Avdelningen för Medicinsk teknik på Akademiska sjukhuset har uppdaterat befintliga kalibreringsprotokoll för Welch Allyn 767 som används som referensmanometer vid kalibrering av blodtrycksmätare. I protokollet ska det enligt ISO 9001 och ISO 13485 ingå att vid varje kalibreringspunkt ange mätosäkerheten.  Rutiner kring detta var inte definierade. En modell för att ta fram mätosäkerhet utformades utifrån standardiserade metoder från “Guide to the expression of uncertainty in measurement” och anpassades för att kunna användas på den medicintekniska avdelningen. En mätmetod för kalibrering togs fram och med modellen beräknades mätosäkerhet för en referensmanometer. Mätosäkerheten med definierad mätmetod blev lägre än den av Welch Allyn specificerade mätosäkerheten på ± 3 mmHg. Felfortplantning från kalibrering till blodtrycksmätning undersöktes. Mätosäkerheten ökade i varje steg, varför avdelningen bör ta fram ett protokoll för hur kalibrering genomförs, och på så sätt förbättra spårbarheten. / The department of Medical Technology at Akademiska sjukhuset has updated their current protocol for calibration for Welch Allyn 767, which serves as a reference manometer for blood pressure meters when being calibrated. According to ISO 9001 and ISO 13485, the protocol has to include a measurement uncertainty for every given point of calibration. The routines regarding this were undefined. A model for retrieving measurement uncertainty was designed using standardized methods from “Guide to the expression of uncertainty in measurement” and was customized to be used at the department of Medical Technology. A method for calibration was created and used to calculate the measurement uncertainty for the reference manometer. This measurement uncertainty was smaller than the one specified by Welch Allyn, which was ± 3 mmHg. Propagation of uncertainty from the calibration to the blood pressure measurement was investigated. The measurement uncertainty increased in every step. Therefore, the department should introduce a protocol for how a calibration is performed, and thereby improve the traceability.

Avdelningen för Medicinsk teknik på Akademiska sjukhuset har uppdaterat befintliga kalibreringsprotokoll för Welch Allyn 767 som används som referensmanometer vid kalibrering av blodtrycksmätare. I protokollet ska det enligt ISO 9001 och ISO 13485 ingå att vid varje kalibreringspunkt ange mätosäkerheten.  Rutiner kring detta var inte definierade. En modell för att ta fram mätosäkerhet utformades utifrån standardiserade metoder från “Guide to the expression of uncertainty in measurement” och anpassades för att kunna användas på den medicintekniska avdelningen. En mätmetod för kalibrering togs fram och med modellen beräknades mätosäkerhet för en referensmanometer. Mätosäkerheten med definierad mätmetod blev lägre än den av Welch Allyn specificerade mätosäkerheten på ± 3 mmHg. Felfortplantning från kalibrering till blodtrycksmätning undersöktes. Mätosäkerheten ökade i varje steg, varför avdelningen bör ta fram ett protokoll för hur kalibrering genomförs, och på så sätt förbättra spårbarheten. / The department of Medical Technology at Akademiska sjukhuset has updated their current protocol for calibration for Welch Allyn 767, which serves as a reference manometer for blood pressure meters when being calibrated. According to ISO 9001 and ISO 13485, the protocol has to include a measurement uncertainty for every given point of calibration. The routines regarding this were undefined. A model for retrieving measurement uncertainty was designed using standardized methods from “Guide to the expression of uncertainty in measurement” and was customized to be used at the department of Medical Technology. A method for calibration was created and used to calculate the measurement uncertainty for the reference manometer. This measurement uncertainty was smaller than the one specified by Welch Allyn, which was ± 3 mmHg. Propagation of uncertainty from the calibration to the blood pressure measurement was investigated. The measurement uncertainty increased in every step. Therefore, the department should introduce a protocol for how a calibration is performed, and thereby improve the traceability.

