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van Kraaij SJW, Hamblin MR, Pickering G, Giannokopoulos B, Kechemir H, Heinz M, Igracki-Turudic I, Yavuz Y, Rissmann R, Gal P. A Phase 1 randomized, open-label clinical trial to evaluate the effect of a far-infrared emitting patch on local skin perfusion, microcirculation and oxygenation. Exp Dermatol 2024; 33:e14962. [PMID: 37950549 DOI: 10.1111/exd.14962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 09/06/2023] [Accepted: 10/06/2023] [Indexed: 11/12/2023]
Abstract
Far-infrared radiation (FIR) has been investigated for reduction of pain and improvement of dermal blood flow. The FIRTECH patch is a medical device designed to re-emit FIR radiated by the body. This phase 1 study was conducted to evaluate the local effects of the FIRTECH patch on local skin perfusion, microcirculation and oxygenation. This prospective, randomized, open-label, parallel designed study admitted 20 healthy participants to a medical research facility for treatment for 31 h on three anatomical locations. During treatment, imaging assessments consisting of laser speckle contrast imaging, near-infrared spectroscopy, side-stream dark-field microscopy, multispectral imaging and thermography were conducted regularly on patch-treated skin and contralateral non-treated skin. The primary endpoint was baseline perfusion increase during treatment on the upper back. Secondary endpoints included change in baseline perfusion, oxygen consumption and temperature of treated versus untreated areas. The primary endpoint was not statistically significantly different between treated and non-treated areas. The secondary endpoints baseline perfusion on the forearm (least square means [LSMs] difference 2.63 PU, 95% CI: 0.97, 4.28), oxygen consumption (LSMs difference: 0.42 arbitrary units [AUs], 95% CI: 0.04, 0.81) and skin temperature (LSMs difference 0.35°C, 95% CI: 0.16, 0.6) were statistically significantly higher in treated areas. Adverse events observed during the study were mild and transient. The vascular response to the FIRTECH patch was short-lived suggesting a non-thermal vasodilatory effect of the patch. The FIRTECH patch was well tolerated, with mild and transient adverse events observed during the study. These results support the therapeutic potential of FIR in future investigations.
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Affiliation(s)
- Sebastiaan J W van Kraaij
- Centre for Human Drug Research, Leiden, the Netherlands
- Leiden University Medical Centre, Leiden, the Netherlands
| | - Michael R Hamblin
- Laser Research Centre, Faculty of Health Science, University of Johannesburg, Johannesburg, South Africa
| | - Gisele Pickering
- Clinical Investigation Center CIC Inserm 1405, University Hospital Clermont-Ferrand, Clermont-Ferrand, France
| | | | | | - Moritz Heinz
- Research & Development, Sanofi, Chilly-Mazarin, France
| | | | - Yalçin Yavuz
- Centre for Human Drug Research, Leiden, the Netherlands
| | - Robert Rissmann
- Centre for Human Drug Research, Leiden, the Netherlands
- Leiden Academic Centre for Drug Research, Leiden, the Netherlands
| | - Pim Gal
- Centre for Human Drug Research, Leiden, the Netherlands
- Leiden University Medical Centre, Leiden, the Netherlands
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Dolgyras P, Lazaridis A, Anyfanti P, Gavriilaki E, Koletsos N, Triantafyllou A, Nikolaidou B, Galanapoulou V, Douma S, Gkaliagkousi E. Microcirculation dynamics in systemic vasculitis: evidence of impaired microvascular response regardless of cardiovascular risk factors. Rheumatology (Oxford) 2023; 62:2510-2516. [PMID: 36394222 DOI: 10.1093/rheumatology/keac652] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Accepted: 11/03/2022] [Indexed: 07/20/2023] Open
Abstract
OBJECTIVES Systemic vasculitides (SVs) are a highly inflammatory group of diseases characterized by significant cardiovascular (CV) mortality. Microvascular damage closely linked with accelerated atherosclerosis and thrombosis represents a core pathophysiological mechanism contributing to the excess CV risk of patients with SVs. Skin represents an easily accessible tissue facilitating non-invasive microvascular study. In this study we aimed to investigate microcirculation dynamics and associate them with disease-related factors in patients with SVs. METHODS We assessed skin microcirculation using laser speckle contrast imaging (LSCI) and vascular reactivity by the post-occlusive reactive hyperaemia (PORH) protocol in a meticulously selected group of patients with SVs without CV disease and compared them to controls, matched for age, sex, BMI and smoking status. RESULTS Sixty individuals were included in the study, 30 patients and 30 controls. Patients with SVs presented a lower peak magnitude during reperfusion phase (median [interquartile range] 207 [60.1] vs 143.7 [41.0] laser speckle perfusion units, P < 0.001) and lower percentage cutaneous vascular conductance increase (mean (s.d.) 190.0 [49.6]% vs 149.6 [48.9]%, P = 0.002) as compared with controls. Importantly, microvascular damage was correlated with disease duration (P < 0.001, r = -0.563 and P < 0.001, r = 0.442, respectively). CONCLUSION For the first time we have shown that patients with SVs exhibit impaired microvascular function and blunted reactivity after occlusion, as this was demonstrated by the LSCI technique. Therefore, skin microcirculation may be a useful, non-invasive method in patients with SVs for the early detection of microvascular dysfunction, which is closely related to the high CV risk that these patients bear.
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Affiliation(s)
- Panagiotis Dolgyras
- 3rd Department of Internal Medicine, Papageorgiou Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Antonios Lazaridis
- 3rd Department of Internal Medicine, Papageorgiou Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Panagiota Anyfanti
- 3rd Department of Internal Medicine, Papageorgiou Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Eleni Gavriilaki
- 3rd Department of Internal Medicine, Papageorgiou Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Nikolaos Koletsos
- 3rd Department of Internal Medicine, Papageorgiou Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Areti Triantafyllou
- 3rd Department of Internal Medicine, Papageorgiou Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Barbara Nikolaidou
- 3rd Department of Internal Medicine, Papageorgiou Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | | | - Stella Douma
- 3rd Department of Internal Medicine, Papageorgiou Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Eugenia Gkaliagkousi
- 3rd Department of Internal Medicine, Papageorgiou Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
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Le Faucheur A, Jéhannin P, Chanteau A, Blanc-Petitjean P, Donnelly A, Hoffmann C, Henni S, Bura-Rivière A, Kaladji A, Lanéelle D, Mahé G. A Multicenter, Investigator-Blinded, Randomized Controlled Trial to Assess the Efficacy of Calf Neuromuscular Electrical Stimulation Program on Walking Performance in Peripheral Artery Disease: The ELECTRO-PAD Study Protocol. J Clin Med 2022; 11:jcm11247261. [PMID: 36555879 PMCID: PMC9784261 DOI: 10.3390/jcm11247261] [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: 10/31/2022] [Revised: 11/23/2022] [Accepted: 12/01/2022] [Indexed: 12/12/2022] Open
Abstract
This paper describes a currently on-going multicenter, randomized controlled trial designed to assess the efficacy of calf neuromuscular electrical stimulation (NMES) on changes in maximal walking distance in people with lower extremity peripheral artery disease (PAD), compared with a non-intervention control-group. This study (NCT03795103) encompasses five participating centers in France. PAD participants with a predominant claudication at the calf level and a maximal treadmill walking distance ≤300 m are randomized into one of the two groups: NMES group or Control group. The NMES program consists of a 12-week program of electrical stimulations at the calf-muscle level. The primary outcome of the study is the change in maximal treadmill walking distance at 12 weeks. Main secondary outcomes include changes in the pain-free treadmill walking distance; 6 min total walking distance; global positioning system (GPS)-measured outdoor walking capacity; daily physical activity level by accelerometry; self-reported walking impairment; self-reported quality of life; ankle-brachial index; and skin microvascular function, both at the forearm and calf levels. Recruitment started in September 2019 and data collection is expected to end in November 2022.
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Affiliation(s)
- Alexis Le Faucheur
- Clinical Investigation Center, INSERM, CIC 1414, F-35033 Rennes, France
- Univ. Rennes, M2S—EA 7470, F-35000 Rennes, France
| | - Pierre Jéhannin
- Clinical Investigation Center, INSERM, CIC 1414, F-35033 Rennes, France
- Univ. Rennes, F-35000 Rennes, France
| | | | | | - Alan Donnelly
- PESS Department, Health Research Institute, University of Limerick, V94 T9PX Limerick, Ireland
| | | | - Samir Henni
- Vascular Medicine Department, CHU Angers, F-49000 Angers, France
- UMR CNRS 6015, INSERM 1083, Univ. Angers, F-49000 Angers, France
| | | | - Adrien Kaladji
- Vascular Surgery Unit, CHU Rennes, University Hospital, F-35033 Rennes, France
| | - Damien Lanéelle
- Vascular Medicine Unit, CHU Caen-Normandie, University Hospital, F-14033 Caen, France
| | - Guillaume Mahé
- Clinical Investigation Center, INSERM, CIC 1414, F-35033 Rennes, France
- Univ. Rennes, M2S—EA 7470, F-35000 Rennes, France
- Univ. Rennes, F-35000 Rennes, France
- Vascular Medicine Unit, CHU Rennes, University Hospital, F-35033 Rennes, France
- Correspondence: ; Tel.: +33-299-289-672
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Skin microvascular function, as assessed with laser speckle contrast imaging, is impaired in untreated essential and masked hypertension. Hypertens Res 2022; 45:445-454. [PMID: 34916663 DOI: 10.1038/s41440-021-00816-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 10/26/2021] [Accepted: 11/01/2021] [Indexed: 11/08/2022]
Abstract
Skin microcirculation has been proposed as a model of generalized microvascular function. Laser speckle contrast imaging (LSCI) is a novel, noninvasive method to assess skin microvascular function (SMF). To date, SMF data in hypertension are conflicting, and no study with LSCI exists. In addition, the application of LSCI in masked hypertension is scarce. We assessed SMF with LSCI coupled with postocclusive reactive hyperemia (PORH) in patients with newly diagnosed untreated essential hypertension (UHT) and masked hypertension (MH) compared to healthy normotensive (NT) individuals. We enrolled consecutive UHT and MH patients and NT individuals matched for age, sex, body mass index, and smoking status. All participants underwent SMF assessment by LSCI coupled with PORH (PeriCam PSI system, Perimed, Sweden). Correlation analyses were performed between SMF and common cardiovascular risk factors and BP parameters. In total, 70 UHT patients, 20 MH patients and 40 NT individuals were enrolled. UHT and MH patients exhibited significantly impaired SMF compared to NT individuals (UHT patients: base-to-peak flux (p < 0.001)), PORH amplitude (p < 0.001); MH patients: base-to-peak flux (p = 0.013), PORH amplitude (p = 0.022). MH patients did not differ compared to UHT patients. SMF was negatively associated with office, ambulatory and central BP. SMF was negatively associated with blood lipids and smoking. Hypertensive status was the single most important predictor of SMF. UHT and MH patients exhibit impaired SMF compared to NT individuals. MH patients did not differ compared to UHT patients. SMF is negatively associated with BP and cardiovascular risk factors. LSCI could be implemented as a useful tool to investigate SMF in hypertension.
