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Lu G, Guo H, Zhang Y, Zhang M, Zhang T, Hu G, Zhang Q. Graphene Far-Infrared Irradiation Can Effectively Relieve the Blood Pressure Level of Rat Untr-HT in Primary Hypertension. Int J Mol Sci 2024; 25:6675. [PMID: 38928382 PMCID: PMC11204347 DOI: 10.3390/ijms25126675] [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: 05/27/2024] [Revised: 06/14/2024] [Accepted: 06/16/2024] [Indexed: 06/28/2024] Open
Abstract
Graphene, when electrified, generates far-infrared radiation within the wavelength range of 4 μm to 14 μm. This range closely aligns with the far-infrared band (3 μm to 15 μm), which produces unique physiological effects. Contraction and relaxation of vascular smooth muscle play a significant role in primary hypertension, involving the nitric oxide-soluble guanylate cyclase-cyclic guanosine monophosphate pathway and the renin-angiotensin-aldosterone system. This study utilized spontaneously hypertensive rats (SHRs) as an untr-HT to investigate the impact of far-infrared radiation at specific wavelengths generated by electrified graphene on vascular smooth muscle and blood pressure. After 7 weeks, the blood pressure of the untr-HT group rats decreased significantly with a notable reduction in the number of vascular wall cells and the thickness of the vascular wall, as well as a decreased ratio of vessel wall thickness to lumen diameter. Additionally, blood flow perfusion significantly increased, and the expression of F-actin in vascular smooth muscle myosin decreased significantly. Serum levels of angiotensin II (Ang-II) and endothelin 1 (ET-1) were significantly reduced, while nitric oxide synthase (eNOS) expression increased significantly. At the protein level, eNOS expression decreased significantly, while α-SMA expression increased significantly in aortic tissue. At the gene level, expressions of eNOS and α-SMA in aortic tissue significantly increased. Furthermore, the content of nitric oxide (NO) in the SHR's aortic tissue increased significantly. These findings confirm that graphene far-infrared radiation enhances microcirculation, regulates cytokines affecting vascular smooth muscle contraction, and modifies vascular morphology and smooth muscle phenotype, offering relief for primary hypertension.
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Affiliation(s)
| | | | | | | | | | | | - Qian Zhang
- College of Animal Science and Technology, Beijing University of Agriculture, Beijing 102206, China; (G.L.); (H.G.); (Y.Z.); (M.Z.); (T.Z.); (G.H.)
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2
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Chen R, Xu J, Shang X, Bulloch G, He M, Wang W, Zhu Z. Association between cardiovascular health metrics and retinal ageing. GeroScience 2023:10.1007/s11357-023-00743-3. [PMID: 36930331 PMCID: PMC10400488 DOI: 10.1007/s11357-023-00743-3] [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: 11/10/2022] [Accepted: 01/25/2023] [Indexed: 03/18/2023] Open
Abstract
The study aims to investigate associations between cardiovascular health (CVH) metrics and retinal ageing indexed by retinal age gap. A total of 26,354 participants from the UK Biobank study with available CVH metrics and qualified retinal imaging were included in the present analysis. CVH included 7 metrics (smoking, physical activity, diet, body mass index [BMI], total cholesterol, blood pressure [BP], blood glucose). These were summarized to classify the overall CVH as poor (0-7), intermediate (8-10) or ideal (11-14). Retinal age gap was defined as the difference between biological age predicted by fundus images and chronological age. Accelerated and non-accelerated retinal ageing was defined if retinal age gap was in the upper or lower 50% quantiles of the study population, respectively. Linear and logistic regression models estimated the association of overall CVH and each metric of CVH with retinal age gap respectively. Our results showed that in the fully adjusted model, each one-unit score increase in overall CVH was negatively associated with retinal age gap (odds ratio [OR] = 0.89, 95% confidence interval [CI]: 0.87-0.92, P < 0.001). Compared with poor overall CVH, people with intermediate and ideal overall CVH had significantly lower retinal age gap (OR = 0.76, 95%CI: 0.67-0.85, P < 0.001; OR = 0.58, 95%CI: 0.50-0.67, P < 0.001). Similar associations were found between overall CVH and accelerated retinal ageing. CVH metrics including smoking, BMI, BP, and blood glucose were also significantly associated with higher retinal age gap. Taken together, we found a significant and inverse dose-response association between CVH metrics and retinal age gap, indicating that maintaining healthy metrics especially smoking, BMI, BP, and blood glucose may be crucial to slow down biological ageing.
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Affiliation(s)
- Ruiye Chen
- Department of Ophthalmology, Guangdong Academy of Medical Sciences, Guangdong Provincial People's Hospital, Guangzhou, China.,Centre for Eye Research Australia; Ophthalmology, University of Melbourne, Melbourne, Australia.,Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, Australia
| | - Jinyi Xu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Xianwen Shang
- Department of Ophthalmology, Guangdong Academy of Medical Sciences, Guangdong Provincial People's Hospital, Guangzhou, China.,Centre for Eye Research Australia; Ophthalmology, University of Melbourne, Melbourne, Australia.,Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, Australia
| | - Gabriella Bulloch
- Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, Australia
| | - Mingguang He
- Department of Ophthalmology, Guangdong Academy of Medical Sciences, Guangdong Provincial People's Hospital, Guangzhou, China. .,Centre for Eye Research Australia; Ophthalmology, University of Melbourne, Melbourne, Australia. .,Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, Australia. .,State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China.
| | - Wei Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China.
| | - Zhuoting Zhu
- Department of Ophthalmology, Guangdong Academy of Medical Sciences, Guangdong Provincial People's Hospital, Guangzhou, China. .,Centre for Eye Research Australia; Ophthalmology, University of Melbourne, Melbourne, Australia. .,Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, Australia.
