortsmouthPortsmouthUK
| | - Matthew J. Maley
- Environmental Ergonomics Research Centre, Loughborough School of Design and Creative ArtsLoughborough UniversityLoughboroughUK
| | - Sarah Hollis
- Regional Occupational Health Team (ROHT) CatterickCatterick GarrisonUK
| | - Heather Massey
- Extreme Environments Laboratory, School of Sport, Health and Exercise ScienceUniversity of PortsmouthPortsmouthUK
| | | | - Michael J. Tipton
- Extreme Environments Laboratory, School of Sport, Health and Exercise ScienceUniversity of PortsmouthPortsmouthUK
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McGarr GW, Saci S, Akerman AP, Fujii N, Kenny GP. Reliability of laser-Doppler flowmetry derived measurements of forearm and calf cutaneous vasodilation during gradual local heating in young adults. Microvasc Res 2023; 146:104470. [PMID: 36549373 DOI: 10.1016/j.mvr.2022.104470] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 12/06/2022] [Accepted: 12/15/2022] [Indexed: 12/24/2022]
Abstract
OBJECTIVES Evaluate reliability of laser-Doppler flowmetry derived cutaneous vasodilation on the upper and lower limbs during gradual local heating. METHODS In twenty-eight young adults (21 (SD 3) years, 14 females), absolute cutaneous vascular conductance (CVCabs) and CVC normalized to maximum vasodilation at 44 °C (%CVCmax) were assessed at two adjacent sites on each of the forearm and calf during gradual local skin heating (33-42 °C at 1 °C·5 min-1) for two identical trials (∼1 week apart). Responses were assessed for baseline, the steady-state heating plateau at 42 °C and the span (i.e. plateau-baseline). RESULTS Between-day reliability was characterized as measurement consistency across trials. Within-day reliability was characterized as within-limb measurement consistency across adjacent skin sites. Between- and within-day absolute reliability (coefficient of variation) generally improved with heating, from poor (>25 %) at baseline to good (<10 %) for %CVCmax and moderate (10-25 %) for CVCabs for plateau and span. However, relative reliability (intraclass correlation coefficient) was generally not acceptable (<0.70) for any condition. Responses were generally consistent for females and males and there were no major forearm and calf differences. CONCLUSIONS Consistency of CVC estimates improved during gradual local heating with negligible limb and sex differences, which are important considerations for experimental design and interpretation.
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Affiliation(s)
- Gregory W McGarr
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Ontario, Canada
| | - Samah Saci
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Ontario, Canada
| | - Ashley P Akerman
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Ontario, Canada
| | - Naoto Fujii
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Ontario, Canada; Faculty of Health and Sport Sciences, University of Tsukuba, Tsukuba City, Japan
| | - Glen P Kenny
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Ontario, Canada.
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Contreras R, Hernández G, Valenzuela ED, González C, Ulloa R, Soto D, Castro R, Guzmán C, Oviedo V, Alegría L, Vidal D, Morales S, Ospina-Tascón GA, Bakker J, Kattan E. Exploring the relationship between capillary refill time, skin blood flow and microcirculatory reactivity during early resuscitation of patients with septic shock: a pilot study. J Clin Monit Comput 2022; 37:839-845. [PMID: 36495360 DOI: 10.1007/s10877-022-00946-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 11/08/2022] [Indexed: 12/14/2022]
Abstract
Capillary refill time (CRT), a costless and widely available tool, has emerged as a promising target to guide septic shock resuscitation. However, it has yet to gain universal acceptance due to its potential inter-observer variability. Standardization of CRT assessment may minimize this problem, but few studies have compared this approach with techniques that directly assess skin blood flow (SBF). Our objective was to determine if an abnormal CRT is associated with impaired SBF and microvascular reactivity in early septic shock patients. Twelve septic shock patients were subjected to multimodal perfusion and hemodynamic monitoring for 24 h. Three time-points (0, 1, and 24 h) were registered for each patient. SBF was measured by laser doppler. We performed a baseline SBF measurement and two microvascular reactivity tests: one with a thermal challenge at 44 °C and other with a vascular occlusion test. Ten healthy volunteers were evaluated to obtain reference values. The patients (median age 70 years) exhibited a 28-day mortality of 50%. Baseline CRT was 3.3 [2.7-7.3] seconds. In pooled data analysis, abnormal CRT presented a significantly lower SBF when compared to normal CRT [44 (13.3-80.3) vs 193.2 (99.4-285) APU, p = 0.0001]. CRT was strongly associated with SBF (R2 0.76, p < 0.0001). An abnormal CRT also was associated with impaired thermal challenge and vascular occlusion tests. Abnormal CRT values observed during early septic shock resuscitation are associated with impaired skin blood flow, and abnormal skin microvascular reactivity. Future studies should confirm these results.
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Kamshilin AA, Zaytsev VV, Belaventseva AV, Podolyan NP, Volynsky MA, Sakovskaia AV, Romashko RV, Mamontov OV. Novel Method to Assess Endothelial Function via Monitoring of Perfusion Response to Local Heating by Imaging Photoplethysmography. SENSORS (BASEL, SWITZERLAND) 2022; 22:5727. [PMID: 35957284 PMCID: PMC9370951 DOI: 10.3390/s22155727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 07/26/2022] [Accepted: 07/28/2022] [Indexed: 06/15/2023]
Abstract
Endothelial dysfunction is one of the most important markers of the risk of cardiovascular complications. This study is aimed to demonstrate the feasibility of imaging photoplethysmography to assess microcirculation response to local heating in order to develop a novel technology for assessing endothelial function. As a measure of vasodilation, we used the relative dynamics of the pulsatile component of the photoplethysmographic waveform, which was assessed in a large area of the outer surface of the middle third of the subject's forearm. The perfusion response was evaluated in six healthy volunteers during a test with local skin heating up to 40-42 °C and subsequent relaxation. The proposed method is featured by accurate control of the parameters affecting the microcirculation during the prolonged study. It was found that in response to local hyperthermia, a multiple increase in the pulsation component, which has a biphasic character, was observed. The amplitude of the first phase of the perfusion reaction depends on both the initial skin temperature and the difference between the basal and heating temperatures. The proposed method allows the assessment of a reproducible perfusion increase in response to hyperthermia developed due to humoral factors associated with the endothelium, thus allowing detection of its dysfunction.
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Affiliation(s)
- Alexei A. Kamshilin
- Institute of Automation and Control Processes of the Far Eastern Branch of the Russian Academy of Sciences, Vladivostok 690041, Russia; (V.V.Z.); (A.V.B.); (N.P.P.); (M.A.V.); (A.V.S.); (R.V.R.); (O.V.M.)
| | - Valeriy V. Zaytsev
- Institute of Automation and Control Processes of the Far Eastern Branch of the Russian Academy of Sciences, Vladivostok 690041, Russia; (V.V.Z.); (A.V.B.); (N.P.P.); (M.A.V.); (A.V.S.); (R.V.R.); (O.V.M.)
- Department of Circulation Physiology, Almazov National Medical Research Centre, Saint Petersburg 197341, Russia
| | - Anzhelika V. Belaventseva
- Institute of Automation and Control Processes of the Far Eastern Branch of the Russian Academy of Sciences, Vladivostok 690041, Russia; (V.V.Z.); (A.V.B.); (N.P.P.); (M.A.V.); (A.V.S.); (R.V.R.); (O.V.M.)
| | - Natalia P. Podolyan
- Institute of Automation and Control Processes of the Far Eastern Branch of the Russian Academy of Sciences, Vladivostok 690041, Russia; (V.V.Z.); (A.V.B.); (N.P.P.); (M.A.V.); (A.V.S.); (R.V.R.); (O.V.M.)
| | - Maxim A. Volynsky
- Institute of Automation and Control Processes of the Far Eastern Branch of the Russian Academy of Sciences, Vladivostok 690041, Russia; (V.V.Z.); (A.V.B.); (N.P.P.); (M.A.V.); (A.V.S.); (R.V.R.); (O.V.M.)
- School of Physics and Engineering, ITMO University, Saint Petersburg 197101, Russia
| | - Anastasiia V. Sakovskaia
- Institute of Automation and Control Processes of the Far Eastern Branch of the Russian Academy of Sciences, Vladivostok 690041, Russia; (V.V.Z.); (A.V.B.); (N.P.P.); (M.A.V.); (A.V.S.); (R.V.R.); (O.V.M.)
- Institute of Therapy and Instrumental Diagnostics, Pacific State Medical University, Vladivostok 690002, Russia
| | - Roman V. Romashko
- Institute of Automation and Control Processes of the Far Eastern Branch of the Russian Academy of Sciences, Vladivostok 690041, Russia; (V.V.Z.); (A.V.B.); (N.P.P.); (M.A.V.); (A.V.S.); (R.V.R.); (O.V.M.)
| | - Oleg V. Mamontov
- Institute of Automation and Control Processes of the Far Eastern Branch of the Russian Academy of Sciences, Vladivostok 690041, Russia; (V.V.Z.); (A.V.B.); (N.P.P.); (M.A.V.); (A.V.S.); (R.V.R.); (O.V.M.)
- Department of Circulation Physiology, Almazov National Medical Research Centre, Saint Petersburg 197341, Russia
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11
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Luck JC, Kunselman AR, Herr MD, Blaha CA, Sinoway LI, Cui J. Multiple Laser Doppler Flowmetry Probes Increase the Reproducibility of Skin Blood Flow Measurements. Front Physiol 2022; 13:876633. [PMID: 35711302 PMCID: PMC9197318 DOI: 10.3389/fphys.2022.876633] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 05/11/2022] [Indexed: 01/18/2023] Open
Abstract
Cutaneous microcirculatory perfusion is commonly measured using laser Doppler flowmetry (LDF) probes, which provide a continuous, non-invasive quantification of skin blood flow (SkBF). However, inhomogeneities in the skin’s microvasculature density contribute to a decrease in reproducibility whenever an LDF probe is removed and replaced, as is the case during pre- and post-intervention or between-day measurements. Therefore, this study aimed to determine whether increasing the total number of individual LDF probes in a localized area improves the reproducibility of the measurement. Seven laser Doppler probes were secured in a custom-made acrylic holder designed to attach to the skin’s surface easily. SkBF, local skin temperature (Tsk), and blood pressure (BP) were assessed in 11 participants (6 M, 5 F, 42 ± 15 years). SkBF and Tsk were measured from the dorsal forearm (arm trial) for 5 min. Next, the multi-laser device was moved to the lateral side of the calf (leg trial), and measurements were obtained for 5 min. Each arm and leg trial was cyclically repeated three times, and all trials were separated by intermissions lasting 10–15 min. The average SkBF and the cutaneous vascular conductance (CVC) from all possible LDF probe combinations were not statistically different across the three arm and leg trials. Two-way mixed-effects models with absolute agreement were used to compute the intraclass correlation coefficient (ICC) for CVC, and the minimum ICC increased with the addition of LDF probes. The ICC of the average CVC from seven LDF probes was 0.96 between the arm trials and 0.91 between the leg trials, which suggests that there is excellent reliability and little difference between trials following the removal and replacement of the device. Moreover, all individual ICC values from ≥3 LDF probe combinations were greater than 0.70 (i.e., good reliability). These data suggest that SkBF measurements with multiple laser Doppler probes in a custom-made holder have excellent reproducibility after replacing the probes within the same participant. Therefore, this application could provide more reproducible assessments between repeated measurements (e.g., before and after exercise or clinical procedures) where the LDF probes must be removed and replaced within the same location.
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Affiliation(s)
- J Carter Luck
- Penn State Health Heart and Vascular Institute, Pennsylvania State University College of Medicine, Hershey, PA, United States
| | - Allen R Kunselman
- Department of Public Health Sciences, Pennsylvania State University College of Medicine, Hershey, PA, United States
| | - Michael D Herr
- Penn State Health Heart and Vascular Institute, Pennsylvania State University College of Medicine, Hershey, PA, United States
| | - Cheryl A Blaha
- Penn State Health Heart and Vascular Institute, Pennsylvania State University College of Medicine, Hershey, PA, United States
| | - Lawrence I Sinoway
- Penn State Health Heart and Vascular Institute, Pennsylvania State University College of Medicine, Hershey, PA, United States
| | - Jian Cui
- Penn State Health Heart and Vascular Institute, Pennsylvania State University College of Medicine, Hershey, PA, United States
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12
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Peng YH, Maarek JMI. Development and validation of quantitative optical index of skin blood content. JOURNAL OF BIOMEDICAL OPTICS 2022; 27:JBO-210250RRR. [PMID: 35773754 PMCID: PMC9243648 DOI: 10.1117/1.jbo.27.6.065003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/08/2021] [Accepted: 06/14/2022] [Indexed: 06/15/2023]
Abstract
SIGNIFICANCE We present an approach to estimate with simple instrumentation the amount of red blood cells in the skin microvasculature, designated as parameter LRBC. Variations of parameter LRBC are shown to reflect local changes in the quantity of skin red blood cells during a venous occlusion challenge. AIM To validate a simple algebraic model of light transport in skin using the Monte Carlo method and to develop a measure of the red blood cell content in skin microvessels using the Monte Carlo predictions; to guide the development of an instrument to measure experimentally variations of the amount of red blood cells in the skin. APPROACH Monte Carlo simulations were carried out in a multilayer model of the skin to compute remitted light intensities as a function of distance from the illumination locus for different values of the skin blood content. The simulation results were used to compute parameter LRBC and its variations with local skin blood content. An experimental setup was developed to measure parameter LRBC in human volunteers in whom skin blood content of the forearm increased during temporary interruption of the venous outflow. RESULTS In the simulations, parameter LRBC was ∼16 μm in baseline conditions, and it increased in near proportion with the blood content of the skin layers. Measuring the diffusely reflected light intensity 0.5 to 1.2 mm away from the illumination locus was optimal to detect appreciable changes of the reflected light intensity as skin blood content was altered. Parameter LRBC measured experimentally on the human forearm was 17 ± 2 μm in baseline conditions it increased at a rate of 4 ± 2 μm / min when venous outflow was temporarily interrupted. CONCLUSION Parameter LRBC derived experimentally with a two-wavelength diffuse reflectometer can be used to measure local variations of the amount of red blood cells in skin microvessels.
