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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
321

Epidemiological study of risk factors associated with progression from ocular hypertension to primary open angle glaucoma

Landers, John Arthur William January 2001 (has links)
Background: As a multifactorial disease glaucoma may be associated with pressure-dependent and -independent factors. Ocular hypertension (OHT) may develop into primary open angle glaucoma (POAG) for many patients. We compared groups with OHT and POAG for pressure-dependent and -independent risk factors. A high prevalence of any factor(s) could indicate a contribution to progression from OHT to POAG. Method: A sample of patients with POAG (n 438) and with OHT (n 301) were selected from those attending a tertiary referral private glaucoma practice, and data were collected regarding age and intraocular pressure at the time of diagnosis, gender, family history of glaucoma, systemic hypertension, diabetes, Raynaud's phenomenon, migraine and myopia. Results: After multivariate analysis, older age at time of diagnosis (P<0.001), myopia (odds ratio (O.R) 1.5, 95percent confidence interval (C.I)1.0-2.2; P 0.05), a family history of glaucoma (O.R 1.6, 95 percent C.I 1.1-2.3; P 0.01) and a high intraocular pressure (P 0.002) were associated with POAG. No other significant differences were found between the two groups. Conclusion: Patients who have OHT may be at higher risk of developing POAG if they also have myopia, a family history of glaucoma or are of older age.
322

Contribution à l’étude de la circulation pulmonaire et de la fonction ventriculaire droite dans l’hypertension pulmonaire : Apports de l’échocardiographie et de l’imagerie par Doppler tissulaire