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3
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Zhan J, Zhong L, Wu J. Assessment and Treatment for Coronary Microvascular Dysfunction by Contrast Enhanced Ultrasound. Front Cardiovasc Med 2022; 9:899099. [PMID: 35795368 PMCID: PMC9251174 DOI: 10.3389/fcvm.2022.899099] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 05/26/2022] [Indexed: 11/17/2022] Open
Abstract
With growing evidence in clinical practice, the understanding of coronary syndromes has gradually evolved out of focusing on the well-established link between stenosis of epicardial coronary artery and myocardial ischemia to the structural and functional abnormalities at the level of coronary microcirculation, known as coronary microvascular dysfunction (CMD). CMD encompasses several pathophysiological mechanisms of coronary microcirculation and is considered as an important cause of myocardial ischemia in patients with angina symptoms without obstructive coronary artery disease (CAD). As a result of growing knowledge of the understanding of CMD assessed by multiple non-invasive modalities, CMD has also been found to be involved in other cardiovascular diseases, including primary cardiomyopathies as well as heart failure with preserved ejection fraction (HFpEF). In the past 2 decades, almost all the imaging modalities have been used to non-invasively quantify myocardial blood flow (MBF) and promote a better understanding of CMD. Myocardial contrast echocardiography (MCE) is a breakthrough as a non-invasive technique, which enables assessment of myocardial perfusion and quantification of MBF, exhibiting promising diagnostic performances that were comparable to other non-invasive techniques. With unique advantages over other non-invasive techniques, MCE has gradually developed into a novel modality for assessment of the coronary microvasculature, which may provide novel insights into the pathophysiological role of CMD in different clinical conditions. Moreover, the sonothrombolysis and the application of artificial intelligence (AI) will offer the opportunity to extend the use of contrast ultrasound theragnostics.
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Glazkova PA, Kulikov DA, Glazkov AA, Terpigorev SA, Rogatkin DA, Shekhyan GG, Krasulina KA, Kulikov AV, Makmatov-Rys MB, Paleev FN. Reactivity of skin microcirculation as a biomarker of cardiovascular events. Pilot study. Clin Hemorheol Microcirc 2021; 78:247-257. [PMID: 33682698 DOI: 10.3233/ch-201016] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND The role of microcirculatory disorders is progressively being accepted in the pathogenesis of cardiovascular diseases. OBJECTIVE The purpose of current study is to assess whether we can consider skin microcirculation disorders as a biomarker of cardiovascular events. METHODS Group 1 consisted of healthy volunteers (n = 31); group 2 (n = 42) consisted of patients with diseases that increase the risk of cardiovascular events; group 3 (n = 39) included patients with the history of cardiovascular events. Skin microcirculation measurement was performed using laser Doppler flowmetry during the heating test. RESULTS LDF parameters reflecting the rapid response of microcirculation to heating ("Slope 120 s" and "Slope 180 s") significantly differed in three groups (p < 0.05). A decrease in the "Slope 180 s" parameter less than 0.5 PU/s is associated with cardiovascular events (sensitivity 69.2%, specificity 66.7%; the area under the ROC curve, 0.667; 95% confidence interval [CI], 0.545-0.788, p = 0.01). Multivariable logistic regression analysis revealed that "Slope 180 s≤0.5 PU/s" was significantly related to cardiovascular events (adjusted odds ratio = 3.9, p = 0.019, CI 95% 1.2-12). CONCLUSIONS Reduced reactivity of the skin microcirculation may be useful as a biomarker of severe damage to the cardiovascular system and is promising as a risk factor for cardiovascular events.
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Affiliation(s)
- P A Glazkova
- Moscow Regional Research and Clinical Institute ("MONIKI"), Moscow, Russian Federation
| | - D A Kulikov
- Moscow Regional Research and Clinical Institute ("MONIKI"), Moscow, Russian Federation.,Moscow Region State University, Mytishchi, Russian Federation
| | - A A Glazkov
- Moscow Regional Research and Clinical Institute ("MONIKI"), Moscow, Russian Federation
| | - S A Terpigorev
- Moscow Regional Research and Clinical Institute ("MONIKI"), Moscow, Russian Federation
| | - D A Rogatkin
- Moscow Regional Research and Clinical Institute ("MONIKI"), Moscow, Russian Federation
| | - G G Shekhyan
- Moscow Regional Research and Clinical Institute ("MONIKI"), Moscow, Russian Federation
| | - K A Krasulina
- Moscow Regional Research and Clinical Institute ("MONIKI"), Moscow, Russian Federation
| | - A V Kulikov
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Russian Federation
| | - M B Makmatov-Rys
- Moscow Regional Research and Clinical Institute ("MONIKI"), Moscow, Russian Federation
| | - F N Paleev
- National medical research center of cardiology of the Ministry of healthcare of the Russian Federation, Moscow, Russian Federation
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5
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Casanova F, Gooding KM, Shore AC, Adingupu DD, Mawson D, Ball C, Anning C, Aizawa K, Gates PE, Strain WD. Weight change and sulfonylurea therapy are related to 3 year change in microvascular function in people with type 2 diabetes. Diabetologia 2020; 63:1268-1278. [PMID: 32185461 PMCID: PMC7228909 DOI: 10.1007/s00125-020-05125-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Accepted: 02/17/2020] [Indexed: 12/26/2022]
Abstract
