Sixteen males and sixteen females were recruited for this study; eight of each gender were aerobically trained athletes; the remaining eight were untrained control subjects. Each subject performed a maximal exercise stress test for aerobic capacity (VO2max). On a separate day the blood volume and the cardiovascular responses to progressive (0 to -50 torr) lower body negative pressure (LBNP) were determined. The female subjects were observed to be significantly more tolerant of the LBNP than the male subjects. No differences between groups were observed in changes in leg volume, cardiac index, blood pressure, or heart rate during LBNP. However, the females, in comparison to the males, maintained stroke index at a higher level, and increased regional vasoconstriction more, during the LBNP induced hypotensive stress. These findings suggest that female subjects withstand LBNP to -50 torr better than male subjects.

O diagnóstico e acompanhamento da hipertensão arterial (HA) no paciente pediátrico dependem da acurácia e da representatividade da medida da pressão arterial (PA). A monitorização ambulatorial da pressão arterial (MAPA), apesar de suas vantagens em relação à medida casual, apresenta custo elevado e pode trazer desconforto ao paciente. A medida residencial da pressão arterial (MRPA), apesar de pouco estudada na criança, apresenta-se como um alternativo potencial à MAPA. Os objetivos deste estudo foram comparar as medidas da PA aferidas no consultório, na MRPA, na Liga de Hipertensão e pela MAPA avaliando o efeito do ambiente/observador e determinando a freqüência de valores compatíveis com HA nessas 4 situações. Este estudo foi transversal,prospectivo e foram incluídos pacientes com HA e PA controlada ou não no consultório. Foram analisadas as médias das pressões arteriais sistólicas e diastólicas. A MRPA foi realizada com aparelho OMRON HEM 705 CP por 14 dias, em dois períodos (manhã ou tarde e noite). Na véspera do início da MRPA, o paciente compareceu à Liga de Hipertensão do HC-FMUSP para colocação do equipamento da MAPA (SPACELABS 90207). Foram analisados os dados de 40 pacientes (14 meninas e 26 meninos), idade média 12,1±3,6 anos. Não houve diferença estatística entre as médias das pressões sistólicas (ANOVA p=0,3100) e diastólicas (ANOVA p=0,7700) no consultório com as médias diurnas da MRPA e nem com as médias sistólicas (ANOVA p=0,8240) e diastólicas(ANOVA p=0,1530) do período noturno da MRPA. As médias das pressões sistólicas e diastólicas da Liga e da MAPA foram maiores do que as médias do consultório e da MRPA (p<0,001), porém não houve diferença estatística entre as médias sistólicas e diastólicas da Liga com a MAPA (p=0,077) e (p=0,962) respectivamente. As médias das pressões diastólicas da MRPA foram menores do que as médias do consultório (p=0,001). Em relação à freqüência de pacientes com PA não controlada, esta foi maior na Liga de Hipertensão (Mc Nemar p<0,005), enquanto as comparações entre consultório MRPA diurna, consultório-MAPA vigília, MRPA diurna- MAPA vigília não foram significantes (Mc Nemar p>0,05). Na MAPA sono, os pacientes apresentaram maior freqüência de PA controlada do que na MRPA noturna. Dez pacientes apresentaram PA não controlada no consultório, a MAPA confirmou o diagnóstico em 7/10 (17,5%) pacientes, enquanto 5/10 (12,5%) confirmaram pela MRPA. Nesse grupo, a hipertensão do avental branco ocorreu em 3/10 (7,5%) pacientes diagnosticados pela MAPA e em 5/10 (12,5%) diagnosticados pela MRPA.Trinta pacientes apresentaram valores de PA controlados no consultório, destes 24/30 (60%) pacientes confirmaram o diagnóstico pela MAPA e 26/30 (65%) pela MRPA. A hipertensão mascarada ocorreu em 6/30 (15%) pacientes diagnosticados pela MAPA e em 4/30 (10%) diagnosticados pela MRPA. Nesse estudo demonstrou-se concordância entre MAPA e MRPA (teste de Mc Nemar p<0,01) com boa reprodutibilidade à avaliação do índice Kappa (0,557). / The diagnosis and monitoring of hypertension in pediatric patients depend on the accuracy and reproducibility of blood pressure (BP) measurement. Ambulatory blood pressure monitoring (ABPM), despite its advantages over office BP, is costly and can cause discomfort to the patient. The blood pressure measured at home (HBP), although poorly studied in children, represents a potential alternative to ABPM. The objectives of this study were to compare BP measurement in four clinical conditions: office BP , casual BP measured at Liga de Hipertensão, HBP and ABPM, evaluate the effect of environment / observer and to determine the frequency of BP values compatible with the diagnosis of hypertension. This study was cross-sectional and prospective and included patients with arterial hypertension with/without