Huez, Sandrine 31 January 2008 (has links)
Chapitre 1. Introduction L’hypertension pulmonaire est un syndrome de dyspnée, fatigue, douleur thoracique et syncope, causé par une augmentation de la résistance vasculaire pulmonaire (RVP) conduisant progressivement à la défaillance cardiaque droite(1). Le cathétérisme du cœur droit est indispensable au diagnostic et à l’évaluation de la gravité de l’hypertension pulmonaire. L’examen permet tout à la fois la quantification du processus morbide par une mesure de la RVP et de ses répercussions fonctionnelles par la mesure du débit cardiaque. Néanmoins, la multiplication des études thérapeutiques randomisées dans l’hypertension artérielle pulmonaire (HTAP) a montré l’inadéquation de ces mesures pour quantifier la réponse fonctionnelle des patients aux traitements(2,3). Ceci s’explique par les limitations de l’évaluation hémodynamique traditionnelle qui ne peut directement quantifier les déterminants de la performance ventriculaire droite (VD): précharge, postcharge et contractilité. Le but de ce travail a été d’étudier l’apport de nouvelles méthodes d’exploration, moins invasives, pour mieux comprendre l’adaptation VD à l’augmentation de postcharge, induite par l’hypertension pulmonaire. Le chapitre introductif est consacré à une revue des concepts de physiologie de base, à savoir : la description de l’état fonctionnel de la circulation pulmonaire par des relations pression-débit instantanées ou continues et de la fonction VD au départ des relations pression-volume ventriculaires. Les principales méthodes utilisées dans ce travail sont présentées, à savoir : l’échocardiographie traditionnelle, mais actualisée par l’introduction de nouveaux indices de fonction VD et l’imagerie par Doppler tissulaire (TDI). Chapitre 2. Faisabilité de l’étude semi-invasive de l’impédance vasculaire pulmonaire chez les patients souffrant d’hypertension artérielle pulmonaire Le calcul de RVP néglige les phénomènes de compliance vasculaire et de réflexion d’ondes, inhérents à l’aspect pulsatile du flux dans la circulation pulmonaire. Ceci sous-estime la charge hydraulique imposée au VD, en particulier dans l’hypertension pulmonaire(4). L’ensemble des forces qui s’opposent à l’éjection du VD peut être quantifié par une analyse fréquentielle des ondes de pression et de débit artériels pulmonaires et un calcul d’impédance vasculaire pulmonaire (PVZ). Néanmoins, cette méthode a été très peu appliquée chez l’Homme, en raison de sa complexité et surtout de son caractère invasif. Nous avons étudié la faisabilité de l’étude systématique de spectres de PVZ chez 22 patients souffrant d’HTAP, avec une méthode simplifiée, couplant le cathétérisme du cœur droit et l’échocardiographie-Doppler transthoracique. Les résultats montrent qu’il est possible d’obtenir au lit du malade des spectres de PVZ cohérents et sensibles aux interventions pharmacologiques. Chapitre 3. Etude par imagerie Doppler tissulaire de l’adaptation ventriculaire droite à la vasoconstriction pulmonaire hypoxique aiguë chez le sujet sain La déprivation en oxygène dans l’air respiré induit une vasoconstriction des petites artères pulmonaires, responsable d’une hypertension pulmonaire modérée. Nous avons étudié la fonction VD par échocardiographie-Doppler conventionnelle et TDI chez 25 volontaires, au cours de la vasoconstriction pulmonaire hypoxique et lors de l’administration intraveineuse de faibles doses de dobutamine (reproduisant la tachycardie associée à la stimulation orthosympathique). Les résultats montrent une adaptation de la fonction des deux ventricules, essentiellement diastolique à droite et systolique à gauche. Ces effets peuvent être expliqués par la conjonction d’une activation sympathique et l’adaptation de la fonction du VD nécessaire à la préservation du couplage entre fonction ventriculaire et postcharge. Chapitre 4. Etude par imagerie Doppler tissulaire de l’adaptation ventriculaire droite à l’hypertension pulmonaire hypoxique, en altitude L’exposition à la haute altitude est un modèle naturel d’hypertension