Le décès d’une personne sur cinq à travers le monde est associé à l’hypertension artérielle (HTA). Or, près de la moitié des individus avec HTA ignorent leur condition : ils n’ont pas été dépistés. Cette thèse a pour objectif, principalement à travers la présentation de deux articles originaux, de contribuer à l’amélioration du dépistage de l’HTA. Avant la présentation des deux articles de cette thèse, les résultats d’un examen de la littérature sur les effets des démarches de dépistage de l’HTA en milieux hors hospitaliers sont exposés. On y constate notamment qu’une telle démarche permet d’identifier près d’un adulte sur trois comme ayant une pression artérielle (PA) élevée. La pratique infirmière dans la prise en charge de l’HTA est également explorée. Il en ressort que leurs interventions non pharmacologiques et leurs interventions directes sur le traitement pharmacologique permettent à la fois une amélioration des habitudes de vie ainsi qu’un abaissement de la PA au moins équivalente aux soins médicaux usuels. Le premier article de cette thèse consiste en une revue systématique effectuée en utilisant le protocole Preferred Reporting Items for Systematic Reviews and Meta-Analyses - Diagnostic Test Accuracy (PRISMA-DTA). Les objectifs de cette revue systématique étaient de décrire la performance (valeur prédictive positive, taux de suivi) de la stratégie de dépistage de l’HTA qui consiste à tirer profit de la mesure de la PA effectuée d’emblée auprès des millions de personnes qui se présentent annuellement dans les départements d’urgence. Les méthodes de mesure de la PA utilisées lors de la consultation initiale à l'urgence, les moyens utilisés pour assurer un suivi, ainsi que les méthodes utilisées pour confirmer un diagnostic de l’HTA sont également décrits. À la suite d’une recension initiale de 1030 articles, 10 de ceux-ci répondaient aux critères d’inclusion. L’outil Quality Assessment of Diagnostic Accuracy Studies-2 (Quadas-2) a été utilisé pour l’évaluation de la qualité des études. L’âge moyen des participants est de 51,6 ± 6,4 ans. Pour effectuer la mesure de la PA au département d’urgence, un appareil au mercure a été utilisé dans la moitié des études, quatre ont utilisé un appareil électronique et pour deux études, cette information n’était pas disponible. Parmi ceux ayant eu un dépistage positif, le taux de suivi moyen est de 61,9 %. Parmi eux, 50,2 % ont reçu la confirmation d’un diagnostic d’HTA à la suite d’une démarche de suivi. L’on retrouve dans seulement deux études une méthode de confirmation diagnostique correspondant aux standards des sociétés savantes en HTA. Une autre solution pour l’amélioration du dépistage de l’HTA est d’augmenter la validité de la méthode de mesure de la PA. Le second article de cette thèse avait pour objectif d’évaluer la performance (valeurs prédictives, sensibilité, spécificité, coefficient de kappa et taux de suivi) d’une nouvelle stratégie de dépistage de l’HTA au moment d’une consultation pour urgence mineure. La stratégie consiste, à la suite d’une mesure initiale de la PA dont le résultat est élevé, en l’ajout d’une seconde méthode de mesure de la PA : la mesure oscillométrique en série. Un monitorage ambulatoire de la pression artérielle (MAPA) d’une durée de 24 heures a été fait pour chaque participant afin d’évaluer la performance de la combinaison des deux méthodes de mesures cliniques. Le MAPA constitue la mesure étalon en HTA. Effectuée dans une clinique GMF de Laval, 50 des 80 participants (62,5 %) inclus ont complété l’étude en se présentant au rendez-vous de suivi pour un MAPA. L’âge moyen des participants est de 51,9 ans. À la suite d’une mesure initiale de la PA dont le résultat est élevé, l’ajout de la mesure oscillométrique en série a été associé à une valeur prédictive positive de 62,5 % et une valeur prédictive négative de 83,3 % (sensibilité, 87 %; spécificité 56 %; coefficient de kappa 0,41). Cette thèse permet d’offrir des pistes de réponses qui pourront contribuer à l’amélioration du dépistage de l’HTA. Tout d’abord, le premier article met en lumière le fait que les consultations au département d’urgence représentent une excellente opportunité pour le dépistage de l’HTA. En effet, cela permet