properly controlled BP in the office. The means of systolic and diastolic BP were analyzed in the 4 clinical conditions. HBP was measured for 14 days using a validated fully automatic Omron HEM 705 CP device. ABPM was measured with SpaceLabs 90207 non-invasive portable oscilometric device. We analyzed data from 40 patients (14 girls and 26 boys), mean age 12.1 ± 3.6 (SD) years. There was no difference between systolic (ANOVA p = 0.3100) and diastolic (ANOVA p= 0.7700) BP in the office and daytime HBP nor with nightime systolic HBP ( ANOVA p = 0.8240) and diastolic HBP(ANOVA p = 0.1530). The average systolic and diastolic BP at the Liga de Hipertensão and ABPM were higher than office and HB P (p <0001), but there was no difference in the average systolic (p= 0.077) and diastolic (p = 0.962) BP between Liga and ABPM. The diastolic HBP was lower than office diastolic BP (p = 0001). The frequency of BP values compatible with hipertension was higher at the Liga de Hipertensão (Mc Nemar p <0005), while comparisons between officedaytime HBP, office- daytime ABPM and daytime HBP-ABPM were not significant (Mc Nemar p> 0.05). The BP measurements during nightime ABPM showed a higher frequency of values compatible with hypertension than the night HBP one. Ten patients were diagnosed hypertension in the office, ABPM confirmed the diagnosis in 7 / 10 (17.5%) patients, while 5 / 10 (12.5%) were confirmed by HBP. In this group, white-coat hypertension occurred in 3 / 10 (7.5%) patients as diagnosed by the ABPM and 5 / 10 (12.5%) as diagnosed by HBP.Thirty patients presented BP values within normal limits in the office, 24 / 30 (60%) patients confirmed this diagnosis by ABPM and 26/30 (65%) by HBP. Masked hypertension was diagnosed in 6 / 30 (15%) patients diagnosed by the ABPM and in 4 / 30 (10%) by HBP. This study confirmed a correlation between ABPM and HBP measurements (Mc Nemar test p <0.01) with good reproducibility as evaluated by the Kappa index (0.557).

Die mittlere Höhe des arteriellen Blutdruckes (AP) ist von zentraler Bedeutung für das kardiovaskuläre Risiko Hochdruckkranker. Zusätzlich zeigen neuere Untersuchungen, daß Änderungen der Blutdruckdynamik eine wichtige Rolle in der Entwicklung hypertonieassoziierten Endorganschäden zukommt. Die Blutdruckvariabilität scheint in diesem Zusammenhang sogar einen eigenständigen Risikofaktor zu bilden. Der Einfluß kurzfristiger Blutdruckschwankungen auf zentrale Mechanismen der Langzeitblutdruckregulation, wie beispielsweise die renale Elimination von Natrium und Wasser, ist weitgehend unbekannt. Unsere Untersuchungen zeigen, daß schnelle Blutdruckschwankungen (BPO) kaum von der renalen Autoregulation der Durchblutung (RBF) unterdrückt werden können und zu Oszillation im Harnzeitvolumen führen. Es ist daher wahrscheinlich, daß BPO intrarenale System der Blutdruckregulation (wie beispielsweise das Renin-Angiotensin-System oder die schubspannungsabhängige Freisetzung von Stickoxid) modulieren können. Um diese Hypothese zu testen wurde der Einfluß von 0,1Hz BPO auf die Entwicklung eines renovaskulären Hypertonus untersucht. BPO um 85mmHg senkten signifikant die Plasmareninaktivität, erhöhten die tägliche Ausscheidung von Wasser, Natrium und Kalium und induzierten einen transienten Anstieg der Nitratspiegel im Urin wobei eine deutliche Senkung des arteriellen Blutdruckes beobachtet wurde. / The average level of arterial blood pressure (AP) is a major determinant of future cardiovascular complications in hypertension. In addition, recent investigations demonstrate that the dynamic properties of BP are of significant importance for the development of hypertension - related end organ damage in patients. Thus, hypertension - related changes in blood pressure dynamics seem to establish an independent risk factor for cardiovascular complications. Little is known regarding the influence of such short - term changes in AP on kidney function, a crucial control element for long - term AP regulation. Our investigations show that fast blood pressure oscillations (BPO) are not effectively buffered by renal blood flow autoregulation and induce oscillations in urine flow. It seems, therefore, likely that AP fluctuations can modulate intrarenally located systems involved in blood pressure regulation (e.g., renin release or shear stress dependent release of endothelium derived nitric oxide). To test this hypothesis we investigated the impact of induced BPO with a frequency of 0.1Hz on the onset of renovascular hypertension. BPO around 85mmHg significantly decreased plasma renin activity, enhanced 24h fluid, sodium and potassium excretion, and induced a transient increase in urinary nitrate excretion, thereby, attenuating renovascular hypertension.