pulmonaire hypoxique. Nous avons étudié la fonction du VD par échocardiographie-Doppler conventionnelle et TDI chez 15 sujets sains au niveau de la mer, dans les premières heures d’exposition à l’altitude (La Paz, Bolivie - 3750 m) et après 10 jours d’acclimatation (Potosi - 4850 m), et chez 20 sujets natifs de l’Altiplano bolivien (~ 4000 m). Les résultats montrent que l’exposition aiguë ou subaiguë à l’altitude s’accompagne d’une hypertension pulmonaire modérée, avec maintien de la fonction systolique du VD et modifications mineures de sa fonction diastolique. Pour une même gravité d’hypertension pulmonaire, l’adaptation chronique des sujets natifs se caractérise par des altérations à la fois systoliques VD et diastoliques ventriculaires droite et gauche. Chez certains sujets, l’hypertension pulmonaire hypoxique peut être rapidement sévère. Nous en avons rapporté un cas dont l’échocardiographie-Doppler avec TDI montre l’existence d’une défaillance cardiaque droite, avec dilatation des cavités droites du cœur, mouvement paradoxal du septum interventriculaire, dilatation de la veine cave inférieure, et raccourcissement myocardique postsystolique prédominant à l’apex, le tout dans un contexte d’examen clinique négatif. Ce cas illustre l’apport de l’échocardiographie avec TDI en tant qu’outil non invasif, d’extension de l’examen clinique du cœur, et suggère que le diagnostic de défaillance cardiaque droite aiguë devrait faire partie de la liste des complications médicales de l’exposition à la haute altitude. Chapitre 5. Etude par imagerie Doppler tissulaire de l’adaptation ventriculaire droite à l’hypertension pulmonaire chronique Chez les patients souffrant d’hypertension pulmonaire chronique, la symptomatologie et le pronostic sont essentiellement déterminés par l’adaptation de la fonction VD à la postcharge. Nous avons exploré la fonction VD par échocardiographie-Doppler complétée par TDI chez 18 patients souffrant d’hypertension pulmonaire, de type HTAP ou hypertension pulmonaire chronique d’origine thrombo-embolique (CTEPH), lors du cathétérisme du cœur droit inclus dans le bilan diagnostic initial. Les résultats montrent une diminution des indices de contraction régionale, prédominante au niveau de l’apex de la paroi libre VD, et des modifications de la relaxation des deux ventricules. Nous montrons également un quasi retour à la normale de la fonction VD, avec une disparition des anomalies à prédominance apicale, au cours d’un test de réversibilité chez un patient HTAP dit « répondeur » (importante diminution de la pression artérielle pulmonaire moyenne à l’administration de vasodilatateurs pulmonaires). Chapitre 6. Application des techniques non invasives modernes à l’étude de la circulation pulmonaire et de la fonction ventriculaire droite chez les patients souffrant de sclérodermie Les patients souffrant de sclérodermie sont à risque de développer de l’HTAP. Néanmoins, le rendement des techniques de dépistage non invasives est décevant. Nous avons émis l’hypothèse que la détection d’une hypertension pulmonaire dans la sclérodermie peut être améliorée par l’échocardiographie d’effort. Nous avons mesuré, par échocardiographie-Doppler, chez 25 patients sclérodermiques, les pressions artérielles pulmonaires et le débit cardiaque, au repos et à l’effort, de façon à déterminer une RVP « dynamique », et corrélé les résultats à l’évaluation échocardiographie-Doppler avec TDI. Les résultats montrent que les patients sclérodermiques présentent fréquemment une altération de la fonction diastolique du VD en présence d’une pression artérielle pulmonaire systolique normale au repos mesurée à partir de la vitesse maximale du jet de régurgitation tricuspide. Cette dysfonction est corrélée au temps d’accélération du flux pulmonaire (indicateur de l’élastance artérielle pulmonaire) et à la RVP dynamique (mesure raffinée de la RVP). Nous en concluons que l’altération de la fonction diastolique du VD est fréquente dans la sclérodermie, et reflète, vraisemblablement, une hypertension pulmonaire latente.
323