AIMS/HYPOTHESIS Although cardiovascular disease is the biggest cause of death in people with diabetes, microvascular complications have a significant impact on quality of life and financial burden of the disease. Little is known about the progression of microvascular dysfunction in the early stages of type 2 diabetes before the occurrence of clinically apparent complications. We aimed to explore the determinants of endothelial-dependent and -independent microvascular function progression over a 3 year period, in people with and without both diabetes and few clinical microvascular complications. METHODS Demographics were collected in 154 participants with type 2 diabetes and in a further 99 participants without type 2 diabetes. Skin microvascular endothelium-dependent response to iontophoresis of acetylcholine and endothelium-independent responses to sodium nitroprusside were measured using laser Doppler fluximetry. All assessments were repeated 3 years later. RESULTS People with type 2 diabetes had impaired endothelial-dependent microvascular response compared with those without (AUC 93.9 [95% CI 88.1, 99.4] vs 111.9 [102.3, 121.4] arbitrary units [AU] × min, p < 0.001, for those with vs without diabetes, respectively). Similarly, endothelial-independent responses were attenuated in those with diabetes (63.2 [59.2, 67.2] vs 75.1 [67.8, 82.4] AU × min, respectively, p = 0.002). Mean microvascular function declined over 3 years in both groups to a similar degree (pinteraction 0.74 for response to acetylcholine and 0.69 for response to sodium nitroprusside). In those with diabetes, use of sulfonylurea was associated with greater decline (p = 0.022 after adjustment for co-prescriptions, change in HbA1c and weight), whereas improving glycaemic control was associated with less decline of endothelial-dependent microvascular function (p = 0.03). Otherwise, the determinants of microvascular decline were similar in those with and without diabetes. The principal determinant of change in microvascular function in the whole population was weight change over 3 years, such that those that lost ≥5% weight had very little decline in either endothelial-dependent or -independent function compared with those that were weight stable, whereas those who gained weight had a greater decline in function (change in endothelial-dependent function was 1.2 [95% CI -13.2, 15.7] AU × min in those who lost weight; -15.8 [-10.5, -21.0] AU × min in those with stable weight; and -37.8 [-19.4, -56.2] AU × min in those with weight gain; ptrend < 0.001). This association of weight change with change in endothelial function was driven by people with diabetes; in people without diabetes, the relationship was nonsignificant. CONCLUSIONS/INTERPRETATION Over 3 years, physiological change in weight was the greatest predictor of change in microvascular function.
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Affiliation(s)
- Francesco Casanova
- Diabetes and Vascular Medicine Research Centre, Institute of Biomedical and Clinical Science and University of Exeter College of Medicine and Health, Royal Devon & Exeter Hospital, Barrack Road, Exeter, EX2 5AX, UK
| | - Kim M Gooding
- Diabetes and Vascular Medicine Research Centre, Institute of Biomedical and Clinical Science and University of Exeter College of Medicine and Health, Royal Devon & Exeter Hospital, Barrack Road, Exeter, EX2 5AX, UK
| | - Angela C Shore
- Diabetes and Vascular Medicine Research Centre, Institute of Biomedical and Clinical Science and University of Exeter College of Medicine and Health, Royal Devon & Exeter Hospital, Barrack Road, Exeter, EX2 5AX, UK
| | - Damilola D Adingupu
- Diabetes and Vascular Medicine Research Centre, Institute of Biomedical and Clinical Science and University of Exeter College of Medicine and Health, Royal Devon & Exeter Hospital, Barrack Road, Exeter, EX2 5AX, UK
| | - David Mawson
- Diabetes and Vascular Medicine Research Centre, Institute of Biomedical and Clinical Science and University of Exeter College of Medicine and Health, Royal Devon & Exeter Hospital, Barrack Road, Exeter, EX2 5AX, UK
- NIHR Exeter Clinical Research Facility, Royal Devon & Exeter NHS Foundation Trust and University of Exeter, College of Medicine and Health, Exeter, UK
| | - Claire Ball
- NIHR Exeter Clinical Research Facility, Royal Devon & Exeter NHS Foundation Trust and University of Exeter, College of Medicine and Health, Exeter, UK
| | - Christine Anning
- NIHR Exeter Clinical Research Facility, Royal Devon & Exeter NHS Foundation Trust and University of Exeter, College of Medicine and Health, Exeter, UK
| | - Kunihiko Aizawa
- Diabetes and Vascular Medicine Research Centre, Institute of Biomedical and Clinical Science and University of Exeter College of Medicine and Health, Royal Devon & Exeter Hospital, Barrack Road, Exeter, EX2 5AX, UK
| | - Philip E Gates
- Diabetes and Vascular Medicine Research Centre, Institute of Biomedical and Clinical Science and University of Exeter College of Medicine and Health, Royal Devon & Exeter Hospital, Barrack Road, Exeter, EX2 5AX, UK
| | - W David Strain
- Diabetes and Vascular Medicine Research Centre, Institute of Biomedical and Clinical Science and University of Exeter College of Medicine and Health, Royal Devon & Exeter Hospital, Barrack Road, Exeter, EX2 5AX, UK.
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6
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Casanova F, Wood AR, Yaghootkar H, Beaumont RN, Jones SE, Gooding KM, Aizawa K, Strain WD, Hattersley AT, Khan F, Shore AC, Frayling TM, Tyrrell J. A Mendelian Randomization Study Provides Evidence That Adiposity and Dyslipidemia Lead to Lower Urinary Albumin-to-Creatinine Ratio, a Marker of Microvascular Function. Diabetes 2020; 69:1072-1082. [PMID: 31915152 PMCID: PMC7611011 DOI: 10.2337/db19-0862] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Accepted: 12/23/2019] [Indexed: 01/22/2023]
Abstract
Urinary albumin-to-creatinine ratio (ACR) is a marker of diabetic nephropathy and microvascular damage. Metabolic-related traits are observationally associated with ACR, but their causal role is uncertain. Here, we confirmed ACR as a marker of microvascular damage and tested whether metabolic-related traits have causal relationships with ACR. The association between ACR and microvascular function (responses to acetylcholine [ACH] and sodium nitroprusside) was tested in the SUMMIT study. Two-sample Mendelian randomization (MR) was used to infer the causal effects of 11 metabolic risk factors, including glycemic, lipid, and adiposity traits, on ACR. MR was performed in up to 440,000 UK Biobank and 54,451 CKDGen participants. ACR was robustly associated with microvascular function measures in SUMMIT. Using MR, we inferred that higher triglyceride (TG) and LDL cholesterol (LDL-C) levels caused elevated ACR. A 1 SD higher TG and LDL-C level caused a 0.062 (95% CI 0.040, 0.083) and a 0.026 (95% CI 0.008, 0.044) SD higher ACR, respectively. There was evidence that higher body fat and visceral body fat distribution caused elevated ACR, while a metabolically "favorable adiposity" phenotype lowered ACR. ACR is a valid marker for microvascular function. MR suggested that seven traits have causal effects on ACR, highlighting the role of adiposity-related traits in causing lower microvascular function.