Estudo de abordagem quantitativa e delineamento quase-experimental com o objetivo de comparar os efeitos dos exercícios dinâmicos contínuo e intervalado sobre a magnitude e duração da resposta hipotensora em hipertensos. A amostra foi composta por 20 idosos hipertensos de um município do interior paulista. As variáveis estudadas foram agrupadas nas categorias: sociodemográficas, antropométricas e hemodinâmicas. Cada participante foi submetido duas sessões de exercício físico, com intervalo de uma semana entre os treinos. As sessões de exercício contínuo foram realizadas a intensidade do limiar anaeróbio. Nas sessões de exercício intervalado, os indivíduos trabalharam no limiar de compensação respiratória por 4 minutos durante a fase ativa; na fase de recuperação, trabalharam a 40% do consumo máximo de oxigênio por 2 minutos. O tempo total de cada sessão foi de 42 minutos. Para obtenção dos dados hemodinâmicos, os participantes realizaram três exames de Monitorização Ambulatorial da Pressão Arterial (MAPA), com duração de 24 horas: MAPA controle, MAPA após exercício contínuo e MAPA após exercício intervalado. As análises descritivas, com cálculo de frequências absolutas e porcentagens e descrição das médias, desvio padrão e medianas, foram realizadas por meio do pacote estatístico SPSS, versão 15.0. A descrição das diferenças proporcionais entre os grupos foi realizada primordialmente por meio de aplicação do teste estatístico não paramétrico de Wilcoxon. Em todas as análises, foi adotado o nível de significância estatística de 5% (p&lt;0,05).Quando comparamos os resultados da MAPA realizada após o exercício contínuo aos valores derivados da MAPA controle, encontramos diferença estatisticamente significante para as variáveis Pressão Arterial Sistólica (PAS) vigília (p&lt;0,001), PAS sono (p&lt;0,001), Pressão Arterial Diastólica (PAD) vigília (p&lt;0,001), PAD sono (p&lt;0,001), Pressão Arterial Média (PAM) vigília (p&lt;0,001), PAD sono (p&lt;0,001), Frequência cardíaca (FC) sono (p&lt;0,03) e Duplo Produto (DP) vigília (p&lt;0,002) e sono (p&lt;0,001), sendo que todos os índices mostraram redução após a prática do exercício contínuo. À comparação dos resultados da MAPA após exercício intervalado aos resultados da MAPA controle, constatamos que, após a prática de exercício, houve redução nos valores de PAS vigília (p&lt;0,001), PAS sono (p&lt;0,001), PAD vigília (p&lt;0,001), PAD sono (p&lt;0,001), PAM vigília (p&lt;0,001), PAM sono (p&lt;0,001) e DP vigília (p&lt;0,001) e DP sono (p&lt;0,001). Na comparação do exercício contínuo ao intervalado, encontramos diferença estatisticamente significante para as variáveis PAS vigília (p&lt;0,001) e sono (p&lt;0,01), PAD vigília (p&lt;0,001), PAM vigília (p&lt;0,001), PAM sono (p&lt;0,01), DP vigília (p&lt;0,01) e DP sono (p&lt;0,001), que se mostraram mais reduzidas após a prática do exercício intervalado. Concluímos que a prática de exercício físico contínuo e intervalado promove a hipotensão pós-exercício (HPE) ao longo das 20 horas subsequentes à atividade. O exercício intervalado gera maior magnitude de HPE e menor sobrecarga cardiovascular em comparação ao exercício contínuo. / Quantitative study with a quasi-experimental design to compare the effect of continuous and interval dynamic exercises on the magnitude and length of the hypotensive response in hypertensive patients. The sample consisted of 20 hypertensive elderly patients from a city in the interior of the State of São Paulo, Brazil. The study variables were grouped in the following categories: sociodemographic, anthropometric and hemodynamic. Each participant was submitted to two physical exercise sessions with a one-week interval between the training. The continuous exercise sessions were held at the intensity level of the anaerobic threshold. In the interval exercise sessions, the participants exercised at the respiratory compensation threshold for four minutes during the active phase; in the recovery phase, they worked at 40% of the maximum oxygen consumption for two minutes. The total length of each session was 42 minutes. To obtain the hemodynamic data, the participants undertook three outpatient Ambulatory Blood Pressure Monitoring (ABPM) tests, which took 24 hours: control ABPM, ABPM after continuous exercise and ABPM after interval exercise. For the descriptive analyses, including the calculation of absolute frequencies and percentages and the description of means, standard deviations and medians, the statistical