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Sunwoo J, Shah P, Thuptimdang W, Khaleel M, Chalacheva P, Kato RM, Coates TD, Khoo MCK. Functional near-infrared spectroscopy-based prefrontal cortex oxygenation during working memory tasks in sickle cell disease. NEUROPHOTONICS 2023; 10:045004. [PMID: 37854507 PMCID: PMC10581024 DOI: 10.1117/1.nph.10.4.045004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Revised: 09/25/2023] [Accepted: 10/02/2023] [Indexed: 10/20/2023]
Abstract
Significance Sickle cell disease (SCD), characterized by painful vaso-occlusive crises, is associated with cognitive decline. However, objective quantification of cognitive decline in SCD remains a challenge, and the associated hemodynamics are unknown. Aim To address this, we utilized functional near-infrared spectroscopy (fNIRS) to measure prefrontal cortex (PFC) oxygenation responses to N -back working memory tasks in SCD patients and compared them with healthy controls. Approach We quantified the PFC oxygenation rate as an index of cognitive activity in each group and compared them. In half of the participants, a Stroop test was administered before they started N -back to elevate their baseline stress level. Results In SCD compared to healthy controls, we found that (1) under a high baseline stress level, there were significantly greater oxygenation responses during the 2-back task, further elevated with histories of stroke; (2) there was a marginally slower N -back response time, and it was even slower with a history of stroke; and (3) the task accuracy was not different. Conclusions Additional requirements for processing time, PFC resources, and PFC oxygenation in SCD patients offer an important basis for understanding their cognitive decline and highlight the potential of fNIRS for evaluating cognitive functions.
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Affiliation(s)
- John Sunwoo
- University of Southern California, Department of Biomedical Engineering, Los Angeles, California, United States
- Massachusetts General Hospital, Harvard Medical School, Athinoula A. Martinos Center for Biomedical Imaging, Boston, Massachusetts, United States
| | - Payal Shah
- Children’s Hospital Los Angeles, Keck School of Medicine, University of Southern California, Hematology Section of Children’s Center for Cancer, Blood Disease and Bone Marrow Transplantation, Los Angeles, California, United States
| | - Wanwara Thuptimdang
- University of Southern California, Department of Biomedical Engineering, Los Angeles, California, United States
- Prince of Songkla University, Faculty of Medicine, Institute of Biomedical Engineering, Department of Biomedical Sciences and Biomedical Engineering, Hat Yai, Songkhla, Thailand
| | - Maha Khaleel
- Children’s Hospital Los Angeles, Keck School of Medicine, University of Southern California, Hematology Section of Children’s Center for Cancer, Blood Disease and Bone Marrow Transplantation, Los Angeles, California, United States
| | - Patjanaporn Chalacheva
- University of Southern California, Department of Biomedical Engineering, Los Angeles, California, United States
- Carnegie Mellon University, Department of Biomedical Engineering, Pittsburgh, Pennsylvania, United States
| | - Roberta M. Kato
- Children’s Hospital Los Angeles, Keck School of Medicine, University of Southern California, Division of Pediatric Pulmonology, Los Angeles, California, United States
| | - Thomas D. Coates
- Children’s Hospital Los Angeles, Keck School of Medicine, University of Southern California, Hematology Section of Children’s Center for Cancer, Blood Disease and Bone Marrow Transplantation, Los Angeles, California, United States
| | - Michael C. K. Khoo
- University of Southern California, Department of Biomedical Engineering, Los Angeles, California, United States
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2
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Clough GF, Chipperfield AJ, Thanaj M, Scorletti E, Calder PC, Byrne CD. Dysregulated Neurovascular Control Underlies Declining Microvascular Functionality in People With Non-alcoholic Fatty Liver Disease (NAFLD) at Risk of Liver Fibrosis. Front Physiol 2020; 11:551. [PMID: 32581841 PMCID: PMC7283580 DOI: 10.3389/fphys.2020.00551] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Accepted: 04/30/2020] [Indexed: 11/30/2022] Open
Abstract
Background/Aims Increasing evidence shows that non-alcoholic fatty liver disease (NAFLD) is associated with dysregulation of microvascular perfusion independently of established cardio-metabolic risk factors. We investigated whether hepatic manifestations of NAFLD such as liver fibrosis and liver fat are associated with microvascular hemodynamics through dysregulation of neurovascular control. Methods Microvascular dilator (post-occlusive reactive hyperemia) and sympathetically mediated constrictor (deep inspiratory breath-hold) responses were measured at the forearm and finger, respectively, using laser Doppler fluximetry. Non-linear complexity-based analysis was used to assess the information content and variability of the resting blood flux (BF) signals, attributable to oscillatory flow-motion activity, and over multiple sampling frequencies. Results Measurements were made in 189 adults (113 men) with NAFLD, with (n = 65) and without (n = 124) type 2 diabetes mellitus (T2DM), age = 50.9 ± 11.7 years (mean ± SD). Microvascular dilator and constrictor capacity were both negatively associated with age (r = −0.178, p = 0.014, and r = −0.201, p = 0.007, respectively) and enhanced liver fibrosis (ELF) score (r = −0.155, p = 0.038 and r = −0.418, p < 0.0001, respectively). There was no association with measures of liver fat, obesity or T2DM. Lempel-Ziv complexity (LZC) and sample entropy (SE) of the BF signal measured at the two skin sites were associated negatively with age (p < 0.01 and p < 0.001) and positively with ELF score (p < 0.05 and p < 0.0001). In individuals with an ELF score ≥7.8 the influence of both neurogenic and respiratory flow-motion activity on LZC was up-rated (p < 0.0001). Conclusion Altered microvascular network functionality occurs in adults with NAFLD suggesting a mechanistic role for dysregulated neurovascular control in individuals at risk of severe liver fibrosis.