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Affiliation(s)
- Yu-Hao Peng
- University of Southern California, Department of Biomedical Engineering, Los Angeles, California, United States
| | - Jean-Michel I. Maarek
- University of Southern California, Department of Biomedical Engineering, Los Angeles, California, United States
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13
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Mongkolpun W, Gardette M, Orbegozo D, Vincent JL, Creteur J. An increase in skin blood flow induced by fluid challenge is associated with an increase in oxygen consumption in patients with circulatory shock. J Crit Care 2022; 69:153984. [DOI: 10.1016/j.jcrc.2022.01.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 11/30/2021] [Accepted: 01/02/2022] [Indexed: 12/29/2022]
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14
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Methods to evaluate vascular function: a crucial approach towards predictive, preventive, and personalised medicine. EPMA J 2022; 13:209-235. [PMID: 35611340 PMCID: PMC9120812 DOI: 10.1007/s13167-022-00280-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 05/02/2022] [Indexed: 11/06/2022]
Abstract
Endothelium, the gatekeeper of our blood vessels, is highly heterogeneous and a crucial physical barrier with the ability to produce vasoactive and protective mediators under physiological conditions. It regulates vascular tone, haemostasis, vascular inflammation, remodelling, and angiogenesis. Several cardio-, reno-, and cerebrovascular diseases begin with the dysfunction of endothelial cells, and more recently, COVID-19 was also associated with endothelial disease highlighting the need to monitor its function towards prevention and reduction of vascular dysfunction. Endothelial cells are an important therapeutic target in predictive, preventive, and personalised (3P) medicine with upmost importance in vascular diseases. The development of novel non-invasive techniques to access endothelial dysfunction for use in combination with existing clinical imaging modalities provides a feasible opportunity to reduce the burden of vascular disease. This review summarises recent advances in the principles of endothelial function measurements. This article presents an overview of invasive and non-invasive techniques to determine vascular function and their major advantages and disadvantages. In addition, the article describes mechanisms underlying the regulation of vascular function and dysfunction and potential new biomarkers of endothelial damage. Recognising these biomarkers is fundamental towards a shift from reactive to 3P medicine in the vascular field. Identifying vascular dysfunction earlier with non-invasive or minimally invasive techniques adds value to predictive diagnostics and targeted prevention (primary, secondary, tertiary care). In addition, vascular dysfunction is a potential target for treatments tailored to the person.
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15
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Laser speckle contrast imaging and laser Doppler flowmetry reproducibly assess reflex cutaneous vasoconstriction. Microvasc Res 2022; 142:104363. [DOI: 10.1016/j.mvr.2022.104363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 03/15/2022] [Accepted: 03/18/2022] [Indexed: 11/20/2022]
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16
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Lima NS, Lefferts EC, Clifford PS. Reactive hyperemia augments local heat-induced skin hyperemia. Exp Physiol 2022; 107:383-389. [PMID: 35218593 DOI: 10.1113/ep090071] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Accepted: 02/11/2022] [Indexed: 11/08/2022]
Abstract
NEW FINDINGS What is the central question of this study? It is valuable to be able to monitor disease or treatment related changes in the microcirculation. Laser doppler flowmetry with local heating allows noninvasive monitoring of the skin microcirculation and its ability to vasodilate. Does reactive hyperemia augment the increase in skin blood flow elicited by local heating? What is the main finding and its importance? The results of this study show that the addition of reactive hyperemia to local heating results in greater vasodilation than heating alone. Thus, reactive hyperemia can augment local heat-induced hyperemia in the skin. ABSTRACT The skin circulation has been proposed as a model of generalized microvascular function which could be monitored noninvasively using laser doppler flowmetry (LDF). The response to heat hyperemia (HH) is commonly used to monitor disease or treatment related changes in microvascular function. We hypothesized that reactive hyperemia would augment the increase in skin blood flow elicited by local heating. Fourteen healthy young adults were subjected to 3 different conditions: reactive hyperemia (RH; skin temperature controlled at 33°C), heat hyperemia (HH; 42°C held for 40 minutes), and HH+RH. Two Peltier-controlled thermomodules with laser LDF probes were placed on the right forearm to continuously monitor skin blood flow. A cuff was placed on the right upper arm to elicit RH by inflation to 220 mmHg for 5 minutes. This procedure was performed with skin temperature at 33°C and again after 40 min of local heating to 42°C. Beat-by-beat mean arterial pressure (MAP) obtained by a photoplethysmographic sensor on the middle finger of the left hand allowed calculation of cutaneous vascular conductance (CVC) as LDF / MAP. Both HH and RH increased LDF (p<0.0001 and p <0.0001, respectively) and CVC (p = 0.0001 and p<0.0001) above baseline values. LDF and CVC values were significantly higher during HH+RH when compared to RH or HH alone (p<0.0001). In summary, HH+RH resulted in greater vasodilation when compared to HH or RH alone. These results indicate that RH can augment local heat-induced hyperemia in the skin. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Natalia S Lima
- Integrative Physiology Laboratory, University of Illinois at Chicago, Chicago, Illinois, United States
| | - Elizabeth C Lefferts
- Integrative Physiology Laboratory, University of Illinois at Chicago, Chicago, Illinois, United States.,Department of Kinesiology, Iowa State University, Ames, Iowa, United States
| | - Philip S Clifford
- Integrative Physiology Laboratory, University of Illinois at Chicago, Chicago, Illinois, United States
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17
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Dillon GA, Wolf ST, Alexander LM. Nitric oxide-mediated cutaneous microvascular function is not altered in young adults following mild-to-moderate SARS CoV-2 infection. Am J Physiol Heart Circ Physiol 2022; 322:H319-H327. [PMID: 34995164 PMCID: PMC8803551 DOI: 10.1152/ajpheart.00602.2021] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 01/05/2022] [Accepted: 01/05/2022] [Indexed: 11/22/2022]
Abstract
Vascular dysfunction has been reported in adults who have recovered from COVID-19. To date, no studies have investigated the underlying mechanisms of persistent COVID-19-associated vascular dysfunction. Our purpose was to quantify nitric oxide (NO)-mediated vasodilation in healthy adults who have recovered from SARS-CoV-2 infection. We hypothesized that COVID-19-recovered adults would have impaired NO-mediated vasodilation compared with adults who have not had COVID-19. In methods, we performed a cross-sectional study including 10 (5 men/5 women, 24 ± 4 yr) healthy control (HC) adults who were unvaccinated for COVID-19, 11 (4 men/7 women, 25 ± 6 yr) healthy vaccinated (HV) adults, and 12 (5 men/7 women, 22 ± 3 yr) post-COVID-19 (PC, 19 ± 14 wk) adults. COVID-19 symptoms severity (survey) was assessed. A standardized 39°C local heating protocol was used to assess NO-dependent vasodilation via perfusion (intradermal microdialysis) of 15 mM NG-nitro-l-arginine methyl ester during the plateau of the heating response. Red blood cell flux was measured (laser-Doppler flowmetry) and cutaneous vascular conductance (CVC = flux/mmHg) was expressed as a percentage of maximum (28 mM sodium nitroprusside + 43°C). In results, the local heating plateau (HC: 61 ± 20%, HV: 60 ± 19%, PC: 67 ± 19%, P = 0.80) and NO-dependent vasodilation (HC: 77 ± 9%, HV: 71 ± 7%, PC: 70 ± 10%, P = 0.36) were not different among groups. Neither symptom severity (25 ± 12 AU) nor time since diagnosis correlated with the NO-dependent vasodilation (r = 0.46, P = 0.13; r = 0.41, P = 0.19, respectively). In conclusion, healthy adults who have had mild-to-moderate COVID-19 do not have altered NO-mediated cutaneous microvascular function.NEW & NOTEWORTHY Healthy young adults who have had mild-to-moderate COVID-19 do not display alterations in nitric oxide-mediated cutaneous microvascular function. In addition, healthy young adults who have COVID-19 antibodies from the COVID-19 vaccinations do not display alterations in nitric oxide-mediated cutaneous microvascular function.
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Affiliation(s)
- Gabrielle A Dillon
- Noll Laboratory, Department of Kinesiology, The Pennsylvania State University, University Park, Pennsylvania
- Center for Healthy Aging, The Pennsylvania State University, University Park, Pennsylvania
| | - S Tony Wolf
- Noll Laboratory, Department of Kinesiology, The Pennsylvania State University, University Park, Pennsylvania
| | - Lacy M Alexander
- Noll Laboratory, Department of Kinesiology, The Pennsylvania State University, University Park, Pennsylvania
- Center for Healthy Aging, The Pennsylvania State University, University Park, Pennsylvania
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18
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Schnorbus B, Jurk K, Lackner KJ, Welk C, Münzel T, Gori T. Effects of Clopidogrel, Prasugrel and Ticagrelor on Microvascular Function and Platelet Reactivity in Patients With Acute Coronary Syndrome Undergoing Coronary Artery Stenting. A Randomized, Blinded, Parallel Group Trial. Front Cardiovasc Med 2021; 8:780605. [PMID: 34966798 PMCID: PMC8710519 DOI: 10.3389/fcvm.2021.780605] [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: 09/21/2021] [Accepted: 11/17/2021] [Indexed: 11/13/2022] Open
Abstract
Aims: In this pre-specified analysis of the "endothelium, stent and antiplatelet therapy" study, we investigate the impact of antiplatelet therapies on microvascular function in patients undergoing stenting for an acute coronary syndrome. Methods and Results: Fifty-six patients [age: 63(55-67) years, males, 10 diabetics, 27 non-ST-elevation myocardial infarction] were randomized to receive clopidogrel, ticagrelor or prasugrel in form of oral loading 2 h before stenting followed by oral therapy. Investigators were blinded to the allocation. Laser-Doppler microvascular function and ADP-induced platelet aggregation capacity were measured at baseline, 2 h after oral antiplatelet loading, and 1 day, 1 week and 1 month after stenting during chronic therapy with the same antiplatelet agent. Platelet aggregation decreased in all groups 2 h after oral loading, with a significantly larger effect in the prasugrel group (P = 0.009). Similarly, prasugrel and ticagrelor loading was followed by an increase in microvascular reactive hyperemia (P = 0.007 and P = 0.042 compared to clopidogrel). This effect disappeared one day after coronary intervention, with a significant decrease in the prasugrel group (P = 0.026). Similarly, analysis of microvascular conductance showed a larger increase in the prasugrel group 2 h after loading (P = 0.022 among groups), and a decrease in all groups after stenting. Conclusions: Oral loading with prasugrel (and less consistently ticagrelor) is associated with improved microvascular function and stronger platelet inhibition in acute coronary syndrome patients. The microvascular effect was however lost 1 day after stenting and during subsequent follow-up. Further studies are necessary to clarify the the long-term effects and potential benefits of P2Y12 inhibitors on microvascular damage. ClINICALTRIALS.gov N°: NCT01700322 EUDRACT-N°: 2011-005305-73.