Effect of prolonged stimulation of the heme oxygenase/carbon monoxide system by hemin on blood pressure and penile erection of spontaneously hypertensive rats

Shamloul, Rany Mohamed 30 November 2006
Essential hypertension (EH) is a risk factor for many cardiovascular disorders. Treatment of established EH, especially for prolonged control of this pathogenic process, represents a great challenge. Moreover, hypertension is considered an important risk factor for the development of many other diseases, e.g. erectile dysfunction. <p> Hemin and other heme derivatives, e.g. heme-L-lysinate (HLL) and heme-L-arginate, have been used extensively to upregulate expression of heme oxygenase (HO) and production of endogenous carbon monoxide (CO). Short-term hemin administration for 4-5 days has been shown to markedly decrease high blood pressure (BP) in spontaneously hypertensive rats (SHR), but not in normotensive Wistar-Kyoto (WKY) or Sprague Dawley (SD) rats. This short-term therapy was effective in treating young, but not adult SHR. In the present study, hemin (15 mg/kg/day) was administered to 12-week old adult SHR through subcutaneously implanted osmotic minipumps for 3 consecutive weeks (the hemin protocol). Into the second week of the hemin protocol, BP of SHR was normalized from 203.2 ± 2.5 to 123.4 ±1.9 mmHg (n=20, p<0.001). There was no further decrease of BP in the remaining days of the hemin protocol. Normalization of BP in these treated SHR was maintained for 9 months after the removal of hemin pumps. <p>To further investigate the metabolic characteristics of hemin during hemin protocol administration, we attempted to monitor circulatory heme levels. A valid standard calibration curve was established using hemin or HLL in <i>in vitro</i> experiments. It was established that the basal serum level of heme was negligible in all rat strains prior to hemin protocol initiation. During the hemin protocol, serum heme level of all rats was significantly elevated; however, it quickly dropped to basal levels thereafter. <p>At the end of the 3-week hemin protocol, HO-1 expression, HO activity, soluble guanylyl cyclase (sGC) expression, and cyclic guanosine monophosphate (cGMP) content were all increased, but phosphodiesterase-5 (PDE-5) expression was down-regulated in the mesenteric arteries. The hemin protocol also reversed SHRs decreased arterial lumen size, and increased expression levels of vascular endothelial growth factor. These changes lasted 9 months after the hemin protocol. The hemin protocol did not cause hepatic or renal toxicity. Our study thus unmasks a novel hemin protocol that will not only normalize BP in SHR with established hypertension but, more importantly, also provide long-lasting anti-hypertension protection. Sustained upregulation of the HO-regulated signaling pathways and reversal of vascular remodeling in small peripheral vessels in treated SHR are among potential underlying mechanisms for the anti-hypertensive effect of the hemin protocol.<p>We further studied if the beneficial effects of hemin protocol on BP of SHR could be extended to improvement of their penile erection. Intracavernosal pressure changes after electrical stimulation of the cavernous nerve (CN) were monitored in adult SHR and age-matched normotensive SD rats after administration of either hemin or hydralazine. Expression levels of HO-1, HO-2, sGC, and PDE-5 in penile tissues were also examined. Frequency-dependent intracavernosal pressure (ICP) changes were reduced in adult SHR. Three weeks after hemin treatment, ICP responses to CN stimulations were significantly increased to the level of normotensive rats, which was linked to normalization of BP of hemin-treated SHR. Hydralazine-treated SHR experienced normalization of BP but not ICP after 3 weeks of treatment. Expression of HO-1 and sGC was upregulated and that of PDE-5 downregulated in hemin-treated SHR. Decreased ICP response in adult SHR can be improved through chronic hemin treatment of SHR. Prolonged upregulation of HO-1 and sGC as well as lowered expression of PDE-5 may account for normalization of erectile dysfunction in SHR subsequent to hemin treatment. <p>This thesis reports for the first time that 21-day hemin administration led to a 9-month normalization of high BP of adult SHR. These effects were mediated through sustained stimulation of the HO/CO system and its downstream effectors targets. Increased activity of HO-1 led to normalization of the abnormally high expression level of VEGF in peripheral mesenteric arteries of adult SHR. Subsequently, this resulted in reversal of the eutrophic remodeling of these arteries, which seems to be the priniciple determinant of the long-term normalization of BP observed for 9 months after stoppage of hemin treatment. The invention of hemin protocol offers a new therapeutic approach for the clinical management of established hypertension for a long duration.<p>Our study, for the first time, correlated changes in serum heme levels with BP levels after injection of hemin or HLL in normotensive and hypertensive rats. Application of this heme monitoring technology will also pave the way for clinical application of hemin therapy in treatment of EH.<p> Another intriguing finding in this thesis is that upregulation of HO-1, through the hemin protocol, led to improvement of abnormally low ICP encountered in adult SHR. Upregulation of HO-1 may represent a novel therapeutic approach to treat hypertension-related erectile dysfunction.
324

Effect of prolonged stimulation of the heme oxygenase/carbon monoxide system by hemin on blood pressure and penile erection of spontaneously hypertensive rats