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Affiliation(s)
- Geraldine F Clough
- Human Development and Health, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| | - Andrew J Chipperfield
- Faculty of Engineering and Physical Sciences, University of Southampton, Southampton, United Kingdom
| | - Marjola Thanaj
- Faculty of Engineering and Physical Sciences, University of Southampton, Southampton, United Kingdom
| | - Eleonora Scorletti
- Human Development and Health, Faculty of Medicine, University of Southampton, Southampton, United Kingdom.,National Institute for Health Research Southampton Biomedical Research Centre, University of Southampton, University Hospital Southampton National Health Service Foundation Trust, Southampton, United Kingdom.,Department of Gastroenterology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Philip C Calder
- Human Development and Health, Faculty of Medicine, University of Southampton, Southampton, United Kingdom.,National Institute for Health Research Southampton Biomedical Research Centre, University of Southampton, University Hospital Southampton National Health Service Foundation Trust, Southampton, United Kingdom
| | - Christopher D Byrne
- Human Development and Health, Faculty of Medicine, University of Southampton, Southampton, United Kingdom.,National Institute for Health Research Southampton Biomedical Research Centre, University of Southampton, University Hospital Southampton National Health Service Foundation Trust, Southampton, United Kingdom
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3
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Brennan LC, Kirkham FJ, Gavlak JC. Sleep-disordered breathing and comorbidities: role of the upper airway and craniofacial skeleton. Nat Sci Sleep 2020; 12:907-936. [PMID: 33204196 PMCID: PMC7667585 DOI: 10.2147/nss.s146608] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Accepted: 04/11/2019] [Indexed: 01/09/2023] Open
Abstract
Obstructive sleep-disordered breathing (SDB), which includes primary snoring through to obstructive sleep apnea syndrome (OSAS), may cause compromise of respiratory gas exchange during sleep, related to transient upper airway narrowing disrupting ventilation, and causing oxyhemoglobin desaturation and poor sleep quality. SDB is common in chronic disorders and has significant implications for health. With prevalence rates globally increasing, this condition is causing a substantial burden on health care costs. Certain populations, including people with sickle cell disease (SCD), exhibit a greater prevalence of OSAS. A review of the literature provides the available normal polysomnography and oximetry data for reference and documents the structural upper airway differences between those with and without OSAS, as well as between ethnicities and disease states. There may be differences in craniofacial development due to atypical growth trajectories or extramedullary hematopoiesis in anemias such as SCD. Studies involving MRI of the upper airway illustrated that OSAS populations tend to have a greater amount of lymphoid tissue, smaller airways, and smaller lower facial skeletons from measurements of the mandible and linear mental spine to clivus. Understanding the potential relationship between these anatomical landmarks and OSAS could help to stratify treatments, guiding choice towards those which most effectively resolve the obstruction. OSAS is relatively common in SCD populations, with hypoxia as a key manifestation, and sequelae including increased risk of stroke. Combatting any structural defects with appropriate interventions could reduce hypoxic exposure and consequently reduce the risk of comorbidities in those with SDB, warranting early treatment interventions.
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Affiliation(s)
- Lucy Charlotte Brennan
- Developmental Neurosciences Section, UCL Great Ormond Street Institute of Child Health, London, UK
| | - Fenella Jane Kirkham
- Developmental Neurosciences Section, UCL Great Ormond Street Institute of Child Health, London, UK.,Department of Child Health, University Hospital Southampton NHS Foundation Trust, Southampton, UK.,Clinical and Experimental Sciences, University of Southampton, Southampton, UK
| | - Johanna Cristine Gavlak
- Department of Child Health, University Hospital Southampton NHS Foundation Trust, Southampton, UK
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4
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Veluswamy S, Shah P, Denton CC, Chalacheva P, Khoo MCK, Coates TD. Vaso-Occlusion in Sickle Cell Disease: Is Autonomic Dysregulation of the Microvasculature the Trigger? J Clin Med 2019; 8:jcm8101690. [PMID: 31618931 PMCID: PMC6832215 DOI: 10.3390/jcm8101690] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 10/11/2019] [Accepted: 10/11/2019] [Indexed: 02/02/2023] Open
Abstract
Sickle cell disease (SCD) is an inherited hemoglobinopathy characterized by polymerization of hemoglobin S upon deoxygenation that results in the formation of rigid sickled-shaped red blood cells that can occlude the microvasculature, which leads to sudden onsets of pain. The severity of vaso-occlusive crises (VOC) is quite variable among patients, which is not fully explained by their genetic and biological profiles. The mechanism that initiates the transition from steady state to VOC remains unknown, as is the role of clinically reported triggers such as stress, cold and pain. The rate of hemoglobin S polymerization after deoxygenation is an important determinant of vaso-occlusion. Similarly, the microvascular blood flow rate plays a critical role as fast-moving red blood cells are better able to escape the microvasculature before polymerization of deoxy-hemoglobin S causes the red cells to become rigid and lodge in small vessels. The role of the autonomic nervous system (ANS) activity in VOC initiation and propagation has been underestimated considering that the ANS is the major regulator of microvascular blood flow and that most triggers of VOC can alter the autonomic balance. Here, we will briefly review the evidence supporting the presence of ANS dysfunction in SCD, its implications in the onset of VOC, and how differences in autonomic vasoreactivity might potentially contribute to variability in VOC severity.