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Affiliation(s)
- Francesco Casanova
- Diabetes and Vascular Medicine, NIHR Exeter Clinical Research Facility and Institute of Biomedical and Clinical Science, University of Exeter Medical School, Exeter, U.K
| | - Andrew R Wood
- Genetics of Complex Traits, Institute of Biomedical and Clinical Science, University of Exeter Medical School, Exeter, U.K
| | - Hanieh Yaghootkar
- Genetics of Complex Traits, Institute of Biomedical and Clinical Science, University of Exeter Medical School, Exeter, U.K
- Research Centre for Optimal Health, School of Life Sciences, University of Westminster, London, U.K
| | - Robert N Beaumont
- Genetics of Complex Traits, Institute of Biomedical and Clinical Science, University of Exeter Medical School, Exeter, U.K
| | - Samuel E Jones
- Genetics of Complex Traits, Institute of Biomedical and Clinical Science, University of Exeter Medical School, Exeter, U.K
| | - Kim M Gooding
- Diabetes and Vascular Medicine, NIHR Exeter Clinical Research Facility and Institute of Biomedical and Clinical Science, University of Exeter Medical School, Exeter, U.K
| | - Kunihiko Aizawa
- Diabetes and Vascular Medicine, NIHR Exeter Clinical Research Facility and Institute of Biomedical and Clinical Science, University of Exeter Medical School, Exeter, U.K
| | - W David Strain
- Diabetes and Vascular Medicine, NIHR Exeter Clinical Research Facility and Institute of Biomedical and Clinical Science, University of Exeter Medical School, Exeter, U.K
| | - Andrew T Hattersley
- Diabetes and Vascular Medicine, NIHR Exeter Clinical Research Facility and Institute of Biomedical and Clinical Science, University of Exeter Medical School, Exeter, U.K
| | - Faisel Khan
- Division of Systems Medicine, School of Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee, U.K
| | - Angela C Shore
- Diabetes and Vascular Medicine, NIHR Exeter Clinical Research Facility and Institute of Biomedical and Clinical Science, University of Exeter Medical School, Exeter, U.K
| | - Timothy M Frayling
- Genetics of Complex Traits, Institute of Biomedical and Clinical Science, University of Exeter Medical School, Exeter, U.K
| | - Jessica Tyrrell
- Genetics of Complex Traits, Institute of Biomedical and Clinical Science, University of Exeter Medical School, Exeter, U.K.
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7
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Islam S, Ahmed N, Rivu SF, Khalil M, Tanjia N, Lehmann C. Challenges for microcirculation research in developing countries. Clin Hemorheol Microcirc 2020; 73:599-607. [PMID: 31156150 DOI: 10.3233/ch-190611] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Microvascular dysfunction is a main contributor to morbidity and mortality worldwide. Sophisticated technical tools (e.g. miniaturized hardware, automated software), along with skilled personnel are the prerequisite for quantitative observations of the microvasculature. OBJECTIVE This review aimed to get an overview about on-going microcirculatory research in developing countries, particularly of the South-East Asia region for the last five years and to project the challenges faced in microcirculation research in developing countries. METHODS Original research articles originating from 194 countries were searched in PubMed database on the field of microcirculation research for the last five years. RESULTS Our findings showed that around 1800 articles have been published from developing countries compared to more than 5000 from developed countries on different aspects of microcirculation. The overall publication per million populations for developing countries was found to be 0.37 where for developed countries it was 3.62. CONCLUSIONS Initiation and execution of sophisticated research in microcirculation is a demand of the time. Such research, initially, may seem unmanageable in developing countries with limited resources and infrastructure settings. Collaborative scientific projects may aid in establishing networks for microvascular research in developing countries.
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Affiliation(s)
- Sufia Islam
- Department of Pharmacy, East West University, Dhaka, Bangladesh
| | - Najneen Ahmed
- Department of Pharmacy, East West University, Dhaka, Bangladesh
| | | | - Marjana Khalil
- Department of Pharmacy, East West University, Dhaka, Bangladesh
| | - Nafisa Tanjia
- Department of Pharmacy, East West University, Dhaka, Bangladesh
| | - Christian Lehmann
- Department of Anesthesia, Pain Management and Perioperative Medicine, Dalhousie University, Halifax, NS, Canada
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8
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Dai G, He W, Xu L, Pazo EE, Lin T, Liu S, Zhang C. Exploring the effect of hypertension on retinal microvasculature using deep learning on East Asian population. PLoS One 2020; 15:e0230111. [PMID: 32134976 PMCID: PMC7058325 DOI: 10.1371/journal.pone.0230111] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 02/23/2020] [Indexed: 11/18/2022] Open
Abstract
Hypertension is the leading risk factor of cardiovascular disease and has profound effects on both the structure and function of the microvasculature. Abnormalities of the retinal vasculature may reflect the degree of microvascular damage due to hypertension, and these changes can be detected with fundus photographs. This study aimed to use deep learning technique that can detect subclinical features appearing below the threshold of a human observer to explore the effect of hypertension on morphological features of retinal microvasculature. We collected 2012 retinal photographs which included 1007 from patients with a diagnosis of hypertension and 1005 from normotensive control. By method of vessel segmentation, we removed interference information other than retinal vasculature and contained only morphological information about blood vessels. Using these segmented images, we trained a small convolutional neural networks (CNN) classification model and used a deep learning technique called Gradient-weighted Class Activation Mapping (Grad-CAM) to generate heat maps for the class “hypertension”. Our model achieved an accuracy of 60.94%, a specificity of 51.54%, a precision of 59.27%, and a recall of 70.48%. The AUC was 0.6506. In the heat maps for the class “hypertension”, red patchy areas were mainly distributed on or around arterial/venous bifurcations. This indicated that the model has identified these regions as being the most important for predicting hypertension. Our study suggested that the effect of hypertension on retinal microvascular morphology mainly occurred at branching of vessels. The change of the branching pattern of retinal vessels was probably the most significant in response to elevated blood pressure.