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Affiliation(s)
- Boris Schnorbus
- Zentrum für Kardiologie, Kardiologie I, Universitätsmedizin Mainz, Johannes Gutenberg-University Mainz, Mainz, Germany.,Center for Thrombosis and Hemostasis, Universitätsmedizin Mainz, Johannes Gutenberg- University Mainz, Mainz, Germany
| | - Kerstin Jurk
- Center for Thrombosis and Hemostasis, Universitätsmedizin Mainz, Johannes Gutenberg- University Mainz, Mainz, Germany
| | - Karl J Lackner
- Institute of Clinical Chemistry and Laboratory Medicine, Universitätsmedizin Mainz, Johannes Gutenberg- University Mainz, Mainz, Germany
| | - Caroline Welk
- Zentrum für Kardiologie, Kardiologie I, Universitätsmedizin Mainz, Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Thomas Münzel
- Zentrum für Kardiologie, Kardiologie I, Universitätsmedizin Mainz, Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Tommaso Gori
- Zentrum für Kardiologie, Kardiologie I, Universitätsmedizin Mainz, Johannes Gutenberg-University Mainz, Mainz, Germany.,Deutsches Zentrum für Herz Kreislauf-Forschung (DZHK), Standort Rhein-Main, Partnereinrichtung Mainz, Mainz, Germany
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19
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Maruhashi T, Higashi Y. Clinical implication of impaired skin microvascular function in patients with hypertension. Hypertens Res 2021; 45:535-537. [PMID: 34955531 DOI: 10.1038/s41440-021-00838-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 12/03/2021] [Indexed: 11/09/2022]
Affiliation(s)
- Tatsuya Maruhashi
- Department of Cardiovascular Regeneration and Medicine, Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima, Japan.
| | - Yukihito Higashi
- Department of Cardiovascular Regeneration and Medicine, Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima, Japan.,Division of Regeneration and Medicine, Medical Center for Translational and Clinical Research, Hiroshima University Hospital, Hiroshima, Japan
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20
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Jonasson H, Bergstrand S, Fredriksson I, Larsson M, Östgren CJ, Strömberg T. Post-ischemic skin peak oxygen saturation is associated with cardiovascular risk factors: a Swedish cohort study. Microvasc Res 2021; 140:104284. [PMID: 34826433 DOI: 10.1016/j.mvr.2021.104284] [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] [Received: 05/10/2021] [Revised: 11/17/2021] [Accepted: 11/17/2021] [Indexed: 02/08/2023]
Abstract
The objective of this study was to explore the associations between skin microcirculatory function and established cardiovascular risk factors in a large Swedish cohort. As part of the Swedish CArdioPulmonary bioImage Study (SCAPIS), microcirculatory data were acquired at Linköping University hospital, Linköping, Sweden during 2016-2017. The subjects, aged 50-64 years, were randomly selected from the national population register. Microcirculatory reactivity was assessed using a 5-min arterial occlusion-release protocol. Comprehensive skin microcirculatory data were continuously acquired by using a fiberoptic probe placed on the lower right arm. After exclusion of missing data (208), 1557 subjects were remaining. Among the parameters, skin microcirculatory peak oxygen saturation after occlusion release, had the strongest relationship to the cardiovascular risk factors. The linear associations between peak oxygen saturation and cardiovascular risk factors were analyzed adjusted for age and sex. We found a negative association with peak oxygen saturation (standardized regression coefficient) for blood pressure (systolic -0.05 (95% CI: -0.10;-0.003) and diastolic -0.05 (-0.10; -0.003)), BMI -0.18 (-0.23; -0.13), waist circumference (males -0.20 (-0.32; -0.16), females -0.18 (-0.25; -0.11)), prevalent diabetes -0.31 (-0.49; -0.12), hypertension -0.30 (-0.42; -0.18), dyslipidemia -0.24 (-0.40; -0.09), fasting glucose level -0.06 (-0.12; -0.01), HbA1c -0.07 (-0.12; -0.02), triglyceride level -0.09 (-0.14; -0.04), hsCRP -0.12 (-0.17; -0.07), and current smoker versus never smoked -0.50 (-0.67; -0.34). A positive association with peak oxygen saturation was found for cholesterol level 0.05 (0.005; 0.11) and HDL 0.11 (0.06; 0.17). This is the first study showing that post-ischemic skin microvascular peak oxygen saturation is associated with virtually all established cardiovascular risk factors in a population-based middle-aged cohort.
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Affiliation(s)
- Hanna Jonasson
- Department of Biomedical Engineering, Linköping University, Linköping, Sweden.
| | - Sara Bergstrand
- Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden
| | - Ingemar Fredriksson
- Department of Biomedical Engineering, Linköping University, Linköping, Sweden; Perimed AB, Järfälla, Stockholm, Sweden
| | - Marcus Larsson
- Department of Biomedical Engineering, Linköping University, Linköping, Sweden
| | - Carl Johan Östgren
- Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden
| | - Tomas Strömberg
- Department of Biomedical Engineering, Linköping University, Linköping, Sweden
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21
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Sixtus RP, Pacharinsak C, Gray CL, Berry MJ, Dyson RM. Differential effects of four intramuscular sedatives on cardiorespiratory stability in juvenile guinea pigs (Cavia porcellus). PLoS One 2021; 16:e0259559. [PMID: 34780534 PMCID: PMC8592412 DOI: 10.1371/journal.pone.0259559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Accepted: 10/22/2021] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Non-invasive physiological monitoring can induce stress in laboratory animals. Sedation reduces the level of restraint required, thereby improving the validity of physiological signals measured. However, sedatives may alter physiological equilibrium introducing unintended bias and/or, masking the experimental outcomes of interest. We aimed to investigate the cardiorespiratory effects of four short-acting sedatives in juvenile guinea pigs. METHOD 12 healthy, 38 (26-46) day-old Dunkin Hartley guinea pigs were included in this blinded, randomised, crossover design study. Animals were sedated by intramuscular injection using pre-established minimum effective doses of either alfaxalone (5 mg/kg), diazepam (5 mg/kg), ketamine (30 mg/kg), or midazolam (2 mg/kg) administered in random order with a minimum washout period of 48 hours between agents. Sedative depth, a composite score comprised of five assessment criteria, was observed every 5-min from dosing until arousal. Physiological monitoring of cardiorespiratory status included measures of heart rate, blood pressure, respiratory rate, and peripheral microvascular perfusion. RESULTS Ketamine and alfaxalone were most effective in inducing stable sedation suitable for physiological monitoring, and diazepam less-so. Midazolam was unsuitable due to excessive hypersensitivity. All sedatives significantly increased heart rate above non-sedated control rates (P<0.0001), without altering blood pressure or microvascular perfusion. Alfaxalone and ketamine reduced respiratory rate relative to their control condition (P<0.0001, P = 0.05, respectively), but within normative ranges. CONCLUSION Ketamine and alfaxalone are the most effective sedatives for inducing short duration, stable sedation with minimal cardiorespiratory depression in guinea pigs, while diazepam is less-so. However, alfaxalone is the most appropriate sedative for longitudinal studies requiring multiple physiological timepoints.
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Affiliation(s)
- Ryan P Sixtus
- Department of Paediatrics and Child Health, & Centre for Translational Research, University of Otago, Wellington, New Zealand
| | - Cholawat Pacharinsak
- Department of Comparative Medicine, Stanford University, Stanford, CA, United States of America
| | - Clint L Gray
- Department of Paediatrics and Child Health, & Centre for Translational Research, University of Otago, Wellington, New Zealand
| | - Mary J Berry
- Department of Paediatrics and Child Health, & Centre for Translational Research, University of Otago, Wellington, New Zealand
| | - Rebecca M Dyson
- Department of Paediatrics and Child Health, & Centre for Translational Research, University of Otago, Wellington, New Zealand
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22
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Reminy K, Ngo Sock ET, Romana M, Connes P, Ravion S, Henri S, Hue O, Hardy-Dessources MD, Antoine-Jonville S. Strenuous exercise in warm environment is associated with improved microvascular function in sickle cell trait. Eur J Appl Physiol 2021; 122:185-197. [PMID: 34633508 DOI: 10.1007/s00421-021-04821-2] [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: 06/05/2021] [Accepted: 09/22/2021] [Indexed: 11/27/2022]
Abstract
PURPOSE Sickle cell trait is characterized by the presence of both normal and abnormal haemoglobin in red blood cells. The rate of exertional collapse is increased in athletes and military recruits who carry the trait, particularly in stressful environmental conditions. The aim of the present study was to investigate microvascular function and its determinants in response to intense exercise at control and warm environmental temperatures in carriers (AS) and non-carriers (AA) of sickle cell trait. METHODS Nine AS and 11 AA, all healthy physically active young men, randomly participated in four experimental sessions (rest at 21 °C and 31 °C and cycling at 21 °C and 31 °C). All participants performed three exercises bouts as follows: 18-min submaximal exercise; an incremental test to exhaustion; and three 30-s sprints spaced with 20-s resting intervals. RESULTS Skin Blood Flow (SkBF) was similar at rest between AA and AS. SkBF for all participants was higher at 31 °C than 21 °C. It was significantly higher in the AS group compared to the AA group immediately after exercise, regardless of the environmental conditions. No significant differences in hemorheological parameters, muscle damage or cardiac injury biomarkers were observed between the two groups. Our data also suggest higher oxidative stress for the AS group, with high superoxide dismutase (P = 0.044 main group effect). CONCLUSION A specific profile is identified in the AS population, with increased microvascular reactivity after maximal exercise in stressful environment and slight pro-/antioxidant imbalance.
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Affiliation(s)
- K Reminy
- Adaptation To Tropical Climate and Exercise Laboratory, EA3596, University of the French West Indies, Pointe-à-Pitre, Guadeloupe, France
| | - E T Ngo Sock
- Adaptation To Tropical Climate and Exercise Laboratory, EA3596, University of the French West Indies, Pointe-à-Pitre, Guadeloupe, France
| | - M Romana
- UMR_S1134, BIGR, University of the French West Indies, Pointe-à-Pitre, Guadeloupe, France.,Laboratoire d'Excellence du Globule Rouge (Labex GR-Ex), PRES Sorbonne, Paris, France
| | - P Connes
- (LIBM) EA7424, Biology and Red Blood Cell, Université Claude Bernard Lyon 1, Université de Lyon, Lyon, France.,Laboratoire d'Excellence du Globule Rouge (Labex GR-Ex), PRES Sorbonne, Paris, France
| | - S Ravion
- UMR_S1134, BIGR, University of the French West Indies, Pointe-à-Pitre, Guadeloupe, France
| | - S Henri
- Adaptation To Tropical Climate and Exercise Laboratory, EA3596, University of the French West Indies, Pointe-à-Pitre, Guadeloupe, France
| | - O Hue
- Adaptation To Tropical Climate and Exercise Laboratory, EA3596, University of the French West Indies, Pointe-à-Pitre, Guadeloupe, France
| | - M D Hardy-Dessources
- UMR_S1134, BIGR, University of the French West Indies, Pointe-à-Pitre, Guadeloupe, France.,Laboratoire d'Excellence du Globule Rouge (Labex GR-Ex), PRES Sorbonne, Paris, France
| | - S Antoine-Jonville
- Adaptation To Tropical Climate and Exercise Laboratory, EA3596, University of the French West Indies, Pointe-à-Pitre, Guadeloupe, France. .,LAPEC EA4278, Avignon University, 84000, Avignon, France.
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Dillon GA, Stanhewicz AE, Serviente C, Greaney JL, Alexander LM. Hydrogen sulfide-dependent microvascular vasodilation is improved following chronic sulfhydryl-donating antihypertensive pharmacotherapy in adults with hypertension. Am J Physiol Heart Circ Physiol 2021; 321:H728-H734. [PMID: 34477463 DOI: 10.1152/ajpheart.00404.2021] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Hypertension is characterized by systemic microvascular endothelial dysfunction, in part due to a functional absence of hydrogen sulfide (H2S)-mediated endothelium-dependent dilation. Treatment with a sulfhydryl-donating ACE inhibitor (SH-ACE inhibitor) improves endothelial function in preclinical models of hypertension. To date, no studies have directly assessed the effects of SH-ACE-inhibitor treatment on H2S-dependent vasodilation in humans with hypertension. We hypothesized that SH-ACE-inhibitor treatment would improve H2S-mediated endothelium-dependent vasodilation. Ten adults with hypertension [1 woman and 9 men; 56 ± 9 yr; systolic blood pressure (SBP): 141 ± 8.5 mmHg; diastolic blood pressure (DBP): 90.3 ± 6 mmHg] were treated (16 wk) with the SH-ACE-inhibitor captopril. Red blood cell flux (laser-Doppler flowmetry) was measured continuously during graded intradermal microdialysis perfusion of the endothelium-dependent agonist acetylcholine (ACh; 10-10 to 10-1 M) alone (control) and in combination with an inhibitor of enzymatic H2S production [10-3 M aminooxyacetate (AOAA)] preintervention and postintervention. Cutaneous vascular conductance (CVC; flux/mmHg) was calculated and normalized to the site-specific maximal CVC (0.028 M sodium nitroprusside and local heat to 43°C). Area under the curve was calculated using the trapezoid method. The 16-wk SH-ACE-inhibitor treatment resulted in a reduction of blood pressure (systolic BP: 129 ± 10 mmHg; diastolic BP: 81 ± 9 mmHg, both P < 0.05). Preintervention, inhibition of H2S production had no effect on ACh-induced vasodilation (316 ± 40 control vs. 322 ± 35 AU AOAA; P = 0.82). Captopril treatment improved ACh-induced vasodilation (316 ± 40 pre vs. 399 ± 55 AU post; P = 0.04) and increased the H2S-dependent component of ACh-induced vasodilation (pre: -6.6 ± 65.1 vs. post: 90.2 ± 148.3 AU, P = 0.04). These data suggest that SH-ACE-inhibitor antihypertensive treatment improves cutaneous microvascular endothelium-dependent vasodilation in adults with hypertension, in part via H2S-dependent mechanisms.NEW & NOTEWORTHY This is the first study to prospectively assess the effects of sulfhydryl antihypertensive treatment on microvascular endothelial function in adults with hypertension. Our data suggest that 16 wk of SH-ACE-inhibitor antihypertensive treatment improves cutaneous microvascular endothelium-dependent vasodilation in middle-aged adults with hypertension, in part via H2S-dependent mechanisms.
