A Thesis submitted to The University of Arizona College of Medicine - Phoenix in partial fulfillment of the requirements for the Degree of Doctor of Medicine. / A detailed pre‐operative examination of a child’s neurovascular status following pediatric elbow fractures is critical to the assessment of these injuries. Without proper documentation of the preoperative exam, apparent postoperative changes in the neurovascular examination may be difficult to determine, and may dictate different treatment strategies. The reported incidence of neurologic (11.3%) and vascular (0.3‐4.6%) injury associated with supracondylar fractures underscores the importance of the preoperative exam. The purpose of this prospective study was to determine how frequently a complete neurovascular exam could be completed in children with elbow fractures. A detailed, specific elbow fracture History and Physical form was developed for prospective use on all pediatric elbow fractures in a tertiary care pediatric trauma hospital from 2013 through 2014. Specific neurovascular exam criteria were documented in an easily used checklist form. Demographic data collected included age, BMI, mechanism of injury, fracture type, comorbidities, pre‐operative pain management, and the operative procedure performed. There were 163 patients meeting the inclusion criteria. Attempted neurovascular (NV) exam was documented in 146 of these patients (89.6%). A clinically reliable, complete NV exam was possible in 104 patients (71.2%). In the remainder of the children, the clinician could not determine at least one aspect of the neurovascular exam. A significant correlation was found between age of the subject and ability to obtain a complete exam, with younger children less than age 5 being more likely to have incomplete information on the NV exam (p<0.000001). Gender, BMI, fracture type, pre‐assessment pain control, and potential language barriers had no effect on whether or not the exam was complete. Although a complete and detailed neurovascular examination is considered necessary when evaluating pediatric elbow fractures, over a fourth of our patients (29%) were unable to reliably participate in a full preoperative neurovascular exam. Younger children (less than 5 years of age) were less likely to participate in a complete neurovascular assessment. Neurovascular examinations in the setting of elbow fractures in children less than five years of age were unreliable and incomplete.

Made available in DSpace on 2014-06-12T23:03:40Z (GMT). No. of bitstreams: 2 arquivo8818_1.pdf: 482770 bytes, checksum: 8ab49974c0d14aadfefe5499306631b8 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2006 / O presente trabalho tem como objetivo verificar alterações na superfície do bulbo raquídeo em indivíduos hipertensos . Avaliamos através de análise morfométrica cortes olivares medianos de bulbos raquídeos obtidos de cadáveres submetidos à necropsia no Serviço de Verificação de Óbitos da Secretaria de Estado de Saúde de Pernambuco Universidade Federal de Pernambuco. Vinte e um casos de hipertensão e doze indivíduos normotensos foram estudados. Observou-se uma grande diversidade nos resultados das medidas da área estudada sem significância estatística. Concluímos que os resultados podem advir do pequeno número de casos estudados, porém estes achados podem ser atribuídos à natureza multifatorial da hipertensão arterial sistêmica

O tecido cerebral é altamente dependente de uma complexa rede vascular e um suprimento adequado de oxigênio, uma vez que o metabolismo oxidativo é a principal via de produção de ATP. Entretanto, durante o aumento da atividade neuronal existe uma relação não linear entre fluxo sanguíneo cerebral e consumo de oxigênio, verificado por tomografia de emissão de pósitrons e posteriormente por técnicas quantitativas de ressonância magnética nuclear. O aumento mais pronunciado do fluxo sanguíneo em comparação com o consumo de oxigênio levanta questões sobre a possibilidade de o oxigênio atuar como um fator limitante. Apesar dos efeitos devastadores da privação completa de oxigênio ao tecido cerebral dentro de minutos, a redução da disponibilidade de oxigênio por curtos períodos de tempo é comum em pacientes com apneia do sono e está associada como fator de risco à hipertensão e acidentes vasculares. Acreditamos que a obtenção de novas informações sobre o efeito da disponibilidade de oxigênio na regulação da resposta vascular e do metabolismo energético no cérebro humano in vivo é crucial para um melhor entendimento de aspectos básicos do metabolismo energético cerebral e sua relação com o sistema neurovascular. Nesta tese foi avaliado o impacto da redução da disponibilidade de oxigênio no acoplamento neurovascular e metabólico do cérebro humano saudável. Dois estudos foram realizados na presença de hipóxia moderada, com saturação sanguínea entre 80 a 85%, e normóxia como condição de controle. O primeiro utilizou técnicas quantitativas de ressonância magnética funcional (fMRI) em 3T para caracterizar a resposta vascular evocada de 9 sujeitos saudáveis perante a estimulação visual. O segundo visou caracterizar as concentrações metabólicas em repouso e também as alterações induzidas pela estimulação visual em 11 sujeitos, utilizando a técnica de espectroscopia de ressonância magnética funcional (fMRS) em 7T. Os dados de fMRI mostraram reduções significativas das áreas corticais recrutadas durante a hipóxia moderada, embora as áreas comuns às três técnicas que continuaram ativas demonstraram respostas com amplitude de fluxo e volume sanguíneos similares a normoxia. Além disto, a variação de consumo de oxigênio devido à estimulação visual foi menor durante a hipóxia. Tais achados potencialmente poderiam indicar diminuição da extensão do recrutamento neuronal, porém um novo desacoplamento entre atividade neuronal e a resposta vascular, ou seja, aumento da atividade neuronal sem uma mesma resposta vascular durante a hipóxia moderada não poderia ser descartado. O estudo de fMRS demonstrou alterações metabólicas (glutamato e lactato) induzidas pela estimulação similares em ambas as condições gasosas. Entretanto, alterações significativas nas concentrações de aspartato, glutamato e glutamina foram observadas entre as condições no repouso. A combinação dos achados de ambos os estudos aqui apresentados sugere que a hipóxia moderada não resulta na diminuição do recrutamento neuronal, pois variações similares de glutamato e lactato, considerados fortes marcadores do aumento de atividade neuronal, foram observadas durante hipóxia moderada. Entretanto, há evidências de que a disponibilidade reduzida de oxigênio leva a alterações no mecanismo do acoplamento vascular e também no metabolismo basal. Análises futuras serão necessárias para verificar se existe um mecanismo fisiológico que explica as alterações vasculares e metabólicas aqui observadas. / The cerebral tissue is highly dependent on a complex vascular network and a tight regulated supply of oxygen, since oxidative metabolism is the primary source of ATP synthesis. Increased neuronal activity leads to a well-established mismatch between CBF and CMRO2, measured by PET and nuclear magnetic resonance techniques. The much larger CBF evoked response as compared to CMRO2 response raises questions about the role played by oxygen as a potential limiting factor. Despite the devastating effects of intense hypoxia to cerebral tissue, moderate oxygen deprivation through short periods of time is frequent in chronic disorders such as obstructive sleep apnea and has been suggested to be a risk factor for morbidities such as hypertension and stroke. Identifying the impact of mild hypoxia on functional brain metabolism in the healthy human brain is a crucial step for understanding basics aspects of cerebral bioenergetics and its relationship with the neurovascular system. In this thesis we evaluate the impact of reduced oxygen availability in the neurovascular and metabolic coupling of the healthy human brain. Two studies were performed in the presence of mild hypoxia, with 80 to 85% arterial blood oxygen saturation, and normoxia as the control condition. The first study utilized functional Magnetic Resonance Imaging techniques (fMRI) at 3T to characterize the vascular response to visual stimulation in 9 subjects. The second study aimed at characterizing the neurochemical profile of the human brain and quantifying the stimulus-induced metabolic changes as measured by fMRS at 7T in 11 subjects. The fMRI data showed significant reductions in the recruited cortical areas during mild hypoxia, although activated areas in all three imaging modalities showed responses with similar amplitude of blood flow and volume from normoxia. In addition, the variation of oxygen consumption due to stimulation was smaller during mild hypoxia. These findings could potentially suggest decreased neuronal recruitment, although a new decoupling between neuronal activity and vascular response (i.e. similar neuronal recruitment with different vascular response) could not be discarded. The fMRS study showed similar stimulus-induced glutamate and lactate changes during both gas conditions. However, significant concentration differences were observed in aspartate, glutamate and glutamine during rest conditions. Finally, the combination of the data from the two studies herein presented suggests that mild hypoxia does not result in reduced neuronal recruitment despite the altered vascular response, as shown by the similar glutamate and lactate stimulus-induced responses, known to be strong markers of increased neuronal activity. However, there are evidences that support altered neurovascular coupling and metabolic concentrations during reduced oxygen availability at rest. Further analysis will be necessary to elucidate how the new steady state concentrations of aspartate, glutamate and glutamine could be linked to physiological mechanism that potentially alters the neurovascular response.