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Wang-Evers M, Casper MJ, Glahn J, Luo T, Doyle AE, Karasik D, Kim AC, Phothong W, Nathan NR, Heesakker T, Kositratna G, Manstein D. Assessing the impact of aging and blood pressure on dermal microvasculature by reactive hyperemia optical coherence tomography angiography. Sci Rep 2021; 11:13411. [PMID: 34183707 PMCID: PMC8238964 DOI: 10.1038/s41598-021-92712-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 06/14/2021] [Indexed: 12/12/2022] Open
Abstract
Visualization and quantification of the skin microvasculature are important for studying the health of the human microcirculation. We correlated structural and pathophysiological changes of the dermal capillary-level microvasculature with age and blood pressure by using the reactive hyperemia optical coherence tomography angiography (RH-OCT-A) technique and evaluated both conventional OCT-A and the RH-OCT-A method as non-invasive imaging alternatives to histopathology. This observational pilot study acquired OCT-A and RH-OCT-A images of the dermal microvasculature of 13 young and 12 old healthy Caucasian female subjects. Two skin biopsies were collected per subject for histological analysis. The dermal microvasculature in OCT-A, RH-OCT-A, and histological images were automatically quantified and significant indications of vessel rarefaction in both old subjects and subjects with high blood pressure were observed by RH-OCT-A and histopathology. We showed that an increase in dermal microvasculature perfusion in response to reactive hyperemia was significantly lower in high blood pressure subjects compared to normal blood pressure subjects (117% vs. 229%). These results demonstrate that RH-OCT-A imaging holds functional information of the microvasculature with respect to physiological factors such as age and blood pressure that may help to monitor early disease progression and assess overall vascular health. Additionally, our results suggest that RH-OCT-A images may serve as a non-invasive alternative to histopathology for vascular analysis.
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Affiliation(s)
- Michael Wang-Evers
- Cutaneous Biology Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
| | - Malte J Casper
- Cutaneous Biology Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.,Laboratory for Functional Optical Imaging, Department of Biomedical Engineering, Columbia University, New York, NY, USA
| | - Joshua Glahn
- Cutaneous Biology Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.,Yale School of Medicine, New Haven, CT, USA
| | - Tuanlian Luo
- Cutaneous Biology Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Abigail E Doyle
- Cutaneous Biology Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Daniel Karasik
- Cutaneous Biology Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Anne C Kim
- Cutaneous Biology Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Weeranut Phothong
- Cutaneous Biology Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.,Department of Dermatology, Siriraj Hospital, Mahidol University, BKK, Thailand
| | - Neera R Nathan
- Cutaneous Biology Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Tammy Heesakker
- Cutaneous Biology Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Garuna Kositratna
- Cutaneous Biology Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Dieter Manstein
- Cutaneous Biology Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
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6
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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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Low BH, Lin YD, Huang BW, Chia T, Bau JG, Huang HY. Impaired Microvascular Response to Muscle Stretching in Chronic Smokers With Type 2 Diabetes. Front Bioeng Biotechnol 2020; 8:602. [PMID: 32596231 PMCID: PMC7300253 DOI: 10.3389/fbioe.2020.00602] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 05/18/2020] [Indexed: 11/25/2022] Open
Abstract
Objective Cigarette smoking promotes endothelial dysfunction and is a prominent catalyst for vascular disease. This study employed laser doppler flowmetry (LDF) and spectral analysis to investigate the skin microvascular response to relatively mild stimulus of stretching in diabetic smokers. Methods The study population consisted of thirty type 2 diabetic male patients (15 smokers vs. 15 non-smokers) and 15 normal non-smoking subjects. The cutaneous blood flow of the calf at both lower limbs was measured by LDF at a supine position throughout and after muscle stretching by passive dorsiflexion of the ankle. Results Following the stretch, post-stretch reactive hyperemia (PSRH) responses were found in all subjects. However, the diabetic non-smokers had relatively higher reactive blood flow than that of the diabetic smokers. The PSRH sustained for a longer time in both diabetic non-smokers and non-diabetic non-smokers in the time domain analysis. By spectral analysis, an observed discrepancy between that of diabetic smokers and diabetic non-smokers was statistically significant. Specifically, the frequency intervals corresponded to a nitric oxide dependent endothelial activity. In addition, an excessive response induced by stretching in frequency intervals of neurogenic activity, when compared with the non-smoking control, was found on diabetic non-smokers. Conclusion All subjects expressed the PSRH effect in cutaneous microcirculation after a 10-s stretch stimulus; however, this effect was observed at a significantly lower intensity in chronic smokers with diabetes. The spectral analysis of the skin blood flow signals provides a pathological index for the assessment of the endothelial dysfunction induced by cigarette smoking. Furthermore, the discrepancy of neurovascular function between that of diabetic non-smokers and normal subjects could also be distinguished via the variations of the spectrum related to neurogenic activity.
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Affiliation(s)
- Boon-Hua Low
- Division of Endocrinology and Metabolism, Kuang Tien General Hospital, Taichung, Taiwan
| | - Yue-Der Lin
- Department of Automatic Control Engineering, Feng Chia University, Taichung, Taiwan
| | - Bo-Wen Huang
- Bioinformatics and Biomedical Engineering, Feng Chia University, Taichung, Taiwan
| | - Taipau Chia
- Department of Safety, Health and Environmental Engineering, Hungkuang University, Taichung, Taiwan
| | - Jian-Guo Bau
- Department of Biomedical Engineering, Hungkuang University, Taichung, Taiwan
| | - Hao-Yu Huang
- Department of Biomolecular Chemistry, UW School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, United States
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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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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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Influence of 8-Week Aerobic Training on the Skin Microcirculation in Patients with Ischaemic Heart Disease. J Aging Res 2020; 2020:4602067. [PMID: 32399295 PMCID: PMC7199599 DOI: 10.1155/2020/4602067] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2019] [Accepted: 11/19/2019] [Indexed: 12/17/2022] Open
Abstract
Materials and Methods In the study, 48 men took part with a stabilized and pharmacologically controlled ischaemic disease. The participants were randomly divided into two groups with 24 people in each of them. The research group participated in an aerobic march training. The march was taking place 3 times a week for 30-40 minutes over a period of 8 weeks. In the time of training, the subjects did not practise any other physical activity for 8 weeks. The measurement of skin microcirculation was done by using the laser Doppler flowmeter estimating the values of regular flow and the reactions provoked in response to occlusion and temperature. Signal frequency was also analysed which was received by means of laser Doppler flowmetry in the range from 0.01 to 2 Hz during the regular flow. Results During the first measurement in relation to the initial values, a decrease in body mass was noted by 2.21 kg on average as well as reduction of systolic and diastolic pressure by 10.4 mmHg and 3.68 mmHg, respectively. The regular flow (RF) increased after the training by 2.21%. The provoked reactions were as follows: hyperemic (PRHmax): an increase occurred by 8.76% and hyperthermic (THmax): an increase occurred by 5.38%. The time needed to achieve PRHmax was reduced by 42% and to achieve THmax, by 22%. The heart rhythm and the signal strength of neurogenic rhythm decreased by approximately 8% and 24%, respectively. The signal strength of endothelial rhythm increased by 19%. In the second measurement, a recourse was noted in the values of indicators under investigation, which were assuming values close to the initial ones. In the control group, the measurement values did not change significantly. Conclusions 8 weeks of systematic aerobic training provides a significant improvement of endothelium functioning, expressed by reactivity improvement in skin microcirculation in patients suffering from ischaemic heart disease. It points to aerobic training as a nonpharmacological effective cardioprotective factor. The improvement effects of skin vascular bed functioning in the group of patients with IHD are impermanent, and they disappear after the period in which patients did not exercise physical activity.