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Affiliation(s)
- Guangzheng Dai
- The Second Clinical College, Dalian Medical University, Dalian, Liaoning, China
- Clinical Research Center, He Eye Specialists Hospitals, Shenyang, Liaoning, China
| | - Wei He
- The Second Clinical College, Dalian Medical University, Dalian, Liaoning, China
- Clinical Research Center, He Eye Specialists Hospitals, Shenyang, Liaoning, China
- Clinical College, He University, Shenyang, Liaoning, China
- * E-mail:
| | - Ling Xu
- Clinical Research Center, He Eye Specialists Hospitals, Shenyang, Liaoning, China
- Clinical College, He University, Shenyang, Liaoning, China
| | - Eric E. Pazo
- Clinical Research Center, He Eye Specialists Hospitals, Shenyang, Liaoning, China
- Clinical College, He University, Shenyang, Liaoning, China
| | - Tiezhu Lin
- Clinical Research Center, He Eye Specialists Hospitals, Shenyang, Liaoning, China
- Clinical College, He University, Shenyang, Liaoning, China
| | - Shasha Liu
- Clinical Research Center, He Eye Specialists Hospitals, Shenyang, Liaoning, China
| | - Chenguang Zhang
- The Second Clinical College, Dalian Medical University, Dalian, Liaoning, China
- Clinical Research Center, He Eye Specialists Hospitals, Shenyang, Liaoning, China
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9
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Struijker-Boudier HAJ. Study of the Microcirculation Through Microscopic Techniques. Microcirculation 2020. [DOI: 10.1007/978-3-030-28199-1_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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10
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Monteiro Rodrigues L, Silva H, Ferreira H, Renault MA, Gadeau AP. Observations on the perfusion recovery of regenerative angiogenesis in an ischemic limb model under hyperoxia. Physiol Rep 2018; 6:e13736. [PMID: 29932507 PMCID: PMC6014455 DOI: 10.14814/phy2.13736] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2018] [Revised: 05/16/2018] [Accepted: 05/18/2018] [Indexed: 12/11/2022] Open
Abstract
This study combines two well‐known vascular research models, hyperoxia and hind limb ischemia, aiming to better characterize capacities of the hyperoxia challenge. We studied two groups of C57/BL6 male mice, a control (C) and a hind limb ischemia (HLI) group. Perfusion from both limbs was recorded in all animals by laser Doppler techniques under an oxygen (O2) saturated atmosphere, once for control and, during 35 days for the HLI group. We used a third set of normoxic animals for HLI morphometric control. The expected variability of responses was higher for the younger animals. In the HLI group, capillary density normalized at Day 21 as expected, but not microcirculatory physiology. In the operated limb, perfusion decreased dramatically following surgery (Day 4), as a slight reduction in the non‐operated limb was also noted. Consistently, the response to hyperoxia was an increased perfusion in the ischemic limb and decreased perfusion in the contralateral limb. Only at Day 35, both limbs exhibited similar flows, although noticeably lower than Day 0. These observations help to understand some of the functional variability attributed to the hyperoxia model, by showing (i) differences in the circulation of the limb pairs to readjust a new perfusion set‐point even after ischemia, an original finding implying that (ii) data from both limbs should be recorded when performing distal measurements in vivo. Our data demonstrate that the new vessels following HLI are not functionally normal, and this also affects the non‐operated limb. These findings confirm the discriminative capacities of the hyperoxia challenge and suggest its potential utility to study other pathologies with vascular impact.
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Affiliation(s)
- Luis Monteiro Rodrigues
- CBIOS - Universidade Lusófona's Research Center for Biosciences and Health Technologies, Lisboa, Portugal.,Pharmacology Science Department, Faculty of Pharmacy, Universidade de Lisboa, Lisboa, Portugal
| | - Henrique Silva
- CBIOS - Universidade Lusófona's Research Center for Biosciences and Health Technologies, Lisboa, Portugal.,Pharmacology Science Department, Faculty of Pharmacy, Universidade de Lisboa, Lisboa, Portugal
| | - Hugo Ferreira
- IBEB - Biophysics and Biomedical Engineering Institute, Universidade de Lisboa Faculty of Sciences, Lisboa, Portugal
| | - Marie-Ange Renault
- Biology of Cardiovascular Diseases, Universite Bordeaux Montaigne, Inserm, Pessac, France
| | - Alain-Pierre Gadeau
- Biology of Cardiovascular Diseases, Universite Bordeaux Montaigne, Inserm, Pessac, France
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11
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Clough GF, Kuliga KZ, Chipperfield AJ. Flow motion dynamics of microvascular blood flow and oxygenation: Evidence of adaptive changes in obesity and type 2 diabetes mellitus/insulin resistance. Microcirculation 2018; 24. [PMID: 27809397 DOI: 10.1111/micc.12331] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Accepted: 10/31/2016] [Indexed: 11/29/2022]
Abstract
An altered spatial heterogeneity and temporal stability of network perfusion can give rise to a limited adaptive ability to meet metabolic demands. Derangement of local flow motion activity is associated with reduced microvascular blood flow and tissue oxygenation, and it has been suggested that changes in flow motion activity may provide an early indicator of declining, endothelial, neurogenic, and myogenic regulatory mechanisms and signal the onset and progression of microvascular pathophysiology. This short conference review article explores some of the evidence for altered flow motion dynamics of blood flux signals acquired using laser Doppler fluximetry in the skin in individuals at risk of developing or with cardiometabolic disease.