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Affiliation(s)
- Gabrielle A Dillon
- Noll Laboratory, Department of Kinesiology, The Pennsylvania State University, University Park, Pennsylvania.,Center for Healthy Aging, The Pennsylvania State University, University Park, Pennsylvania
| | - Anna E Stanhewicz
- Noll Laboratory, Department of Kinesiology, The Pennsylvania State University, University Park, Pennsylvania.,Department of Health and Human Physiology, The University of Iowa, Iowa City, Iowa
| | - Corinna Serviente
- Noll Laboratory, Department of Kinesiology, The Pennsylvania State University, University Park, Pennsylvania.,Center for Healthy Aging, The Pennsylvania State University, University Park, Pennsylvania.,Institute for Applied Life Sciences, University of Massachusetts Amherst, Amherst, Massachusetts.,Department of Kinesiology, University of Massachusetts Amherst, Amherst, Massachusetts
| | - Jody L Greaney
- Noll Laboratory, Department of Kinesiology, The Pennsylvania State University, University Park, Pennsylvania.,Department of Kinesiology, University of Texas Arlington, Arlington, Texas
| | - Lacy M Alexander
- Noll Laboratory, Department of Kinesiology, The Pennsylvania State University, University Park, Pennsylvania.,Center for Healthy Aging, The Pennsylvania State University, University Park, Pennsylvania
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Oral Glucose Load and Human Cutaneous Microcirculation: An Insight into Flowmotion Assessed by Wavelet Transform. BIOLOGY 2021; 10:biology10100953. [PMID: 34681052 PMCID: PMC8533385 DOI: 10.3390/biology10100953] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 08/31/2021] [Accepted: 09/10/2021] [Indexed: 01/10/2023]
Abstract
Simple Summary There is increasing evidence to suggest that microcirculation becomes dysfunctional earlier than large blood vessels or the heart in several diseases. In diabetes mellitus, a disease characterized by chronic hyperglycemia, microvascular impairment is well-established; on the contrary, the effect of acute hyperglycemia in microcirculation remains unclarified. Our aim was to investigate the microvascular effect of an oral glucose load (OGL) using laser Doppler flowmetry (LDF) as a perfusion quantification technique, coupled with wavelet transform (WT) to perform a spectral decomposition of the LDF signal. On two distinct occasions (pre-load and post-load), sixteen healthy subjects drank either a standard glucose solution or water. Perfusion was assessed by LDF and WT while resting and during post-occlusive reactive hyperemia (PORH), evoked by a transient three-min occlusion of the brachial artery, in the forearm and the finger pulp. The OGL affected microcirculation in both sites compared to water, significantly blunting the PORH response in the forearm. The WT revealed significant differences in the cardiac and sympathetic components after OGL between the pre-load and post-load periods. These results suggest that an OGL induces a short-term subtle microvascular impairment, probably involving a modulation of the sympathetic nervous system. Abstract Microcirculation in vivo has been assessed using non-invasive technologies such as laser Doppler flowmetry (LDF). In contrast to chronic hyperglycemia, known to induce microvascular dysfunction, the effects of short-term elevations in blood glucose on microcirculation are controversial. We aimed to assess the impact of an oral glucose load (OGL) on the cutaneous microcirculation of healthy subjects, quantified by LDF and coupled with wavelet transform (WT) as an interpretation tool. On two separate occasions, sixteen subjects drank either a glucose solution (75 g in 250 mL water) or water (equal volume). LDF signals were obtained in two anatomical sites (forearm and finger pulp) before and after each load (pre-load and post-load, respectively), in resting conditions and during post-occlusive reactive hyperemia (PORH). The WT allowed decomposition of the LDF signals into their spectral components (cardiac, respiratory, myogenic, sympathetic, endothelial NO-dependent). The OGL blunted the PORH response in the forearm, which was not observed with the water load. Significant differences were found for the cardiac and sympathetic components in the glucose and water groups between the pre-load and post-load periods. These results suggest that an OGL induces a short-term subtle microvascular impairment, probably involving a modulation of the sympathetic nervous system.
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Masi S, Rizzoni D, Taddei S, Widmer RJ, Montezano AC, Lüscher TF, Schiffrin EL, Touyz RM, Paneni F, Lerman A, Lanza GA, Virdis A. Assessment and pathophysiology of microvascular disease: recent progress and clinical implications. Eur Heart J 2021; 42:2590-2604. [PMID: 33257973 PMCID: PMC8266605 DOI: 10.1093/eurheartj/ehaa857] [Citation(s) in RCA: 57] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 05/23/2020] [Accepted: 10/08/2020] [Indexed: 12/13/2022] Open
Abstract
The development of novel, non-invasive techniques and standardization of protocols to assess microvascular dysfunction have elucidated the key role of microvascular changes in the evolution of cardiovascular (CV) damage, and their capacity to predict an increased risk of adverse events. These technical advances parallel with the development of novel biological assays that enabled the ex vivo identification of pathways promoting microvascular dysfunction, providing novel potential treatment targets for preventing cerebral-CV disease. In this article, we provide an update of diagnostic testing strategies to detect and characterize microvascular dysfunction and suggestions on how to standardize and maximize the information obtained from each microvascular assay. We examine emerging data highlighting the significance of microvascular dysfunction in the development CV disease manifestations. Finally, we summarize the pathophysiology of microvascular dysfunction emphasizing the role of oxidative stress and its regulation by epigenetic mechanisms, which might represent potential targets for novel interventions beyond conventional approaches, representing a new frontier in CV disease reduction.
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Affiliation(s)
- Stefano Masi
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy.,Institute of Cardiovascular Science, University College London, London, UK
| | - Damiano Rizzoni
- Clinica Medica, Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy.,Division of Medicine, Istituto Clinico Città di Brescia, Brescia, Italy
| | - Stefano Taddei
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Robert Jay Widmer
- Division of Cardiovascular Diseases, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Augusto C Montezano
- Institute of Cardiovascular & Medical Sciences, BHF Glasgow Cardiovascular Research Centre, University of Glasgow, Glasgow, UK
| | - Thomas F Lüscher
- Heart Division, Royal Brompton and Harefield Hospital and Imperial College, London, UK.,Center for Molecular Cardiology, University of Zürich, Zürich, Switzerland
| | - Ernesto L Schiffrin
- Department of Medicine and Lady Davis Institute, Sir Mortimer B. Davis-Jewish General Hospital, McGill University, Montreal, QC, Canada
| | - Rhian M Touyz
- Institute of Cardiovascular & Medical Sciences, BHF Glasgow Cardiovascular Research Centre, University of Glasgow, Glasgow, UK
| | - Francesco Paneni
- Center for Molecular Cardiology, University of Zürich, Zürich, Switzerland.,Department of Cardiology, University Heart Center, University Hospital Zurich, Zürich, Switzerland.,Department of Research and Education, University Hospital Zurich, Zürich, Switzerland
| | - Amir Lerman
- Division of Cardiovascular Diseases, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Gaetano A Lanza
- Department of Cardiovascular and Thoracic Medicine, Fondazione Policlinico Universitario A. Gemelli IRCCS, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Agostino Virdis
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
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Troy AM, Cheng HM. Human microvascular reactivity: a review of vasomodulating stimuli and non-invasive imaging assessment. Physiol Meas 2021; 42. [PMID: 34325417 DOI: 10.1088/1361-6579/ac18fd] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 07/29/2021] [Indexed: 11/11/2022]
Abstract
The microvasculature serves an imperative function in regulating perfusion and nutrient exchange throughout the body, adaptively altering blood flow to preserve hemodynamic and metabolic homeostasis. Its normal functioning is vital to tissue health, whereas its dysfunction is present in many chronic conditions, including diabetes, heart disease, and cognitive decline. As microvascular dysfunction often appears early in disease progression, its detection can offer early diagnostic information. To detect microvascular dysfunction, one uses imaging to probe the microvasculature's ability to react to a stimulus, also known as microvascular reactivity (MVR). An assessment of MVR requires an integrated understanding of vascular physiology, techniques for stimulating reactivity, and available imaging methods to capture the dynamic response. Practical considerations, including compatibility between the selected stimulus and imaging approach, likewise require attention. In this review, we provide a comprehensive foundation necessary for informed imaging of MVR, with a particular focus on the challenging endeavor of assessing microvascular function in deep tissues.
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Affiliation(s)
- Aaron M Troy
- Institute of Biomedical Engineering, University of Toronto, Toronto, CANADA
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27
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Monitoring skin blood flow to rapidly identify alterations in tissue perfusion during fluid removal using continuous veno-venous hemofiltration in patients with circulatory shock. Ann Intensive Care 2021; 11:59. [PMID: 33855645 PMCID: PMC8046875 DOI: 10.1186/s13613-021-00847-z] [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: 01/16/2021] [Accepted: 03/29/2021] [Indexed: 12/13/2022] Open
Abstract
Background Continuous veno-venous hemofiltration (CVVH) can be used to reduce fluid overload and tissue edema, but excessive fluid removal may impair tissue perfusion. Skin blood flow (SBF) alters rapidly in shock, so its measurement may be useful to help monitor tissue perfusion. Methods In a prospective, observational study in a 35-bed department of intensive care, all patients with shock who required fluid removal with CVVH were considered for inclusion. SBF was measured on the index finger using skin laser Doppler (Periflux 5000, Perimed, Järfälla, Sweden) for 3 min at baseline (before starting fluid removal, T0), and 1, 3 and 6 h after starting fluid removal. The same fluid removal rate was maintained throughout the study period. Patients were grouped according to absence (Group A) or presence (Group B) of altered tissue perfusion, defined as a 10% increase in blood lactate from T0 to T6 with the T6 lactate ≥ 1.5 mmol/l. Receiver operating characteristic curves were constructed and areas under the curve (AUROC) calculated to identify variables predictive of altered tissue perfusion. Data are reported as medians [25th–75th percentiles]. Results We studied 42 patients (31 septic shock, 11 cardiogenic shock); median SOFA score at inclusion was 9 [8–12]. At T0, there were no significant differences in hemodynamic variables, norepinephrine dose, lactate concentration, ScvO2 or ultrafiltration rate between groups A and B. Cardiac index and MAP did not change over time, but SBF decreased in both groups (p < 0.05) throughout the study period. The baseline SBF was lower (58[35–118] vs 119[57–178] perfusion units [PU], p = 0.03) and the decrease in SBF from T0 to T1 (ΔSBF%) higher (53[39–63] vs 21[12–24]%, p = 0.01) in group B than in group A. Baseline SBF and ΔSBF% predicted altered tissue perfusion with AUROCs of 0.83 and 0.96, respectively, with cut-offs for SBF of ≤ 57 PU (sensitivity 78%, specificity 87%) and ∆SBF% of ≥ 45% (sensitivity 92%, specificity 99%). Conclusion Baseline SBF and its early reduction after initiation of fluid removal using CVVH can predict worsened tissue perfusion, reflected by an increase in blood lactate levels. Supplementary Information The online version contains supplementary material available at 10.1186/s13613-021-00847-z.
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Thorn CE, Adio AO, Fox RH, Gardner AM, Winlove CP, Shore AC. Intermittent compression induces transitory hypoxic stimuli, upstream vasodilation and enhanced perfusion of skin capillaries, independent of age and diabetes. J Appl Physiol (1985) 2021; 130:1072-1084. [PMID: 33571053 DOI: 10.1152/japplphysiol.00657.2020] [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] [Indexed: 12/30/2022] Open
Abstract
The benefit of enhanced shear stress to the vascular endothelium has been well-documented in conduit arteries but is less understood in skin microcirculation. The aim of this study was to provide physiological evidence of the vascular changes in skin microcirculation induced by intermittent pneumatic compression (IPC) of 1 s cuff inflation (130 mmHg) every 20 s to the palm of the hand for 30 min. The oxygenation and hemodynamics of dorsal mid-phalangeal finger skin microcirculation were assessed by laser Doppler fluximetry and reflectance spectroscopy before, during, and after IPC in 15 young (18-39 years old) and 39 older (40-80 years old) controls and 32 older subjects with type 2 diabetes mellitus. Each individual cuff inflation induced: 1) brief surge in flux immediately after cuff deflation followed by 2) transitory reduction in blood oxygen for ∼4 s, and 3) a second increase in perfusion and oxygenation of the microcirculation peaking ∼11 s after cuff deflation in all subject groups. With no significant change in blood volume observed by reflectance spectroscopy, despite the increased shear stress at the observed site, this second peak in flux and blood oxygen suggests a delayed vasoactive response upstream inducing increased arterial influx in the microcirculation that was higher in older controls and subjects with diabetes compared to young controls (P < 0.001, P < 0.001, respectively) and achieving maximum capillary recruitment in all subject groups. Transitory hypoxic stimuli with conducted vasodilation may be a mechanism through which IPC enhances capillary perfusion in skin microcirculation independent of age and type 2 diabetes mellitus.NEW & NOTEWORTHY This study demonstrates that hand intermittent pneumatic compression evokes transitory hypoxic stimuli in distal finger skin microcirculation inducing vasodilation of arterial inflow vessels, enhanced perfusion, and maximum capillary recruitment in young and older subjects and older subjects with type 2 diabetes mellitus. Enhanced shear stress in the microcirculation did not appear to induce local skin vasodilation.