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Rahman A, Munisamy S, Ghaffar NA, Mahmood NZ, Rasool AHG. Impaired microvascular reactivity in gestational diabetes is associated with altered glycemic parameters. Microcirculation 2018; 26:e12513. [PMID: 30422359 DOI: 10.1111/micc.12513] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 11/08/2018] [Indexed: 11/26/2022]
Abstract
OBJECTIVES To assess microvascular reactivity and glycemic parameters in GDM compared to age and GA matched controls. METHODS This study involved 21 GDM patients and 31 controls. Microvascular reactivity was assessed using LDF and PORH. Microvascular parameters; PORHmax , PORHpeak , and time to peak perfusion (Tp) were recorded after the release of 3 minutes' upper arm occlusion. HOMA-IR was performed to evaluate insulin resistance. RESULTS Average age and GA for subjects were 32.9 years and 29.2 weeks. Mean FBG and a 2-hour postprandial for GDM and controls were 4.87 ± 0.71 vs 3.99 ± 0.59 mmol/L; P < 0.001 and 9.50 ± 1.8 vs 5.67 ± 1.0 mmol/L; P < 0.001. Fasting insulin (13.88 ± 18.9 vs 8.37 ± 11.0 μLU/mL; P = 0.031) and HOMA-IR (3.14 ± 4.6 vs 1.52 ± 2.2; P = 0.004) were higher in GDM. Tp was prolonged in GDM (16.27 ± 4.3 vs 13.86 ± 2.1 seconds; P = 0.011). Positive correlations were seen between Tp and FBG and 2-hour postprandial levels. CONCLUSION Tp was prolonged in GDM compared to age-matched controls, indicating impaired microvascular reactivity.
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Affiliation(s)
- Aisyah Rahman
- Pharmacology Vascular Laboratory, Universiti Sains Malaysia, Kota Bharu, Malaysia
| | - Seetha Munisamy
- Pharmacology Vascular Laboratory, Universiti Sains Malaysia, Kota Bharu, Malaysia
| | | | - Nik Zaki Mahmood
- Obstetric & Gynecology Department, School of Medical Sciences, Universiti Sains Malaysia, Kota Bharu, Malaysia.,Hospital Universiti Sains Malaysia, Universiti Sains Malaysia, Kota Bharu, Malaysia
| | - Aida H G Rasool
- Pharmacology Vascular Laboratory, Universiti Sains Malaysia, Kota Bharu, Malaysia.,Hospital Universiti Sains Malaysia, Universiti Sains Malaysia, Kota Bharu, Malaysia
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12
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Henni S, Hersant J, Loufrani L, Duval G, Humeau-Heurtier A, Riou J, Abraham P. Painless local pressure application to test microvascular reactivity to ischemia. Microvasc Res 2018; 122:13-21. [PMID: 30399363 DOI: 10.1016/j.mvr.2018.10.013] [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: 06/29/2018] [Revised: 10/26/2018] [Accepted: 10/29/2018] [Indexed: 10/27/2022]
Abstract
BACKGROUND Forearm cutaneous blood flux (CBF) measurement with post-occlusive reactive hyperemia (PORH) is uncomfortable and may not be devoid of risks. We aimed to investigate post-compression reactive hyperemia (PCRH) with a custom-made indenter that was designed to be easily used routinely by inexperienced observers. METHODS Medical students evaluated PCRH with 1- to 4-min pressure applications of 16 to 34 kPa and PORH with 3-min forearm cuff occlusion using laser speckle contrast imaging in 15 healthy volunteers. Participants were asked to quantify their discomfort with a visual analogue scale (VAS) of 10 cm. Total ischemia (ISCH) was quantified by the product of CBF during ischemia and ischemia duration (min). We subtracted the CBF changes in the skin from a reference ipsilateral (PCRH) or contralateral (PORH) non-stimulated area. RESULTS The average VAS was 1.0 for PCRH vs. 6.0 for PORH (p < 0.001). A strong linear relationship between ISCH and peak PCRH (r2 = 0.915, p < 0.001) was noted. Peak PORH values (63.9 laser perfusion units (LPU)) were significantly lower than all values of the 3-min PCRH (72.6 LPU), including the one obtained with 16 kPa. CONCLUSION Inexperienced observers could test microvascular reactivity with PCRH without inducing the discomfort that is typically experienced with PORH. Further, PCRH elicits a higher peak response to ischemia compared with PORH. This extremely simple method could influence a broad spectrum of routine cutaneous microcirculation investigations, especially when a painful approach is particularly inadequate or if the patient is fragile. CLINICAL TRIAL REGISTRATION NCT02861924.
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Affiliation(s)
- Samir Henni
- Vascular Medicine, University Hospital of Angers, France; MitoVasc Institute, UMR CNRS 6015 - INSERM U 1083, Faculté de Médecine, Angers, France
| | - Jeanne Hersant
- Vascular Medicine, University Hospital of Angers, France; MitoVasc Institute, UMR CNRS 6015 - INSERM U 1083, Faculté de Médecine, Angers, France
| | - Laurent Loufrani
- MitoVasc Institute, UMR CNRS 6015 - INSERM U 1083, Faculté de Médecine, Angers, France
| | - Guillaume Duval
- Department of Gerontology, University Hospital of Angers, France
| | - Anne Humeau-Heurtier
- Université Angers, LARIS - Laboratoire Angevin de Recherche en Ingénierie des Systèmes, Angers, France
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- Vascular Medicine, University Hospital of Angers, France
| | - Jeremie Riou
- UMR Inserm 1066 - CNRS 6021, Faculté de Médecine, Angers, France
| | - Pierre Abraham
- MitoVasc Institute, UMR CNRS 6015 - INSERM U 1083, Faculté de Médecine, Angers, France; Sports Medicine, University Hospital of Angers, France.
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13
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Ibrahim NNIN, Rasool AHG. Assessment of macrovascular endothelial function using pulse wave analysis and its association with microvascular reactivity in healthy subjects. Skin Res Technol 2016; 23:321-325. [PMID: 27868242 DOI: 10.1111/srt.12338] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/23/2016] [Indexed: 01/02/2023]
Abstract
BACKGROUND Pulse wave analysis (PWA) and laser Doppler fluximetry (LDF) are non-invasive methods of assessing macrovascular endothelial function and microvascular reactivity respectively. The aim of this study was to assess the correlation between macrovascular endothelial function assessed by PWA and microvascular reactivity assessed by LDF. METHOD 297 healthy and non-smoking subjects (159 females, mean age (±SD) 23.56 ± 4.54 years) underwent microvascular reactivity assessment using LDF followed by macrovascular endothelial function assessments using PWA. RESULTS Pearson's correlation showed no correlation between macrovascular endothelial function and microvascular reactivity (r = -0.10, P = 0.12). CONCLUSION There was no significant correlation between macrovascular endothelial function assessed by PWA and microvascular reactivity assessed by LDF in healthy subjects.
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Affiliation(s)
- N N I N Ibrahim
- Department of Pharmacology, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, Malaysia
| | - A H G Rasool
- Department of Pharmacology, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, Malaysia
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14
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Rodriguez-Miguelez P, Thomas J, Seigler N, Crandall R, McKie KT, Forseen C, Harris RA. Evidence of microvascular dysfunction in patients with cystic fibrosis. Am J Physiol Heart Circ Physiol 2016; 310:H1479-85. [PMID: 27084387 DOI: 10.1152/ajpheart.00136.2016] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Accepted: 04/12/2016] [Indexed: 12/28/2022]
Abstract
Cystic fibrosis (CF) is a genetic, multisystemic disorder with broad clinical manifestations apart from the well-characterized pulmonary dysfunction. Recent findings have described impairment in conduit vessel function in patients with CF; however, whether microvascular function is affected in this population has yet to be elucidated. Using laser-Doppler imaging, we evaluated microvascular function through postocclusive reactive hyperemia (PORH), local thermal hyperemia (LTH), and iontophoresis with acetylcholine (ACh). PORH [518 ± 174% (CF) and 801 ± 125% (control), P = 0.039], LTH [1,338 ± 436% (CF) and 1,574 ± 620% (control), P = 0.045], and iontophoresis with ACh [416 ± 140% (CF) and 617 ± 143% (control), P = 0.032] were significantly lower in patients with CF than control subjects. In addition, the ratio of PORH to LTH was significantly (P = 0.043) lower in patients with CF (55.3 ± 5.1%) than control subjects (68.8 ± 3.1%). Significant positive correlations between LTH and forced expiratory volume in 1 s (%predicted) (r = 0.441, P = 0.013) and between the PORH-to-LTH ratio and exercise capacity (r = 0.350, P = 0.049) were observed. These data provide evidence of microvascular dysfunction in patients with CF compared with control subjects. In addition, our data demonstrate a complex relationship between microvascular function and classical markers of disease severity (i.e., pulmonary function and exercise capacity) in CF.