Shamloul, Rany Mohamed 30 November 2006 (has links)
Essential hypertension (EH) is a risk factor for many cardiovascular disorders. Treatment of established EH, especially for prolonged control of this pathogenic process, represents a great challenge. Moreover, hypertension is considered an important risk factor for the development of many other diseases, e.g. erectile dysfunction. <p> Hemin and other heme derivatives, e.g. heme-L-lysinate (HLL) and heme-L-arginate, have been used extensively to upregulate expression of heme oxygenase (HO) and production of endogenous carbon monoxide (CO). Short-term hemin administration for 4-5 days has been shown to markedly decrease high blood pressure (BP) in spontaneously hypertensive rats (SHR), but not in normotensive Wistar-Kyoto (WKY) or Sprague Dawley (SD) rats. This short-term therapy was effective in treating young, but not adult SHR. In the present study, hemin (15 mg/kg/day) was administered to 12-week old adult SHR through subcutaneously implanted osmotic minipumps for 3 consecutive weeks (the hemin protocol). Into the second week of the hemin protocol, BP of SHR was normalized from 203.2 ± 2.5 to 123.4 ±1.9 mmHg (n=20, p<0.001). There was no further decrease of BP in the remaining days of the hemin protocol. Normalization of BP in these treated SHR was maintained for 9 months after the removal of hemin pumps. <p>To further investigate the metabolic characteristics of hemin during hemin protocol administration, we attempted to monitor circulatory heme levels. A valid standard calibration curve was established using hemin or HLL in <i>in vitro</i> experiments. It was established that the basal serum level of heme was negligible in all rat strains prior to hemin protocol initiation. During the hemin protocol, serum heme level of all rats was significantly elevated; however, it quickly dropped to basal levels thereafter. <p>At the end of the 3-week hemin protocol, HO-1 expression, HO activity, soluble guanylyl cyclase (sGC) expression, and cyclic guanosine monophosphate (cGMP) content were all increased, but phosphodiesterase-5 (PDE-5) expression was down-regulated in the mesenteric arteries. The hemin protocol also reversed SHRs decreased arterial lumen size, and increased expression levels of vascular endothelial growth factor. These changes lasted 9 months after the hemin protocol. The hemin protocol did not cause hepatic or renal toxicity. Our study thus unmasks a novel hemin protocol that will not only normalize BP in SHR with established hypertension but, more importantly, also provide long-lasting anti-hypertension protection. Sustained upregulation of the HO-regulated signaling pathways and reversal of vascular remodeling in small peripheral vessels in treated SHR are among potential underlying mechanisms for the anti-hypertensive effect of the hemin protocol.<p>We further studied if the beneficial effects of hemin protocol on BP of SHR could be extended to improvement of their penile erection. Intracavernosal pressure changes after electrical stimulation of the cavernous nerve (CN) were monitored in adult SHR and age-matched normotensive SD rats after administration of either hemin or hydralazine. Expression levels of HO-1, HO-2, sGC, and PDE-5 in penile tissues were also examined. Frequency-dependent intracavernosal pressure (ICP) changes were reduced in adult SHR. Three weeks after hemin treatment, ICP responses to CN stimulations were significantly increased to the level of normotensive rats, which was linked to normalization of BP of hemin-treated SHR. Hydralazine-treated SHR experienced normalization of BP but not ICP after 3 weeks of treatment. Expression of HO-1 and sGC was upregulated and that of PDE-5 downregulated in hemin-treated SHR. Decreased ICP response in adult SHR can be improved through chronic hemin treatment of SHR. Prolonged upregulation of HO-1 and sGC as well as lowered expression of PDE-5 may account for normalization of erectile dysfunction in SHR subsequent to hemin treatment. <p>This thesis reports for the first time that 21-day hemin administration led to a 9-month normalization of high BP of adult SHR. These effects were mediated through sustained stimulation of the HO/CO system and its downstream effectors targets. Increased activity of HO-1 led to normalization of the abnormally high expression level of VEGF in peripheral mesenteric arteries of adult SHR. Subsequently, this resulted in reversal of the eutrophic remodeling of these arteries, which seems to be the priniciple determinant of the long-term normalization of BP observed for 9 months after stoppage of hemin treatment. The invention of hemin protocol offers a new therapeutic approach for the clinical management of established hypertension for a long duration.<p>Our study, for the first time, correlated changes in serum heme levels with BP levels after injection of hemin or HLL in normotensive and hypertensive rats. Application of this heme monitoring technology will also pave the way for clinical application of hemin therapy in treatment of EH.<p> Another intriguing finding in this thesis is that upregulation of HO-1, through the hemin protocol, led to improvement of abnormally low ICP encountered in adult SHR. Upregulation of HO-1 may represent a novel therapeutic approach to treat hypertension-related erectile dysfunction.
325

Intramural Stress and Inflammation in Arterial Branches: A Histology-Based Approach

