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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.
471

Obstructive sleep apnea : the relationship to cardiovascular disease, diabetes mellitus, motor vehicle driving and ambient temperature

Valham, Fredrik January 2011 (has links)
Background: Obstructive sleep apnea is a common disorder, especially in men. Patients with this condition often snore and suffer from excessive daytime sleepiness. It is a treatable condition related to cardiovascular disease, road traffic accidents and obesity. Aims: To study whether snoring and witnessed sleep apnea are related to diabetes mellitus and whether sleepy subjects who snore or report sleep apneas drive more than others. To investigate whether sleep apnea is related to stroke, mortality and myocardial infarction in patients with coronary artery disease. To study the effect of ambient temperature on sleep apnea, morning alertness and sleep quality in patients with obstructive sleep apnea. Methods and results: Questions on snoring, sleep apnea, daytime sleepiness and yearly driving distance were included in the northern Sweden component of the WHO MONICA study. Analyzed were 7905 randomly selected men and women aged 25-79 years. Snoring and witnessed sleep apnea were related to diabetes mellitus in women, (OR 1.58, p = 0.041 and OR 3.29, p = 0.012 respectively), independent of obesity, age and smoking, but not in men. Sleepy snoring men drove a mean of 22566 km per year which was more than others who drove 17751 km per year independent of age, BMI, smoking and physical activity (p = 0.02). Sleepy men reporting sleep apnea also drove more (p = 0.01). 392 men and women with coronary artery disease referred for coronary angiography were examined with overnight sleep apnea recordings and followed for 10 years. Sleep apnea was recorded in 211 (54%) of patients at baseline. Stroke occurred in 47 (12%) patients at follow up. Sleep apnea was associated with an increased risk of stroke (HR 2.89, 95% CI 1.37 - 6.09, p = 0.005) independent of age , BMI, left ventricular function, diabetes mellitus, gender, intervention, hypertension, atrial fibrillation, a previous stroke or TIA and smoking. The risk of stroke increased with the severity of sleep apnea. 40 patients with obstructive sleep apnea were investigated with overnight polysomnography in ambient temperatures of 16°C, 20°C and 24°C in random order. Total sleep time was a mean of 30 minutes longer (p = 0.009), sleep efficiency higher (p = 0.012), patients were more alert in the morning (p = 0.028), but sleep apnea was more severe when sleeping in 16°C (p = 0.001) and 20°C (p = 0.033) vs. 24°C. The AHI was 30 ± 17 in 16ºC room temperature, 28 ± 17 in 20°C and 24 ± 18 in 24°C. Conclusions: Snoring and witnessed sleep apneas are related to diabetes mellitus in women. Sleepy men who snore or report sleep apnea drive more than others. Sleep apnea is independently associated with the risk of stroke among patients with coronary artery disease. Subjects with obstructive sleep apnea sleep longer, are more alert in the morning after a night’s sleep, but sleep apnea is more severe when sleeping in a colder environment.
472

The effect of four reduced-fat diets varying in glycaemic index, glycaemic load, carbohydrate and protein, on weight loss, body composition and cardiovascular disease risk factors.