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Affiliation(s)
| | - Jeffrey Thomas
- Georgia Prevention Institute, Augusta University, Augusta, Georgia
| | - Nichole Seigler
- Georgia Prevention Institute, Augusta University, Augusta, Georgia
| | - Reva Crandall
- Pediatric Pulmonology, Augusta University, Augusta, Georgia
| | | | - Caralee Forseen
- Pulmonary and Critical Care Medicine, Augusta University, Augusta, Georgia; and
| | - Ryan A Harris
- Georgia Prevention Institute, Augusta University, Augusta, Georgia; Sport and Exercise Science Research Institute, University of Ulster, Jordanstown, Northern Ireland, United Kingdom
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15
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Tran BD, Chiu A, Tran C, Rogacion DR, Tfaye N, Ganesan G, Galassetti PR. Exercise and Repeated Testing Improves Accuracy of Laser Doppler Assessment of Microvascular Function Following Shortened (1-minute) Blood Flow Occlusion. Microcirculation 2016; 23:293-300. [PMID: 26998587 DOI: 10.1111/micc.12277] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Accepted: 03/14/2016] [Indexed: 11/27/2022]
Abstract
OBJECTIVES To determine whether stability/accuracy of post-occlusive LDF following shortened, one-minute blood flow occlusion, increases in the post-exercise state or by averaging multiple measurements. METHODS Six healthy adults (3F) underwent LDF eight times at rest and following exercise, assessing post-occlusive (one-minute occlusion) reactive hyperemia in the cutaneous microcirculation of the forefinger. Measured variables included: pre- and post-occlusion steady-state perfusion (Plat1, Plat2), maximum post-occlusive perfusion (Max), PkT, and the ratio Max/Plat1. RESULTS Stability/accuracy of all variables improved performing measurements after exercise (p < 0.05 Plat 1, Plat 2, Max and Max/Plat1). PkT and Max/Plat 1 displayed the greatest accuracy at rest (26.6 ± 5.1% and 26.6 ± 4.4% average difference, %Diff, of single measurements from individual "true" means, respectively); for these variables, %Diff improved to 19.5 ± 5.3 and 17.6 ± 2.1, respectively, following exercise. Overall, averaging multiple measurements performed at rest also improved stability/accuracy in all variables. This improvement was comparable to that obtained with a single measurement following exercise. CONCLUSIONS A standardized exercise stimulus prior to testing significantly improves stability/accuracy of LDF following shortened, one-minute blood flow occlusion. Our results suggest the possibilities of broader applications of exercise to optimize measurements from a variety of skin perfusion methodologies.
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Affiliation(s)
- Brian D Tran
- Institute for Clinical and Translational Science, University of California - Irvine, Irvine, California, USA
| | - Abraham Chiu
- Institute for Clinical and Translational Science, University of California - Irvine, Irvine, California, USA
| | - Charlene Tran
- Institute for Clinical and Translational Science, University of California - Irvine, Irvine, California, USA
| | - Danica Rose Rogacion
- Institute for Clinical and Translational Science, University of California - Irvine, Irvine, California, USA
| | - Nicole Tfaye
- Institute for Clinical and Translational Science, University of California - Irvine, Irvine, California, USA
| | - Goutham Ganesan
- Institute for Clinical and Translational Science, University of California - Irvine, Irvine, California, USA
| | - Pietro R Galassetti
- Institute for Clinical and Translational Science, University of California - Irvine, Irvine, California, USA
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Iredahl F, Löfberg A, Sjöberg F, Farnebo S, Tesselaar E. Non-Invasive Measurement of Skin Microvascular Response during Pharmacological and Physiological Provocations. PLoS One 2015; 10:e0133760. [PMID: 26270037 PMCID: PMC4536230 DOI: 10.1371/journal.pone.0133760] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2015] [Accepted: 07/01/2015] [Indexed: 11/18/2022] Open
Abstract
Introduction Microvascular changes in the skin due to pharmacological and physiological provocations can be used as a marker for vascular function. While laser Doppler flowmetry (LDF) has been used extensively for measurement of skin microvascular responses, Laser Speckle Contrast Imaging (LSCI) and Tissue Viability Imaging (TiVi) are novel imaging techniques. TiVi measures red blood cell concentration, while LDF and LSCI measure perfusion. Therefore, the aim of this study was to compare responses to provocations in the skin using these different techniques. Method Changes in skin microcirculation were measured in healthy subjects during (1) iontophoresis of sodium nitroprusside (SNP) and noradrenaline (NA), (2) local heating and (3) post-occlusive reactive hyperemia (PORH) using LDF, LSCI and TiVi. Results Iontophoresis of SNP increased perfusion (LSCI: baseline 40.9±6.2 PU; 10-min 100±25 PU; p<0.001) and RBC concentration (TiVi: baseline 119±18; 10-min 150±41 AU; p = 0.011). No change in perfusion (LSCI) was observed after iontophoresis of NA (baseline 38.0±4.4 PU; 10-min 38.9±5.0 PU; p = 0.64), while RBC concentration decreased (TiVi: baseline 59.6±11.8 AU; 10-min 54.4±13.3 AU; p = 0.021). Local heating increased perfusion (LDF: baseline 8.8±3.6 PU; max 112±55 PU; p<0.001, LSCI: baseline 50.8±8.0 PU; max 151±22 PU; p<0.001) and RBC concentration (TiVi: baseline 49.2±32.9 AU; max 99.3±28.3 AU; p<0.001). After 5 minutes of forearm occlusion with prior exsanguination, a decrease was seen in perfusion (LDF: p = 0.027; LSCI: p<0.001) and in RBC concentration (p = 0.045). Only LSCI showed a significant decrease in perfusion after 5 minutes of occlusion without prior exsanguination (p<0.001). Coefficients of variation were lower for LSCI and TiVi compared to LDF for most responses. Conclusion LSCI is more sensitive than TiVi for measuring microvascular changes during SNP-induced vasodilatation and forearm occlusion. TiVi is more sensitive to noradrenaline-induced vasoconstriction. LSCI and TiVi show lower inter-subject variability than LDF. These findings are important to consider when choosing measurement techniques for studying skin microvascular responses.
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Affiliation(s)
- Fredrik Iredahl
- Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
- * E-mail:
| | - Andreas Löfberg
- Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
| | - Folke Sjöberg
- Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
- Department of Plastic Surgery, Hand Surgery, and Burns, Linköping University, Linköping, Sweden
| | - Simon Farnebo
- Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
- Department of Plastic Surgery, Hand Surgery, and Burns, Linköping University, Linköping, Sweden
| | - Erik Tesselaar
- Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
- Department of Radiation Physics, Linköping University, Linköping, Sweden
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17
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Khalil A, Humeau-Heurtier A, Mahé G, Abraham P. Laser speckle contrast imaging: age-related changes in microvascular blood flow and correlation with pulse-wave velocity in healthy subjects. JOURNAL OF BIOMEDICAL OPTICS 2015; 20:051010. [PMID: 25423123 DOI: 10.1117/1.jbo.20.5.051010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Accepted: 10/29/2014] [Indexed: 06/04/2023]
Abstract
In the cardiovascular system, the macrocirculation and microcirculation—two subsystems—can be affected by aging. Laser speckle contrast imaging (LSCI) is an emerging noninvasive optical technique that allows the monitoring of microvascular function and can help, using specific data processing, to understand the relationship between the subsystems. Using LSCI, the goals of this study are: (i) to assess the aging effect over microvascular parameters (perfusion and moving blood cells velocity, MBCV) and macrocirculation parameters (pulse-wave velocity, PWV) and (ii) to study the relationship between these parameters. In 16 healthy subjects (20 to 62 years old), perfusion and MBCV computed from LSCI are studied in three physiological states: rest, vascular occlusion, and post-occlusive reactive hyperaemia (PORH). MBCV is computed from a model of velocity distribution. During PORH, the experimental results show a relationship between perfusion and age (R(2) = 0.67) and between MBCV and age (R(2) = 0.72), as well as between PWV and age at rest (R(2) = 0.91). A relationship is also found between perfusion and MBCV for all physiological states (R(2) = 0.98). Relationships between microcirculation and macrocirculation (perfusion-PWV or MBCV-PWV) are found only during PORH with R(2) = 0.76 and R(2) = 0.77, respectively. This approach may prove useful for investigating dysregulation in blood flow.
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Affiliation(s)
- Adil Khalil
- University of Angers, LARIS-Laboratoire Angevin de Recherche en Ingénierie des Systémes, 62 Avenue Notre-Dame du Lac, 49000 Angers, France
| | - Anne Humeau-Heurtier
- University of Angers, LARIS-Laboratoire Angevin de Recherche en Ingénierie des Systémes, 62 Avenue Notre-Dame du Lac, 49000 Angers, France
| | - Guillaume Mahé
- Pôle Imagerie Médicale et Explorations Fonctionnelles, Inserm CIC 1414, Hospital Pontchaillou of Rennes, University of Rennes 1, 35033 Rennes Cedex 9, France
| | - Pierre Abraham
- University of Angers, Hospital of Angers, Laboratoire de Physiologie et d'Explorations Vasculaires UMR CNRS 6214-INSERM 1083, 49033 Angers Cedex 01, France
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18
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Barwick A, Lanting S, Chuter V. Intra-tester and inter-tester reliability of post-occlusive reactive hyperaemia measurement at the hallux. Microvasc Res 2015; 99:67-71. [DOI: 10.1016/j.mvr.2015.03.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Revised: 03/06/2015] [Accepted: 03/07/2015] [Indexed: 11/29/2022]
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Zyoud S, Al-Jabi S, Sweileh W, Awang R. A bibliometric analysis of research productivity of Malaysian publications in leading toxicology journals during a 10-year period (2003-2012). Hum Exp Toxicol 2014; 33:1284-93. [PMID: 24505047 DOI: 10.1177/0960327113514101] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND Toxicology in Malaysia has experienced rapid development and made great progress in education and research in conjunction with economic development in Malaysia over the past two decades. OBJECTIVES The main objectives of this study were to analyse the research originating from Malaysia and published in toxicology journals and to examine the authorship pattern and the citations retrieved from the Scopus database. METHODS Data from 1 January 2003 till 31 December 2012 were searched for documents with specific words in the toxicology field as a 'source title' and Malaysia as an affiliation country. Research productivity was evaluated based on a methodology we developed and used in other bibliometric studies by analysing: (a) total and trends of contributions in toxicology fields between 2003 and 2012; (b) Malaysian authorship pattern and productivity; (c) collaboration patterns; (d) journals in which Malaysian researchers publish; (e) the classification of journals to Institute for Scientific Information (ISI) or non-ISI; (f) impact factors (IFs) of all publications; and (g) citations received by the publications. RESULTS In total, 290 documents were retrieved from 55 international peer-reviewed toxicology journals. The quantity of publication increased by around 10-fold from 2003 to 2012. The h-index of the retrieved documents was 20. Of the 55 journal titles, 42 (76.4%) have their IF listed in the journal citation reports 2012. Forty-two documents (14.5%) were published in journals that had no official IF. The total number of citations, at the time of manuscript writing (5 August 2013), was 1707, with a median (interquartile range) of 3 (0-7). Malaysia collaborated mostly with countries in the Asia-Pacific regions (18.3%), especially India and Japan, followed by the Middle East and Africa (10.0%), especially Palestine and Yemen. CONCLUSION The present data show a promising rise and a good start for toxicology research activity in Malaysia. The sharing of relevant research questions by developed and developing countries can lead to research opportunities in the field of toxicology.