de rejoindre un nombre très important d’individus. Une mesure de la PA est effectuée à chacun d’eux, ils sont plutôt jeunes et lorsque le résultat de la mesure est élevé, cela correspond réellement à une HTA pour la moitié des cas. Le taux de suivi se situe à environ 60 %. La démarche de dépistage à l’urgence consiste essentiellement à reconnaitre une PA élevée, puis d’effectuer une référence afin d’obtenir une prise en charge. Cela implique qu’à chaque 100 adultes avec une PA élevée à l’urgence et pour qui une démarche de dépistage serait effectuée, 30 individus pourraient avoir un diagnostic d’HTA confirmé ainsi qu’une prise en charge subséquente. Malgré cela, le défi de la validité de la mesure et du suivi demeure. La contribution originale du deuxième article s’attarde à cette question. À la suite d’une mesure initiale de la PA dont le résultat est élevé, l’ajout de la mesure oscillométrique en série permet d’augmenter la validité de la démarche de dépistage. En effet, ceux pour qui le résultat de cette mesure est normal peuvent être considérés, d’une façon sécuritaire, comme étant non hypertendus. Ainsi, les individus dirigés afin d’effectuer un examen de confirmation diagnostique seront mieux ciblés, les ressources existantes mieux utilisées. Enfin, des recommandations sont présentées relativement au dépistage de l’HTA, à sa prise en charge, mais également sur la pratique infirmière. / One out of five people worldwide dies from causes linked to hypertension (HTN). Yet, nearly half of individuals with HTN are unaware of their condition as they have not been screened. The goal of this thesis, mainly through the presentation of two original articles, is to help improve HTN screening. Before presenting the two articles, the results of a literature review on the effects of the HTN screening process in an out-of-hospital setting are outlined. In particular, it is noted that such a process helps to identify nearly one out of three adults as having elevated blood pressure (BP). The nursing practice in HTN management is also explored. It is concluded that their non-pharmacological interventions and direct interventions on the pharmacological treatment help to improve lifestyles and lower BP by at least the same amount as customary medical care. The first article of this thesis consists in a systematic review conducted with the use of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses - Diagnostic Test Accuracy (PRISMA-DTA) protocol. The purposes of this systematic review are to describe the performance (positive predictive value, follow-up rate) of the HTN screening strategy, which consists in drawing on the BP measurement taken on millions of people who show up in the emergency department (ED) annually. The BP measurement methods used during the initial ED consultation, the methods used to ensure follow-up, and the methods used to confirm an HTN diagnosis are also described. Following an initial review of 1030 articles, 10 of these met the inclusion criteria. The Quality Assessment of Diagnostic Accuracy Studies-2 (Quadas-2) tool was used to evaluate the quality of the studies. The average age of participants is 51.6 ± 6.4 years. To take a BP measurement in the ED, a mercury device was used in half of the studies, four used an electronic device and for two studies, this information was unavailable. Among those with a positive screen, the average monitoring rate is 61.9%. Among them, 50.2% received confirmation of an HTN diagnosis following the follow-up process. Only two studies mention a diagnosis confirmation method that meets the standards of learned HTN societies. Another solution to improve HTN screening is to increase the validity of the BP measurement method. The goal of the second article of this thesis was to evaluate the performance (predictive values, sensitivity, specificity, kappa coefficient and monitoring rate) of a new HTN screening strategy when consulting for a minor emergency. Following the initial high BP measurement, the strategy consists in adding a second BP measurement method: the automated office blood pressure measurement (AOBP). Each participant underwent 24-hour ambulatory blood pressure monitoring (ABPM) to evaluate the performance of