software SPSS version 15.0 was used. The description of the proportional differences between the groups was mainly based on the application of Wilcoxon\'s non-parametric statistical test. In all analyses, statistical significance was set at 5% (p&lt;0,05).When comparing the ABPM results after continuous exercise with the results of the control ABPM, a statistically significant difference was found for the variables Systolic Blood Pressure (SBP) wake (p&lt;0.001), SBP sleep (p&lt;0.001), Diastolic Blood Pressure (DBP) wake (p&lt;0.001), DBP sleep (p&lt;0.001), Mean Blood Pressure (MBP) wake (p&lt;0.001), MBP sleep (p&lt;0.001), Heart frequency (HF) sleep (p&lt;0.03) and Double Product (DP) wake (p&lt;0.002) and sleep (p&lt;0.001). All indices showed a drop after continuous exercise. In the comparison between the ABPM results after interval exercise with the control ABPM results, after the exercise, the following levels dropped: SBP wake (p&lt;0.001), SBP sleep¬ (p&lt;0.001), DBP wake (p&lt;0.001), DBP sleep (p&lt;0.001), MBP wake (p&lt;0.001), MBP sleep (p&lt;0.001) and DP wake (p&lt;0.001) and DP sleep (p&lt;0.001). In the comparison between the continuous and interval exercises, a statistically significant difference was found for the variables SBP wake (p&lt;0.001) and sleep (p&lt;0.01), DBP wake (p&lt;0.001), MBP wake (p&lt;0.001), MBP sleep (p&lt;0.01), DP wake (p&lt;0.01) and DP sleep (p&lt;0.001), which were lower after the interval exercise sessions. In conclusion, the practice of continuous and interval physical exercise promotes post-exercise hypotension (PEH) during the 20 hours after the exercise. Interval exercises lead to a larger HPE and less cardiovascular burden in comparison with continuous exercise.

Chen Fei. / "October 2004." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references. / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.

O pré-diabetes (PDM), da mesma forma que o diabetes mellitus (DM), associa-se com complicações micro e macrovasculares. Existem evidências de que existem anormalidades da homestoase da pressão arterial em indivíduos com PDM. Através da monitorização ambulatorial da pressão arterial (MAPA) é possível identificar o padrão de homeostase pressórica de indivíduos com diferentes graus de tolerância à glicose. Evidências demonstram que as medidas de pressão arterial (PA) obtidas por MAPA apresentam melhor associação com lesões de órgãos alvo se comparadas a medidas obtidas em consultório. Medidas de PA obtidas através de MAPA demonstram melhor correlação com complicações crônicas microvasculares do DM. Entretanto, dispõe-se de poucos dados na literatura sobre o comportamento da pressão arterial de 24 horas em indivíduos com PDM. Este trabalho é inicialmente constituído de uma revisão direcionada sobre homeostase pressórica em indivíduos com diferentes graus de tolerância à glicose seguido de um artigo original a respeito do tema. O artigo se trata de um estudo transversal que avaliou o padrão de homeostase pressórica de 24 horas em 138 indivíduos com diferentes graus de tolerância à glicose. O estudo demonstrou que através da MAPA é possível observar uma elevação dos níveis de pressão arterial ao longo de 24 horas de acordo com a piora da tolerância à glicose. / As diabetes mellitus (DM), prediabetes is associated with microvascular and macrovascular complications. There is evidence of presence of abnormalities in blood pressure (BP) homeostasis in individuals with prediabetes (PDM). Ambulatory blood pressure monitoring (ABPM) enables to identify the pattern of BP homeostasis in individuals with different degrees of glucose tolerance. Evidences have shown that BP measurements obtained by ABPM have a better association with target organ damage compared to measurements obtained in the office. Studies have also shown better correlation of BP measurements obtained by ABPM with microvascular chronic complications of DM. However, there are few data in literature about the behavior of 24 hours BP in subjects with prediabetes. This study consists of a review focused on BP homeostasis in subjects with different degrees of glucose tolerance and an original article about this issue. This is a cross-sectional study that evaluated how BP homeostasis behaves along 24 hours in 138 subjects with different degrees of glucose tolerance. The study demonstrated that through the ABPM is possible to observe an increase in blood pressure levels over 24 hours according to a worsening of glucose tolerance.