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Affiliation(s)
- Sh Zyoud
- Poison Control and Drug Information Center (PCDIC), College of Medicine and Health Sciences, An-Najah National University, Nablus, Palestine Department of Pharmacology and Toxicology, College of Medicine and Health Sciences, An-Najah National University, Nablus, Palestine WHO Collaborating Centre for Drug Information, National Poison Centre, Universiti Sains Malaysia (USM), Penang, Malaysia
| | - Sw Al-Jabi
- Department of Clinical Pharmacy and Pharmacotherapy, College of Medicine and Health Sciences, An-Najah National University, Nablus, Palestine
| | - Wm Sweileh
- Department of Pharmacology and Toxicology, College of Medicine and Health Sciences, An-Najah National University, Nablus, Palestine
| | - R Awang
- WHO Collaborating Centre for Drug Information, National Poison Centre, Universiti Sains Malaysia (USM), Penang, Malaysia
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20
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Impact of long-term exposure to cigarette smoking on skin microvascular function. Microvasc Res 2014; 93:46-51. [DOI: 10.1016/j.mvr.2014.03.001] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Revised: 02/11/2014] [Accepted: 03/03/2014] [Indexed: 11/17/2022]
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21
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Wojtkiewicz S, Wojcik-Sosnowska E, Jasik M, Maniewski R, Karnafel W, Liebert A. Assessment of speed distribution of red blood cells in the microvascular network in healthy volunteers and type 1 diabetes using laser Doppler spectra decomposition. Physiol Meas 2014; 35:283-95. [PMID: 24434915 DOI: 10.1088/0967-3334/35/2/283] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We applied a recently reported method of decomposition of laser Doppler power density spectra for in vivo monitoring of speed distributions of red blood cells (RBCs) in the microvascular network. The spectrum decomposition technique allows us to derive the distribution of RBC speed (in absolute units (mm s(-1))) versus RBC concentration (in arbitrary units). We carried out postocclusive reactive hyperaemia (PORH) test in 15 healthy volunteers and 21 diabetic patients in which the duration of type 1 diabetes was longer than 10 years. Measurements were carried out simultaneously with the use of a typical laser Doppler commercial instrument and speed resolved laser Doppler instrument utilizing the new technique based on decomposition of the laser Doppler spectra. We show that for the classical laser Doppler instrument, none of the PORH parameters revealed a statistical significance of difference between the groups analyzed. In contrast, the RBC speed distributions obtained from laser Doppler spectra during rest in the control group and type 1 diabetes are statistically significant. This result suggests that speed distribution measurements in the rest state (without any kind of stimulation test) allows for the assessment of microcirculation disorders. Measurements carried out in healthy subjects show that the first moment of speed distributions (mean speed of the distributions) is 2.32 ± 0.54 mm s(-1) and 2.57 ± 0.41 mm s(-1) for optodes located on the toe and finger of the hand, respectively. Respective values in type 1 diabetes were higher: 3.00 ± 0.36 mm s(-1) and 3.10 ± 0.48 mm s(-1).
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Affiliation(s)
- S Wojtkiewicz
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Warsaw, Poland
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22
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Puissant C, Abraham P, Durand S, Humeau-Heurtier A, Faure S, Rousseau P, Mahé G. [Endothelial function: role, assessment and limits]. ACTA ACUST UNITED AC 2013; 39:47-56. [PMID: 24355615 DOI: 10.1016/j.jmv.2013.11.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2013] [Accepted: 10/24/2013] [Indexed: 12/16/2022]
Abstract
For several years, detecting and preventing cardiovascular diseases have become a major issue. Different methods have been developed to evaluate endothelial function. Endothelial dysfunction is one of the first steps leading to atherosclerosis. This review presents an insight into endothelial function, the interests of its assessment and methods for studying endothelial function. To date, the vascular endothelium must be considered as a specific organ with its own functions that contribute to the homeostasis of the cardiovascular system. Endothelial dysfunction typically corresponds to a decrease of nitric oxide NO bioavailability. Biological or physico-chemical methods may be used to assess dysfunction. Biological methods allow measuring NO metabolites and pro-inflammatory and vasoconstrictor mediators released by the endothelium. The physico-chemical methods include intra-coronary injections, plethysmography, flow-mediated dilation (FMD), digital plethysmography and optical techniques using laser (laser Doppler single-point, laser Doppler imager, laser speckle contrast imaging) that can be coupled with provocation tests (iontophoresis, microdialysis, post-ischemic hyperemia, local heating). The principle of each technique and its use in clinical practice are discussed. Studying endothelial dysfunction is a particularly promising field because of new drugs being developed. Nevertheless, assessment methodology still needs further development to enable reliable, non-invasive, reproducible, and inexpensive ways to analyze endothelial dysfunction.
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Affiliation(s)
- C Puissant
- Service des explorations fonctionnelles vasculaires, centre hospitalier universitaire, 49933 Angers cedex 9, France
| | - P Abraham
- Service des explorations fonctionnelles vasculaires, centre hospitalier universitaire, 49933 Angers cedex 9, France; Biologie neurovasculaire et mitochondriale intégrée (BNMI) - unité mixte UMR CNRS 6214/Inserm U 1083, faculté de médecine, LUNAM université, 49045 Angers, France
| | - S Durand
- EA 4334 motricity, interactions, and performance, LUNAM université, université du Maine, 72085 Le Mans cedex 9, France
| | - A Humeau-Heurtier
- Laboratoire d'ingénierie des systèmes automatisés (LISA), LUNAM université, université d'Angers, 49000 Angers, France
| | - S Faure
- Stress oxydant et pathologies métaboliques (SOPAM), Inserm U1063, LUNAM université, université d'Angers, 40045 Angers, France
| | - P Rousseau
- Département de chirurgie plastique, centre hospitalier universitaire, 49933 Angers cedex 9, France
| | - G Mahé
- Biologie neurovasculaire et mitochondriale intégrée (BNMI) - unité mixte UMR CNRS 6214/Inserm U 1083, faculté de médecine, LUNAM université, 49045 Angers, France; Pôle imagerie médicale, centre hospitalier universitaire Pontchaillou, 2, avenue du Pr-Léon-Bernard, 35033 Rennes cedex 9, France.
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Babos L, Járai Z, Nemcsik J. Evaluation of microvascular reactivity with laser Doppler flowmetry in chronic kidney disease. World J Nephrol 2013; 2:77-83. [PMID: 24255889 PMCID: PMC3832914 DOI: 10.5527/wjn.v2.i3.77] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Revised: 07/31/2013] [Accepted: 08/20/2013] [Indexed: 02/06/2023] Open
Abstract
Cardiovascular diseases are the major causes of mortality in patients with chronic kidney disease (CKD). The complex process of accelerated athero- and arteriosclerosis in CKD is associated with this phenomenon, where endothelial dysfunction (ED) is one of the initial steps. Hence, the early diagnosis of ED can potentially lead to early interventions which could result in a better outcome for these patients. Several methodologies have been developed for the diagnosis of ED. Laser Doppler flowmetry (LDF) enables us to study the microcirculation continuously in a non-invasive manner. In our review we would like to focus on different tests developed for LDF, like postocclusive reactive hyperaemia, local heating, iontophoresis, microdialysis or analysis of flowmotion. We would also like to summarize the available data in CKD with these methodologies to enlighten their perspectives in the clinical use on this patient population.
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Abraham P, Bourgeau M, Camo M, Humeau-Heurtier A, Durand S, Rousseau P, Mahe G. Effect of skin temperature on skin endothelial function assessment. Microvasc Res 2013; 88:56-60. [DOI: 10.1016/j.mvr.2013.04.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2013] [Accepted: 04/18/2013] [Indexed: 11/16/2022]
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Binzoni T, Humeau-Heurtier A, Abraham P, Mahe G. Blood Perfusion Values of Laser Speckle Contrast Imaging and Laser Doppler Flowmetry: Is a Direct Comparison Possible? IEEE Trans Biomed Eng 2013; 60:1259-65. [DOI: 10.1109/tbme.2012.2232294] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Tikhonova IV, Tankanag AV, Chemeris NK. Age-related changes of skin blood flow during postocclusive reactive hyperemia in human. Skin Res Technol 2012; 19:e174-81. [DOI: 10.1111/j.1600-0846.2012.00624.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/26/2012] [Indexed: 12/01/2022]
Affiliation(s)
- Irina V. Tikhonova
- Institute of Cell Biophysics; Russian Academy of Sciences; Institutskaya st. 3; Pushchino; Moscow Region; 142290; Russia
| | - Arina V. Tankanag
- Institute of Cell Biophysics; Russian Academy of Sciences; Institutskaya st. 3; Pushchino; Moscow Region; 142290; Russia
| | - Nikolay K. Chemeris
- Institute of Cell Biophysics; Russian Academy of Sciences; Institutskaya st. 3; Pushchino; Moscow Region; 142290; Russia
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Mahé G, Humeau-Heurtier A, Durand S, Leftheriotis G, Abraham P. Assessment of Skin Microvascular Function and Dysfunction With Laser Speckle Contrast Imaging. Circ Cardiovasc Imaging 2012; 5:155-63. [DOI: 10.1161/circimaging.111.970418] [Citation(s) in RCA: 100] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Guillaume Mahé
- From the Laboratory of Vascular Investigations, University Hospital of Angers and Biologie Neurovasculaire et Mitochondriale Intégrée (BNMI)-Unité mixte UMR CNRS 6214/INSERM 771, Faculté de Médecine, Angers, France (G.M., G.L., P.A.); Laboratoire d'Ingénierie des Systèmes Automatisés (LISA), Université d'Angers, Angers, France (A.H.-H.); and Laboratory “Motricité, Interactions, Performance” EA 4334, University of Le Mans, Faculty of Sport Sciences, Le Mans, France (S.D.)