Carnell, Peter Hamilton 22 September 2004 (has links)
Hypertension is a major risk factor for coronary artery disease, stroke, and kidney disease. Many studies suggest that elevated intramural stresses caused by hypertension may stimulate inflammatory changes, but little has been done to ascertain whether inflammation and stress are spatially correlated. Such correlations are a first step in identifying the mechanisms that may relate intramural stress to disease so that more effective clinical treatments may be developed. Arterial branches exhibit local stress peaks and are focal points for the onset of disease. They are thus a logical place to examine whether high stresses spatially correlate with increased inflammation. This research seeks to 1) develop a histology-based method to reconstruct small arterial branches; 2) use finite element analysis to evaluate intramural stresses where experimental testing is of limited use; 3) quantify biological measures of inflammation; and 4) visually and statistically compare the distribution of stress with the distribution of inflammation. Hypertension was induced in Sprague-Dawley rats by implanting Angiotensin II pumps for 7 days or 21 days. Normotensive rats were used as controls. To preserve morphology the mesentery was pressure-fixed in situ, harvested, processed, and embedded in glycol methacrylate resin. Branch geometry was reconstituted from serial sections. This involved: correcting deformations caused by sectioning; aligning sections into an image stack; identifying vessel boundaries; creating a surface suitable for finite element analysis; reducing the branch geometry to a midplane surface; and using Ansys (Ansys, Inc.) to mesh the midplane surface with a variable-thickness shell element. The pattern of inflammation was characterized by measuring the local density of monocytes and macrophages. Cell density was expressed as a distribution on the branch surface, which simplified visualization and facilitated statistical comparisons of inflammation with stress. Both intramural stresses and inflammation were greater near branches during hypertension. In most cases, however, high stresses and high cell density were not spatially collocated. The onset of an adaptive response may reduce the strength of this correlation. Maximal wall tension, defined as the maximal midplane stress multiplied by the wall thickness, was elevated near branches and strongly correlated with cell density.
326

Influence of knowledge and of contingency contracting on adherence to hypertensive treatment regimes

Steckel, Susan Boehm. January 1976 (has links)
Thesis--University of Michigan. / Cover title: Adherence to hypertensive treatment regimes. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 62-76).
327

An evaluation of the Doctor Interactive Group Medical Appointment : assessing changes in health behaviors attributed to an integrated healthcare model

Capello, Jeremy, 1970- 06 September 2012 (has links)
This dissertation investigated the effect of a Doctor Interactive Group Medical Appointment (DIGMA), a unique multidisciplinary medical treatment modality, upon the health behavior of hypertensive patients at the Veterans Health Administration Outpatient Clinic (VA-OPC) in Austin, Texas. Health behavior modification, differences in stress perceptions, blood pressure changes due to the intervention and differences in coping strategies were assessed. Integrated healthcare utilizes a multidisciplinary approach in considering physiological and psychological aspects of health, promoting patients to act on their own behalf in managing health. Increased healthcare costs, decreased patient satisfaction of care received and practitioner satisfaction in care provided currently afflict primary healthcare. Earlier, a “drop-in” shared medical appointment aimed to improve continuity of care, and increase patient and physician satisfaction by allowing patients better access to physicians without taxing more resources. Contrasting the “drop-in” model, this study examined the efficacy of a multi-session DIGMA. Functioning as an adjunct to hypertensive management, participants attended 5 sessions, including one introduction meeting, three consecutive weekly group sessions and an individual telephone session occurring one week following the intervention. The study utilized a pretest/posttest design, with participants acting as their own controls. Self-report measures and blood pressure readings were administered prior to the onset, and again at termination of the DIGMA program. Analyses of variance and hierarchical regression models helped reveal any significant changes in health behaviors, perceptions of stress, and coping styles related to hypertension among 58 participants occurring over time for 7 distinct cohorts participating in the DIGMA. Findings revealed significant differences in both systolic and diastolic blood pressure readings between pre and post intervention. Significant changes in health promoting behaviors among participants who successfully completed all components of the program were also detected. In addition, adaptive coping strategies were found to significantly impact components of health behaviors. Qualitative information supports the quantitative data in determining whether the agent of change is the group process itself, the information imparted in the group, or some other variable. Findings reveal the dynamic of the group, as well as the modality in which information was conveyed positively influenced health behavior changes. Results, implications, and limitations of the study as well as future directions are discussed. / text
328