O tecido cerebral é altamente dependente de uma complexa rede vascular e um suprimento adequado de oxigênio, uma vez que o metabolismo oxidativo é a principal via de produção de ATP. Entretanto, durante o aumento da atividade neuronal existe uma relação não linear entre fluxo sanguíneo cerebral e consumo de oxigênio, verificado por tomografia de emissão de pósitrons e posteriormente por técnicas quantitativas de ressonância magnética nuclear. O aumento mais pronunciado do fluxo sanguíneo em comparação com o consumo de oxigênio levanta questões sobre a possibilidade de o oxigênio atuar como um fator limitante. Apesar dos efeitos devastadores da privação completa de oxigênio ao tecido cerebral dentro de minutos, a redução da disponibilidade de oxigênio por curtos períodos de tempo é comum em pacientes com apneia do sono e está associada como fator de risco à hipertensão e acidentes vasculares. Acreditamos que a obtenção de novas informações sobre o efeito da disponibilidade de oxigênio na regulação da resposta vascular e do metabolismo energético no cérebro humano in vivo é crucial para um melhor entendimento de aspectos básicos do metabolismo energético cerebral e sua relação com o sistema neurovascular. Nesta tese foi avaliado o impacto da redução da disponibilidade de oxigênio no acoplamento neurovascular e metabólico do cérebro humano saudável. Dois estudos foram realizados na presença de hipóxia moderada, com saturação sanguínea entre 80 a 85%, e normóxia como condição de controle. O primeiro utilizou técnicas quantitativas de ressonância magnética funcional (fMRI) em 3T para caracterizar a resposta vascular evocada de 9 sujeitos saudáveis perante a estimulação visual. O segundo visou caracterizar as concentrações metabólicas em repouso e também as alterações induzidas pela estimulação visual em 11 sujeitos, utilizando a técnica de espectroscopia de ressonância magnética funcional (fMRS) em 7T. Os dados de fMRI mostraram reduções significativas das áreas corticais recrutadas durante a hipóxia moderada, embora as áreas comuns às três técnicas que continuaram ativas demonstraram respostas com amplitude de fluxo e volume sanguíneos similares a normoxia. Além disto, a variação de consumo de oxigênio devido à estimulação visual foi menor durante a hipóxia. Tais achados potencialmente poderiam indicar diminuição da extensão do recrutamento neuronal, porém um novo desacoplamento entre atividade neuronal e a resposta vascular, ou seja, aumento da atividade neuronal sem uma mesma resposta vascular durante a hipóxia moderada não poderia ser descartado. O estudo de fMRS demonstrou alterações metabólicas (glutamato e lactato) induzidas pela estimulação similares em ambas as condições gasosas. Entretanto, alterações significativas nas concentrações de aspartato, glutamato e glutamina foram observadas entre as condições no repouso. A combinação dos achados de ambos os estudos aqui apresentados sugere que a hipóxia moderada não resulta na diminuição do recrutamento neuronal, pois variações similares de glutamato e lactato, considerados fortes marcadores do aumento de atividade neuronal, foram observadas durante hipóxia moderada. Entretanto, há evidências de que a disponibilidade reduzida de oxigênio leva a alterações no mecanismo do acoplamento vascular e também no metabolismo basal. Análises futuras serão necessárias para verificar se existe um mecanismo fisiológico que explica as alterações vasculares e metabólicas aqui observadas. / The cerebral tissue is highly dependent on a complex vascular network and a tight regulated supply of oxygen, since oxidative metabolism is the primary source of ATP synthesis. Increased neuronal activity leads to a well-established mismatch between CBF and CMRO2, measured by PET and nuclear magnetic resonance techniques. The much larger CBF evoked response as compared to CMRO2 response raises questions about the role played by oxygen as a potential limiting factor. Despite the devastating effects of intense hypoxia to cerebral tissue, moderate oxygen deprivation through short periods of time is frequent in chronic disorders such as obstructive sleep apnea and has been suggested to be a risk factor for morbidities such as hypertension and stroke. Identifying the impact of mild hypoxia on functional brain metabolism in the healthy human brain is a crucial step for understanding basics aspects of cerebral bioenergetics and its relationship with the neurovascular system. In this thesis we evaluate the impact of reduced oxygen availability in the neurovascular and metabolic coupling of the healthy human brain. Two studies were performed in the presence of mild hypoxia, with 80 to 85% arterial blood oxygen saturation, and normoxia as the control condition. The first study utilized functional Magnetic Resonance Imaging techniques (fMRI) at 3T to characterize the vascular response to visual stimulation in 9 subjects. The second study aimed at characterizing the neurochemical profile of the human brain and quantifying the stimulus-induced metabolic changes as measured by fMRS at 7T in 11 subjects. The fMRI data showed significant reductions in the recruited cortical areas during mild