Price, Joanna McMillan January 2006 (has links)
Doctor of Philosophy (PhD) / Introduction: The conventional approach to weight loss, recommended by almost all health authorities around the world, has been to reduce the total amount of fat in the diet and replace with carbohydrates. However, research trials using this approach have produced only modest results at best, and despite the active promotion of low fat eating and an apparent decline in fat consumption, rates of overweight and obesity have continued to climb. More recently low glycaemic index (GI) and high protein diets have become popular and are widely used by the public. However, only a small number of randomised controlled trials have been conducted and none directly comparing the two. Both approaches effectively reduce glycaemic load (GL) and aim to reduce post-prandial glycaemia and insulinaemia. This study aimed to evaluate the ability of diets with reduced GL to enhance the weight loss effects of a reduced-fat diet, to compare the two approaches of reducing GL on metabolic and anthropometric changes, and to investigate any benefit of combining both approaches to produce the lowest GL. Methods: We conducted a 12-week intervention in 129 overweight or obese young adults who were assigned to one of four diets with varying GL, protein, carbohydrate and GI, but similar fat (30% energy), fat type and fibre content. DIET 1 (highest GL) contained 55% E as carbohydrate; DIET 2 was a low-GI version of DIET 1; DIET 3 was a high protein diet with 25% E as protein; DIET 4 (lowest GL) was a low-GI version of DIET 3. The increase in protein in DIETS 3 and 4 came primarily from lean red meat. All key foods and some pre-prepared frozen meals were provided to maximise dietary compliance. Outcome measures were body weight, body fat, lean mass, waist circumference and the following blood parameters: total cholesterol, LDL-cholesterol, HDL-cholesterol, triacylglycerols (TAG), free fatty acids, C-reactive protein, fasting insulin, fasting glucose and leptin. Insulin resistance and β-cell function were assessed using homeostatic model assessment (HOMA) and the newer computer models HOMA2-insulin sensitivity and HOMA2-β-cell function. Results: While all groups lost similar amounts of weight (4.2 to 6.2% of initial weight, p=0.09), the proportion who lost >5% of body weight varied significantly by diet: 31%, 56%, 66% and 33% in groups 1, 2, 3 and 4 respectively (p=0.011). Differences were strongest in women (76% of the total group) who showed significant differences among groups in percentage weight change (-3.7 ± 0.6%, -5.7 ± 0.6%, -6.5 ± 0.5%, -4.1 ± 0.7% respectively, p=0.005) and fat loss (-3.1 ± 0.4kg, -4.9 ± 0.6kg, -4.8 ± 0.4kg, -3.6 ± 0.7kg respectively, p=0.007). Total and LDL-cholesterol increased on DIET 3 (high protein) compared to a fall on diet 2 (high carbohydrate/low-GI, p=0.013). TAG, HDL-cholesterol and glucose homeostasis improved on all four diets, with no effect of diet composition. Goals for energy distribution were not achieved exactly: both carbohydrate groups ate less fat and the diet 2 group ate more fibre. Conclusions: Reducing GL, through either substituting low-GI foods or replacing some carbohydrate with protein, improved the efficacy of a reduced-fat diet in women and in those with high TAG. Combining both approaches to produce the lowest GL did not promote further weight or body fat loss. Although weight loss was similar in all four diets for the group as a whole, overall clinical outcomes were superior on the high carbohydrate, low-GI diet.
473

Kurunpa [Spirit]: Exploring the Psychosocial Determinants of Coronary Heart Disease among Indigenous men in Central Australia