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Affiliation(s)
- Saranya Veluswamy
- Hematology Section, Children’s Center for Cancer and Blood Diseases, Children’s Hospital Los Angeles, 4650 Sunset boulevard, Los Angeles, CA 90027, USA; (S.V.); (P.S.); (C.C.D.)
| | - Payal Shah
- Hematology Section, Children’s Center for Cancer and Blood Diseases, Children’s Hospital Los Angeles, 4650 Sunset boulevard, Los Angeles, CA 90027, USA; (S.V.); (P.S.); (C.C.D.)
| | - Christopher C. Denton
- Hematology Section, Children’s Center for Cancer and Blood Diseases, Children’s Hospital Los Angeles, 4650 Sunset boulevard, Los Angeles, CA 90027, USA; (S.V.); (P.S.); (C.C.D.)
| | - Patjanaporn Chalacheva
- Department of Biomedical Engineering, University of Southern California, 1042 Downey Way, Los Angeles, CA 90089, USA; (P.C.)
| | - Michael C. K. Khoo
- Department of Biomedical Engineering, University of Southern California, 1042 Downey Way, Los Angeles, CA 90089, USA; (P.C.)
| | - Thomas D. Coates
- Hematology Section, Children’s Center for Cancer and Blood Diseases, Children’s Hospital Los Angeles, 4650 Sunset boulevard, Los Angeles, CA 90027, USA; (S.V.); (P.S.); (C.C.D.)
- Correspondence: ; Tel.: +1-323-361-2352
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5
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Stotesbury H, Kawadler JM, Hales PW, Saunders DE, Clark CA, Kirkham FJ. Vascular Instability and Neurological Morbidity in Sickle Cell Disease: An Integrative Framework. Front Neurol 2019; 10:871. [PMID: 31474929 PMCID: PMC6705232 DOI: 10.3389/fneur.2019.00871] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Accepted: 07/26/2019] [Indexed: 12/20/2022] Open
Abstract
It is well-established that patients with sickle cell disease (SCD) are at substantial risk of neurological complications, including overt and silent stroke, microstructural injury, and cognitive difficulties. Yet the underlying mechanisms remain poorly understood, partly because findings have largely been considered in isolation. Here, we review mechanistic pathways for which there is accumulating evidence and propose an integrative systems-biology framework for understanding neurological risk. Drawing upon work from other vascular beds in SCD, as well as the wider stroke literature, we propose that macro-circulatory hyper-perfusion, regions of relative micro-circulatory hypo-perfusion, and an exhaustion of cerebral reserve mechanisms, together lead to a state of cerebral vascular instability. We suggest that in this state, tissue oxygen supply is fragile and easily perturbed by changes in clinical condition, with the potential for stroke and/or microstructural injury if metabolic demand exceeds tissue oxygenation. This framework brings together recent developments in the field, highlights outstanding questions, and offers a first step toward a linking pathophysiological explanation of neurological risk that may help inform future screening and treatment strategies.
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Affiliation(s)
- Hanne Stotesbury
- Developmental Neurosciences, UCL Great Ormond Institute of Child Health, London, United Kingdom
| | - Jamie M Kawadler
- Developmental Neurosciences, UCL Great Ormond Institute of Child Health, London, United Kingdom
| | - Patrick W Hales
- Developmental Neurosciences, UCL Great Ormond Institute of Child Health, London, United Kingdom
| | - Dawn E Saunders
- Developmental Neurosciences, UCL Great Ormond Institute of Child Health, London, United Kingdom.,Department of Radiology, Great Ormond Hospital, London, United Kingdom
| | - Christopher A Clark
- Developmental Neurosciences, UCL Great Ormond Institute of Child Health, London, United Kingdom
| | - Fenella J Kirkham
- Developmental Neurosciences, UCL Great Ormond Institute of Child Health, London, United Kingdom.,Clinical and Experimental Sciences, University of Southampton, Southampton, United Kingdom.,Department of Child Health, University Hospital Southampton, Southampton, United Kingdom.,Department of Paediatric Neurology, Kings College Hospital NHS Foundation Trust, London, United Kingdom
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6
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Chalacheva P, Kato RM, Shah P, Veluswamy S, Denton CC, Sunwoo J, Thuptimdang W, Wood JC, Detterich JA, Coates TD, Khoo MCK. Sickle Cell Disease Subjects Have a Distinct Abnormal Autonomic Phenotype Characterized by Peripheral Vasoconstriction With Blunted Cardiac Response to Head-Up Tilt. Front Physiol 2019; 10:381. [PMID: 31031633 PMCID: PMC6470196 DOI: 10.3389/fphys.2019.00381] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2019] [Accepted: 03/19/2019] [Indexed: 12/26/2022] Open
Abstract
In sickle cell disease (SCD), prolonged capillary transit times, resulting from reduced peripheral blood flow, increase the likelihood of rigid red cells entrapment in the microvasculature, predisposing to vaso-occlusive crisis. Since changes in peripheral flow are mediated by the autonomic nervous system (ANS), we tested the hypothesis that the cardiac and peripheral vascular responses to head-up tilt (HUT) are abnormal in SCD. Heart rate, respiration, non-invasive continuous blood pressure and finger photoplethysmogram (PPG) were monitored before, during, and after HUT in SCD, anemic controls and healthy subjects. Percent increase in heart rate from baseline was used to quantify cardiac ANS response, while percent decrease in PPG amplitude represented degree of peripheral vasoconstriction. After employing cluster analysis to determine threshold levels, the HUT responses were classified into four phenotypes: (CP) increased heart rate and peripheral vasoconstriction; (C) increased heart rate only; (P) peripheral vasoconstriction only; and (ST) subthreshold cardiac and peripheral vascular responses. Multinomial logistic regression (MLR) was used to relate these phenotypic responses to various parameters representing blood properties and baseline cardiovascular activity. The most common phenotypic response, CP, was found in 82% of non-SCD subjects, including those with chronic anemia. In contrast, 70% of SCD subjects responded abnormally to HUT: C-phenotype = 22%, P-phenotype = 37%, or ST-phenotype = 11%. MLR revealed that the HUT phenotypes were significantly associated with baseline cardiac parasympathetic activity, baseline peripheral vascular variability, hemoglobin level and SCD diagnosis. Low parasympathetic activity at baseline dramatically increased the probability of belonging to the P-phenotype in SCD subjects, even after adjusting for hemoglobin level, suggesting a characteristic autonomic dysfunction that is independent of anemia. Further analysis using a mathematical model of heart rate variability revealed that the low parasympathetic activity in P-phenotype SCD subjects was due to impaired respiratory-cardiac coupling rather than reduced cardiac baroreflex sensitivity. By having strong peripheral vasoconstriction without compensatory cardiac responses, P-phenotype subjects may be at increased risk for vaso-occlusive crisis. The classification of autonomic phenotypes based on HUT response may have potential use for guiding therapeutic interventions to alleviate the risk of adverse outcomes in SCD.