the combination of both clinical measurement methods. ABPM is the gold standard for BP measurement. Conducted in a GMF clinic in Laval, Quebec, 50 of the 80 participants (62.5%) included completed the study by showing up to the follow-up ABPM appointment. The average age of participants is 51.9 years old. Following an initial high BP measurement, adding the AOBP is linked to a positive predictive value of 62.5% and a negative predictive value of 83.3% (sensitivity 87%, specificity 56%, kappa coefficient 0.41). This thesis offers possibilities that can help improve HTN screening. The first article highlights the fact that ED consultations are an excellent opportunity to screen for HTN. Indeed, this helps to reach many individuals: BP measurement is taken on each one, they are rather young, and when the measurement is high, this actually corresponds to an HTN for half of the cases. The follow-up rate is about 60%. The ED screening process mainly consists in recognizing high BP, and then making a referral to obtain treatment. This implies that for every 100 adults with high BP in the ED and on whom a screening process would be conducted, 30 people could have a confirmed HTN diagnosis and subsequent treatment. And yet, the validity of the measurement and follow-up remains a challenge. The original contribution of the second article examines this question. Following an initial high BP measurement, adding the AOBP helps to increase the validity of the screening process. Indeed, those for whom the result of this measurement is normal can safely be considered as non-hypertensive. As such, those referred to complete a diagnosis confirmation exam will be better targeted and the existing resources better used. Lastly, recommendations are made regarding HTN screening, its management, and the related nursing practice.

Hypertension, a medical condition, predisposes to other cardiovascular diseases, and can be impacted by the social determinants of health (SDOH). Self-measured blood pressure monitoring (SMBP) is an evidence-based approach to hypertension control, but not much is known about the influence of SDOH on SMBP. This dissertation aims to: 1) highlight the SDOH factors whose relationship with SMBP have been explored in research studies; 2) examine the relationship between SDOH and SMBP among United States (U.S.) adults with high blood pressure; and 3) examine the current state of SMBP in the U.S., highlight policy implications from the empirical study and provide recommendations. Aims 1 and 2 were informed by an adapted SDOH framework, which comprised of upstream structural determinants, and downstream intermediary determinants. Aim 1 was achieved via a scoping review of studies across three databases following the PRISMA-SCR checklist. Aim 2 was achieved via a cross-sectional analysis of data from adult respondents to the 2019 Behavioral Risk Factor Surveillance System, with self-reported hypertension. Bivariate and Multiple Logistic regression analyses were conducted. Aim 3 involved a literature scan on policy concerning SMBP, highlighting the policy implications of findings from the empirical study, and providing recommendations for policy/practice. For aim 1, findings suggest that research studies examined the relationship of relatively more structural determinants, than the few, but highly significant intermediary determinants, with SMBP. For aim 2, looking at the structural determinants, males and those who identify as Black and other minority racial groups were more likely to report SMBP. For intermediary determinants, respondents who consumed fruits, vegetables, and exercised were likely to report SMBP, while those who smoke, who drink, and those with poor mental health days were less likely to report SMBP. Respondents with health coverage and whose provider recommended SMBP were likely to report SMBP use. Those ≥65 years were more likely to report SMBP. For aim 3, I recommend that the Centers for Medicare and Medicaid Services lead policy efforts on SMBP reimbursements. Also, healthcare practices should strengthen their technological infrastructure e.g., telehealth to promote access, and Electronic Health Records to promote efficient data collection and tracking.