hypoxia, although activated areas in all three imaging modalities showed responses with similar amplitude of blood flow and volume from normoxia. In addition, the variation of oxygen consumption due to stimulation was smaller during mild hypoxia. These findings could potentially suggest decreased neuronal recruitment, although a new decoupling between neuronal activity and vascular response (i.e. similar neuronal recruitment with different vascular response) could not be discarded. The fMRS study showed similar stimulus-induced glutamate and lactate changes during both gas conditions. However, significant concentration differences were observed in aspartate, glutamate and glutamine during rest conditions. Finally, the combination of the data from the two studies herein presented suggests that mild hypoxia does not result in reduced neuronal recruitment despite the altered vascular response, as shown by the similar glutamate and lactate stimulus-induced responses, known to be strong markers of increased neuronal activity. However, there are evidences that support altered neurovascular coupling and metabolic concentrations during reduced oxygen availability at rest. Further analysis will be necessary to elucidate how the new steady state concentrations of aspartate, glutamate and glutamine could be linked to physiological mechanism that potentially alters the neurovascular response.

Name of the thesis Effect of nitric oxide on cerebral blood flow during neuronal activity Aim of the thesis The aim of this thesis is to determine whether the application of 7-nitroindazole, relatively specific inhibitor of neuronal nitric oxide synthase, affects the baseline blood pressure. Furthermore, to determine whether the application of the substance affects the baseline cerebral blood flow and whether it influences blood flow in brain during transcallosal stimulation with increasing frequency. Research method The research took place at the premises of the Institute of Physiology, Academy of Sciences of the Czech Republic. Experiments were carried out on laboratory albino Wistar rats. The group contained both experimental and control sample. General anesthesia was performed to rats, stimulating and sensing electrodes were implanted in epidural area of sensorimotor cortex and Laser Doppler flow probe was implanted into the contralateral hemisphere. A plastic catheter was applied in the carotid artery for measuring systemic blood pressure. In the first part of the experiment, we tested the effects of 7-nitroindazole on the systemic blood pressure. In the second part of the experiment, we investigated the effects of 7-nitroindazole on baseline cerebral blood flow. The third part of the...

No abstract available. / Thesis (M.Med.)--University of KwaZulu-Natal, Durban, 2014.

Idiopathic Parkinson’s disease (IPD) is the second most common neurodegenerative disease, yet effective disease modifying treatments are still lacking. Neurodegeneration involves multiple interacting pathological pathways. The extent to which neurovascular mechanisms are involved in IPD is not well defined. Indeed within the umbrella term of IPD great heterogeneity of motor (and non-motor) features exists, suggesting that different phenotypes may have differing underlying pathophysiologies. We aimed to determine whether novel magnetic resonance imaging (MRI) techniques can reveal changes in structural or physiological neurovascular measures, herein also referred to as ‘altered neurovascular status (NVS)’, in IPD.Based on preliminary data from our initial exploratory study in a small IPD cohort, phenotypic differences in structural and physiological MRI measures of NVS were investigated in a larger study. The 3 Tesla (3T) MRI protocol included T2-weighted fluid-attenuated inversion recovery (FLAIR) imaging to assess white matter lesion (WML) burden, arterial spin labelling (ASL) measurements of cerebral blood flow (CBF) and arterial arrival time (AAT) and dynamic contrast enhanced (DCE) measures of blood-brain barrier (BBB) integrity. Analysis was undertaken of IPD clinical phenotypes, by comparison with two control groups. In total, fifty-one patients with IPD (mean age 69.0 ± 7.7 years) (21 tremor dominant [TD], 24 postural instability and gait disorder [PIGD] and 6 intermediates) were compared with 2 control groups, the first comprising 18 control positive (CP) subjects with a history of clinical cerebrovascular disease (CVD) (mean age 70.1 ± 8.0 years) and the second comprising 34 control negative (CN) subjects without a history of clinical CVD (mean age 67.4 ± 7.6 years). IPD patients showed diffuse regions of significantly prolonged AAT and lower CBF by comparison with CN subjects, and a few regions of prolonged AAT by comparison with CP subjects, despite significantly fewer vascular risk factors. TD patients showed regions of significantly prolonged AAT and lower WML volume by comparison with PIGD patients. IPD patients also showed increased leakiness of the BBB in basal ganglia regions compared to the CN group, with a similar pattern in both IPD phenotypes. These data provide evidence of altered NVS in IPD, with IPD phenotype specific differences.