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Affiliation(s)
- Patjanaporn Chalacheva
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, United States
| | - Roberta M Kato
- Divisions of Pulmonology, Children's Hospital Los Angeles, Los Angeles, CA, United States
| | - Payal Shah
- Hematology Section, Children's Center for Cancer, Blood Disease and Bone Marrow Transplantation, Children's Hospital Los Angeles, Keck School of Medicine of University of Southern California, Los Angeles, CA, United States
| | - Saranya Veluswamy
- Hematology Section, Children's Center for Cancer, Blood Disease and Bone Marrow Transplantation, Children's Hospital Los Angeles, Keck School of Medicine of University of Southern California, Los Angeles, CA, United States
| | - Christopher C Denton
- Hematology Section, Children's Center for Cancer, Blood Disease and Bone Marrow Transplantation, Children's Hospital Los Angeles, Keck School of Medicine of University of Southern California, Los Angeles, CA, United States
| | - John Sunwoo
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, United States
| | - Wanwara Thuptimdang
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, United States
| | - John C Wood
- Divisions of Cardiology, Children's Hospital Los Angeles, Los Angeles, CA, United States
| | - Jon A Detterich
- Divisions of Cardiology, Children's Hospital Los Angeles, Los Angeles, CA, United States
| | - Thomas D Coates
- Hematology Section, Children's Center for Cancer, Blood Disease and Bone Marrow Transplantation, Children's Hospital Los Angeles, Keck School of Medicine of University of Southern California, Los Angeles, CA, United States
| | - Michael C K Khoo
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, United States
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7
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Dougherty KA, Bertolaso C, Schall JI, Smith-Whitley K, Stallings VA. Muscle Strength, Power, and Torque Deficits in Children With Type SS Sickle Cell Disease. J Pediatr Hematol Oncol 2018; 40:348-354. [PMID: 29621064 PMCID: PMC6019164 DOI: 10.1097/mph.0000000000001143] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
In African-American children aged 5 to 17 years with and without type SS sickle cell disease (SCD-SS), dominant hand maximal handgrip strength, peak power, and plantar flexion isometric maximal voluntary contraction (MVC) torque were compared with adjustments for body size and composition. Children with SCD-SS (n=21; age, 11±1 y) compared with healthy control children (n=23; 10±1 y) did not differ by age, sex, or maturation stage, but had significantly lower Z scores for height, weight, body mass index, arm circumference, upper arm muscle area, and lean mass-for-height. Children with SCD-SS had significantly lower unadjusted handgrip strength (16±2 vs. 23±2 kg, P<0.01), peak power (1054±107 vs. 1488±169 W, P<0.04) and MVC torques at 2 angles (10 degrees: 27±3 vs. 42±5 Nm; 20 degrees: 21±3 vs. 34±4 Nm; all P<0.05). Performance decrements persisted when handgrip strength was adjusted for lean body mass and fat mass explaining 66% of the variance; peak power adjusted for age, lean body mass, fat mass, and height explaining 91% of the variance; and the highest MVC torque (10-degree angle) adjusted for left leg length, lean mass-for-height, and fat mass-for-height Z scores explaining 65% of the variance. This suggests additional factors contribute to the attenuated anaerobic performance.