Thesis (MMed)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: OBJECTIVE: The aim of this study was to compare the accuracy of non-invasive brachial blood pressure measurements, using automated and manual devices, to invasive brachial intra-arterial blood pressure measurements in patients with preeclampsia, during acute severe hypertension. STUDY DESIGN: A prospective descriptive cross sectional study was conducted in the Obstetrics Critical Care Unit (OCCU) of Tygerberg Hospital. Pre-eclamptic patients with acute severe hypertension, who required the placement of brachial intra-arterial lines due to failed radial intra-arterial line placement, were included in the study. Both automated oscillometric and blinded manual aneroid sphygmomanometric blood pressures were recorded during hypertensive peaks and after stabilization of BP using intravenous Labetalol or Nepresol. These two noninvasive methods of blood pressure measurements were compared to brachial intraarterial blood pressure measurements. RESULTS: There was weak correlation between manual and intra-arterial SBP (r = 0.27, p = 0.048) for SBP≥160mmHg. The calculated mean difference between manual SBP compared to the intra-arterial SBP in this group was -23.19mmHg (+/- 19.40). There was moderate correlation between automated and intra-arterial SBP (r = 0.69, p < 0.05). The calculated mean difference between automated SBP compared to the intra-arterial SBP in this group was -16.85mmHg (+/- 11.58). CONCLUSION: This study of pre-eclamptic women demonstrated that both non-invasive methods of BP measurement were inaccurate measures of the true systolic intra-arterial BP and significantly underestimated SBP≥160mmHg when compared to brachial intra-arterial measurements. The SBP was also underestimated, to a lesser degree, for mild moderate hypertension. This study also demonstrated that direct invasive BP monitoring using the brachial artery is a safe method for accurate haemodynamic monitoring. We recommend the use of intra-arterial BP monitoring in pre-eclamptic women with acute severe hypertension. Radial arterial cannulation should be used as the first option and the brachial artery should be used if the first option fails. / AFRIKAANSE OPSOMMING: DOELWIT: Die doel van hierdie studie was om die akuraatheid van nie indringende bragiale bloeddruk metings, wat met outomatiese en manuele aparate geneem is, te vergelyk met bragiale intra-arteriele bloeddruk metings gedurend akute erge hipertensie in pasiente met pre-eklampsie, STUDIE ONTWERP: ʼn Prospektiewe beskrywende dwarssnit studie was in die Obstetriese Kritiese Sorg Eenheid (OCCU) van Tygerberg Hospitaal uit gevoer. Preeklamptiese pasiente met akute erge hipertensie, wat bragiale intra-arteriele lyne nodig gehad het, as gevolg van gefaalde radiale intra-arteriele lyn plasing, was in hierdie studie ingesluit. Beide outomatiese ossilometriese en geblinde aneroide sfigmomanometriese bloeddrukke, tydens hipertensiewe pieke en na stabilisering van bloeddrukke met binneaarse Labetalol of Nepresol, was aangeteken, Die twee nie indringende metodes van bloeddruk meting was met bragiale intra-arteriele bloeddruk metings vergelyk. RESULTATE: Daar was ʼn swak korrelasie tussen manuele en intra-arteriele sistoliese bloedrukke SBP (r = 0.27, p = 0.048) vir SBP≥160mmHg. Die berekende gemiddelde verskil tussen manuele SBP en intra-arteriele SBP was -23.19mmHg (+/- 19.40) in hierdie groep. Daar was ʼn matige korrelasie tussen outomatiese en intra-arteriele SBP (r = 0.69, p < 0.05). Die berekende gemiddelde verskil tussen outomaties SBP vergelyk met intra-arteriele SBP was -16.85mmHg (+/- 11.58) in hierdie groep. GEVOLGTREKKING: Hierdie studie van pre-eklamptiese vrouens, het getoon dat beide nie indringende metodes van bloeddruk meting, nie akurate metings van ware sistoliese intraarteriele bloeddruk is nie, en SBP≥160mmHg word aansienlik onderskat wanneer dit met bragiale intra-arteriele metings vergelyk word. Die SBP was ook tot ʼn minder mate onderskat vir matige hipertensie. Die studie het ook getoon dat die direkte bragiale intra-arteriele metode van bloeddruk monitering, ʼn veilige metode van hemodinamiese monitering is. Ons beveel die gebruik van intra-arteriele bloeddruk monitering aan, in preeklamptiese vrouens met akute erge hipertensie. Radiale arteriele kanulasie moet gebruik word as die eerste opsie en die bragiale arterie moet gebruik word as die eerste opsie faal.