| | - Anne Humeau-Heurtier
- From the Laboratory of Vascular Investigations, University Hospital of Angers and Biologie Neurovasculaire et Mitochondriale Intégrée (BNMI)-Unité mixte UMR CNRS 6214/INSERM 771, Faculté de Médecine, Angers, France (G.M., G.L., P.A.); Laboratoire d'Ingénierie des Systèmes Automatisés (LISA), Université d'Angers, Angers, France (A.H.-H.); and Laboratory “Motricité, Interactions, Performance” EA 4334, University of Le Mans, Faculty of Sport Sciences, Le Mans, France (S.D.)
| | - Sylvain Durand
- From the Laboratory of Vascular Investigations, University Hospital of Angers and Biologie Neurovasculaire et Mitochondriale Intégrée (BNMI)-Unité mixte UMR CNRS 6214/INSERM 771, Faculté de Médecine, Angers, France (G.M., G.L., P.A.); Laboratoire d'Ingénierie des Systèmes Automatisés (LISA), Université d'Angers, Angers, France (A.H.-H.); and Laboratory “Motricité, Interactions, Performance” EA 4334, University of Le Mans, Faculty of Sport Sciences, Le Mans, France (S.D.)
| | - Georges Leftheriotis
- From the Laboratory of Vascular Investigations, University Hospital of Angers and Biologie Neurovasculaire et Mitochondriale Intégrée (BNMI)-Unité mixte UMR CNRS 6214/INSERM 771, Faculté de Médecine, Angers, France (G.M., G.L., P.A.); Laboratoire d'Ingénierie des Systèmes Automatisés (LISA), Université d'Angers, Angers, France (A.H.-H.); and Laboratory “Motricité, Interactions, Performance” EA 4334, University of Le Mans, Faculty of Sport Sciences, Le Mans, France (S.D.)
| | - Pierre Abraham
- From the Laboratory of Vascular Investigations, University Hospital of Angers and Biologie Neurovasculaire et Mitochondriale Intégrée (BNMI)-Unité mixte UMR CNRS 6214/INSERM 771, Faculté de Médecine, Angers, France (G.M., G.L., P.A.); Laboratoire d'Ingénierie des Systèmes Automatisés (LISA), Université d'Angers, Angers, France (A.H.-H.); and Laboratory “Motricité, Interactions, Performance” EA 4334, University of Le Mans, Faculty of Sport Sciences, Le Mans, France (S.D.)
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Air movements interfere with laser speckle contrast imaging recordings. Lasers Med Sci 2011; 27:1073-6. [DOI: 10.1007/s10103-011-1015-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2011] [Accepted: 10/06/2011] [Indexed: 10/15/2022]
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Distance between laser head and skin does not influence skin blood flow values recorded by laser speckle imaging. Microvasc Res 2011; 82:439-42. [DOI: 10.1016/j.mvr.2011.06.014] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2011] [Revised: 06/27/2011] [Accepted: 06/30/2011] [Indexed: 11/19/2022]
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Investigation of skin vasoreactivity and blood flow oscillations in hypertensive patients. J Hypertens 2011; 29:1569-76. [DOI: 10.1097/hjh.0b013e328348b653] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Cheng C, Daskalakis C, Falkner B. Association of capillary density and function measures with blood pressure, fasting plasma glucose, and insulin sensitivity. J Clin Hypertens (Greenwich) 2011; 12:125-35. [PMID: 20167040 DOI: 10.1111/j.1751-7176.2009.00231.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The pathophysiology underlying the association between hypertension and insulin resistance remains unclear. The study purpose was to determine whether reduced capillary density and/or function underlie, and may therefore explain, this association. The study was conducted on 115 black and non-black participants aged 18 to 55 years: 91 with normal blood pressure (systolic blood pressure [SBP] <130 mm Hg) and 24 with mild blood pressure elevation (SBP 130-159 mm Hg). Capillary density and function were quantified using direct capillaroscopy measures. Insulin sensitivity (IS) was estimated using the Quantitative Insulin Sensitivity Check Index (QUICKI). Endothelial function (EF) was measured using strain-gauge plethysmography. Data were analyzed by linear regression adjusted for age, sex, race, and body mass index (BMI). After adjustment for BMI, capillary density and function measures were significant predictors of SBP ( P<.01), fasting plasma glucose (P=.012, P=.03, and P=.004, respectively), and EF (P=.033, P=.001, and P=.009, respectively). However, none of the capillary measures were significant predictors of fasting insulin or IS. These capillaroscopy data demonstrated an association with SBP but not insulin resistance, suggesting that capillary measures are unlikely to explain the association between hypertension and insulin resistance, at least with modest degrees of blood pressure elevation.
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Affiliation(s)
- Cynthia Cheng
- Department of Family and Community Medicine, Thomas Jefferson University, Philadelphia, PA 19107, USA.
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Rousseau P, Mahé G, Haj-Yassin F, Durand S, Humeau A, Leftheriotis G, Abraham P. Increasing the "region of interest" and "time of interest", both reduce the variability of blood flow measurements using laser speckle contrast imaging. Microvasc Res 2011; 82:88-91. [PMID: 21439303 DOI: 10.1016/j.mvr.2011.03.009] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2011] [Revised: 03/11/2011] [Accepted: 03/15/2011] [Indexed: 10/18/2022]
Abstract
OBJECTIVE Both spatial variability and temporal variability of skin blood flow are high. Laser speckle contrast imagers (LSCI) allow non-contact, real-time recording of cutaneous blood flow on large skin surfaces. Thereafter, the observer can define different sizes for the region of interest (ROI) in the images to decrease spatial variability and different durations over which the blood flow values are averaged (time of interest, TOI) to decrease temporal variability. We aimed to evaluate the impact of the choices of ROI and TOI on the analysis of rest blood flow and post occlusive reactive hyperemia (PORH). METHODS Cutaneous blood flow (CBF) was assessed at rest and during PORH. Three different sizes of ROI (1mm(2), 10mm(2) and 100mm(2)), and three different TOI (CBF averaged over 1s, 15s, and 30s for rest, and over 1s, 5s and 10s for PORH peak) were evaluated. Inter-subjects and intra-subjects coefficient of variations (inter-CV and intra-CV) were studied. RESULTS The inter-subject variability of CBF is about 25% at rest and is moderately improved when the size of the ROI increases (inter-CV=31%, for 1s and 1mm(2) versus inter-CV=23%, for 15s and 100mm(2)). However, increasing the TOI does not improve the results. The variability of the PORH peak is lower with an inter-CV varying between 11.4% (10s and 100mm(2)) and 21.6% (5s and 1mm(2)). The lowest intra-CV for the CBF at rest was 7.3% (TOI of 15s on a ROI of 100mm(2)) and was 3.1% for the PORH peak (TOI of 10s on a ROI of 100mm(2)). CONCLUSION We suggest that a size of ROI larger than 10mm(2) and a TOI longer than 1s are required to reduce the variability of CBF measurements both at rest and during PORH peak evaluations at the forearm level. Many technical aspects such as comparison of laser speckle contrast imaging and laser Doppler imaging or the effect of skin to head distance on recorded values with LCSI are required to improve future studies using this fascinating clinical tool.
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Affiliation(s)
- Pascal Rousseau
- Laboratory of Vascular Investigations, University Hospital of Angers, France
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Mahé G, Rousseau P, Durand S, Bricq S, Leftheriotis G, Abraham P. Laser speckle contrast imaging accurately measures blood flow over moving skin surfaces. Microvasc Res 2010; 81:183-8. [PMID: 21156183 DOI: 10.1016/j.mvr.2010.11.013] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2010] [Revised: 11/29/2010] [Accepted: 11/30/2010] [Indexed: 12/01/2022]
Abstract
Cutaneous blood flow (CBF) can be assessed non-invasively with lasers. Unfortunately, movement artefacts in the laser skin signal (LS(sk)) might sometimes compromise the interpretation of the data. To date, no method is available to remove movement artefacts point-by-point. Using a laser speckle contrast imager, we simultaneously recorded LS(sk) and the signal backscattered from an adjacent opaque surface (LS(os)). The completion of a first protocol allowed a definition of a simple equation to calculate the CBF from movement artefact-affected traces of LS(sk) and LS(os). We then recorded LS(sk) and LS(os) before, during and for 5 min after the tourniquet ischemia, both when subjects (n=8) were immobile or submitted to external passive movements of random intensity throughout the test. The typical post-occlusive reactive hyperemia trace was not identifiable within the LS(sk) recordings, with LS(sk) being 2 to 3 times higher during movements than in the immobile situation. After the calculation of CBF, traces in the immobile versus movement conditions were comparable, with the "r" cross-correlation coefficient being 0.930+/-0.010. Our method might facilitate future investigations in microvascular physiology and pathophysiology, specifically in subjects who have frequent or continuous involuntary movements.