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Affiliation(s)
| | | | - Joan I. Schall
- Division of Hematology, Department of Pediatrics, Children’s Hospital of Philadelphia, Philadelphia, PA, USA
| | - Kim Smith-Whitley
- Division of Hematology, Department of Pediatrics, Children’s Hospital of Philadelphia, Philadelphia, PA, USA
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Virginia A. Stallings
- Division of Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, Children’s Hospital of Philadelphia, Philadelphia, PA, USA
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
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8
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Birkhoff W, de Vries J, Dent G, Verma A, Kerkhoffs J, van Meurs A, de Kam M, Moerland M, Burggraaf J. Retinal microcirculation imaging in sickle cell disease patients. Microvasc Res 2018; 116:1-5. [DOI: 10.1016/j.mvr.2017.09.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 09/05/2017] [Accepted: 09/05/2017] [Indexed: 01/24/2023]
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9
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Khaleel M, Puliyel M, Shah P, Sunwoo J, Kato RM, Chalacheva P, Thuptimdang W, Detterich J, Wood JC, Tsao J, Zeltzer L, Sposto R, Khoo MCK, Coates TD. Individuals with sickle cell disease have a significantly greater vasoconstriction response to thermal pain than controls and have significant vasoconstriction in response to anticipation of pain. Am J Hematol 2017; 92:1137-1145. [PMID: 28707371 DOI: 10.1002/ajh.24858] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Revised: 07/07/2017] [Accepted: 07/10/2017] [Indexed: 12/17/2022]
Abstract
The painful vaso-occlusive crises (VOC) that characterize sickle cell disease (SCD) progress over hours from the asymptomatic steady-state. SCD patients report that VOC can be triggered by stress, cold exposure, and, pain itself. We anticipated that pain could cause neural-mediated vasoconstriction, decreasing regional blood flow and promoting entrapment of sickle cells in the microvasculature. Therefore, we measured microvascular blood flow in the fingers of both hands using plethysmography and laser-Doppler flowmetry while applying a series of painful thermal stimuli on the right forearm in 23 SCD patients and 25 controls. Heat pain applied to one arm caused bilateral decrease in microvascular perfusion. The vasoconstriction response started before administration of the thermal pain stimulus in all subjects, suggesting that pain anticipation also causes significant vasoconstriction. The time delay between thermal pain application and global vasoconstriction ranged from 5 to 15.5 seconds and increased with age (P < .01). Although subjective measures, pain threshold and pain tolerance were not different between SCD subjects and controls, but the vaso-reactivity index characterizing the microvascular blood flow response to painful stimuli was significantly higher in SCD patients (P = .0028). This global vasoconstriction increases microvascular transit time, and may promote entrapment of sickle cells in the microvasculature, making vaso-occlusion more likely. The rapidity of the global vasoconstriction response indicates a neural origin that may play a part in the transition from steady-state to VOC, and may also contribute to the variability in VOC frequency observed in SCD patients.
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Affiliation(s)
- Maha Khaleel
- Section of Hematology; Children's Center for Cancer and Blood Diseases, Children's Hospital Los Angeles, Keck School of Medicine; Los Angeles California
| | - Mammen Puliyel
- Section of Hematology; Children's Center for Cancer and Blood Diseases, Children's Hospital Los Angeles, Keck School of Medicine; Los Angeles California
| | - Payal Shah
- Section of Hematology; Children's Center for Cancer and Blood Diseases, Children's Hospital Los Angeles, Keck School of Medicine; Los Angeles California
| | - John Sunwoo
- Biomedical engineering; Viterbi School of Engineering; Los Angeles California
| | - Roberta M. Kato
- Division of Pulmonology; Children's Hospital Los Angeles, Keck School of Medicine; Los Angeles California
| | | | - Wanwara Thuptimdang
- Biomedical engineering; Viterbi School of Engineering; Los Angeles California
| | - Jon Detterich
- Division of Cardiology; Children's Hospital Los Angeles, Keck School of Medicine; Los Angeles California
| | - John C. Wood
- Biomedical engineering; Viterbi School of Engineering; Los Angeles California
- Division of Cardiology; Children's Hospital Los Angeles, Keck School of Medicine; Los Angeles California
| | - Jennie Tsao
- Pediatric Pain Program, University of California Los Angeles; Los Angeles California
| | - Lonnie Zeltzer
- Pediatric Pain Program, University of California Los Angeles; Los Angeles California
| | - Richard Sposto
- Section of Hematology; Children's Center for Cancer and Blood Diseases, Children's Hospital Los Angeles, Keck School of Medicine; Los Angeles California
- Department of Preventive Medicine, Keck School of Medicine; University of Southern California; Los Angeles California
| | - Michael C. K. Khoo
- Biomedical engineering; Viterbi School of Engineering; Los Angeles California
| | - Thomas D. Coates
- Section of Hematology; Children's Center for Cancer and Blood Diseases, Children's Hospital Los Angeles, Keck School of Medicine; Los Angeles California
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Agra KF, Pontes IEA, da Silva JR, Figueiroa JN, Clough GF, Alves JGB. Impaired neurovascular reactivity in the microvasculature of pregnant women with preeclampsia. Microcirculation 2017; 24. [DOI: 10.1111/micc.12383] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Accepted: 05/08/2017] [Indexed: 01/24/2023]
Affiliation(s)
- Karine Ferreira Agra
- Department of Mother and Child Health; Instituto de Medicina Integral Prof. Fernando Figueira-IMIP; Recife Brazil
| | | | - José Roberto da Silva
- Department of Mother and Child Health; Instituto de Medicina Integral Prof. Fernando Figueira-IMIP; Recife Brazil
| | - José Natal Figueiroa
- Department of Mother and Child Health; Instituto de Medicina Integral Prof. Fernando Figueira-IMIP; Recife Brazil
| | | | - João Guilherme Bezerra Alves
- Department of Mother and Child Health; Instituto de Medicina Integral Prof. Fernando Figueira-IMIP; Recife Brazil
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11
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Chalacheva P, Khaleel M, Sunwoo J, Shah P, Detterich JA, Kato RM, Thuptimdang W, Meiselman HJ, Sposto R, Tsao J, Wood JC, Zeltzer L, Coates TD, Khoo MCK. Biophysical markers of the peripheral vasoconstriction response to pain in sickle cell disease. PLoS One 2017; 12:e0178353. [PMID: 28542469 PMCID: PMC5443571 DOI: 10.1371/journal.pone.0178353] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Accepted: 05/11/2017] [Indexed: 02/07/2023] Open
Abstract
Painful vaso-occlusive crisis (VOC), a complication of sickle cell disease (SCD), occurs when sickled red blood cells obstruct flow in the microvasculature. We postulated that exaggerated sympathetically mediated vasoconstriction, endothelial dysfunction and the synergistic interaction between these two factors act together to reduce microvascular flow, promoting regional vaso-occlusions, setting the stage for VOC. We previously found that SCD subjects had stronger vasoconstriction response to pulses of heat-induced pain compared to controls but the relative degrees to which autonomic dysregulation, peripheral vascular dysfunction and their interaction are present in SCD remain unknown. In the present study, we employed a mathematical model to decompose the total vasoconstriction response to pain into: 1) the neurogenic component, 2) the vascular response to blood pressure, 3) respiratory coupling and 4) neurogenic-vascular interaction. The model allowed us to quantify the contribution of each component to the total vasoconstriction response. The most salient features of the components were extracted to represent biophysical markers of autonomic and vascular impairment in SCD and controls. These markers provide a means of phenotyping severity of disease in sickle-cell anemia that is based more on underlying physiology than on genotype. The marker of the vascular component (BMv) showed stronger contribution to vasoconstriction in SCD than controls (p = 0.0409), suggesting a dominant myogenic response in the SCD subjects as a consequence of endothelial dysfunction. The marker of neurogenic-vascular interaction (BMn-v) revealed that the interaction reinforced vasoconstriction in SCD but produced vasodilatory response in controls (p = 0.0167). This marked difference in BMn-v suggests that it is the most sensitive marker for quantifying combined alterations in autonomic and vascular function in SCD in response to heat-induced pain.