Streptococcus pyogenes infections can give rise to a diverse array of long-term secondary sequelae, including those in the brain characterized by both motor and neuropsychiatric disorders: Sydenham’s chorea and Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcus infections (PANDAS). These conditions are thought to be mediated by neuroinflammatory responses and autoantibody entry into the brain, but the mechanisms are not well understood.Previous work by our laboratory has demonstrated that recurrent intranasal S. pyogenes (Group A Streptococcus, or GAS) inoculations in mice cause infiltration of CD4 T cells into the anterior brain, disruption of the blood-brain barrier (BBB), increased numbers of activated myeloid cells and degradation of excitatory synapses leading to neural circuitry deficits. However, the molecular mechanisms underlying these phenotypes have not been fully explored. To understand how the neurovasculature and myeloid cells respond to recurrent GAS infections at the transcriptome level, I profiled cells from mouse olfactory bulb (OB) and nasal lymphoid tissue by single-cell RNA sequencing (scRNAseq). I found marked shifts in both endothelial cell and microglia populations at the transcriptome level after GAS infections, including downregulation of BBB-associated transcripts by endothelial cells (ECs), and increased production of inflammatory cytokines and chemokines, type I interferon response, and antigen presentation genes by microglia (Chapter 3). I validated several differentially expressed genes using flow cytometry, immunosorbant assays, RNA fluorescence in situ hybridization (FISH), and multiplexed error-robust FISH (MERFISH). Single-cell spatial transcriptomics of the OB revealed regional heterogeneity among microglial responses to GAS, possibly driven by proximity to infiltrating T cells. Analysis of transgenic CX3CR1/TMEM119 dual myeloid reporter mice confirmed that perivascular and meningeal macrophage numbers increase in response to GAS, but, unlike in other neuroinflammatory diseases, few macrophages infiltrate the brain parenchyma. Our laboratory has previously shown that Th17 cells are critical for BBB damage and activated microglia in response to repeated intranasal GAS infections, but the contribution of T helper (Th) 17 cell-derived cytokines in this process, as well as the transcriptional effects of Th17 cells on endothelial cells and microglia are unknown. To expand on these findings, I performed scRNAseq on retinoic acid-related orphan receptor γt (RORγt) mutant mice (Chapter 4) which showed a significant rescue in BBB-associated genes (e.g. Mfsd2a, Itm2a and Itih5) in endothelial cells. Chemokine production and type I interferon gene expression by microglia was also significantly rescued in RORγt mutants; surprisingly antigen presentation by microglia in response to GAS was exacerbated, at both the gene and protein level. Interleukin (IL)-17A is a major cytokine produced by Th17 cells. To examine the role of IL-17A in disease pathogenesis, I treated wild-type mice with an IL-17A neutralizing antibody during the course of GAS infections (Chapter 4). This treatment was sufficient to recapitulate the transcriptional effects on microglia and endothelial cells, as well as rescue BBB permeability previously found in RORγt mutants, indicating that IL-17A may play a critical role in transcriptional responses of endothelial cells and microglia to recurrent GAS infections in vivo. However, IL-17A did not disrupt tight junctions or induce transcytosis on ECs in vitro, suggesting that its effects on ECs in vivo are indirect. Th17 cells are capable of considerable phenotypic plasticity in response to chronic inflammation. To understand this process during recurrent GAS infections, I performed a time course analysis of CD4 T cell subsets after two, three, four and five infections (Chapter 5). This analysis revealed that proportions of “pathogenic” interferon γ-expressing Th17 cells increased over time, as did the number of CD4 T cells expressing granulocyte-macrophage colony stimulating factor (GM-CSF), a cytokine with pleiotropic effects on autoimmunity. Moreover, I determined that RORγt mutants have decreased proportions of GM-CSF+ CD4 T