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Affiliation(s)
| | - Katarzyna Z Kuliga
- Faculty of Medicine, University of Southampton, Southampton, UK.,Faculty of Engineering and the Environment, University of Southampton, Southampton, UK
| | - Andrew J Chipperfield
- Faculty of Engineering and the Environment, University of Southampton, Southampton, UK
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12
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Melik Z, Zaletel P, Virtic T, Cankar K. L-arginine as dietary supplement for improving microvascular function. Clin Hemorheol Microcirc 2017; 65:205-217. [DOI: 10.3233/ch-16159] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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13
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Evidence of Microvascular Changes in the Retina following Kawasaki Disease. Sci Rep 2017; 7:40513. [PMID: 28094311 PMCID: PMC5240332 DOI: 10.1038/srep40513] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Accepted: 12/06/2016] [Indexed: 01/19/2023] Open
Abstract
It is unclear whether all children with Kawasaki disease (KD) have increased later cardiovascular risk. The retinal microvasculature reflects changes in the microcirculation and is associated with traditional cardiovascular risk factors and events. The aim of this study was to investigate retinal microvascular parameters in two populations of patients with previous KD and control participants. We performed case-control studies of 116 (57 patients and 59 control participants) Australian and 156 (78 patients and 78 control participants) Singaporean individuals, at least two years since their acute illness. Standardised retinal photographs were graded by trained technicians using a semi-automated software, which quantifies the retinal microvasculature (calibre, branching angle, fractal dimensions, and tortuosity). Retinal venules of Singaporean KD patients were 9.67 μm (95% CI 4.87 to 14.51, p < 0.001) larger than control participants following correction for traditional cardiovascular risk factors. An incremental increase in the size of retinal venules in those with coronary artery abnormalities was observed. There was limited evidence that retinal venules were larger in Australian KD patients with coronary artery abnormalities compared to control participants (7.34 μm, 95% CI 1.30 to 15.99, p = 0.10). Differences in retinal microvasculature were particularly evident in Singaporean KD patients. Larger retinal venules may reflect chronic inflammation and endothelial dysfunction, and are associated with coronary artery disease in adults.
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14
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Gutterman DD, Chabowski DS, Kadlec AO, Durand MJ, Freed JK, Ait-Aissa K, Beyer AM. The Human Microcirculation: Regulation of Flow and Beyond. Circ Res 2016; 118:157-72. [PMID: 26837746 DOI: 10.1161/circresaha.115.305364] [Citation(s) in RCA: 187] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The microcirculation is responsible for orchestrating adjustments in vascular tone to match local tissue perfusion with oxygen demand. Beyond this metabolic dilation, the microvasculature plays a critical role in modulating vascular tone by endothelial release of an unusually diverse family of compounds including nitric oxide, other reactive oxygen species, and arachidonic acid metabolites. Animal models have provided excellent insight into mechanisms of vasoregulation in health and disease. However, there are unique aspects of the human microcirculation that serve as the focus of this review. The concept is put forth that vasculoparenchymal communication is multimodal, with vascular release of nitric oxide eliciting dilation and preserving normal parenchymal function by inhibiting inflammation and proliferation. Likewise, in disease or stress, endothelial release of reactive oxygen species mediates both dilation and parenchymal inflammation leading to cellular dysfunction, thrombosis, and fibrosis. Some pathways responsible for this stress-induced shift in mediator of vasodilation are proposed. This paradigm may help explain why microvascular dysfunction is such a powerful predictor of cardiovascular events and help identify new approaches to treatment and prevention.
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Affiliation(s)
- David D Gutterman
- From the Cardiovascular Center (A.M.B., A.O.K., D.D.G., D.S.C., J.K.F., K.A.-A., M.J.D.), Departments of Medicine (A.M.B., A.O.K., D.D.G., D.S.C., J.K.F., K.A.-A.), Pharmacology and Toxicology (D.S.C., J.K.F.), Physiology (A.M.B., A.O.K.), Physical Medicine and Rehabilitation (M.J.D.), and Anesthesiology (J.K.F.), Medical College of Wisconsin, Milwaukee.