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Affiliation(s)
- Patjanaporn Chalacheva
- Department of Biomedical Engineering, University of Southern California, Los Angeles, California, United States of America
- * E-mail:
| | - Maha Khaleel
- Division of Hematology, Oncology and Blood & Marrow Transplantation, Children's Center for Cancer and Blood Diseases, Children's Hospital Los Angeles, Los Angeles, California, United States of America
| | - John Sunwoo
- Department of Biomedical Engineering, University of Southern California, Los Angeles, California, United States of America
| | - Payal Shah
- Division of Hematology, Oncology and Blood & Marrow Transplantation, Children's Center for Cancer and Blood Diseases, Children's Hospital Los Angeles, Los Angeles, California, United States of America
| | - Jon A. Detterich
- Division of Cardiology, Children’s Hospital Los Angeles, Los Angeles, California, United States of America
- Department of Pediatrics, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Roberta M. Kato
- Department of Pediatrics, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
- Division of Pulmonology, Children’s Hospital Los Angeles, Los Angeles, California, United States of America
| | - Wanwara Thuptimdang
- Department of Biomedical Engineering, University of Southern California, Los Angeles, California, United States of America
| | - Herbert J. Meiselman
- Department of Physiology and Biophysics, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Richard Sposto
- Division of Hematology, Oncology and Blood & Marrow Transplantation, Children's Center for Cancer and Blood Diseases, Children's Hospital Los Angeles, Los Angeles, California, United States of America
- Department of Preventative Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Jennie Tsao
- Pediatric Pain Program, David Geffen School of Medicine, University of California at Los Angeles, California, United States of America
| | - John C. Wood
- Department of Biomedical Engineering, University of Southern California, Los Angeles, California, United States of America
- Division of Cardiology, Children’s Hospital Los Angeles, Los Angeles, California, United States of America
| | - Lonnie Zeltzer
- Pediatric Pain Program, David Geffen School of Medicine, University of California at Los Angeles, California, United States of America
| | - Thomas D. Coates
- Division of Hematology, Oncology and Blood & Marrow Transplantation, Children's Center for Cancer and Blood Diseases, Children's Hospital Los Angeles, Los Angeles, California, United States of America
- Department of Pediatrics, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Michael C. K. Khoo
- Department of Biomedical Engineering, University of Southern California, Los Angeles, California, United States of America
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12
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Charlot K, Antoine-Jonville S, Moeckesch B, Jumet S, Romana M, Waltz X, Divialle-Doumdo L, Hardy-Dessources MD, Petras M, Tressières B, Tarer V, Hue O, Etienne-Julan M, Connes P. Cerebral and muscle microvascular oxygenation in children with sickle cell disease: Influence of hematology, hemorheology and vasomotion. Blood Cells Mol Dis 2017; 65:23-28. [PMID: 28411485 DOI: 10.1016/j.bcmd.2017.03.015] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 03/03/2017] [Accepted: 03/30/2017] [Indexed: 10/19/2022]
Abstract
The present study investigated cerebral and muscle hemoglobin oxygen saturation (tissue oxygen index, TOI) in children with sickle cell anemia (SS), sickle cell hemoglobin C disease (SC) and healthy children (AA). TOI was measured by near-infrared spectroscopy (NIRS) and spectral analysis of the TOI variability was used to assess flowmotion and vasomotion. Arterial oxyhemoglobin saturation (SpO2), hemorheological and hematological parameters were also measured in SS and SC children. Both TOI were lower in SS compared to both AA and SC children, with SC exhibiting lower values than AA children. Cerebral vasomotion expressed in absolute values was enhanced in SS compared to AA and SC children. Muscle vasomotion did not differ between the three groups. Hematocrit, SpO2 and red blood cell deformability were positively associated with cerebral TOI in SS children. We demonstrated that 1) cerebral and muscle TOI were markedly decreased in SS children while the decrease of TOI was milder in SC children, 2) cerebral TOI level was associated with several biological markers in SS children only and 3) cerebral vasomotion was enhanced in SS, possibly to counterbalance the effects of chronic cerebral hypoxia.