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Affiliation(s)
- Guillaume Mahé
- Laboratory of Vascular Investigations, University Hospital of Angers, France
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Keymel S, Sichwardt J, Balzer J, Stegemann E, Rassaf T, Kleinbongard P, Kelm M, Heiss C, Lauer T. Characterization of the non-invasive assessment of the cutaneous microcirculation by laser Doppler perfusion scanner. Microcirculation 2010; 17:358-66. [PMID: 20618693 DOI: 10.1111/j.1549-8719.2010.00037.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE Microcirculatory dysfunction contributes to morbidity and mortality in vascular diseases. Here, we aimed at establishing a sensitive and valid method to measure microvascular reactivity during post-occlusive reactive hyperemia (PORH) using scanning laser Doppler perfusion imaging (LDPI) of the forearm. METHODS In a first series, LDPI was methodologically evaluated on the volar forearm of healthy volunteers (n = 10) before and after one to five minutes of upper arm occlusion. In a second series, readings were performed in 20 healthy subjects and 20 patients with coronary artery disease (CAD). RESULTS Three minutes of forearm occlusion were sufficient to induce maximal vasodilation during PORH as indicated by maximal increase in perfusion unit (PU) amplitude that did not further increase after five-minute occlusion. Five-minute occlusion led to a significant prolongation of PORH with greater area under curve (AUC) suggesting longer lasting vasodilation of microvessels. The five-minute occlusion was associated with lower variability as compared with three minutes (intraindividual variability: 9-17% vs. 12-21%; interindividual variability: 13-24% vs. 14-26%). CAD patients exhibited significantly reduced amplitude (105 +/- 49 vs. 164 +/- 35 PU; p < 0.001), ratio (4.7 +/- 1.8 vs. 7.1 +/- 1.8; p < 0.001), and AUC (1656 +/- 1070 vs. 2723 +/- 864 PU x minutes; p = 0.001). CONCLUSION Scanning LDPI is a feasible and reproducible method for non-invasive assessment of the cutaneous microcirculatory response during PORH.
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Affiliation(s)
- Stefanie Keymel
- Department of Medicine, Division of Cardiology, Pneumology, and Vascular Diseases, University Hospital, Heinrich-Heine University Duesseldorf, Duesseldorf, Germany
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Ley O, Dhindsa M, Sommerlad SM, Barnes JN, DeVan AE, Naghavi M, Tanaka H. Use of temperature alterations to characterize vascular reactivity. Clin Physiol Funct Imaging 2010; 31:66-72. [DOI: 10.1111/j.1475-097x.2010.00981.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Chen DK, Erb MK, Tong Y, Yu Y, Sassaroli A, Bergethon PR, Fantini S. Spectral and spatial dependence of
diffuse optical signals in response to
peripheral nerve stimulation. BIOMEDICAL OPTICS EXPRESS 2010; 1:923-942. [PMID: 21258519 PMCID: PMC3018062 DOI: 10.1364/boe.1.000923] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/08/2010] [Revised: 08/20/2010] [Accepted: 09/14/2010] [Indexed: 05/30/2023]
Abstract
Using non-invasive, near-infrared spectroscopy we have previously reported optical signals measured at or around peripheral nerves in response to their stimulation. Such optical signals featured amplitudes on the order of 0.1% and peaked about 100 ms after peripheral nerve stimulation in human subjects. Here, we report a study of the spatial and spectral dependence of the optical signals induced by stimulation of the human median and sural nerves, and observe that these optical signals are: (1) unlikely due to either dilation or constriction of blood vessels, (2) not associated with capillary bed hemoglobin, (3) likely due to blood vessel(s) displacement, and (4) unlikely due to fiber-skin optical coupling effects. We conclude that the most probable origin of the optical response to peripheral nerve stimulation is from displacement of blood vessels within the optically probed volume, as a result of muscle twitch in adjacent areas.
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Affiliation(s)
- Debbie K. Chen
- Tufts University, Department of Biomedical Engineering, Medford, MA, USA
| | - M. Kelley Erb
- Boston University School of Medicine, Department of Anatomy and Neurobiology, Boston, MA, USA
| | - Yunjie Tong
- Tufts University, Department of Biomedical Engineering, Medford, MA, USA
- Current address: Brain Imaging Center, McLean Hospital, Belmont, MA, USA
| | - Yang Yu
- Tufts University, Department of Biomedical Engineering, Medford, MA, USA
| | - Angelo Sassaroli
- Tufts University, Department of Biomedical Engineering, Medford, MA, USA
| | - Peter R. Bergethon
- Boston University School of Medicine, Department of Anatomy and Neurobiology, Boston, MA, USA
| | - Sergio Fantini
- Tufts University, Department of Biomedical Engineering, Medford, MA, USA
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Tikhonova IV, Tankanag AV, Chemeris NK. Time–amplitude analysis of skin blood flow oscillations during the post-occlusive reactive hyperemia in human. Microvasc Res 2010; 80:58-64. [DOI: 10.1016/j.mvr.2010.03.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2009] [Revised: 03/01/2010] [Accepted: 03/17/2010] [Indexed: 10/19/2022]
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Tikhonova IV, Tankanag AV, Chemeris NK. Age-related differences in the dynamics of the skin blood flow oscillations during postocclusive reactive hyperemia. ACTA ACUST UNITED AC 2010. [DOI: 10.1134/s0362119710020143] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Stirban A, Nandrean S, Götting C, Tamler R, Pop A, Negrean M, Gawlowski T, Stratmann B, Tschoepe D. Effects of n-3 fatty acids on macro- and microvascular function in subjects with type 2 diabetes mellitus. Am J Clin Nutr 2010; 91:808-13. [PMID: 20071644 DOI: 10.3945/ajcn.2009.28374] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Recent evidence supports the protective effects of n-3 (omega-3) fatty acids (n-3 FAs), such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), on vascular function. OBJECTIVE We investigated the effects of EPA and DHA on postprandial vascular function in subjects with type 2 diabetes mellitus. DESIGN In a double-blind, placebo-controlled, randomized, crossover manner, 34 subjects with type 2 diabetes mellitus received daily either 2 g purified EPA/DHA (termed n-3 FAs) or olive oil (placebo) for 6 wk. At the end of this period, we measured macrovascular (brachial ultrasound of flow-mediated dilatation; FMD) and microvascular [laser-Doppler measurements of reactive hyperemia (RH) of the hand] function at fasting and 2, 4, and 6 h after a high-fat meal (600 kcal, 21 g protein, 41 g carbohydrates, 40 g fat). RESULTS Fasting vascular function remained unchanged after n-3 FAs and placebo. Postprandial FMD decreased from fasting after placebo, with a maximum decrease (38%) at 4 h-an effect that was significantly reduced (P = 0.03 for time x treatment interaction) by n-3 FA supplementation (maximum decrease in FMD was at 4 h: 13%). RH remained unchanged after placebo, whereas it improved significantly (P = 0.04 for time x treatment interaction) after n-3 FA supplementation (maximum increase was at 2 h: 27%). CONCLUSIONS In subjects with type 2 diabetes mellitus, 6 wk of supplementation with n-3 FAs reduced the postprandial decrease in macrovascular function relative to placebo. Moreover, n-3 FA supplementation improved postprandial microvascular function. These observations suggest a protective vascular effect of n-3 FAs.
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McNamara PM, O'Doherty J, O'Connell ML, Fitzgerald BW, Anderson CD, Nilsson GE, Toll R, Leahy MJ. Tissue viability (TiVi) imaging: temporal effects of local occlusion studies in the volar forearm. JOURNAL OF BIOPHOTONICS 2010; 3:66-74. [PMID: 19718683 DOI: 10.1002/jbio.200910061] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Tissue Viability (TiVi) imaging is a promising new technology for the assessment of microcirculation in the upper human dermis. Although the technique is easily implemented and develops large amounts of observational data, its role in the clinical workplace awaits the development of standardised protocols required for routine clinical practice. The present study investigates the use of TiVi technology in a human, in vivo, localized, skin blood flow occlusion protocol. In this feasibility study, the response of the cutaneous microcirculation after provocation on the volar surface of the forearm was evaluated using a high temporal-low spatial resolution TiVi camera. 19 healthy subjects - 10 female and 9 male - were studied after a localized pressure was applied for 5 different time periods ranging from 5 to 25 seconds. Areas corresponding to 100 x 100 pixels (2.89 cm(2)) were monitored for 60 seconds prior to, during and after each occlusion period. Our results demonstrated the removal of blood from the local area and a hyperaemic response supporting the suitability of TiVi imaging for the generation of detailed provocation response data of relevance for the physiological function of the skin microcirculation in health and disease.