cells in their nasal mucosa, raising the question of whether GM-CSF may also contribute to CNS pathology (BBB permeability or microglial activation) in addition to IL-17A. To address this question, I generated mice deficient for GM-CSF in T cells and found that conditional deletion of GM-CSF in CD4+ cells partly rescued type I interferon and antigen presentation responses in microglia by scRNAseq, but did not rescue BBB leakage, suggesting that GM-CSF and IL-17A have distinct roles in the neurovascular and neuroinflammatory responses to GAS. To relate the findings in mice to the human disease, in Chapter 6 we performed cytokine profiling in sera from PANDAS/PANS patients at the acute phase of the disease using a multiplex bead-based immunoassay. We found that many chemokines and cytokines produced by activated microglia or macrophages in the mouse model were also highly elevated in the sera of PANDAS/PANS patients. These findings suggest an important link to the human disorder both to understand disease mechanisms in humans and to use them as future clinical biomarkers for diagnosis and treatment monitoring.

Neurovascular injuries are leading causes of disability implicated in neurological dysfunction. Much of the Central Nervous System (CNS) homeostasis depends on concerted signaling between neurons, glial cells, and vasculature–the neurovascular unit (NVU). Neurovascular injuries disrupt the NVU causing hypoxia, ischemia, neuroinflammation, and neuronal death. Much of the neuroinflammatory responses associated with neurovascular injuries have been characterized, but the contribution of specific signaling pathways from the injured endothelium to inflammatory response remains to be established. To understand vascular-glial communication in the context of vascular injury, the Troy lab has used a mouse model of retinal vascular injury, retinal vein occlusion (RVO). The retina is a CNS enclosed tissue that allows live visualization of vascular and neuronal condition upon injury, genotype, and/or treatment. Previous studies in the laboratory determined that non-apoptotic expression of endothelial caspase-9 (EC Casp9) was key for the development of retinal edema, capillary ischemia, and neuronal death. Caspases are known for their role in mediating cell death, but how and if glial cells orchestrated outcomes remain unknown. This thesis work aimed to investigate the role of caspase-9 signaling in vascular-glial communication and its contribution to pro-inflammatory cytokine levels and neurodegeneration in neurovascular injury. To answer this, we first optimized the mouse model of RVO and profiled the levels of caspases in RVO retinas treated or untreated with a caspase-9 inhibitor using immunohistochemistry. Then, we used tamoxifen inducible endothelial and astroglial caspase-9 KO lines, subjected them to RVO and measured glial changes, cytokine levels, capillary ischemia, retinal edema, neuronal death, and vision dysfunction. We first found that RVO induces a range of cell-specific levels of caspases and that inhibition of caspase-9 specifically modulated the levels of endothelial caspase-9 and 8, neuronal caspase-9, 7, and 6, astroglial caspase-6, and leukocytic caspase-9 and 7. Our studies also suggest that endothelial caspase-9 induces a decrease in reactive microglia, inflammatory cytokines, cleaved- caspase-6 and GFAP cleavage in astrocytes. EC Casp9 deletion also altered changes in GFAP, nestin and AQP4 levels in Müller glia. Through investigating an astroglial caspase-9 KO, we discovered that astroglial caspase-9 could be upstream of astroglia caspase-6. Additionally, we found that astroglial caspase-9 loss protected hypoxic retinas from capillary ischemia but not from retinal edema nor neuronal death. Lastly, we used an optokinetic test to study the potential role of endothelial and astroglial caspase-9 in RVO-induced vision disfunction. Our results indicate that removing caspase-9 from endothelial cells or astrocytes protected contrast sensitivity damage in visual function one day post-RVO. In sum, the present thesis work demonstrates that endothelial and astroglial caspase-9 signaling can lead to inflammation and worsening of visual function in neurovascular injury.