Bakgrund: Sällskapsdjur har ett flertal positiva hälsoeffekter på människor och det har lett till att viidag använder djur inom vården, främst hundar. Syfte: Syftet med denna litteraturstudie var att undersöka hundens användande inom vården, attbeskriva och förklara dess effekt på människor. Metod: Metoden var en litteraturstudie och elva vetenskapliga artiklar granskades. Dessaanalyserades och sammanställdes utifrån gemensamma teman. Resultat: Vårdhundar inom vården kan i de flesta fall reducera ångest och acceptansen av vårdhundär mycket god både bland patienter, anhöriga och personal. Minskning av blodtryck ochhjärtfrekvens råder det delade meningar om, då vissa studier visar en minskning av dessa och andragör det inte. Vårdhundar kan användes till att vara motivationshöjande för patienten. Slutsats: Vårdhundar har många positiva effekter på människor, men fler studier behövs för att seom dessa resultat inte bara gäller för de grupper som har undersökts i studien utan även äröverförbara till andra grupper. / Background: Pets have a number of positive health effects in humans and this has led to ourcurrent use of animals in health care, particularly dogs. Aim: The aim of this study was to investigate the dog's use in health care, to describe and explainits effect on humans. Method: The method was a littareture review and eleven scientific studies was examined. Thesewere analyzed and summarized by common themes. Results: Therapydogs can in most cases reduce anxiety and acceptance of therapydogs is very goodamong patients, relatives and staff. There is a disagreement about bloodpressure and heart rate,since some studie show a decrease of these factors and others do not. Thearpydogs can be used as amotivation for patients. Conclusion: Thearpydogs have a number of positive effects on people in health care, but morestudies are needed to see if these results apply not only to those groups that has participated in thestudy but are also transferable to other groups.

Tikslas: Išanalizuoti kvėpavimo sulaikymo įtaka blauzdos raumenų arterinei kraujotakai. Uždaviniai: 1. Nustatyti sportuojančių ir nesportuojančių merginų blauzdos raumenų arterinės kraujotakos kaitą sulaikius kvėpavimą iki negalėjimo. 2. Nustatyti arterinio kraujo spaudimo dažnių rodiklių kaita sulaikius kvėpavimą. Tyrimo metodai: Arterinio kraujo spaudimo (AKS) matavimai Korotkovo metodu ir arterinės kraujotakos registracija – veninės okliuzinės pletizmografijos metodu. Tyrimo organizavimas: Tyrime dalyvavo dešimt sportuojančių (adaptuotų greitumo – jėgos fiziniams krūviams) ir aštuoniolika nesportuojančių merginų. Arterinė kraujotaka blauzdos raumenyse ir AKS buvo registruojami po 20 min adaptacijos ramybės būsenoje, bei sulaikius kvėpavimą ir atsigavimo metu. Buvo atliekami du kvėpavimo sulaikymai iki negalėjimo. Rezultatai. Pirmojo kvėpavimo sulaikymo metu sportuojančių merginų kraujotaka mažėjo ir pabaigoje ji sumažėjo iki 1,5±0,3ml/100 ml/min. Atsigavimo metu kraujotakos intensyvumas pirmąją minutę didėjo ir prieš antrąjį sulaikymą beveik pasiekė pradinį lygį. Arterinės kraujotakos intensyvumas antrojo kvėpavimo sulaikymo metu didėjo, tačiau praėjus 45sek pradėjo nežymiai mažėti. Atsigavimo metu kraujotakos intensyvumas sumažėjo analogiškai, kaip ir po pirmo sulaikymo. Atsigavimo pabaigoje pradėjo didėti link pradinio lygio. Nesportuojančių merginų pirmojo kvėpavimo sulaikymo metu kraujotaka mažėjo ir pabaigoje ji sumažėjo iki 1,6±0,38ml/100 ml/min (p<0.05)... [toliau žr. visą tekstą] / Research aim - is to assess influence of arterial blood flow changes in the calf muscles during breathing stop. Research tasks – 1. Establish changes in the calf muscle blood flow before, during and after breathing stop for athletic and non-athletic girls. 2. Establish changes in arterial blood pressure before, during and after breathing stop for athletic and non-athletic girls. Research methods – arterial blood flow changes using venous occlusive plethysmography method, arterial blood pressure using Korotkoff sounds method. Research organization – The study involved 10 athletic (adapted to speed - strength exercise) and 18 non-athletic girls. The examinations were conducted at a room temperature of 18–20O C with the patient in a sitting position. Each girl was introduced with instruction of the research and explained to them, how everything will work. Arterial blood flow in the calf muscle and arterial blood pressure was recorded after 20 min of adaptation at rest, during breathing stop and at recovery time. Research was made of two breathing stop. Recovery from breathing stop was recorded 5min. The blood flow in the calf was determined by venous occlusion plethysmography. Research results – Athletic girls arterial blood flow during first breathing going down and in the end of first breathing stop was stop 1,5±0,3ml/100 ml/min. For non-athletic girls it was similar 1,6±0,38ml/100 ml/min. But during second breathing stop for athletic girls arterial blood flow was 2,4±0,7... [to full text]