| | - Dawid S Chabowski
- From the Cardiovascular Center (A.M.B., A.O.K., D.D.G., D.S.C., J.K.F., K.A.-A., M.J.D.), Departments of Medicine (A.M.B., A.O.K., D.D.G., D.S.C., J.K.F., K.A.-A.), Pharmacology and Toxicology (D.S.C., J.K.F.), Physiology (A.M.B., A.O.K.), Physical Medicine and Rehabilitation (M.J.D.), and Anesthesiology (J.K.F.), Medical College of Wisconsin, Milwaukee
| | - Andrew O Kadlec
- From the Cardiovascular Center (A.M.B., A.O.K., D.D.G., D.S.C., J.K.F., K.A.-A., M.J.D.), Departments of Medicine (A.M.B., A.O.K., D.D.G., D.S.C., J.K.F., K.A.-A.), Pharmacology and Toxicology (D.S.C., J.K.F.), Physiology (A.M.B., A.O.K.), Physical Medicine and Rehabilitation (M.J.D.), and Anesthesiology (J.K.F.), Medical College of Wisconsin, Milwaukee
| | - Matthew J Durand
- From the Cardiovascular Center (A.M.B., A.O.K., D.D.G., D.S.C., J.K.F., K.A.-A., M.J.D.), Departments of Medicine (A.M.B., A.O.K., D.D.G., D.S.C., J.K.F., K.A.-A.), Pharmacology and Toxicology (D.S.C., J.K.F.), Physiology (A.M.B., A.O.K.), Physical Medicine and Rehabilitation (M.J.D.), and Anesthesiology (J.K.F.), Medical College of Wisconsin, Milwaukee
| | - Julie K Freed
- From the Cardiovascular Center (A.M.B., A.O.K., D.D.G., D.S.C., J.K.F., K.A.-A., M.J.D.), Departments of Medicine (A.M.B., A.O.K., D.D.G., D.S.C., J.K.F., K.A.-A.), Pharmacology and Toxicology (D.S.C., J.K.F.), Physiology (A.M.B., A.O.K.), Physical Medicine and Rehabilitation (M.J.D.), and Anesthesiology (J.K.F.), Medical College of Wisconsin, Milwaukee
| | - Karima Ait-Aissa
- From the Cardiovascular Center (A.M.B., A.O.K., D.D.G., D.S.C., J.K.F., K.A.-A., M.J.D.), Departments of Medicine (A.M.B., A.O.K., D.D.G., D.S.C., J.K.F., K.A.-A.), Pharmacology and Toxicology (D.S.C., J.K.F.), Physiology (A.M.B., A.O.K.), Physical Medicine and Rehabilitation (M.J.D.), and Anesthesiology (J.K.F.), Medical College of Wisconsin, Milwaukee
| | - Andreas M Beyer
- From the Cardiovascular Center (A.M.B., A.O.K., D.D.G., D.S.C., J.K.F., K.A.-A., M.J.D.), Departments of Medicine (A.M.B., A.O.K., D.D.G., D.S.C., J.K.F., K.A.-A.), Pharmacology and Toxicology (D.S.C., J.K.F.), Physiology (A.M.B., A.O.K.), Physical Medicine and Rehabilitation (M.J.D.), and Anesthesiology (J.K.F.), Medical College of Wisconsin, Milwaukee
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15
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Li LJ, Ikram MK, Wong TY. Retinal vascular imaging in early life: insights into processes and risk of cardiovascular disease. J Physiol 2015; 594:2175-203. [PMID: 26435039 DOI: 10.1113/jp270947] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Accepted: 09/28/2015] [Indexed: 12/18/2022] Open
Abstract
Cardiovascular disease (CVD) is the leading cause of morbidity and mortality globally. In recent years, studies have shown that the origins of CVD may be traced to vascular and metabolic processes in early life. Retinal vascular imaging is a new technology that allows detailed non-invasive in vivo assessment and monitoring of the microvasculature. In this systematic review, we described the application of retinal vascular imaging in children and adolescents, and we examined the use of retinal vascular imaging in understanding CVD risk in early life. We reviewed all publications with quantitative retinal vascular assessment in two databases: PubMed and Scopus. Early life CVD risk factors were classified into four groups: birth risk factors, environmental risk factors, systemic risk factors and conditions linked to future CVD development. Retinal vascular changes were associated with lower birth weight, shorter gestational age, low-fibre and high-sugar diet, lesser physical activity, parental hypertension history, childhood hypertension, childhood overweight/obesity, childhood depression/anxiety and childhood type 1 diabetes mellitus. In summary, there is increasing evidence supporting the view that structural changes in the retinal microvasculature are associated with CVD risk factors in early life. Thus, the retina is a useful site for pre-clinical assessment of microvascular processes that may underlie the future development of CVD in adulthood.
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Affiliation(s)
- Ling-Jun Li
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore.,Duke-NUS Graduate Medical School, National University of Singapore, Singapore
| | - Mohammad Kamran Ikram
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore.,Duke-NUS Graduate Medical School, National University of Singapore, Singapore
| | - Tien Yin Wong
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore.,Duke-NUS Graduate Medical School, National University of Singapore, Singapore
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16
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Adingupu DD, Thorn CE, Casanova F, Elyas S, Gooding K, Gilchrist M, Aizawa K, Gates PE, Shore AC, Strain DW. Blood Oxygen Saturation After Ischemia is Altered With Abnormal Microvascular Reperfusion. Microcirculation 2015; 22:294-305. [DOI: 10.1111/micc.12198] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Accepted: 02/28/2015] [Indexed: 11/30/2022]
Affiliation(s)
- Damilola D. Adingupu
- Vascular Medicine; Institute of Biomedical and Clinical Science and NIHR Exeter Clinical Research Facility; University of Exeter Medical School; Exeter UK
| | - Clare E. Thorn
- Vascular Medicine; Institute of Biomedical and Clinical Science and NIHR Exeter Clinical Research Facility; University of Exeter Medical School; Exeter UK
| | - Francesco Casanova
- Vascular Medicine; Institute of Biomedical and Clinical Science and NIHR Exeter Clinical Research Facility; University of Exeter Medical School; Exeter UK
| | - Salim Elyas
- Vascular Medicine; Institute of Biomedical and Clinical Science and NIHR Exeter Clinical Research Facility; University of Exeter Medical School; Exeter UK
| | - Kim Gooding
- Vascular Medicine; Institute of Biomedical and Clinical Science and NIHR Exeter Clinical Research Facility; University of Exeter Medical School; Exeter UK
| | - Mark Gilchrist
- Vascular Medicine; Institute of Biomedical and Clinical Science and NIHR Exeter Clinical Research Facility; University of Exeter Medical School; Exeter UK
| | - Kunihiko Aizawa
- Vascular Medicine; Institute of Biomedical and Clinical Science and NIHR Exeter Clinical Research Facility; University of Exeter Medical School; Exeter UK
| | - Phillip E. Gates