Fundamento. A frequente associação da síndrome metabólica (SMet) com a apneia obstrutiva do sono (AOS) prejudica o balanço simpato-vagal, cujos mecanismos não são totalmente conhecidos. Alterações metabólicas e inflamatórias podem explicar, pelo menos em parte, esta disfunção autonômica. Dieta hipocalórica associada ao treinamento físico (D+TF) é a terapia de primeira escolha no tratamento da SMet e pode impactar na melhora desses parâmetros. Objetivos. Investigar se a sobreposição da AOS na SMet tem um efeito aditivo nas alterações metabólicas e inflamatórias e se essas alterações estão associadas com o desbalanço simpato-vagal. Adicionalmente, investigar o efeito da D+TF nos fatores de risco da SMet, na severidade da AOS, na recuperação da frequência cardíaca pós-esforço máximo (FCrec), no balanço simpato-vagal e nos marcadores metabólicos e inflamatórios. Métodos. Foram estudados 67 pacientes recém-diagnosticados com SMet (ATP-III), não diabéticos e sem uso de medicamentos. Um grupo controle saudável (CS, n=19) também foi recrutado no estudo. A AOS foi definida pelo índice de apneia/hipopneia (IAH) > 15eventos/hora (polissonografia, PSG). Os grupos SMet com AOS (SMet+AOS, n=36) e SMet sem AOS (SMet-AOS, n=31) foram subdivididos consecutivamente em dois grupos:D+TF (D, decréscimo de 500 kcal/dia; e TF, 50-70% VO2pico, 3x/sem, 1h) ou seguimento clínico sem intervenção (C), compondo, assim, os seguintes 4 grupos: SMet+AOS/D+TF (n=19), SMet+AOS/C (n=10), SMet-AOS/D+TF (n=14) e SMet-AOS/C (n=13). No período pré e pós 4 meses de D+TF ou período C, foram realizadas as seguintes avaliações: PSG; microneurografia (atividade nervosa simpática muscular, ANSM); teste esforço cardiopulmonar (TECP) para avaliar o consumo de oxigênio (VO2pico) e o comportamento da FC; glicose e insulina de jejum (índice HOMA-IR e índice QUICKI); teste de tolerância oral à glicose para avaliação da área sobre a curva (ASCglicose e ASCinsulina); leptina; adiponectina; TNF-alfa; PCR; IL1-beta ; e IL-6. Adicionalmente, foi realizado o estudo da variabilidade da FC (banda de alta frequência, AF; banda de baixa frequência, BF e o balanço simpato-vagal cardíaco, AF/BF). Resultados. No período pré-intervenção, exceto pela glicemia de jejum, ambos os grupos com SMet foram semelhantes entre si e diferentes do grupo CS nas variáveis peso, fatores de risco da SMet e na BF e AF/BF. SMet+AOS e SMet-AOS apresentaram prejuízo na ANSM e AF comparados ao CS, enquanto que SMet+AOS apresentou prejuízo na ANSM e AF comparado ao SMet-AOS. Comparado com o CS, somente SMet+AOS apresentou prejuízo na glicemia de jejum (P < 0,001), leptina (P=0,03), ASC glicose (P=0,001), ASCinsulina (P=0,02), HOMA-IR (P < 0,001), QUICKI (P < 0,001) e TNF-alfa (P < 0,05). Adicionalmente, ASCglicose (P=0,004) e QUICKI (P=0,04) foram piores no SMet+AOS que SMet-AOS. AANSM se correlacionou positivamente com leptina (R=0,27; P=0,03), ASCglicose (R=0,38; P=0,002), ASCinsulina (R=0,26; P=0,04) e QUICK (R=-0,30; P=0,02). Após a intervenção por D+TF, os grupos SMet+AOS e SMet-AOS apresentaram redução na ANSM e melhora na recuperação da FC após o TECP. Somente o grupo SMet+AOS submetido à D+TF apresentou redução no IAH (37±3,5 vs. 23±3,4 eventos/h, P=0,003), na insulina de jejum (13±1,3 vs. 9±1, ?UI/mL,P=0,02) no HOMA-IR (3,4±0,4 vs. 2,2±0,3 P=0,03) e no QUICKI (0,32±0,01 vs. 0,35±0,01, P=0,04). Os grupos C para a intervenção não apresentaram alterações no período pós-seguimento clínico. Conclusão. Em pacientes com SMet não diabéticos, a presença da AOS leva a um estado inflamatório e prejudica o controle metabólico e autonômico. A AOS também leva uma exacerbação simpática que pode ser explicada, em parte, pelo prejuízo metabólico da glicemia, insulinemia e