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Affiliation(s)
- Clare E Thorn
- Diabetes and Vascular Medicine, Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, College of Medicine and Health and NIHR Exeter Clinical Research Facility, and School of Physics and Astronomy, University of Exeter, Exeter, United Kingdom
| | - Aminat O Adio
- Diabetes and Vascular Medicine, Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, College of Medicine and Health and NIHR Exeter Clinical Research Facility, and School of Physics and Astronomy, University of Exeter, Exeter, United Kingdom
| | - Roger H Fox
- Diabetes and Vascular Medicine, Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, College of Medicine and Health and NIHR Exeter Clinical Research Facility, and School of Physics and Astronomy, University of Exeter, Exeter, United Kingdom
| | - A Michael Gardner
- Diabetes and Vascular Medicine, Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, College of Medicine and Health and NIHR Exeter Clinical Research Facility, and School of Physics and Astronomy, University of Exeter, Exeter, United Kingdom
| | - C Peter Winlove
- Diabetes and Vascular Medicine, Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, College of Medicine and Health and NIHR Exeter Clinical Research Facility, and School of Physics and Astronomy, University of Exeter, Exeter, United Kingdom
| | - Angela C Shore
- Diabetes and Vascular Medicine, Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, College of Medicine and Health and NIHR Exeter Clinical Research Facility, and School of Physics and Astronomy, University of Exeter, Exeter, United Kingdom
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Lindstedt S, Wlosinska M, Nilsson AC, Hlebowicz J, Fakhro M, Sheikh R. Successful improved peripheral tissue perfusion was seen in patients with atherosclerosis after 12 months of treatment with aged garlic extract. Int Wound J 2021; 18:681-691. [PMID: 33590955 PMCID: PMC8450802 DOI: 10.1111/iwj.13570] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Accepted: 02/01/2021] [Indexed: 12/30/2022] Open
Abstract
Patients with arteriolosclerosis have impaired microvascular perfusion leading to impaired wound healing. Aged garlic extract has shown to have a positive impact on vascular elasticity. The present study aimed to assess the effect of long‐term treatment with AGE on peripheral tissue perfusion in patients with confirmed atherosclerosis. Ninety three patients with a CT‐scan confirmed coronary artery arteriolosclerosis were randomised in a double‐blind manner to placebo or 2400 mg AGE daily for 1 year. Peripheral tissue perfusion was evaluated at 0‐ and 12‐months using Laser Speckle Contrast Imaging. Measurement of post occlusive reactive hyperemia (PORH) and cutaneous vascular conductance (CVC) using acetylcholine iontophoresis (Ach) was conducted. After 12 months a significant increase of 21.6% (95% CI 3.2%‐40.0%, P < .05) was seen in the relative change of PORH in the AGE compared with the placebo group. The same response was seen for CVC and Ach with an increase of 21.4% (95% CI 3.4%‐39.4%, P < .05) in the AGE group compared with the placebo group. Aged garlic extract regenerated peripheral tissue perfusion and increase microcirculation in patients with arteriolosclerosis. Adequate peripheral tissue perfusion and tissue oxygen tension are important prerequisites for successful tissue repair. Restored microcirculation in patients could hypothetically facilitate wound healing.
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Affiliation(s)
- Sandra Lindstedt
- Department of Cardiothoracic Surgery and Transplantation, Clinical Science, Lund University, Skane University Hospital, Lund, Sweden
| | - Martiné Wlosinska
- Department of Cardiothoracic Surgery and Transplantation, Clinical Science, Lund University, Skane University Hospital, Lund, Sweden
| | - Ann-Christin Nilsson
- Department of Cardiothoracic Surgery and Transplantation, Clinical Science, Lund University, Skane University Hospital, Lund, Sweden
| | - Joanna Hlebowicz
- Department of Cardiology, Clinical Sciences, Lund University, Skane University Hospital, Lund, Sweden
| | - Mohammed Fakhro
- Department of Cardiothoracic Surgery and Transplantation, Clinical Science, Lund University, Skane University Hospital, Lund, Sweden
| | - Rafi Sheikh
- Department of Ophthalmology, Clinical Sciences, Lund University, Skane University Hospital, Lund, Sweden
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Barr LC, Pudwell J, Smith GN. Postpartum microvascular functional alterations following severe preeclampsia. Am J Physiol Heart Circ Physiol 2021; 320:H1393-H1402. [PMID: 33481699 DOI: 10.1152/ajpheart.00767.2020] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Preeclampsia is associated with adverse maternal health outcomes later in life. Vascular endothelial dysfunction has been previously described following preeclampsia. We hypothesized that microvascular endothelial dysfunction associated with preeclampsia persists postpartum and may identify those at greatest risk of future cardiovascular disease. The objective of this study was to examine postpartum microvascular endothelial function in women after a pregnancy complicated by preeclampsia. Women with previous preeclampsia (n = 30) and normotensive controls (n = 30) between 6 mo and 5 yr postpartum were recruited. Severity of preeclampsia [severe (n = 16) and mild (n = 14)] was determined by standardized chart review. Microvascular reactivity in the forearm was measured with laser speckle contrast imaging, coupled with iontophoresis; endothelium-dependent and endothelium-independent vasodilation was induced with 1% acetylcholine and sodium nitroprusside solutions, respectively. A postocclusive reactive hyperemia test assessed vasodilatory response following three minutes of suprasystolic (200 mmHg) occlusion with a mechanized cuff. Women with prior severe preeclampsia exhibited significantly higher vasodilation to acetylcholine and sodium nitroprusside compared to controls (P < 0.01; P = 0.03) and prior mild preeclampsia (P = 0.03; P < 0.01). Neither the degree of postocclusive reactive hyperemia (P = 0.98), nor time to return halfway to baseline [OR = 1.026 (0.612, 1.72); P = 0.92], differed between preeclampsia and controls. In conclusion, severe preeclampsia is associated with heightened postpartum microvascular endothelium-dependent and endothelium-independent vasoreactivity. These changes, or a common antecedent, may be linked to postpartum alterations in vascular function that predispose women to disease after preeclampsia. Further investigation should identify the contributing mechanism and the degree to which it could be amenable to medical intervention.NEW & NOTEWORTHY We examine maternal microvascular function after preeclampsia, identifying heightened endothelium-dependent and endothelium-independent microvascular reactivity following severe disease. Our study represents a noteworthy addition to the existing literature with the use of a novel imaging modality, vascular perturbation, postpartum time point, and patient population with differentiation of preeclampsia into severe and nonsevere subtypes. These results represent a novel addition to the growing clinical and academic understanding of maternal health outcomes following preeclampsia.
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Affiliation(s)
- Logan C Barr
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada
| | - Jessica Pudwell
- Department of Obstetrics & Gynaecology, Queen's University, Kingston, Ontario, Canada
| | - Graeme N Smith
- Department of Obstetrics & Gynaecology, Queen's University, Kingston, Ontario, Canada
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Shirazi BR, Valentine RJ, Lang JA. Reproducibility and normalization of reactive hyperemia using laser speckle contrast imaging. PLoS One 2021; 16:e0244795. [PMID: 33412561 PMCID: PMC7790538 DOI: 10.1371/journal.pone.0244795] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 12/16/2020] [Indexed: 12/27/2022] Open
Abstract
Background Impaired perfusion indices signal potential microvascular dysfunction preceding atherosclerosis and other cardiometabolic pathologies. Post-occlusive reactive hyperemia (PORH), a vasodilatory response following a mechanically induced ischemia, is a transient increase in perfusion and can assess microvascular function. The greatest blood flow change corresponding to the first minute of hyperemia (represented by time-to-peak, hyperemic velocity, AUC within 1st min) has been shown to indicate microvascular dysfunction. However, the reproducibility of these temporal kinetic indices of the PORH response is unknown. Our aim was to examine the inter- and intra-day reproducibility and standardization of reactive hyperemia, with emphasis on the kinetic indices of PORH, using laser speckle contrast imaging (LSCI) technique. Methods and results Seventeen healthy adults (age = 24 ± 3 years) completed three PORH bouts over two lab visits. LSCI region of interest was a standardized 10 cm region on the dominant ventral forearm. A 5-min brachial artery occlusion period induced by inflating an arm cuff to 200 mmHg, preceded a 4-min hyperemic period. Inter- and intra-day reliability and reproducibility of cutaneous vascular conductance (LSCI flux / mean arterial pressure) were determined using intraclass correlation (ICC) and coefficient of variation (CV%). Maximal flow and area under the curve standardized to zero perfusion showed intra- and inter-day reliability (ICC > 0.70). Time to maximal flow (TMF) was not reproducible (inter-day CV = 18%). However, alternative kinetic indices such as 1-min AUC and overshoot rate-of-change (ORC), represented as a piecewise function (at 5s, 10s, 15s, and 20s into hyperemia), were reproducible (CV< 11%). Biological zero was a reliable normalization point. Conclusion PORH measured with LSCI is a reliable assessment of microvascular function. However, TMF or its derived hyperemic velocity are not recommended for longitudinal assessment. Piecewise ORC and 1-min AUC are reliable alternatives to assess the kinetic response of PORH.
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Affiliation(s)
| | - Rudy J. Valentine
- Department of Kinesiology, Iowa State University, Ames, Iowa, United States of America
| | - James A. Lang
- Department of Kinesiology, Iowa State University, Ames, Iowa, United States of America
- * E-mail:
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Chia PY, Teo A, Yeo TW. Overview of the Assessment of Endothelial Function in Humans. Front Med (Lausanne) 2020; 7:542567. [PMID: 33117828 PMCID: PMC7575777 DOI: 10.3389/fmed.2020.542567] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 08/27/2020] [Indexed: 12/26/2022] Open
Abstract
The endothelium is recognized to play an important role in various physiological functions including vascular tone, permeability, anticoagulation, and angiogenesis. Endothelial dysfunction is increasingly recognized to contribute to pathophysiology of many disease states, and depending on the disease stimuli, mechanisms underlying the endothelial dysfunction may be markedly different. As such, numerous techniques to measure different aspects of endothelial dysfunction have been developed and refined as available technology improves. Current available reviews on quantifying endothelial dysfunction generally concentrate on a single aspect of endothelial function, although diseases may affect more than one aspect of endothelial function. Here, we aim to provide an overview on the techniques available for the assessment of the different aspects of endothelial function in humans, human tissues or cells, namely vascular tone modulation, permeability, anticoagulation and fibrinolysis, and the use of endothelial biomarkers as predictors of outcomes.
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Affiliation(s)
- Po Ying Chia
- National Centre for Infectious Diseases, Singapore, Singapore
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
- Department of Infectious Diseases, Tan Tock Seng Hospital, Singapore, Singapore
| | - Andrew Teo
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
- Department of Medicine and Radiology and Doherty Institute, University of Melbourne, Victoria, VIC, Australia
| | - Tsin Wen Yeo
- National Centre for Infectious Diseases, Singapore, Singapore
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
- Department of Infectious Diseases, Tan Tock Seng Hospital, Singapore, Singapore
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Rice TB, Yang B, White S. Effect of skin optical absorption on speckleplethysmographic (SPG) signals. BIOMEDICAL OPTICS EXPRESS 2020; 11:5352-5361. [PMID: 33014619 PMCID: PMC7510879 DOI: 10.1364/boe.403501] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 08/21/2020] [Accepted: 08/23/2020] [Indexed: 05/02/2023]
Abstract
Recent advances in optical technology have emerged for measuring blood flow in the extremities using speckleplethysmography (SPG), which may address needs in vascular medicine and other fields. SPG has demonstrated a highly linear response with flow rate, but the susceptibility to differences in skin tone is unclear. Two validation studies using skin-simulating phantoms and a simple clinical protocol were conducted to determine the impact of absorbing skin layers on SPG measurements. Benchtop results demonstrated that the coefficient of determination between known flow rate and SPG was highly linear (R2 = 0.990) and was unaffected by the addition of skin-phantom layers with variable absorption (R2 = 0.996-0.999). Additionally, no significant trend was found between the fit residuals of SPG and flow rate with increasing skin-phantom absorption (R2=0.025, p = 0.29). In clinical testing, no significant difference was found using both a 4-way ANOVA between demographic classifications (F = 0.89, p = 0.45), and a 2-way ANOVA test between lower- and higher-melanin subclassifications (F = 0.4, p = 0.52).
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Argarini R, McLaughlin RA, Joseph SZ, Naylor LH, Carter HH, Yeap BB, Jansen SJ, Green DJ. Optical coherence tomography: a novel imaging approach to visualize and quantify cutaneous microvascular structure and function in patients with diabetes. BMJ Open Diabetes Res Care 2020; 8:8/1/e001479. [PMID: 32847842 PMCID: PMC7451490 DOI: 10.1136/bmjdrc-2020-001479] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 06/05/2020] [Accepted: 06/27/2020] [Indexed: 01/13/2023] Open
Abstract
INTRODUCTION The pathophysiology of microvascular disease is poorly understood, partly due to the lack of tools to directly image microvessels in vivo. RESEARCH DESIGN AND METHODS In this study, we deployed a novel optical coherence tomography (OCT) technique during local skin heating to assess microvascular structure and function in diabetics with (DFU group, n=13) and without (DNU group, n=10) foot ulceration, and healthy controls (CON group, n=13). OCT images were obtained from the dorsal foot, at baseline (33°C) and 30 min following skin heating. RESULTS At baseline, microvascular density was higher in DFU compared with CON (21.9%±11.5% vs 14.3%±5.6%, p=0.048). Local heating induced significant increases in diameter, speed, flow rate and density in all groups (all p<0.001), with smaller changes in diameter for the DFU group (94.3±13.4 µm), compared with CON group (115.5±11.7 µm, p<0.001) and DNU group (106.7±12.1 µm, p=0.014). Heating-induced flow rate was lower in the DFU group (584.3±217.0 pL/s) compared with the CON group (908.8±228.2 pL/s, p<0.001) and DNU group (768.8±198.4 pL/s, p=0.014), with changes in density also lower in the DFU group than CON group (44.7%±15.0% vs 56.5%±9.1%, p=0.005). CONCLUSIONS This proof of principle study indicates that it is feasible to directly visualize and quantify microvascular function in people with diabetes; and distinguish microvascular disease severity between patients.