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Affiliation(s)
- Keyne Charlot
- Université des Antilles, Inserm, Unité Biologie Intégrée du Globule Rouge, Laboratoire d'Excellence du Globule Rouge GR-Ex, Paris, France; Université des Antilles, Laboratoire ACTES (EA 3596), Pointe-à-Pitre, Guadeloupe; Département Institut de Recherche Biomédicale des Armées, Environnements Opérationnels, Brétigny-sur-Orge, France
| | | | - Berenike Moeckesch
- Université des Antilles, Inserm, Unité Biologie Intégrée du Globule Rouge, Laboratoire d'Excellence du Globule Rouge GR-Ex, Paris, France; Université des Antilles, Laboratoire ACTES (EA 3596), Pointe-à-Pitre, Guadeloupe.
| | - Stéphane Jumet
- Université des Antilles, Laboratoire ACTES (EA 3596), Pointe-à-Pitre, Guadeloupe
| | - Marc Romana
- Université des Antilles, Inserm, Unité Biologie Intégrée du Globule Rouge, Laboratoire d'Excellence du Globule Rouge GR-Ex, Paris, France.
| | - Xavier Waltz
- Université des Antilles, Inserm, Unité Biologie Intégrée du Globule Rouge, Laboratoire d'Excellence du Globule Rouge GR-Ex, Paris, France; Université des Antilles, Laboratoire ACTES (EA 3596), Pointe-à-Pitre, Guadeloupe.
| | - Lydia Divialle-Doumdo
- CHU de Pointe-à-Pitre, Unité transversale de la Drépanocytose, Pointe-à-Pitre, Guadeloupe.
| | - Marie-Dominique Hardy-Dessources
- Université des Antilles, Inserm, Unité Biologie Intégrée du Globule Rouge, Laboratoire d'Excellence du Globule Rouge GR-Ex, Paris, France.
| | - Marie Petras
- CHU de Pointe-à-Pitre, Unité transversale de la Drépanocytose, Pointe-à-Pitre, Guadeloupe.
| | - Benoît Tressières
- Centre Investigation Clinique Antilles Guyane, Inserm/DGOS CIC 1424, Pointe-à-Pitre, Guadeloupe
| | - Vanessa Tarer
- CHU de Pointe-à-Pitre, Unité transversale de la Drépanocytose, Pointe-à-Pitre, Guadeloupe.
| | - Olivier Hue
- Université des Antilles, Laboratoire ACTES (EA 3596), Pointe-à-Pitre, Guadeloupe.
| | - Maryse Etienne-Julan
- CHU de Pointe-à-Pitre, Unité transversale de la Drépanocytose, Pointe-à-Pitre, Guadeloupe.
| | - Philippe Connes
- Université des Antilles, Inserm, Unité Biologie Intégrée du Globule Rouge, Laboratoire d'Excellence du Globule Rouge GR-Ex, Paris, France; Institut Universitaire de France (IUF), Paris, France; Université Claude Bernard Lyon 1, Laboratoire Interuniversitaire de Biologie de la Motricité (LIBM) EA7424, Equipe "Biologie Vasculaire et du Globule Rouge", Villeurbanne, France.
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13
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L'Esperance VS, Ekong T, Cox SE, Makani J, Newton CR, Soka D, Komba A, Kirkham FJ, Hill CM. Nocturnal haemoglobin oxygen desaturation in urban and rural East African paediatric cohorts with and without sickle cell anaemia: a cross-sectional study. Arch Dis Child 2016; 101:352-5. [PMID: 26699539 PMCID: PMC4819640 DOI: 10.1136/archdischild-2014-306468] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2014] [Accepted: 10/01/2015] [Indexed: 11/30/2022]
Abstract
Low haemoglobin oxygen saturation (SpO2) predicts complications in children with sickle cell anaemia (SCA) in the North but there are few data from Africa, where the majority of the patients reside. We measured daytime and overnight SpO2 in children with SCA in routine follow-up clinic, and controls without symptoms of SCA, comparing rural (Kilifi, Kenya) and urban (Dar-es-Salaam, Tanzania) cohorts. Daytime SpO2 was lower in 65 Tanzanian children with SCA (TS; median 97 (IQR 94-100)%); p<0.0001) than in 113 Kenyan children with SCA (KS; 99 (98-100)%) and 20 Tanzanian controls (TC; 100 (98-100)%). Compared with 95 Kenyan children with SCA, in 54 Tanzanian children with SCA and 19 TC who returned for overnight oximetry, mean (KS 99.0 (96.7-99.8)%; TS 97.9 (95.4-99.3)%; TC 98.4 (97.5-99.1)%; p=0.01) and minimum nocturnal SpO2 (92 (86-95)%; 87 (78.5-91)%; 90 (83.5-93)% p=0.0001) were lower. The difference between children with SCA persisted after adjustment for haemoglobin (p=0.004). Urban Tanzanian children, with and without SCA, experience greater exposure to low daytime and night-time SpO2 compared with rural Kenyan children with SCA. Possible explanations include differences in the prevalence of obstructive sleep apnoea or asthma, alterations in the oxyhaemoglobin desaturation curve or cardiovascular compromise, for example, to shunting at atrial or pulmonary level secondary to increased pulmonary artery pressure. The fact that non-SCA siblings in the urban area are also affected suggests that environmental exposures, for example, air pollution, nutrition or physical exercise, may play a role. Further studies should determine aetiology and clinical relevance for the SCA phenotype in children resident in Africa.