Background: In the past 37 years, increased efforts have been directed toward a better understanding of the importance of Hcy in disease and it has now become clear that hyperhomocysteinemia is a major independent risk factor for CVD. Extensive research on the influence of vitamin supplementation leading to reductions in Hcy levels and improvements in cardiovascular function has been done. The importance of exercise in the lowering of cardiovascular risk factors, as well as its favourable influence on cardiovascular function has also been indicated in several studies, however, the limited number of studies investigating the effect of exercise on Hcy concentrations revealed contradicting results. Furthermore, a relationship between Hcy concentration and cardiovascular function with the intervention of an exercise training and a vitamin supplementation programme respectively has also not been investigated. Objective: The objective of this study was to examine the effect of a 12-week exercise training and a 12-week vitamin supplementation intervention respectively on tHcy concentrations and cardiovascular function, and whether the change in tHcy concentration within the different interventions correlated with the change in cardiovascular function. Methods: In a randomised controlled cross-over intervention study, 52 men matched for age, cardiorespiratory fitness levels and cardiovascular risk factors were randomly assigned to one of 3 groups (Group A = exercise training programme, 20-30min. at 70-80% of HRmax; Group B = 400 g folic acid and 25 g vitamin B12 supplement; Group C = control). Group A and B were crossed over for phase 11, and Group C remained the control. The questionnaires were completed, and the body composition variables (BMI, WHR and body fat percentage), cardiovascular function (Finometer), tHcy concentrations and VO2max, were measured before and after each 12-week intervention period. A 6-week washout period separated the crossovers. Results: The ANCOVA, adjusted for age and BMI, showed that the percentage change from baseline to end, corrected for baseline of the tHcy concentration increased significantly (p ≤ .05) by 9.7% with the exercise training intervention and decreased significantly (p ≤ .05) by 12.9%, with the vitamin supplementation intervention. The ANCOVA of the percentage change from baseline to end in cardiovascular function showed that the vitamin supplementation intervention resulted in improvements in cardiovascular function (decreased resting MAP, TPR and increased resting SV, CO, Cw) in comparison to the impairment in cardiovascular function with the exercise training intervention (increased resting DBP, MAP and TPR). The relationship between the tHcy concentration and cardiovascular function at baseline and within each of the different interventions were assessed by partial correlations adjusted for age, BMI and VO2max. Significant (p ≤ .05) relationships only occurred within the vitamin supplementation intervention, where decreased percentage change in tHcy concentration significantly correlated with increased percentage change of resting SV and CO and decreased percentage change of resting TPR. Conclusion: The general conclusion that can be drawn is that a 12-week vitamin supplementation intervention showed increased health related results, e.g. a significant reduction in tHcy concentration, an improvement in cardiovascular function and a significant positive relationship between these b o factors, in comparison to the 12-week exercise training intervention that significantly increased the tHcy concentration and did not show increased health related results. Due to inadequate compliance to the exercise training intervention, no conclusion can be drawn with regard to the effect of exercise training on tHcy concentrations and cardiovascular function. / Thesis (M.Sc. (Human Movement Science))--North-West University, Potchefstroom Campus, 2007