Evaluation of white coat hypertension in Chinese children : predictive factors and outcome

Chow, Chin-ying, 周展盈 January 2013 (has links)
Objectives Hypertension is increasingly found in children. 24 hour ambulatory blood pressure monitoring is now preferred to office blood pressure measurement for diagnosis and monitoring. Blood pressure of children tends to fluctuate widely throughout the day and night. A number of children suffer from a condition called white coat hypertension in which elevation of blood pressure is only transient and they usually have normal blood pressure on continuous monitoring. This condition is not totally benign. Some patients will evolve into hypertension over time. This retrospective case control study is to compare the demographic characteristics and blood investigations of these 2 groups namely white coat hypertension cases and a control group so as to identify factors predictive of white coat hypertension in a Chinese population to help allocate resources for timely diagnostic investigation. Method 100 patients referred from primary health care units aged 6-18 year old for suspected hypertension based on raised office blood pressure measurements were recruited as cases in the white coat hypertension group and 100 age-matched patients as a control group. The factors studied included gender, body mass index, length of gestation, birth weight, family history of hypertension, positive past medical history, blood pressure at first presentation, blood pressure of ambulatory blood pressure monitoring, serum glucose, urate and cholesterol and triglyceride level. Univariate analysis was used to detect significant difference between the cases and the controls for continuous and categorized variables. Logistic regression was used to assess the independent associations of significant predictive factors of white coat hypertension. Correlations with the scatterplots for the relation of office systolic blood pressure and diastolic blood pressure with 24 hour ambulatory blood pressure monitoring within cases was done to see if there was any significant relations. The outcome of cases was also studied for the proportion which progressed into genuine hypertension. Results Body mass index (BMI) was identified as a significant predictive factor in logistic regression with an odds ratio of 1.18 (95% CI = 1.11-1.25) with p-value <0.001. The correlation between 24 hour ambulatory blood pressure and office blood pressure measurement was not significant. None of the cases progressed into genuine hypertension upon follow up. Conclusion To conclude, this study showed that high BMI might be predictive of white coat hypertension in Chinese children in Hong Kong. This result could be act as a hypothesis for future research. Multi-centre prospective cohort studies might be of value in testing this factor together with factors which were shown to be significant in other studies. White coat hypertension is not always as benign as thought. Obesity is a condition which requires attention from patients, parents, paramedics and healthcare practitioners especially in primary healthcare settings and should be monitored more closely for the emergence of associated complications. / published_or_final_version / Public Health / Master / Master of Public Health
329

Body composition, blood pressure and their tracking in children and adolescents

Williams, Daniel Patrick, 1964- January 1989 (has links)
Blood pressure (BP) measurement reliability, year-to-year BP tracking, distinguishing characteristics of upper quintile (UQ) vs lower four quintiles' (LQ) systolic BP (SBP) tracking and the relationships of fat distribution and body composition to SBP were examined in 57 youth. Subjects were measured on two occasions approximately one year apart. Longitudinal measures included auscultatory BPs, height, weight, body circumferences, skeletal widths, bioelectrical impedance and skinfolds. Inter-trial reliability of right/left arm averaged BP (RLBP) exceeded that of either limb alone; tracking magnitude was likewise greater with RLBP. Greater total body mass and fatness as well as larger anthropometric dimensions distinguished UQ from LQ SBP trackers. Fat distribution and SBP were not consistently associated with each other across study years. Irrespective of gender differences, fatness and fat free mass per unit height2 were independently related to within year SBP, yet only initial fatness was independently predictive of future SBP.
330

A sensitive method for measuring plasma catecholamines and its application on the study of the effect of alfentanil and esmolol onintra-operative hypertension

蕭德成, Siu, Tak-shing. January 1998 (has links)
published_or_final_version / abstract / toc / Anaesthesiology / Master / Master of Philosophy

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