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Affiliation(s)
- Raden Argarini
- Physiology, Airlangga University Faculty of Medicine, Surabaya, Jawa Timur, Indonesia
- Cardiovascular Research Group, School of Human Sciences (Exercise and Sport Science), The University of Western Australia, Crawley, Western Australia, Australia
| | - Robert A McLaughlin
- Faculty of Health and Medical Sciences, Adelaide Medical School, Australian Research Council Centre of Excellence for Nanoscale Biophotonics, University of Adelaide, Adelaide, South Australia, Australia
- Institute for Photonics and Advanced Sensing, University of Adelaide, Adelaide, South Australia, Australia
| | - Simon Z Joseph
- Faculty of Health and Medical Sciences, School of Surgery, The University of Western Australia, Perth, Western Australia, Australia
| | - Louise H Naylor
- Cardiovascular Research Group, School of Human Sciences (Exercise and Sport Science), The University of Western Australia, Crawley, Western Australia, Australia
| | - Howard H Carter
- Cardiovascular Research Group, School of Human Sciences (Exercise and Sport Science), The University of Western Australia, Crawley, Western Australia, Australia
| | - Bu B Yeap
- School of Medicine and Pharmacology, The University of Western Australia, Perth, Western Australia, Australia
- Department of Endocrinology and Diabetes, Fiona Stanley Hospital, Perth, Western Australia, Australia
| | - Shirley J Jansen
- Faculty of Health and Medical Sciences, School of Surgery, The University of Western Australia, Perth, Western Australia, Australia
- Vascular and Endovascular Surgery, Sir Charles Gairdner Hospital, Perth, Western Australia, Australia
| | - Daniel J Green
- Cardiovascular Research Group, School of Human Sciences (Exercise and Sport Science), The University of Western Australia, Crawley, Western Australia, Australia
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Jonasson H, Bergstrand S, Fredriksson I, Larsson M, Östgren CJ, Strömberg T. Normative data and the influence of age and sex on microcirculatory function in a middle-aged cohort: results from the SCAPIS study. Am J Physiol Heart Circ Physiol 2020; 318:H908-H915. [PMID: 32142355 DOI: 10.1152/ajpheart.00668.2019] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The objective of this study was to assess normative values for comprehensive forearm skin microcirculatory function: oxygen saturation, tissue fraction of red blood cells (RBCs), and speed-resolved perfusion. Furthermore, to examine the influence of age and sex on microcirculatory function. Measurements were performed using a noninvasive probe-based system, including diffuse reflectance spectroscopy and laser-Doppler flowmetry, yielding output data in absolute units. The study was conducted within the Swedish CArdioPulmonary BioImage Study (SCAPIS) and included 1,765 men and women aged 50-65 yr from the Linköping general population. Normative values are given at baseline, at the end of a 5-min occlusion of the brachial artery and during hyperemia after occlusion release. We found a consistent age distribution, in which the oldest individuals had the lowest peak oxygen saturation (P < 0.001) and the highest baseline low-speed perfusion (P < 0.001). Women had higher peak oxygen saturation (P < 0.001), lower RBC tissue fraction, in general (P < 0.001), lower baseline perfusion in all speed regions (P = 0.01), and lower peak high-speed perfusion at hyperemia (P < 0.001). The normative data can be used as reference values in future studies of disease-specific populations. The results show that age and sex are important aspects to consider in studies of microvascular function. Women and younger age were factors associated with higher peak oxygen saturation after ischemia. This is a novel parameter that reflects overall microcirculatory function associated with vascular dilation capacity.NEW & NOTEWORTHY This study expands experimental microcirculatory research to clinical use by providing normative values on microcirculatory function in a large population-based cohort. Women and younger age were factors associated with higher peak oxygen saturation after ischemia, which implies that age and sex are important aspects to consider in studies of microvascular function. This study is the first step toward using microcirculatory assessment as a tool to improve diagnosis, prognosis, and treatment in disease-specific populations.
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Affiliation(s)
- Hanna Jonasson
- Department of Biomedical Engineering, Linköping University, Linköping, Sweden
| | - Sara Bergstrand
- Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden
| | - Ingemar Fredriksson
- Department of Biomedical Engineering, Linköping University, Linköping, Sweden.,Perimed AB, Järfälla, Stockholm, Sweden
| | - Marcus Larsson
- Department of Biomedical Engineering, Linköping University, Linköping, Sweden
| | - Carl Johan Östgren
- Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden
| | - Tomas Strömberg
- Department of Biomedical Engineering, Linköping University, Linköping, Sweden
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Monteiro Rodrigues L, Rocha C, Ferreira HT, Silva HN. Lower limb massage in humans increases local perfusion and impacts systemic hemodynamics. J Appl Physiol (1985) 2020; 128:1217-1226. [PMID: 32191595 DOI: 10.1152/japplphysiol.00437.2019] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Massage is commonly used as a complementary therapy for many different conditions. Demonstration of its physiological impact and understanding of its therapeutic mechanisms is still insufficient and often inconclusive. This study aims to characterize the physiological effects of effleurage, one of the most popular techniques, on human in vivo microcirculation and its impact on cardiovascular function. Two differently oriented variations of the technique, referred to influence physiological outcomes, were applied to 32 young (mean 19.8 ± 1.6 yr old) healthy volunteers of both sexes in a single, randomly chosen limb after informed written consent. Each protocol included a 10-min baseline (Phase I), a 5-min massage (Phase II), and a 10-min recovery (Phase III) register. A 30-min washout period separated both protocols. Perfusion was assessed by laser Doppler flowmetry (LDF) and reflection photoplethysmography (PPG), with their sensors applied distally in both feet. Blood pressure and pulse were also obtained. LDF signals were further analyzed in their components by the (Morlet) wavelet transform to probe the mechanisms involved. Results showed that effleurage consistently evoked a significant (P < 0.001) perfusion increase in the massaged limb, also visible in the contralateral limb (not significant) independently from the orientation (variant) used. No matter the perfusion differences known between sexes, the adaptive response was equivalent in both sexes. The component analysis of the LDF curves also suggests that these procedures, although brief and superficial, do modify multiple components of cardiovascular integration, with cardiac, respiratory, and myogenic components appearing to play a major role in reestablishing distal microcirculatory homeostasis.NEW & NOTEWORTHY The impact of effleurage, a well-known massage procedure used in human rehabilitation, in the lower limb hemodynamics, is demonstrated. When applied in a sole limb, massage increases skin microcirculatory flowmotion not only locally but also beyond, affecting systemic hemodynamics. This observation is an interesting example of the efficacy of cardiovascular integration mechanisms involving distal microcirculatory homeostasis. The proposed methodology allows a mechanistic view over skin flowmotion regulation, being applicable to further explore massage and its impact on microcirculatory physiology.
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Affiliation(s)
- Luis Monteiro Rodrigues
- CBIOS Research Center for Biosciences and Health Technologies, Universidade Lusófona, Lisbon, Portugal
| | - Clemente Rocha
- CBIOS Research Center for Biosciences and Health Technologies, Universidade Lusófona, Lisbon, Portugal
| | - Hugo T Ferreira
- Faculty of Sciences, Institute for Biophysics and Biomedical Engineering, Universidade de Lisboa, Lisbon, Portugal
| | - Henrique N Silva
- CBIOS Research Center for Biosciences and Health Technologies, Universidade Lusófona, Lisbon, Portugal.,Faculty of Pharmacy and Pharmacology, Science Department, Universidade de Lisboa, Lisbon, Portugal
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Hijazi MM, Buchmann SJ, Sedghi A, Illigens BM, Reichmann H, Schackert G, Siepmann T. Assessment of cutaneous axon-reflex responses to evaluate functional integrity of autonomic small nerve fibers. Neurol Sci 2020; 41:1685-1696. [PMID: 32125538 PMCID: PMC7359149 DOI: 10.1007/s10072-020-04293-w] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2019] [Accepted: 02/11/2020] [Indexed: 12/12/2022]
Abstract
Cutaneous autonomic small nerve fibers encompass unmyelinated C-fibers and thinly myelinated Aδ-fibers, which innervate dermal vessels (vasomotor fibers), sweat glands (sudomotor fibers), and hair follicles (pilomotor fibers). Analysis of their integrity can capture early pathology in autonomic neuropathies such as diabetic autonomic neuropathy or peripheral nerve inflammation due to infectious and autoimmune diseases. Furthermore, intraneural deposition of alpha-synuclein in synucleinopathies such as Parkinson’s disease can lead to small fiber damage. Research indicated that detection and quantitative analysis of small fiber pathology might facilitate early diagnosis and initiation of treatment. While autonomic neuropathies show substantial etiopathogenetic heterogeneity, they have in common impaired functional integrity of small nerve fibers. This impairment can be evaluated by quantitative analysis of axonal responses to iontophoretic application of adrenergic or cholinergic agonists to the skin. The axon-reflex can be elicited in cholinergic sudomotor fibers to induce sweating and in cholinergic vasomotor fibers to induce vasodilation. Currently, only few techniques are available to quantify axon-reflex responses, the majority of which is limited by technical demands or lack of validated analysis protocols. Function of vasomotor small fibers can be analyzed using laser Doppler flowmetry, laser Doppler imaging, and laser speckle contrast imaging. Sudomotor function can be assessed using quantitative sudomotor axon-reflex test, silicone imprints, and quantitative direct and indirect testing of sudomotor function. More recent advancements include analysis of piloerection (goose bumps) following stimulation of adrenergic small fibers using pilomotor axon-reflex test. We provide a review of the current literature on axon-reflex tests in cutaneous autonomic small fibers.
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Affiliation(s)
- Mido M Hijazi
- Department of Neurosurgery, University Hospital Carl Gustav Carus, Technische Universität Dresden, Fetscherstr 74, 01307, Dresden, Germany
| | - Sylvia J Buchmann
- Department of Anaesthesiology, Operative Intensive Care Medicine and Pain Medicine, Vivantes Klinikum Spandau, Berlin, Germany
| | - Annahita Sedghi
- Department of Neurology, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Ben M Illigens
- Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Heinz Reichmann
- Department of Neurology, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Gabriele Schackert
- Department of Neurosurgery, University Hospital Carl Gustav Carus, Technische Universität Dresden, Fetscherstr 74, 01307, Dresden, Germany
| | - Timo Siepmann
- Department of Neurology, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany.
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Tóth-Szűki V, Bari F, Domoki F. Stable laser-Doppler flow-motion patterns in the human cutaneous microcirculation: Implications for prospective geroscience studies. Physiol Int 2020; 107:134-144. [DOI: 10.1556/2060.2020.00013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 02/25/2020] [Indexed: 11/19/2022]
Abstract
AbstractMicrovascular function has been assessed by determining the rhythmic oscillations in blood flow induced by the vasomotion of resistance vessels. Although laser-Doppler flowmetry (LDF) allows simple, non-invasive evaluation of this flow-motion in the cutaneous microcirculation, the temporal and spatial reproducibility of such assessments remains unclear.In the present study, we investigated cutaneous flow-motion in three consecutive years in eight skin regions using LDF in six healthy young volunteers. The characteristic flow-motion frequency was determined using fast-Fourier transformation. Additionally, in two years a more traditional measure of microvascular reactivity, postocclusive reactive hyperemia (PORH) was evoked in the forearm after transient brachial artery occlusion (1–2–3 min) induced by cuff inflation.Well-defined flow-motion was found in six regions showing significant differences in frequency: the highest flow-motion frequency was found in the frontal and temporal regions (8.0 ± 1.1 and 8.5 ± 1.0 cycles/min, cpm, respectively, mean ± SD) followed by the scapular, infraclavicular and coxal regions (7.5 ± 1.3; 6.7 ± 1.1 and 6.5 ± 1.2 cpm, respectively). The lowest, stable flow-motion was found in the posterior femoral region (5.5 ± 1.0 cpm), whereas flow-motion was detectable only sporadically in the limbs. The region-dependent flow-motion frequencies were very stable within individuals either between the body sides, or among the three measurements, only the infraclavicular region showed a small difference (114 ± 17%∗, % of value in 1st year; ∗P < 0.05). However, PORH indices differed after 2–3 min occlusions significantly in consecutive years.We report that flow-motion frequencies determined from LDF signals show both region-specificity and excellent intra-individual temporal and spatial reproducibility suggesting their usefulness for non-invasive follow-up of microvascular reactivity.