leptinemia. Nos pacientes com AOS, a intervenção por D+TF diminuiu a IAH e a resistência à insulina. Independente da AOS, D+TF diminuiu o número de pacientes com SMet e melhorou o controle autonômico / Background. The frequent association between metabolic syndrome (MetS) and obstructive sleep apnea (OSA) impairs the sympathovagal balance, which mechanisms are not fully known. Metabolic and inflammatory alterations could be explain, at least in part, this autonomic dysfunction. Hypocaloric diet and exercise training (D+ET) the first choice therapy in the treatment of SMet and may impact the improvement of these parameters. Objectives. Verify whether the overlap of OSA and MetS has an additive effect on metabolic and inflammatory markers and if these alterations are associated with sympathovagal unbalance. Additionally, to investigate the effect of D+ET over MetS risk factors, OSA severity, heart rate recovery after maximal exercise, the sympathovagal balance and metabolic and inflammatory markers. Methods. We studied 67 patients newly diagnosed with MetS (ATP-III), non-diabetic, without medication. A healthy control group (CS, n=19) was also recruited for the study. OSA was defined by the apnea-hypopnea index (AHI) >15 events/hour (polysomnography, PSG). The groups MetS with OSA (MetS+OSA, n=36) and without OSA (MetS-OSA, n=31) were divided in two groups. The intervention by D+ET (D was decrease of 500 kcal/day, and ET, 50-70% of peakVO2, 3x/week, 1h) or control group (C, follow up without intervention): MetS+OSA/D+ET (n=19), MetS+OSA/C (n=10), MetS-OSA/D+ET (n=14) and MetS + OSA/C (n=13). The pre and post period of 4 months of D+ET or C, were measured: PSG; microneurography (muscular sympathetic nerve activity, MSNA); cardiopulmonary exercise test (CPET) for evaluated the oxygen uptake (peakVO2) and heart rate (HR) response; glucose and insulin (HOMA-IR, QUICKI); oral glucose tolerance test for evaluate the area under the curve (AUCglucose and AUCinsulin); leptin; adiponectin; TNF-alpha; PCR; IL1-beta; IL-6. In addition, HR variability (LF=low frequency, HF=high frequency, LF/HF=sympathovagal balance). Results. In pre-intervention, except for fasting glucose, both MetS groups were similar and different from CS group in the weight, MetS risk factors and LF and HF/LF. MetS+OSA and MetS-OSA showed impairment in ANSM and HF compared to CS. In addition, MetS+OSA impairment in ANSM and HF compared to MetS-OSA. Compared to CS, only the MetS+OSA showed differences in fasting glucose (P < 0.001), leptin (P=0.03), glucose ASC (P=0.001), insulin ASC (P=0.02), HOMA-IR (P < 0.001), QUICKI (P < 0.001), TNF-alpha (P < 0.05). In addition, glycemia ASC (P = 0.004) and QUICKI (P = 0.04) were worse in MetS+OSA than to MetS-OSA. The ANSM correlated with leptin (R=0.27, P=0.03), ASC (R=0.38, P=0.002), ASC insulin; (R=0.26; P=0.04) and QUICK (R=-0.30; P=0.02). After intervention by D+TF, the MetS+OSA and MetS-OSA groups showed a reduction in the ANSM and improvement in the recovery of the HR after the TECP.Only the MetS+OSA group submitted to D+ET showed a diminished in AHI (37±3.5 vs. 23±3.4 events/h, P=0.003), fasting insulin (13±1.3 vs. 9±1, P=0.02), HOMA-IR (3.4±0.4 vs. 2.2±0.3 ?UI/mL, P=0.03) and QUICKI (0.32±0.01 vs. 0.35±0.01, P=0.04). The C groups did not change for intervention. Conclusion. In patients with non-diabetic MetS, the OSA leads to an inflammatory state and impairs in metabolic and autonomic control. The OSA also carries a sympathetic exacerbation that can be explained in part by the metabolic glucose, insulin, and leptin impairment. In patients with OSA, D+ET decreased the AHI and insulin resistance. Independently of AOS, D+ET decreased SMet number and improved autonomic control