Alexander Brown Unknown Date (has links)
The life expectancy (LE) gap experienced by Aboriginal and Torres Strait Islander peoples in one of Australians most enduring health divides. Whilst there are many likely reasons, cardiovascular diseases (CVD) stand as the primary contributor. In particular, it is the almost ten-fold higher mortality from CVD at young ages that distinguishes this epidemic. The reasons for this disparity remain incompletely understood. Current research has focused on the likely contribution of traditional risk factor burdens in Aboriginal people, who demonstrate higher levels of smoking, obesity, hypertension and dyslipidaemia. Less attention has focused on the potential contribution of disadvantage and its interplay with psychosocial factors. Research on the psychosocial determinants of health, particularly in relation to CVD, has a long pedigree. Social context, particularly inequality between individuals, has assumed its rightful place at the forefront of our understandings of population levels of disease. Among them, socioeconomic position [SEP] and depression are the most robust, and most widely researched. They have not been adequately explored in the context of Aboriginal Australians, nor has the manner in which culture shapes, sustains or transforms disadvantage and psychosocial stress been outlined. The objective of the Men Hearts and Minds (MHM) Study was to identify the possible ways in which social disadvantage may lead to CVD in Aboriginal men in Central Australia and consider the role of psychosocial factors in modifying or mediating this relationship. This required a detailed and multi-disciplinary plan of research, covering the epidemiology of mental illness and chronic diseases, biomedical science, ethnographic field work and qualitative methodologies. Stage I required the development of measurement tools for exploring depression, stress, resilience, mastery and socioeconomic indicators that were valid and robust for use with Aboriginal men within Central Australia. This involved multi-stage qualitative techniques, engaging Aboriginal men, traditional healers (Ngangkari Tjuta) and mental health experts, to define the expressions and construction of mental illness in Aboriginal men. Depression existed, was recognizable, common, and had profound impacts on the social, emotional and physical well-being of Aboriginal men. ‘Worry’ was the most recognisable element, and the principle contributor to depression in Aboriginal men. Much of this was focused on the increasingly heavy and cumulative social and cultural burdens experienced throughout Aboriginal men’s lives, and manifest as a sense of inner turmoil and questioning of self, and of feelings of disconnectedness from all the things of critical importance within their lives. Kurunpa [spirit] was seen as the foundation of vitality and was critical to the physical, emotional and spiritual well-being of Aboriginal people. These findings were then used to interrogate existing psychological testing tools and develop novel measures to explore the interplay of SEP, stress and depression. These tools were then used in a community dwelling sample of Aboriginal men in Central Australia to explore the interaction of SEP, stress and depression and their potential contribution to CVD risk. In total 186 Aboriginal men across urban and remote community settings were assessed. Almost 40% of the sample had elevated depressive symptoms. Depression was highly correlated with standard measures of distress and inversely with mastery. Newly created measures, assessing Chronic Stress, the ‘Sense of Injury’ and deprivation, were highly correlated, reliable and fulfilled many validity criteria. There was a high level of cardiovascular risk, which was related to a number of psychosocial factors, particularly depression. Major depression was over 9 times as common in individuals with prevalent CVD. Cardiovascular risk was patterned across social strata, but not evident with the use of routine measures of SEP. Psychosocial factors modified the observed social gradient. In those with high chronic stress, the social gradient in CVD risk gradient was amplified. This pattern was mirrored in those who had been removed or had family forcible removed. Depression was correlated with a number of atherogenic pathways. Smokers were more likely to be depressed, and depression was strongly related to obesity. Individual with high depression scores were more than 20 times more likely to have a Body Mass Index >30. The interplay between the Autonomic Nervous System (ANS) (estimated with measures of Heart Rate Variability) and the Hypothalamic Pituitary Adrenal (HPA) axis (as measured according to obesity) highlights the interconnections across atherogenic pathways and may frame the cardiometabolic risk and psychosocial pathways to cardiovascular disease in this sample. The phenomenology of cumulative stress, distress and depression within the narratives of Aboriginal men constructed illness as a consequence of the ongoing fight to maintain balance - physically, emotionally and spiritually. From both a social and biological perspective, the construction of depression and heart disease as a consequence of cumulative chronic stress among Aboriginal men was supported in the findings of this work.
474

Vitamin E and atherosclerosis : investigation of novel biological activities and metabolism of gamma-tocopherol in humans