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Affiliation(s)
- Paul M McNamara
- NBIPI, Department of Physics, University of Limerick, Ireland
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Rossi M, Puccini R, Romagnoli MC, Di Maria C, Mattei P, Bernini M, Marconcini C, Santoro G. Acute and Subacute Effect of Rheopheresis on Microvascular Endothelial Function in Patients Suffering From Age-related Macular Degeneration. Ther Apher Dial 2009; 13:540-8. [DOI: 10.1111/j.1744-9987.2009.00705.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Selvaraj N, Jaryal AK, Santhosh J, Anand S, Deepak KK. Monitoring of reactive hyperemia using photoplethysmographic pulse amplitude and transit time. J Clin Monit Comput 2009; 23:315-22. [DOI: 10.1007/s10877-009-9199-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2009] [Accepted: 08/17/2009] [Indexed: 11/29/2022]
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Comparison of two mathematical models for the study of vascular reactivity. Comput Biol Med 2009; 39:579-89. [DOI: 10.1016/j.compbiomed.2008.12.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2007] [Revised: 05/27/2008] [Accepted: 12/08/2008] [Indexed: 11/18/2022]
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Abstract
INTRODUCTION The endothelial monolayer plays a crucial role in the vasodilation and hemodynamic events involved in erection physiology. Due to its relevant functions, a close link has been established between endothelial integrity and erectile dysfunction (ED). Endothelial dysfunction is induced by the detrimental actions of vascular risk factors (VRFs), identified as common correlates for the development of cardiovascular disease and ED. It is currently recognized that ED is the early harbinger of a more generalized vascular systemic disorder, and, therefore, an evaluation of endothelial health in ED patients should be of prime relevance. Several noninvasive methods for endothelial function assessment have been proposed, including the Penile Nitric Oxide Release Test (PNORT). AIM To highlight the most recent gathered knowledge on basic and clinical mechanisms underlying loss of cavernosal endothelial function promoted by VRFs and to discuss local and systemic methods for endothelial function assessment in ED individuals, focusing on the PNORT. MAIN OUTCOME MEASURES A complete revision on the novel basic and clinical links between endothelial and ED. METHODS A systematic review of the literature regarding the aforementioned issues. RESULTS Risk factor-associated cavernosal endothelial dysfunction is mostly induced by unifying mechanisms, including oxidative stress and impaired endothelial nitric oxide functional activities, which present clinically as ED. Several techniques to evaluate endothelial dysfunction were revised, with advantages and limitations debated, focusing on our detailed expertise using the PNORT method. CONCLUSIONS The established endothelial-erectile dysfunction connection was thoroughly revised, from basic mechanisms to the clinical importance of endothelial dysfunction assessment as diagnosis for generalized vascular disease. Further studies are required to disclose efficient approaches to repair disabled endothelium and both restore and prevent endothelial dysfunction.
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Affiliation(s)
- Carla Costa
- Faculty of Medicine of the University of Porto, Department of Biochemistry (U38-FCT), Porto, Portugal.
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Humeau A, Trzepizur W, Rousseau D, Chapeau-Blondeau F, Abraham P. Fisher information and Shannon entropy for on-line detection of transient signal high-values in laser Doppler flowmetry signals of healthy subjects. Phys Med Biol 2008; 53:5061-76. [DOI: 10.1088/0031-9155/53/18/014] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Ley O, Deshpande C, Prapamcham B, Naghavi M. Lumped parameter thermal model for the study of vascular reactivity in the fingertip. J Biomech Eng 2008; 130:031012. [PMID: 18532861 DOI: 10.1115/1.2913233] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Vascular reactivity (VR) denotes changes in volumetric blood flow in response to arterial occlusion. Current techniques to study VR rely on monitoring blood flow parameters and serve to predict the risk of future cardiovascular complications. Because tissue temperature is directly impacted by blood flow, a simplified thermal model was developed to study the alterations in fingertip temperature during arterial occlusion and subsequent reperfusion (hyperemia). This work shows that fingertip temperature variation during VR test can be used as a cost-effective alternative to blood perfusion monitoring. The model developed introduces a function to approximate the temporal alterations in blood volume during VR tests. Parametric studies are performed to analyze the effects of blood perfusion alterations, as well as any environmental contribution to fingertip temperature. Experiments were performed on eight healthy volunteers to study the thermal effect of 3 min of arterial occlusion and subsequent reperfusion (hyperemia). Fingertip temperature and heat flux were measured at the occluded and control fingers, and the finger blood perfusion was determined using venous occlusion plethysmography (VOP). The model was able to phenomenologically reproduce the experimental measurements. Significant variability was observed in the starting fingertip temperature and heat flux measurements among subjects. Difficulty in achieving thermal equilibration was observed, which indicates the important effect of initial temperature and thermal trend (i.e., vasoconstriction, vasodilatation, and oscillations).
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Affiliation(s)
- O Ley
- Texas A&M University, College Station, TX 77843-3123, USA
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Alpha adrenoceptor agonist-induced microcirculatory oscillations are reduced in diabetic neuropathy. Microvasc Res 2008; 76:124-31. [DOI: 10.1016/j.mvr.2008.04.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2007] [Revised: 04/30/2008] [Accepted: 04/30/2008] [Indexed: 11/21/2022]
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Assessment of endothelial function in the patient with erectile dysfunction: an opportunity for the urologist. Int J Impot Res 2008; 20:370-7. [DOI: 10.1038/ijir.2008.13] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Blunted post-ischemic increase of the endothelial skin blood flowmotion component as early sign of endothelial dysfunction in chronic kidney disease patients. Microvasc Res 2007; 75:315-22. [PMID: 17931669 DOI: 10.1016/j.mvr.2007.08.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2007] [Revised: 07/16/2007] [Accepted: 08/13/2007] [Indexed: 01/14/2023]
Abstract
With the aim to investigate microvascular endothelial function in chronic kidney disease (CKD) patients on conservative treatment, skin blood flowmotion (SBF) was explored by spectral Fourier analysis of skin forearm laser Doppler tracing, registered before and following forearm ischemia in 32 III to V stage CKD patients (23 males, mean age: 52+/-12 years), without diabetes or cardiovascular disease, and in 32 age and sex matched healthy subjects. The power spectral density (PSD) of the 0.009-1.6 Hz total spectrum SBF, as well as of five sub-intervals, each of them related to endothelial (0.009-0.02 Hz), sympathetic (0.02-0.06 Hz), myogenic (0.06-0.2 Hz), respiratory (0.2-0.6 Hz) or cardiac (0.6-1.6 Hz) activity, was measured in PU(2)/Hz (PU=perfusion unit; 1 PU=10 mV). Under basal conditions CKD patients and controls did not differ in skin perfusion or in PSD of total spectrum SBF, as well as of each of the five subintervals considered. No substantial difference was also observed in skin post-ischemic hyperemia between patients and controls. A significant post-ischemic increase in the normalized value of endothelial sub-interval was observed in controls (p<0.05, GLM ANOVA analysis of variance), but not in CKD patients. A lower per cent increase in absolute PSD value of endothelial sub-interval was also observed in CKD patients compared to controls (185+/-98 % vs 279+/-243 %, p<0.05). The post-ischemic per cent increase in absolute PSD of endothelial sub-interval was negatively related to the systolic blood pressure (r=-0.45, p<0.01), to the mean arterial blood pressure (r=-0.40, p<0.05) and to the PTH serum levels (r=-0.38, p<0.05) in CKD patients. The blunted post-ischemic increase of the endothelial SBF sub-interval can be considered an early sign of microvascular endothelial dysfunction in the CKD studied patients. Arterial hypertension seems to be the main factor related to this SBF abnormality, together with the hormonal CKD related abnormalities.
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Negrean M, Stirban A, Stratmann B, Gawlowski T, Horstmann T, Götting C, Kleesiek K, Mueller-Roesel M, Koschinsky T, Uribarri J, Vlassara H, Tschoepe D. Effects of low- and high-advanced glycation endproduct meals on macro- and microvascular endothelial function and oxidative stress in patients with type 2 diabetes mellitus. Am J Clin Nutr 2007; 85:1236-43. [PMID: 17490958 DOI: 10.1093/ajcn/85.5.1236] [Citation(s) in RCA: 154] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND An advanced glycation endproducts (AGEs)-rich diet induces significant increases in inflammatory and endothelial dysfunction markers in type 2 diabetes mellitus (T2DM). OBJECTIVE The aim was to investigate the acute effects of dietary AGEs on vascular function in T2DM patients. DESIGN Twenty inpatients with T2DM [x (+/-SEM) age: 55.4 +/- 2.2 y; glycated hemoglobin: 8.8 +/- 0.5%] were investigated. In a randomized crossover design, the effects of a low-AGE (LAGE) and high-AGE (HAGE) meal on macrovascular [by flow-mediated dilatation (FMD)] and microvascular (by Laser-Doppler flowmetry) function, serum markers of endothelial dysfunction (E-selectin, intracellular adhesion molecule 1, and vascular cell adhesion molecule 1), oxidative stress, and serum AGE were assessed. The meals had identical ingredients but different AGE amounts (15.100 compared with 2.750 kU AGE for the HAGE and LAGE meals, respectively), which were obtained by varying the cooking temperature and time. The measurements were performed at baseline and 2, 4, and 6 h after each meal. RESULTS After the HAGE meal, FMD decreased by 36.2%, from 5.77 +/- 0.65% (baseline) to 3.93 +/- 0.48 (2 h), 3.70 +/- 0.42 (4 h), and 4.42 +/- 0.54% (6 h) (P<0.01 for all compared with baseline). After the LAGE meal, FMD decreased by 20.9%, from 6.04 +/- 0.68% (baseline) to 4.75 +/- 0.48% (2 h), 4.69 +/- 0.51% (4 h), and 5.62 +/- 0.63% (6 h), respectively (P<0.01 for all compared with baseline; P<0.001 for all compared with the HAGE meal). This impairment of macrovascular function after the HAGE meal was paralleled by an impairment of microvascular function (-67.2%) and increased concentrations of serum AGE and markers of endothelial dysfunction and oxidative stress. CONCLUSIONS In patients with T2DM, a HAGE meal induces a more pronounced acute impairment of vascular function than does an otherwise identical LAGE meal. Therefore, chemical modifications of food by means of cooking play a major role in influencing the extent of postprandial vascular dysfunction.
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Affiliation(s)
- Monica Negrean
- Diabetes Clinic, Heart and Diabetes Centre NRW Bad Oeynhausen, Ruhr University Bochum, Germany
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