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Affiliation(s)
- V. Tóth-Szűki
- 1Department of Physiology, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - F. Bari
- 2Department of Medical Physics and Informatics, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - F. Domoki
- 1Department of Physiology, Faculty of Medicine, University of Szeged, Szeged, Hungary
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Tehrani S, Bergen K, Azizi L, Jörneskog G. Skin microvascular reactivity correlates to clinical microangiopathy in type 1 diabetes: A pilot study. Diab Vasc Dis Res 2020; 17:1479164120928303. [PMID: 32538145 PMCID: PMC7607411 DOI: 10.1177/1479164120928303] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
AIM The aim of this study was to investigate the correlation between skin microvascular reactivity and clinical microangiopathy in patients with type 1 diabetes. METHODS We included 61 patients with type 1 diabetes, that is, 31 patients with and 30 without clinical microangiopathy, and 31 healthy controls. A microangiopathy scoring system was introduced for comparison of data between patients with microangiopathy. Responses to iontophoresis of acetylcholine and sodium nitroprusside were assessed by laser Doppler imaging. RESULTS Patients with microangiopathy had reduced acetylcholine- and sodium nitroprusside-mediated flux in forearm skin microcirculation compared to healthy controls (p = 0.03 and p < 0.001, respectively, repeated measures analysis of variance), whereas no significant differences were found between patients without microangiopathy and controls. Skin reactivity was reduced in patients with microangiopathy compared to patients without microangiopathy: 1.43 ± 0.38 versus 1.59 ± 0.39 arbitrary units for acetylcholine-mediated peak flux and 1.44 ± 0.46 versus 1.74 ± 0.34 arbitrary units for sodium nitroprusside-mediated peak flux (p < 0.05 for both). A tendency of gradual decrease in acetylcholine and sodium nitroprusside responses was found in patients with increasing microangiopathy scores. CONCLUSION We conclude that skin microvascular reactivity is associated with clinical microangiopathy in patients with type 1 diabetes. Impaired skin microvascular function in type 1 diabetes seems to be multifactorial and involves both endothelial-dependent and endothelial-independent pathways. We introduce a novel microangiopathy score that could easily be used in a clinical setting for comparison of patients with various degrees of microangiopathy.
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Affiliation(s)
- Sara Tehrani
- Division of Internal Medicine, Department of Clinical Sciences, Danderyd University Hospital, Karolinska Institutet, Stockholm, Sweden
- Sara Tehrani, Division of Internal Medicine, Department of Clinical Sciences, Danderyd University Hospital, Karolinska Institutet, Stockholm 18288, Sweden.
| | - Karin Bergen
- Division of Nephrology, Department of Clinical Sciences, Danderyd University Hospital, Karolinska Institutet, Stockholm, Sweden
| | - Louisa Azizi
- Department of Clinical Sciences, Danderyd University Hospital, Karolinska Institutet, Stockholm, Sweden
| | - Gun Jörneskog
- Division of Internal Medicine, Department of Clinical Sciences, Danderyd University Hospital, Karolinska Institutet, Stockholm, Sweden
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Fabregate-Fuente M, Arbeitman CR, Cymberknop LJ, Bara-Ledesma N, Arriazu-Galindo M, Martin-Fernandez L, Armentano RL, Saban-Ruiz J. Characterization of Microvascular Post Occlusive Hyperemia Using Laser Doppler Flowmetry Technique in Subjects With Cardiometabolic Disorders. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2020; 2019:514-517. [PMID: 31945950 DOI: 10.1109/embc.2019.8856623] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
INTRODUCTION Laser Doppler flowmetry (LDF) provides a noninvasive real-time quantification of relative changes in cutaneous perfusion. Assessment of the microvascular function can provide information on the development of various cardiometabolic disorders. In recent years, non-invasive measurements have gain attention, due to the potential complications associated to invasive procedures. OBJECTIVE To differentiate the microvascular function between subjects with cardiometabolic disorders and healthy controls. METHODS Evaluation through LDF during post-occlusive reactive hyperemia (PORH) in patients with or without history of cardiometabolic disorders. RESULTS Peak values of microvascular flow during post-occlusive reactive hyperemia and both upload and recovery slopes were lesser in the pathological group. CONCLUSION A novel approach to characterize LDF during PORH was useful to differentiate patients with cardiometabolic disorders from healthy subjects.
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Smith KJ, Argarini R, Carter HH, Quirk BC, Haynes A, Naylor LH, McKirdy H, Kirk RW, McLaughlin RA, Green DJ. Novel Noninvasive Assessment of Microvascular Structure and Function in Humans. Med Sci Sports Exerc 2020; 51:1558-1565. [PMID: 30688767 DOI: 10.1249/mss.0000000000001898] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
INTRODUCTION Optical coherence tomography (OCT) is a novel high-resolution imaging technique capable of visualizing in vivo structures at a resolution of ~10 μm. We have developed specialized OCT-based approaches that quantify diameter, speed, and flow rate in human cutaneous microvessels. In this study, we hypothesized that OCT-based microvascular assessments would possess comparable levels of reliability when compared with those derived using conventional laser Doppler flowmetry (LDF). METHODS Speckle decorrelation images (OCT) and red blood cell flux (LDF) measures were collected from adjacent forearm skin locations on 2 d (48 h apart), at baseline, and after a 30-min rapid local heating protocol (30°C-44°C) in eight healthy young individuals. OCT postprocessing quantified cutaneous microvascular diameter, speed, flow rate, and density (vessel recruitment) within a region of interest, and data were compared between days. RESULTS Forearm skin LDF (13 ± 4 to 182 ± 31 AU, P < 0.05) and OCT-derived diameter (41.8 ± 6.6 vs 64.5 ± 6.9 μm), speed (68.4 ± 9.5 vs 89.0 ± 7.3 μm·s), flow rate (145.0 ± 60.6 vs 485 ± 132 pL·s), and density (9.9% ± 4.9% vs 45.4% ± 5.9%) increased in response to local heating. The average OCT-derived microvascular flow response (pL·s) to heating (234% increase) was lower (P < 0.05) than the LDF-derived change (AU) (1360% increase). Pearson correlation was significant for between-day local heating responses in terms of OCT flow (r = 0.93, P < 0.01), but not LDF (P = 0.49). Bland-Altman analysis revealed that between-day baseline OCT-derived flow rates were less variable than LDF-derived flux. CONCLUSIONS Our findings indicate that OCT, which directly visualizes human microvessels, not only allows microvascular quantification of diameter, speed, flow rate, and vessel recruitment but also provides outputs that are highly reproducible. OCT is a promising novel approach that enables a comprehensive assessment of cutaneous microvascular structure and function in humans.
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Affiliation(s)
- Kurt J Smith
- Cardiovascular Research Group, School of Human Sciences (Exercise and Sport Science), Faculty of Science, The University of Western Australia, Perth, AUSTRALIA.,School of Kinesiology, Faculty of Health and Behavioural Science, Lakehead University, Thunderbay, Ontario, CANADA
| | - Raden Argarini
- Cardiovascular Research Group, School of Human Sciences (Exercise and Sport Science), Faculty of Science, The University of Western Australia, Perth, AUSTRALIA.,Department of Physiology, Faculty of Medicine, Airlangga University, Surabaya, INDONESIA
| | - Howard H Carter
- Cardiovascular Research Group, School of Human Sciences (Exercise and Sport Science), Faculty of Science, The University of Western Australia, Perth, AUSTRALIA
| | - Bryden C Quirk
- Australian Research Council Centre of Excellence for Nanoscale Biophotonics, Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, AUSTRALIA.,Institute for Photonics and Advanced Sensing, University of Adelaide, Adelaide, AUSTRALIA
| | - Andrew Haynes
- Cardiovascular Research Group, School of Human Sciences (Exercise and Sport Science), Faculty of Science, The University of Western Australia, Perth, AUSTRALIA
| | - Louise H Naylor
- Cardiovascular Research Group, School of Human Sciences (Exercise and Sport Science), Faculty of Science, The University of Western Australia, Perth, AUSTRALIA
| | - Hamish McKirdy
- Cardiovascular Research Group, School of Human Sciences (Exercise and Sport Science), Faculty of Science, The University of Western Australia, Perth, AUSTRALIA
| | - Rodney W Kirk
- Australian Research Council Centre of Excellence for Nanoscale Biophotonics, Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, AUSTRALIA.,Institute for Photonics and Advanced Sensing, University of Adelaide, Adelaide, AUSTRALIA
| | - Robert A McLaughlin
- Australian Research Council Centre of Excellence for Nanoscale Biophotonics, Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, AUSTRALIA.,Institute for Photonics and Advanced Sensing, University of Adelaide, Adelaide, AUSTRALIA.,School of Electrical, Electronic and Computer Engineering, Faculty of Engineering and Mathematical Sciences, The University of Western Australia, Perth, AUSTRALIA
| | - Daniel J Green
- Cardiovascular Research Group, School of Human Sciences (Exercise and Sport Science), Faculty of Science, The University of Western Australia, Perth, AUSTRALIA
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Didier KD, Hammer SM, Alexander AM, Caldwell JT, Sutterfield SL, Smith JR, Ade CJ, Barstow TJ. Microvascular blood flow during vascular occlusion tests assessed by diffuse correlation spectroscopy. Exp Physiol 2019; 105:201-210. [DOI: 10.1113/ep087866] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Accepted: 10/29/2019] [Indexed: 01/13/2023]
Affiliation(s)
- Kaylin D. Didier
- Department of Kinesiology Kansas State University Manhattan KS USA
| | - Shane M. Hammer
- Department of Kinesiology Kansas State University Manhattan KS USA
| | | | | | | | - Joshua R. Smith
- Department of Kinesiology Kansas State University Manhattan KS USA
| | - Carl J. Ade
- Department of Kinesiology Kansas State University Manhattan KS USA
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Low DA, Jones H, Cable NT, Alexander LM, Kenney WL. Historical reviews of the assessment of human cardiovascular function: interrogation and understanding of the control of skin blood flow. Eur J Appl Physiol 2019; 120:1-16. [PMID: 31776694 PMCID: PMC6969866 DOI: 10.1007/s00421-019-04246-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Accepted: 10/19/2019] [Indexed: 02/06/2023]
Abstract
Several techniques exist for the determination of skin blood flow that have historically been used in the investigation of thermoregulatory control of skin blood flow, and more recently, in clinical assessments or as an index of global vascular function. Skin blood flow measurement techniques differ in their methodology and their strengths and limitations. To examine the historical development of techniques for assessing skin blood flow by describing the origin, basic principles, and important aspects of each procedure and to provide recommendations for best practise. Venous occlusion plethysmography was one of the earliest techniques to intermittently index a limb’s skin blood flow under conditions in which local muscle blood flow does not change. The introduction of laser Doppler flowmetry provided a method that continuously records an index of skin blood flow (red cell flux) (albeit from a relatively small skin area) that requires normalisation due to high site-to-site variability. The subsequent development of laser Doppler and laser speckle imaging techniques allows the mapping of skin blood flow from larger surface areas and the visualisation of capillary filling from the dermal plexus in two dimensions. The use of iontophoresis or intradermal microdialysis in conjunction with laser Doppler methods allows for the local delivery of pharmacological agents to interrogate the local and neural control of skin blood flow. The recent development of optical coherence tomography promises further advances in assessment of the skin circulation via three-dimensional imaging of the skin microvasculature for quantification of vessel diameter and vessel recruitment.
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Affiliation(s)
- David A Low
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, L3 3AF, UK.
| | - Helen Jones
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, L3 3AF, UK
| | - N Tim Cable
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Liverpool, UK
| | - Lacy M Alexander
- Noll Laboratory, Department of Kinesiology, The Pennsylvania State University, University Park, PA, USA
| | - W Larry Kenney
- Noll Laboratory, Department of Kinesiology, The Pennsylvania State University, University Park, PA, USA
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Argarini R, Smith KJ, Carter HH, Naylor LH, McLaughlin RA, Green DJ. Visualizing and quantifying the impact of reactive hyperemia on cutaneous microvessels in humans. J Appl Physiol (1985) 2019; 128:17-24. [PMID: 31725361 DOI: 10.1152/japplphysiol.00583.2019] [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] [Indexed: 11/22/2022] Open
Abstract
The mechanisms underlying reactive hyperemia (RH) responses in microvessels are poorly understood. Previous assessment tools have not been capable of directly visualizing microvessels during physiological stimulation in humans. Optical coherence tomography (OCT) is capable of imaging and quantifying subcutaneous microvessels as small as ~30 µm. In this study we use OCT to visualize and quantify skin microvascular changes in response to RH for the first time in humans. We also assessed the reproducibility of this technique. OCT and laser Doppler flowmetry (LDF) were used simultaneously to scan cutaneous microvessels in 10 young healthy subjects on 2 days. We applied a speckle decorrelation algorithm to assess OCT images and calculated flow rate, speed, diameter, and density parameters. Measures were obtained at rest (baseline) and 30-s following a 5-min cuff inflation (RH). All data were compared between days. The RH stimulus significantly increased (P < 0.0001) OCT-derived microvascular diameter (37.6 ± 3.4 vs. 44.5 ± 5.2 µm), flow rate (82.4 ± 23.4 vs. 240.1 ± 58.6 pl/s), speed (48 ± 5.7 vs. 101.5 ± 17.1 µm/s), density (5.1 ± 1.7 vs. 14.6 ± 2.6%), and also LDF-derived flux (12.3 ± 5.7 vs. 31.6 ± 9.1 perfusion units). At baseline, OCT-derived diameter (r = 0.55), flow rate (r = 0.64), speed (r = 0.55), and density (r = 0.75) showed significant between-day correlations (P < 0.05), as did LDF results (r = 0.74). In response to RH, OCT-derived diameter (r = 0.63) and density (r = 0.64) showed significant correlations (P < 0.05), whereas flow rate (r = 0.45), speed (r = 0.43), and LDF (r = 0.26) were less reproducible. Our study is novel in that it establishes the feasibility of using OCT to visualize and quantify microvascular structure and function responses to RH in humans.NEW & NOTEWORTHY This study describes the first evidence in humans that optical coherence tomography provides direct visualization and comprehensive quantification of cutaneous microvascular hemodynamics as a response to reactive hyperemia. This imaging technique will greatly improve human cutaneous microvascular assessment in physiological and clinical settings.