- Vascular Medicine; Institute of Biomedical and Clinical Science and NIHR Exeter Clinical Research Facility; University of Exeter Medical School; Exeter UK
| | - Angela C. Shore
- Vascular Medicine; Institute of Biomedical and Clinical Science and NIHR Exeter Clinical Research Facility; University of Exeter Medical School; Exeter UK
| | - David W. Strain
- Vascular Medicine; Institute of Biomedical and Clinical Science and NIHR Exeter Clinical Research Facility; University of Exeter Medical School; Exeter UK
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17
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Kuliga KZ, McDonald EF, Gush R, Michel C, Chipperfield AJ, Clough GF. Dynamics of Microvascular Blood Flow and Oxygenation Measured Simultaneously in Human Skin. Microcirculation 2014; 21:562-73. [DOI: 10.1111/micc.12136] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Accepted: 03/27/2014] [Indexed: 12/24/2022]
Affiliation(s)
- Katarzyna Z. Kuliga
- Human Development & Health; Faculty of Medicine; University of Southampton; Southampton UK
| | - Erin F. McDonald
- Human Development & Health; Faculty of Medicine; University of Southampton; Southampton UK
| | | | - Charles Michel
- Department of Bioengineering; Imperial College London; London UK
| | | | - Geraldine F. Clough
- Human Development & Health; Faculty of Medicine; University of Southampton; Southampton UK
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18
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Baumann M, Burkhardt K, Heemann U. Microcirculatory marker for the prediction of renal end points: a prospective cohort study in patients with chronic kidney disease stage 2 to 4. Hypertension 2014; 64:338-46. [PMID: 24866146 DOI: 10.1161/hypertensionaha.114.03354] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Retinal arteriolar narrowing reflects aging, hypertension, chronic kidney disease (CKD), and other vascular processes. We examined the predictive value of retinal arteriolar narrowing alone and in combination with albuminuria on renal disease progression in CKD. A white CKD stage 2 to 4 cohort of 164 men and women (60.8±13.8 years) underwent retinal photography and determination of albuminuria. The calibers of all retinal arterioles were measured after digital conversion of the photographs. Cases of incident renal end points defined as 50% renal function loss and start of renal replacement therapy were identified and validated by case record reviews. Over an average period of 1410 (range, 106-1606) days, 25 patients with CKD had incident renal end points. Kaplan-Meier analysis revealed that patients with CKD within the tertile of narrowest arterioles had more renal end points (log-rank P<0.001). Cox regression analysis confirmed this before (β=1.183±0.411) and after adjusting for age and baseline renal function (β=1.204±0.416). With respect to renal end points, a significant interaction was present between narrow arterioles and albuminuria. The relative risk for renal end points of narrow arterioles was 3.7 (1.7-8.4), of albuminuria was 5.4 (2.5-12.0), and of combined narrow arterioles and albuminuria was 16.2 (4.6-57.2). Hence retinal arteriolar narrowing is related to incident renal end points. Narrow arterioles and albuminuria reveal a synergistic predictive value. The findings support a leading role of the microvasculature in the pathogenesis of renal disease progression. They also suggest that retinal photography in combination with albuminuria determination may be useful for risk stratification with respect to renal disease progression in patients with CKD stage 2 to 4.
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Affiliation(s)
- Marcus Baumann
- From the Department of Nephrology, Klinikum rechts der Isar, Technische Universität München, Munich, Germany (M.B., U.H.); and Nephrological Clinic, Weissenburg, Germany (K.B.)
| | - Klaus Burkhardt
- From the Department of Nephrology, Klinikum rechts der Isar, Technische Universität München, Munich, Germany (M.B., U.H.); and Nephrological Clinic, Weissenburg, Germany (K.B.)
| | - Uwe Heemann
- From the Department of Nephrology, Klinikum rechts der Isar, Technische Universität München, Munich, Germany (M.B., U.H.); and Nephrological Clinic, Weissenburg, Germany (K.B.)
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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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21
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MAHÉ GUILLAUME, DURAND SYLVAIN, HUMEAU-HEURTIER ANNE, LEFTHERIOTIS GEORGES, ABRAHAM PIERRE. Impact of Experimental Conditions on Noncontact Laser Recordings in Microvascular Studies. Microcirculation 2012; 19:669-75. [DOI: 10.1111/j.1549-8719.2012.00205.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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22
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Affiliation(s)
- Harry A J Struijker-Boudier
- Departments of Pharmacology, Maastricht University, room 4.254, Universiteitssingel 50, 6229 ER, Maastricht, The Netherlands.
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Abstract
This spotlight issue of Microcirculation contains five articles written from a clinical perspective on the role of microcirculatory abnormalities in the pathogenesis of cardiovascular disease. The reviews address issues such as the impact of modifiable (life style and environmental risk factors) and non modifiable (age) on microvascular form and function; inter- and intra-cell signaling pathways underlying microvascular dysfunction; microvascular assessment as a prognostic tool in clinical practice; and the potential impact of targeted therapeutic intervention on microvascular health. The articles also describe and evaluate methodological approaches to the assessment of microvascular function in organs such as the skin, retina, muscle and adipose tissue, and provide a perspective on how such approaches might be employed in future in disease risk stratification in large epidemiological studies. This timely edition of the journal Microcirculation highlights that while there is currently no identified unifying mechanism to explain the association between microvascular phenotype and susceptibility to disease, there is accumulating evidence that deficits in microvascular structure and function may be an early and important prodromal indicator and risk determinant in a wide range of chronic non-communicable disorders, including cardiovascular and metabolic disease.
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