O diagnóstico e acompanhamento da hipertensão arterial (HA) no paciente pediátrico dependem da acurácia e da representatividade da medida da pressão arterial (PA). A monitorização ambulatorial da pressão arterial (MAPA), apesar de suas vantagens em relação à medida casual, apresenta custo elevado e pode trazer desconforto ao paciente. A medida residencial da pressão arterial (MRPA), apesar de pouco estudada na criança, apresenta-se como um alternativo potencial à MAPA. Os objetivos deste estudo foram comparar as medidas da PA aferidas no consultório, na MRPA, na Liga de Hipertensão e pela MAPA avaliando o efeito do ambiente/observador e determinando a freqüência de valores compatíveis com HA nessas 4 situações. Este estudo foi transversal,prospectivo e foram incluídos pacientes com HA e PA controlada ou não no consultório. Foram analisadas as médias das pressões arteriais sistólicas e diastólicas. A MRPA foi realizada com aparelho OMRON HEM 705 CP por 14 dias, em dois períodos (manhã ou tarde e noite). Na véspera do início da MRPA, o paciente compareceu à Liga de Hipertensão do HC-FMUSP para colocação do equipamento da MAPA (SPACELABS 90207). Foram analisados os dados de 40 pacientes (14 meninas e 26 meninos), idade média 12,1±3,6 anos. Não houve diferença estatística entre as médias das pressões sistólicas (ANOVA p=0,3100) e diastólicas (ANOVA p=0,7700) no consultório com as médias diurnas da MRPA e nem com as médias sistólicas (ANOVA p=0,8240) e diastólicas(ANOVA p=0,1530) do período noturno da MRPA. As médias das pressões sistólicas e diastólicas da Liga e da MAPA foram maiores do que as médias do consultório e da MRPA (p<0,001), porém não houve diferença estatística entre as médias sistólicas e diastólicas da Liga com a MAPA (p=0,077) e (p=0,962) respectivamente. As médias das pressões diastólicas da MRPA foram menores do que as médias do consultório (p=0,001). Em relação à freqüência de pacientes com PA não controlada, esta foi maior na Liga de Hipertensão (Mc Nemar p<0,005), enquanto as comparações entre consultório MRPA diurna, consultório-MAPA vigília, MRPA diurna- MAPA vigília não foram significantes (Mc Nemar p>0,05). Na MAPA sono, os pacientes apresentaram maior freqüência de PA controlada do que na MRPA noturna. Dez pacientes apresentaram PA não controlada no consultório, a MAPA confirmou o diagnóstico em 7/10 (17,5%) pacientes, enquanto 5/10 (12,5%) confirmaram pela MRPA. Nesse grupo, a hipertensão do avental branco ocorreu em 3/10 (7,5%) pacientes diagnosticados pela MAPA e em 5/10 (12,5%) diagnosticados pela MRPA.Trinta pacientes apresentaram valores de PA controlados no consultório, destes 24/30 (60%) pacientes confirmaram o diagnóstico pela MAPA e 26/30 (65%) pela MRPA. A hipertensão mascarada ocorreu em 6/30 (15%) pacientes diagnosticados pela MAPA e em 4/30 (10%) diagnosticados pela MRPA. Nesse estudo demonstrou-se concordância entre MAPA e MRPA (teste de Mc Nemar p<0,01) com boa reprodutibilidade à avaliação do índice Kappa (0,557). / The diagnosis and monitoring of hypertension in pediatric patients depend on the accuracy and reproducibility of blood pressure (BP) measurement. Ambulatory blood pressure monitoring (ABPM), despite its advantages over office BP, is costly and can cause discomfort to the patient. The blood pressure measured at home (HBP), although poorly studied in children, represents a potential alternative to ABPM. The objectives of this study were to compare BP measurement in four clinical conditions: office BP , casual BP measured at Liga de Hipertensão, HBP and ABPM, evaluate the effect of environment / observer and to determine the frequency of BP values compatible with the diagnosis of hypertension. This study was cross-sectional and prospective and included patients with arterial hypertension with/without properly controlled BP in the office. The means of systolic and diastolic BP were analyzed in the 4 clinical conditions. HBP was measured for 14 days using a validated fully automatic Omron HEM 705 CP device. ABPM was measured with SpaceLabs 90207 non-invasive portable oscilometric device. We analyzed data from 40 patients (14 girls and 26 boys), mean age 12.1 ± 3.6 (SD) years. There was no difference between systolic (ANOVA p = 0.3100) and diastolic (ANOVA p= 0.7700) BP in the office and daytime HBP nor with nightime systolic HBP ( ANOVA p = 0.8240) and diastolic HBP(ANOVA p = 0.1530). The average systolic and diastolic BP at the Liga de Hipertensão and ABPM were higher than office and HB P (p <0001), but there was no difference in the average systolic (p= 0.077) and diastolic (p = 0.962) BP between Liga and ABPM. The diastolic HBP was lower than office diastolic BP (p = 0001). The frequency of BP values compatible with hipertension was higher at the Liga de Hipertensão (Mc Nemar p <0005), while comparisons between officedaytime HBP, office- daytime ABPM and daytime HBP-ABPM were not significant (Mc Nemar p> 0.05). The BP measurements during nightime ABPM showed a higher frequency of values compatible with hypertension than the night HBP one. Ten patients were diagnosed hypertension in the office, ABPM confirmed the diagnosis in 7 / 10 (17.5%) patients, while 5 / 10 (12.5%) were confirmed by HBP. In this group, white-coat hypertension occurred in 3 / 10 (7.5%) patients as diagnosed by the ABPM and 5 / 10 (12.5%) as diagnosed by HBP.Thirty patients presented BP values within normal limits in the office, 24 / 30 (60%) patients confirmed this diagnosis by ABPM and 26/30 (65%) by HBP. Masked hypertension was diagnosed in 6 / 30 (15%) patients diagnosed by the ABPM and in 4 / 30 (10%) by HBP. This study confirmed a correlation between ABPM and HBP measurements (Mc Nemar test p <0.01) with good reproducibility as evaluated by the Kappa index (0.557).