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Affiliation(s)
- Raden Argarini
- Physiology Department, Faculty of Medicine, Airlangga University, Surabaya, Indonesia.,Cardiovascular Research Group, School of Human Sciences (Exercise and Sport Science), The University of Western Australia, Perth, Australia
| | - Kurt J Smith
- Cardiovascular Research Group, School of Human Sciences (Exercise and Sport Science), The University of Western Australia, Perth, Australia.,Lakehead University Vascular Research Laboratory, School of Kinesiology, Faculty of Health and Behavioural Sciences, Lakehead University, Thunder Bay, Canada
| | - Howard H Carter
- Cardiovascular Research Group, School of Human Sciences (Exercise and Sport Science), The University of Western Australia, Perth, Australia
| | - Louise H Naylor
- Cardiovascular Research Group, School of Human Sciences (Exercise and Sport Science), The University of Western Australia, Perth, Australia
| | - Robert A McLaughlin
- Australian Research Council Centre of Excellence for Nanoscale Biophotonics, Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, Australia.,Institute for Photonics and Advanced Sensing, University of Adelaide, Adelaide, Australia
| | - Daniel J Green
- Cardiovascular Research Group, School of Human Sciences (Exercise and Sport Science), The University of Western Australia, Perth, Australia
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Varetto G, Verzini F, Trucco A, Frola E, Spalla F, Gibello L, Boero M, Capaldi G, Rispoli P. Oxygen Delivery Therapy with EPIFLO Reduces Wound Hyperperfusion in Patients with Chronic Leg Ulcers: A Laser Speckle Contrast Analysis. Ann Vasc Surg 2019; 64:246-252. [PMID: 31634600 DOI: 10.1016/j.avsg.2019.09.036] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 09/13/2019] [Accepted: 09/17/2019] [Indexed: 01/02/2023]
Abstract
BACKGROUND Today transdermal continuous oxygen therapy (TCOT) is used in wound care to promote healing by improving local hypoxia and preventing infection, and it has been described to reduce local inflammation over 1 month of administration. The present study aims to investigate the effects of this treatment on wound microcirculation through laser speckle contrast analysis (LASCA). METHODS 20 adult patients (mean age: 76 ± 11.5 years) were prospectively enrolled. Inclusion criteria were presence of venous or mixed lower limb ulcers from three or more months without dimension reduction and without indication to surgery and weekly treatment by our outpatient clinic with silver dressings. Subjects underwent 1 month of TCOT (EPIFLO®) in addition to foam dressing. The primary endpoint was the comparison of ulcer and healthy skin perfusion through LASCA, performed before and after the treatment period. Secondary considered endpoints were wound area, wound area severity index and PUSH Tools 3.0 ulcer severity scales, and pain assessment (Numerical Rating Scale [NRS]). RESULTS Before treatment, the wound area was significantly more perfused than healthy skin (+45%; P = 0.005). At the end of the study, this difference was not significant anymore (+20.5%; P = 0.11). Ulcer perfusion decreased (-12.5%, P = 0.047), whereas healthy skin perfusion did not vary significantly. A reduction of the wound dimension (median difference: 2 cm; P = 0.009) and pain (median difference: 2 NRS point; P < 0.001) after therapy were assessed. CONCLUSIONS LASCA shows that 1 month of TCOT can help reduce hyperperfusion of ulcer bed in patients with chronic lower limb ulcers, strengthening the hypothesis that this treatment effectively contrasts inflammation. This could correlate with the area and pain reduction assessed; however, the absence of a control group in this study does not allow a generalization of this hypothesis. Larger, controlled trials are needed to properly assess the relationship between TCOT effects on wound microenvironment and effective healing process.
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Affiliation(s)
- Gianfranco Varetto
- Division of Vascular and Endovascular Surgery, Department of surgical sciences, University of Torino, A. O. U. Città della Salute e della Scienza, Molinette Hospital, Torino, Italy.
| | - Fabio Verzini
- Division of Vascular and Endovascular Surgery, Department of surgical sciences, University of Torino, A. O. U. Città della Salute e della Scienza, Molinette Hospital, Torino, Italy
| | - Andrea Trucco
- Division of Vascular and Endovascular Surgery, Department of surgical sciences, University of Torino, A. O. U. Città della Salute e della Scienza, Molinette Hospital, Torino, Italy
| | - Edoardo Frola
- Division of Vascular and Endovascular Surgery, Department of surgical sciences, University of Torino, A. O. U. Città della Salute e della Scienza, Molinette Hospital, Torino, Italy
| | - Flavia Spalla
- Division of Vascular and Endovascular Surgery, Department of surgical sciences, University of Torino, A. O. U. Città della Salute e della Scienza, Molinette Hospital, Torino, Italy
| | - Lorenzo Gibello
- Division of Vascular and Endovascular Surgery, Department of surgical sciences, University of Torino, A. O. U. Città della Salute e della Scienza, Molinette Hospital, Torino, Italy
| | - Michele Boero
- Division of Vascular and Endovascular Surgery, Department of surgical sciences, University of Torino, A. O. U. Città della Salute e della Scienza, Molinette Hospital, Torino, Italy
| | - Giacomo Capaldi
- Division of Vascular and Endovascular Surgery, Department of surgical sciences, University of Torino, A. O. U. Città della Salute e della Scienza, Molinette Hospital, Torino, Italy
| | - Pietro Rispoli
- Division of Vascular and Endovascular Surgery, Department of surgical sciences, University of Torino, A. O. U. Città della Salute e della Scienza, Molinette Hospital, Torino, Italy
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Chaseling GK, Crandall CG, Gagnon D. Skin blood flow measurements during heat stress: technical and analytical considerations. Am J Physiol Regul Integr Comp Physiol 2019; 318:R57-R69. [PMID: 31596109 DOI: 10.1152/ajpregu.00177.2019] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
During heat stress, the skin vasculature can greatly increase conductance secondary to vasodilation. The subsequent increase in skin blood flow allows for convective heat transfer from the core to the skin and between the skin surface and the surrounding environment. Measurement of skin blood flow, therefore, provides valuable information regarding heat exchange between the body and the environment. In addition, assessment of skin blood flow can be used to study vascular control mechanisms. Most often, skin blood flow is measured by venous occlusion plethysmography, Doppler ultrasound, laser-Doppler flowmetry, and, more recently, optical coherence tomography. However, important delimitations to each of these methods, which may be dependent on the research question, must be considered when responses from these approaches are interpreted. In this brief review, we discuss these methods of skin blood flow measurement and highlight potential sources of error and limitations. We also provide recommendations to guide the interpretation of skin blood flow data.
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Affiliation(s)
- Georgia K Chaseling
- Cardiovascular Prevention and Rehabilitation Centre, Montreal Heart Institute, Montréal, Québec, Canada.,Département de Pharmacologie et Physiologie, Faculté de Médecine, Université de Montréal, Montréal, Québec, Canada
| | - Craig G Crandall
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, and University of Texas Southwestern Medical Center, Dallas, Texas
| | - Daniel Gagnon
- Cardiovascular Prevention and Rehabilitation Centre, Montreal Heart Institute, Montréal, Québec, Canada.,Département de Pharmacologie et Physiologie, Faculté de Médecine, Université de Montréal, Montréal, Québec, Canada
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48
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Neubauer-Geryk J, Hoffmann M, Wielicka M, Piec K, Kozera G, Brzeziński M, Bieniaszewski L. Current methods for the assessment of skin microcirculation: Part 1. Postepy Dermatol Alergol 2019; 36:247-254. [PMID: 31333339 PMCID: PMC6640017 DOI: 10.5114/ada.2019.83656] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 02/22/2018] [Indexed: 11/17/2022] Open
Abstract
Microcirculation accounts for about 99% of blood vessels in adults and mediates between the arterial and venous parts of the cardiovascular system, both structurally and functionally. Skin microcirculation consists of two vascular plexuses: superficial and deep. Microcirculation includes vessels with a diameter of less than 150 μm, i.e. arteries, small veins, lymphatic vessels and arteriovenous anastomoses, which build the microcirculation unit. Skin microcirculation may be affected both in systemic pathologies and specific skin disorders. Several non-invasive techniques are available to assess the skin microcirculation. The clinical value is recognised for capillaroscopy and videocapillaroscopy, laser Doppler flowmetry thermography and transcutaneous oxygen measurement. The list of methods that may be used in clinical research also includes: photoplethysmography, orthogonal spectral polarization, near infrared spectroscopy and tissue reflectance spectrophotometry and optical coherence tomography.
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Affiliation(s)
- Jolanta Neubauer-Geryk
- Clinical Physiology Unit, Medical Simulation Centre, Medical University of Gdansk, Gdansk, Poland
| | | | - Melanie Wielicka
- Clinical Physiology Unit, Medical Simulation Centre/Students’ Scientific Circle, Medical University of Gdansk, Gdansk, Poland
| | - Katarzyna Piec
- Department of Neurology, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Torun, Poland
| | - Grzegorz Kozera
- Department of Neurology, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Torun, Poland
| | - Maciej Brzeziński
- Department of Cardiac and Vascular Surgery, Medical University of Gdansk, Gdansk, Poland
| | - Leszek Bieniaszewski
- Clinical Physiology Unit, Medical Simulation Centre, Medical University of Gdansk, Gdansk, Poland
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49
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Stepanov R, Podtaev S, Tsiberkin K. Sample size determination in the laser-Doppler measurements of skin blood flow. Microvasc Res 2019; 125:103883. [PMID: 31103448 DOI: 10.1016/j.mvr.2019.103883] [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: 01/10/2019] [Revised: 05/08/2019] [Accepted: 05/11/2019] [Indexed: 10/26/2022]
Abstract
Pre-study calculations of the required sample size are vital to a large majority of studies. Using the method based on the Monte-Carlo simulations, we have illustrated how the sample size is related to the statistic power value, the significance level, the variability of observations and the minor magnitude of the effect of interest under study. If the study has been already completed, one should not perform any 'post hoc' power calculations. In this case, calculation of confidence intervals is a better choice. We assessed the confidence intervals given in a number of publications where microcirculation is studied by LDF techniques using different protocols. We have found that types I and II errors are frequently encountered in the LDF studies, which is a consequence of an inappropriate sample size.
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Affiliation(s)
- Rodion Stepanov
- Institute of Continuous Media Mechanics, Korolyov str. 1, 614013 Perm, Russia; Perm National Research Polytechnic University, Komsomolskii av. 29, 614990 Perm, Russia.
| | - Sergey Podtaev
- Institute of Continuous Media Mechanics, Korolyov str. 1, 614013 Perm, Russia
| | - Kirill Tsiberkin
- Department of Physics, Perm State University, Bukirev str. 15, Perm 614990, Russia
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50
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Hohenauer E, Deliens T, Clarys P, Clijsen R. Perfusion of the skin's microcirculation after cold-water immersion (10°C) and partial-body cryotherapy (-135°C). Skin Res Technol 2019; 25:677-682. [PMID: 31038232 PMCID: PMC6849860 DOI: 10.1111/srt.12703] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 04/14/2019] [Indexed: 12/21/2022]
Abstract
Background Investigations of the perfusion of the skin's microcirculation with laser speckle contrast imaging (LSCI) after cold treatments are rare. Therefore, the aim of this study was to compare the effects between cold‐water immersion (CWI) conduction and partial‐body cryotherapy (PBC) convection on perfusion of the microcirculation and skin temperature on the thigh. Materials and Methods Twenty healthy males were randomly allocated to CWI (10°C for 10 minutes) or PBC (−60°C for 30 seconds, −135°C for 2 minutes). Perfusion and skin temperature measurements were conducted on the anterior thigh region up to 60 minutes post‐treatment. Results Cold‐water immersion decreased perfusion of the microcirculation significantly compared to baseline values between 10 minutes (P = 0.003) and 30 minutes (P = 0.01) post‐treatment. PBC increased perfusion of the microcirculation and decreased skin temperature only at the first measurement interval (0 minute, both P = 0.01) post‐treatment. Additionally, local skin temperature was significantly decreased compared to baseline values only after CWI up to 30 minutes (P = 0.04) post‐treatment. Conclusion Cold‐water immersion reduced local skin microcirculation and skin temperature while PBC only slightly increased the perfusion of the microcirculation immediately after the treatment. For cooling purposes, the conduction method seems superior compared to the convection method, assessed with a LSCI device.
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Affiliation(s)
- Erich Hohenauer
- Department of Business Economics, Health and Social Care, University of Applied Sciences and Arts of Southern Switzerland, Landquart, Switzerland.,International University of Applied Sciences THIM, Landquart, Switzerland.,Department of Movement and Sport Sciences, Faculty of Physical Education and Physiotherapy, Vrije Universiteit Brussel, Brussels, Belgium
| | - Tom Deliens
- Department of Movement and Sport Sciences, Faculty of Physical Education and Physiotherapy, Vrije Universiteit Brussel, Brussels, Belgium
| | - Peter Clarys
- Department of Movement and Sport Sciences, Faculty of Physical Education and Physiotherapy, Vrije Universiteit Brussel, Brussels, Belgium
| | - Ron Clijsen
- Department of Business Economics, Health and Social Care, University of Applied Sciences and Arts of Southern Switzerland, Landquart, Switzerland.,International University of Applied Sciences THIM, Landquart, Switzerland.,Department of Movement and Sport Sciences, Faculty of Physical Education and Physiotherapy, Vrije Universiteit Brussel, Brussels, Belgium
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