Reductions in baroreflex responsiveness have been thought to increase the prevalence of orthostatic hypotension in endurance trained athletes. To test this hypothesis, cardiovascular responses to orthostatic stress, cardiopulmonary and carotid baroreflex responsiveness, and the effect of cardiopulmonary receptor deactivation on carotid baroreflex responses were examined in 24 men categorized by maximal aerobic power (V02max) into one of three groups: high fit (HF, V0-2max=67.0±1.9 ml•kg^-1•min^-1), moderately fit (MF, V0-2max=50.9±1.4 ml•kg^-1•min^-1), and low fit (LF, V0-2max=38.9±1.5 ml•kg^-1•min^-1). Orthostatic stress was induced using lower body negative pressure (LBNP) at -5, -10, -15, -20, -35, and -50 torr. Cardiopulmonary baroreflex responsiveness was assessed as the slope of the relationship between forearm vascular resistance (FVR, strain gauge plethysmography) and central venous pressure (CVP, dependent arm technigue) during LBNP<-35 torr. Carotid baroreflex responsiveness was assessed as the change in heart rate (HR, electrocardiography) or mean arterial pressure (MAP, radial artery catheter) elicited by 600 msec pulses of neck pressure and neck suction (NP/NS) from +40 to -70 torr. Pressures were applied using a lead collar wrapped about the subjects' necks during held expiration. Stimulus response data were fit to a logistic model and the parameters describing the curve were compared using two-factor ANOVA. The reductions CVP, mean (MAP), systolic, and pulse pressures during LBNP were similar between groups (P<0.05). However, diastolic blood pressure increased during LBNP m all but the HF group. (P<0.05). The slope of the FVR/CVP relationship did not differ between groups, nor did the form of the carotid-cardiac baroreflex stimulus response curve change during LBNP. changes in HR elicited with NP/NS were not different between groups (£>0.05). The range of the MAP stimulus response curve, however, was significantly less in the HP group compared to either the MP or LF group (£<0.05). These data imply that carotid baroreflex control of HR is unaltered by endurance exercise training, but carotid baroreflex control of blood pressure is impaired significantly, predisposing athletes to faintness.

BACKGROUND: Little is known of the effects of obesity, body size and body composition, and blood pressure (BP) in childhood on hypertension (HBP) and cardiac structure and function in adulthood due to the lack of long-term serial data on these parameters from childhood into adulthood. In the present study, we are poised to analyze these serial data from the Fels Longitudinal Study (FLS) to evaluate the extent to which body size during childhood determines HBP and cardiac structure and function in the same individuals in adulthood through mathematical modeling. METHODS: The data were from 412 males and 403 females in the FLS. Stature and BMI parameters were estimated using the Preeze-Baines model and the third degree polynomial model to describe the timing, velocity and duration of these measure from 2 to 25 years of age. The biological parameters were related to adult BP and echocardiographic (Echo-) measurements using Generalized Linear Models (GLM). RESULTS: The parameters of stature and BMI were compared between male and female to their overall goodness of fit and their capabilities to quantify the timing, rate of increase, and duration of the growth events. For stature parameters, the age at onset and peak velocity was earlier for girls; but the peak velocity was greater in boys; the velocity at onset was about the same for boys and girls; and stature at onset, peak velocity and adult was greater for boys. For BMI parameters, boys tended to have larger BMI values than girls, but the rates of change in BMI were almost the same; there was no sex difference in the timing of BMI rebound, but there was for the age of the peak velocity of BMI and maximum BMI, both of which were earlier in girls than in boys. CONCLUSIONS: Changes in childhood stature and BMI parameters were related to adult BP and Echo-measurements more so in females than males. Also the relationship of the adult BP measurements with corresponding childhood biological parameters was stronger than the relationship for adult Echo-measurements.