Chan, Chun Hung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 77-84). / Abstracts in Chinese and English. / Acknowledgment: --- p.i / 摘要 --- p.ii / Abstract --- p.iv / List of Figure --- p.vi / List of Table --- p.viii / Content Page --- p.ix / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- The Difficulties --- p.1 / Chapter 1.2 --- The Solution --- p.2 / Chapter 1.3 --- Goal of the Present Work --- p.2 / Chapter Chapter 2 --- Background and Methodology --- p.3 / Chapter 2.1 --- Hypertension Situation and Problems Around the World --- p.3 / Chapter 2.1.1 --- Blood Pressure Variability (BPV) --- p.4 / Chapter 2.2 --- Blood Pressure Measuring Methods --- p.5 / Chapter 2.2.1 --- Traditional Blood Pressure Meters --- p.6 / Chapter 2.2.2 --- Limitation of Commercial Blood Pressure Meters --- p.7 / Chapter 2.2.3 --- Pulse-Transit-Time (PTT) Based Blood Pressure Measuring Watch --- p.7 / Chapter 2.3 --- Wearable Body Sensors Network / System --- p.8 / Chapter 2.4 --- Current Status of e-Textile Garment --- p.9 / Chapter 2.4.1 --- Blood Pressure Measurement in e-Textile Garment --- p.13 / Chapter 2.5 --- Wearable Intelligent Sensors and System for e-Health (WISSH) --- p.15 / Chapter 2.5.1 --- "Monitoring, Connection and Display" --- p.15 / Chapter 2.5.2 --- Treatment --- p.16 / Chapter 2.5.3 --- Alarming --- p.17 / Chapter Chapter 3 --- "A h-Shirt to Non-invasive, Continuous Monitoring of Arterial Blood Pressure" --- p.18 / Chapter 3.1 --- Design and Inner Structure of h-Shirt --- p.18 / Chapter 3.1.1 --- Choose of e-Textile Material --- p.21 / Chapter 3.1.2 --- Design of ECG Circuit --- p.23 / Chapter 3.1.3 --- Design of PPG Circuit --- p.26 / Chapter 3.2 --- Blood Pressure Estimation Using Pulse-Transit-Time Algorithm --- p.28 / Chapter 3.2.1 --- Principal --- p.28 / Chapter 3.2.2 --- Equations --- p.29 / Chapter 3.2.3 --- Calibration --- p.29 / Chapter 3.3 --- Performance Tests on h-Shirt --- p.30 / Chapter 3.3.1 --- Test I: BP Measurement Accuracy --- p.30 / Chapter 3.3.2 --- Test I: Procedure and Protocol --- p.30 / Chapter 3.3.3 --- Test I-Results --- p.31 / Chapter 3.3.4 --- Test II: Continuality BP Estimation Performance --- p.31 / Chapter 3.3.5 --- Test II - Experiment Procedure and Protocol --- p.32 / Chapter 3.3.6 --- Test II - Experiment Result --- p.33 / Chapter 3.3.7 --- Test II 一 Discussion --- p.43 / Chapter 3.4 --- Follow-up Tests on ECG Circuit --- p.47 / Chapter 3.4.1 --- Problems --- p.47 / Chapter 3.4.2 --- Assumptions --- p.48 / Chapter 3.4.3 --- Experiment Protocol and Setup --- p.48 / Chapter 3.4.4 --- Experiment Results --- p.53 / Chapter 3.4.5 --- Discussion --- p.56 / Chapter Chapter 4: --- Hybrid Body Sensor Network in h-Shirt --- p.59 / Chapter 4.1 --- A Hybrid Body Sensor Network --- p.59 / Chapter 4.2 --- Biological Channel Used in h-Shirt --- p.60 / Chapter 4.3 --- Tests of Bio-channel Performance --- p.62 / Chapter 4.3.1 --- Experiment Protocol --- p.62 / Chapter 4.3.2 --- Results --- p.62 / Chapter 4.4 --- Discussion and Conclusion --- p.63 / Chapter Chapter 5: --- Conclusion and Suggestions for Future Works --- p.66 / Chapter 5.1 --- Conclusion --- p.66 / Chapter 5.1.1 --- Structure of h-Shirt --- p.66 / Chapter 5.1.2 --- Blood Pressure Estimating Ability of h-Shirt --- p.67 / Chapter 5.1.3 --- Tests and Amendments on h-Shirt ECG Circuit --- p.67 / Chapter 5.1.4 --- Hybrid Body Sensor Network in h-Shirt --- p.67 / Chapter 5.2 --- Suggestions for Future Work --- p.68 / Chapter 5.2.1 --- Further Development of Bio-channel Biological Model --- p.68 / Chapter 5.2.2 --- Positioning and Motion Sensing with h-Shirt --- p.69 / Chapter 5.2.3 --- Implementation of Updated Advance Technology into h-Shirt --- p.69 / Appendix: Non-invasive BP Measuring Device - Finometer --- p.71 / Reference: --- p.77

This thesis presents studies relating to the role of the gastrointestinal tract in postprandial blood pressure regulation. The areas that have been addressed include : ( i ) the methodological approaches to the evaluation of gastric emptying, blood pressure, splanchnic blood flow, intraluminal manometry and gut hormones and ( ii ) the pathophysiological mechanisms underlying postprandial hypotension, with a particular focus on ' gastric ' and ' small intestinal ' mechanisms and their potential therapeutic relevance. All of the studies have been either published or manuscripts have been prepared for publication. While scintigraphy represents the ' gold standard ' for the measurement of gastric emptying, recent studies suggest that three - dimensional ( 3D ) ultrasonography may also allow a precise measure of gastric emptying. Concurrent scintigraphic and ultrasonographic measurements of gastric emptying of liquids were performed in healthy young volunteers. There was a good correlation and agreement between scintigraphic measurements of gastric emptying and 3D ultrasonography after ingestion of both low - and high - nutrient drinks, indicating that 3D ultrasonography, provides a valid measure of gastric emptying of liquid meals in normal subjects. Postprandial hypotension, defined as a fall in systolic blood pressure of ≥ 20mmHg,occurring within two hours of a meal is now recognised as an important clinical problem, particularly in the elderly and in patients with type 2 diabetes. The mechanisms mediating postprandial hypotension are poorly understood. The effects of variations in concentration of intraduodenal glucose on the magnitude of the fall in blood pressure were evaluated in healthy elderly subjects. Blood pressure fell, and heart rate and blood glucose increased over time during infusions, however, there was no difference in blood pressure, heart rate or blood glucose concentrations between the study days. These observations suggest that glucose induced postprandial hypotension is a load rather, than concentration, dependent phenomenon. The effect of meal composition has been reported to influence the hypotensive response to a meal and information relating to the effects of triglyceride and protein on blood pressure is inconsistent. The comparative effects of isocaloric and isovolaemic intraduodenal infusions of glucose, triglyceride and protein on the magnitude of the postprandial fall in blood pressure and rise in heart rate and superior mesenteric artery blood flow were evaluated in healthy elderly subjects. There were comparable falls in systolic blood pressure and rises in heart rate, however, the maximum fall in systolic blood pressure occurred later after triglyceride and protein and the stimulation of superior mesenteric artery blood flow was less after protein. These observations suggest that the relatively slower systolic blood pressure response after triglyceride and protein may potentially reflect the time taken for digestion of triglyceride to free fatty acids and protein to amino acids. Acarbose is an antidiabetic drug that slows both gastric emptying and small intestinal glucose absorption. The effects of acarbose, on blood pressure, heart rate, gastric emptying of, and the glycaemic, insulin, glucagon - like peptide - 1 ( GLP - 1 ) and glucosedependent insulinotropic - polypeptide ( GIP ) responses to, an oral sucrose load were evaluated in healthy elderly subjects. Acarbose attenuated the fall in blood pressure and increase in heart rate induced by oral sucrose. Acarbose slowed gastric emptying and was associated with increased retention in the distal stomach. Stimulation of GLP - 1 may contribute to the slowing of gastric emptying and suppression of postprandial glycaemia by acarbose. These findings suggest that acarbose may represent a therapeutic option for the treatment of patients with postprandial hypotension. Recent studies indicate that gastric distension attenuates the postprandial fall in blood pressure. The effects of gastric distension on blood pressure and heart rate during intraduodenal infusion of glucose at a constant load and concentration were evaluated in healthy elderly subjects. Intragastric administration of water markedly attenuated the falls in systolic and diastolic blood pressure induced by intraduodenal glucose. Heart rate increased, with and without gastric distension, in response to intraduodenal glucose infusion but not after intraduodenal saline infusion. This study suggests that gastric distension may potentially be used as a simple adjunctive treatment in the management of postprandial hypotension. Studies employing nitric oxide synthase blockers have established, in animals, that nitric oxide mechanisms are important in the regulation of splanchnic blood flow and, hence, may effect postprandial blood pressure. The role of the nitric oxide synthase inhibitor, NG - nitro - L - arginine - methyl - ester ( L - NAME ), on gastric emptying, postprandial blood pressure, plasma insulin concentration and incretin hormone ( ie GIP and GLP - 1 ) release, following an oral glucose load, were evaluated in healthy elderly subjects. L - NAME attenuated the postprandial fall in blood pressure and increase in heart rate but had no effect on gastric