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Affiliation(s)
- VS L'Esperance
- Division of Clinical Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
| | - T Ekong
- Division of Clinical Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
| | - SE Cox
- MRC International Nutrition Group, London School of Tropical Medicine and Hygiene, London, UK,Muhimbili Wellcome Programme, Muhimbili University of Health and Allied Sciences, Dar-es-Salaam, Tanzania
| | - J Makani
- Muhimbili Wellcome Programme, Muhimbili University of Health and Allied Sciences, Dar-es-Salaam, Tanzania,Neuroassessment department, KEMRI-Wellcome Trust Research Programme, Centre for Geographic Medicine Research (Coast), Kilifi, Kenya
| | - CR Newton
- Muhimbili Wellcome Programme, Muhimbili University of Health and Allied Sciences, Dar-es-Salaam, Tanzania,Neuroassessment department, KEMRI-Wellcome Trust Research Programme, Centre for Geographic Medicine Research (Coast), Kilifi, Kenya,Department of Psychiatry, University of Oxford, Oxford, UK,Neurosciences Unit, UCL Institute of Child Health, London, UK
| | - D Soka
- Muhimbili Wellcome Programme, Muhimbili University of Health and Allied Sciences, Dar-es-Salaam, Tanzania
| | - A Komba
- Muhimbili Wellcome Programme, Muhimbili University of Health and Allied Sciences, Dar-es-Salaam, Tanzania,Neuroassessment department, KEMRI-Wellcome Trust Research Programme, Centre for Geographic Medicine Research (Coast), Kilifi, Kenya
| | - FJ Kirkham
- Division of Clinical Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK,Neurosciences Unit, UCL Institute of Child Health, London, UK
| | - CM Hill
- Division of Clinical Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
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14
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Perry M, Simon J, Gareau D, Glassberg J. Bayesian analyses demonstrate tissue blood volume is not decreased during acute sickle cell pain episodes: A preliminary study. Clin Hemorheol Microcirc 2015; 62:19-26. [PMID: 25624412 DOI: 10.3233/ch-141927] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Pain is the most common complication of Sickle Cell Disease (SCD). Tissue oximetry properties in SCD during steady state and acute pain are not well described. METHODS This was a cross sectional study of tissue oximetry properties in individuals with SCD during steady state, acute pain and healthy controls without SCD. A novel tissue oximetry device was used to better account for tissue pigmentation interference. We hypothesized that during acute SCD pain, blood volume to painful areas would be at least 10% less than steady state. Bayesian analyses of the data (with flat piors) were planned a priori because of the small projected sample size. RESULTS The sample included 14 individuals (4 during crisis, 5 steady state, and 5 controls). In individuals with SCD, blood volume to the lower back was higher during crisis (0.18% of tissue volume vs. 0.14% ). Bayesian analyses yielded a 3% probability that our hypothesis (that blood volume would decrease by 10% ) was correct. CONCLUSIONS During acute SCD pain, blood volume to painful areas is not decreased. Bayesian analyses were useful for interpretation of small sample data and may have utility in early phase trials for rare diseases.
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Affiliation(s)
- Maria Perry
- Department of Biology, Massachusetts Institute of Technology (MIT), Cambridge, MA, USA
| | - Jena Simon
- Division of Hematology and Medical Oncology, Mount Sinai Hospital, New York, NY, USA
| | - Daniel Gareau
- Laboratory of Investigative Dermatology, The Rockefeller University, New York, NY, USA
| | - Jeffrey Glassberg
- Department of Emergency Medicine, Division of Hematology and Medical Oncology, Mount Sinai School of Medicine, New York, NY, USA
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15
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Pontes IEA, Afra KF, Silva JR, Borges PSN, Clough GF, Alves JGB. Microvascular reactivity in women with gestational diabetes mellitus studied during pregnancy. Diabetol Metab Syndr 2015; 7:27. [PMID: 26056535 PMCID: PMC4459465 DOI: 10.1186/s13098-015-0017-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2014] [Accepted: 03/03/2015] [Indexed: 01/11/2023] Open
Abstract
AIM To compare microvascular reactivity assessed in the skin using laser Doppler fluximetry (LDF) in women with gestational diabetes mellitus (GDM) and gestational age-matched control during pregnancy. METHODS 110 pregnant women at ~33 weeks gestation participated in the study. Skin microvascular reactivity was evaluated by LDF, at rest, during the response to brief arterial occlusion (post occlusive hyperaemic response) and during sympathetically mediated vasoconstrictor response to deep inspiratory breath hold. RESULTS No statistically significant differences were found in the microvascular variables studied (resting and maximum rate flux, post-ischaemic reactive hyperaemia and deep inspiratory breath holds) between +GDM and -GDM groups women. In women with GDM there was a negative correlation between resting flux and the response to the oral glucose tolerance test (OGTT), r = -0.282 (p = 0.037). There was also a negative correlation between the response to the OGTT and the sympathetically mediated constrictor response to inspiratory breath holds (r = -.298, p = .030) but not in women with GDM (r = .102, r = .468). CONCLUSION Attenuated microvascular reactivity as an early marker of endothelial dysfunction is not present in women with GDM when assessed during pregnancy.
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Affiliation(s)
- Isabelle EA Pontes
- />Mother and Child Unit, Instituto de Medicina Integral Prof. Fernando Figueira (IMIP), Rua dos Coelhos, 300, 50070-550 Boa Vista Recife, Pernambuco Brazil
| | - Karine F Afra
- />Mother and Child Unit, Instituto de Medicina Integral Prof. Fernando Figueira (IMIP), Rua dos Coelhos, 300, 50070-550 Boa Vista Recife, Pernambuco Brazil
| | - José R Silva
- />Mother and Child Unit, Instituto de Medicina Integral Prof. Fernando Figueira (IMIP), Rua dos Coelhos, 300, 50070-550 Boa Vista Recife, Pernambuco Brazil
| | - Paulo SN Borges
- />Faculty of Medicine, University of Southampton, Southampton, UK
| | | | - João GB Alves
- />Mother and Child Unit, Instituto de Medicina Integral Prof. Fernando Figueira (IMIP), Rua dos Coelhos, 300, 50070-550 Boa Vista Recife, Pernambuco Brazil
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16
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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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