emptying of glucose. L - NAME attenuated the glucose - induced rise in plasma insulin but had no effect on the incretin ( GIP and GLP - 1 ) hormone response to oral glucose. The study indicates that the magnitude of the fall in blood pressure and increase in heart rate and stimulation of insulin secretion induced by oral glucose in healthy elderly subjects are mediated by nitric oxide mechanisms by an effect unrelated to changes in gastric emptying, or the secretion of GIP and GLP - 1. Studies utilising 5 - hydroxytryptamine ( 5 - HT ) infusions in animals have demonstrated regional variations in intestinal blood flow suggesting a role for 5 - HT in postprandial haemodynamic responses. The effects of the 5 - hydroxytryptamine 3 ( 5 - HT3 ) antagonist, granisetron, on the blood pressure, heart rate, antropyloroduodenal motility and glycaemic responses to intraduodenal glucose infusion were assessed in healthy elderly subjects. Granisetron had no effect on blood pressure, heart rate or antral and pyloric motor responses but modulated the duodenal motor response, to intraduodenal glucose. This study indicates that while the cardiovascular response to intraduodenal glucose does not appear to be influenced by the stimulation of 5 - HT3 receptors, this receptor may be involved in the modulation of the duodenal motor activity. / Thesis (Ph.D.)--School of Medicine, 2006.

The aim of the present thesis was to assess the occurrence of early lower extremity arterial disease (LEAD) in patients with diabetes and to assess novel potential risk markers for development or worsening of LEAD in the same patients. In parallel different measures of impaired peripheral circulation were evaluated. The measurement of ankle-to- brachial blood pressure index (ABI) to screen for asymptomatic LEAD in diabetic subjects is unreliable since a large proportion of patients have stiff ankle arteries (mediasclerosis) and thus may display a too high ABI. We studied type 1-, type 2 diabetic and non-diabetic subjects without a previous history of LEAD and a composite variable of ankle – plus toe blood pressures and indices was compared to ABI alone in detecting LEAD. Significantly more subjects with reduced peripheral circulation were detected using the composite variable compared to ABI alone. This was particularly true in diabetic subjects, about 30% of whom had signs of impaired peripheral circulation. Thus, it was found that toe blood pressure measurements, alone or in combination with ankle blood pressure measurements, increase the sensitivity for finding early asymptomatic LEAD in diabetic subjects. No significant difference in reproducibility between measurements of absolute ankle- and toe blood pressure and indices was found, but a correlation between systemic (brachial) and toe blood pressure variations over time may suggest that indices are more correct in assessing peripheral arterial circulation. Furthermore, toe blood pressure measurements can be performed using either the great toe or dig II and a strong concordance is found between these measurements. In addition, since the pole-test, another non-invasive method to measure peripheral blood pressure which is less sensitive to the presence of mediasclerosis compared to ABI, correlated significantly with toe blood pressure measurements this method may be used as an alternative screening method in subjects with previously known LEAD. Age, hypertension and glycemic control are well known risk factors and, in addition, high tissue plasminogen activator (tPA) activity turned out to be a novel early marker for asymptomatic LEAD in diabetic subjects, particularly in patients with type 2 diabetes. Age and hyperglycemia are the most important risk factors for development and progression of subclinical lower extremity arterial disease in type 2 diabetic subjects. No independent associations between markers of inflammation, such as CRP, interleukin-6 and TNF-α and early asymptomatic LEAD were seen among non-diabetic or diabetic subjects. In conclusion, impaired arterial circulation in the lower extremities is common in diabetic subjects even in the absence of symptoms. Including toe blood pressure measurement when screening for asymptomatic LEAD in diabetic subjects improves the ability to detect reduced peripheral circulation and this method avoids falsely elevated blood pressures readings due to mediasclerosis in the ankle arteries. Moreover, an altered fibrinolytic activity should be further evaluated as an early marker of atherosclerosis and LEAD.