Wu, Jason H. Y January 2006 (has links)
[Truncated abstract] Current understanding of atherosclerosis suggests that it is a chronic inflammatory disease, and that increased oxidative stress may be an important pathological event contributing to the disease process. There has been interest in the ability of dietary derived nutrients such as vitamin E, to act as antioxidants and protect against atherosclerosis. Despite promising epidemiological data which suggested benefits from a higher intake of &alpha-tocopherol (&alphaT), one of the major forms of dietary vitamin E, for protection against atherosclerosis, large scale, randomised controlled trials have generally shown no protective effect of high dose &alphaT supplementation. Recent studies suggest that the other major dietary tocopherol isomer, &gamma-tocopherol (&gammaT), may possess biological activities not shared by &alphaT. Supplementation with &gammaT, or mixtures of tocopherols rich in &gammaT, have shown biological activities that may help protect against atherosclerosis. The aim of this PhD project is to further characterise the biological relevance of ?T for protection against CVD... Both ?- and mixed tocopherol supplementation resulted in reduced plasma F2-isoprostanes (P < 0.001 and P = 0.001, respectively) but did not affect 24 hour urinary F2-isoprostanes and erythrocyte antioxidant enzyme activities. Neither &alphaT nor mixed tocopherol supplementation affected any measured plasma markers of inflammation. The tocopherol supplementation also did not affect COX-2 activity as assessed by 14 stimulated whole blood prostaglandin E2 synthesis, and urinary prostacyclin metabolite output. Compared to the placebo group, stimulated neutrophil leukotriene B4 (LTB4) production decreased significantly in the mixed tocopherol group (P=0.02) but not in the &alphaT group (P=0.15). The ability of both pure &alphaT and mixed tocopherol supplementation to reduce systemic lipid peroxidation in patients with type 2 diabetes, suggests potential benefits of vitamin E supplementation in this population. However, despite decreasing oxidative stress, our results also suggests that in populations with well controlled type 2 diabetes, supplementation with either &alphaT, or mixed tocopherol rich in &gammaT, is unlikely to confer further benefits in reducing systemic inflammation. Future research into the possible unique biological activity of different tocopherol isomers other than &alphaT, for example, their ability to affect the 5-LO pathway and production of inflammatory mediators such as LTB4, is warranted.
475

Coenzyme Q10 for statin-induced myopathy : a systematic review

Pietersen, Lauren 12 1900 (has links)
Thesis (MNutrition (ITE))--Stellenbosch University, 2012. / ENGLISH ABSTRACT: Background Statins are drugs of known efficacy in the treatment of hypercholesterolaemia. However, statin-induced myopathy, an adverse effect of statins in up to 15% of its users, has warranted a reduction in the prescription dose or discontinuation of the drug. The exact mechanism of statin-induced myopathy is unknown, but the potential of Coenzyme Q10 (CoQ10) as treatment has been recognized due to decreased human plasma CoQ10 levels found after statin use and the concomitant role of CoQ10 in muscle function. Objectives This systematic review assessed the effect of CoQ10 supplementation on: the severity of statin-induced myopathic symptoms, levels of plasma creatine kinase, intramuscular and plasma CoQ10, as well as whether any adverse effects of CoQ10 supplementation such as abdominal pain, nausea and vomiting or headaches were experienced. Search methods Two searches for studies were conducted in The Cochrane Central Register of Controlled Trials (inception to March 2011 and inception to November 2011), MEDLINE (inception to March 2011 and inception to November 2011), Web of Science (inception to March 2011 and inception to November 2011), Science Direct (inception to March 2011 and inception to February 2012), Wiley Online Library (inception to March 2011 and inception to February 2012), Springerlink (inception to April 2011 and inception to February 2012), EBSCOhost [Academic Search Premier and CAB abstracts (inception to March 2011 and inception to February 2012), CINAHL (inception to March 2011 and inception to November 2011)], Scopus (inception to March 2011 and inception to November 2011) and Google Scholar (inception to March 2011 and inception to February 2012). Reference lists of articles were hand searched for relevant clinical trials. Only trials with a full text were included in the review. Selection criteria Randomised controlled trials (RCTs) were included with adult participants (mean of 18-64.99 years) of all race/ethnic groups and gender on statin therapy with reported myopathic symptoms from an unknown cause. The intervention was in the form of a pure oral supplement of CoQ10 irrespective of dose, duration and frequency, and the control in the form of a placebo, a similar antioxidant, or no intervention. Outcomes included the severity of myopathic symptoms, levels of plasma creatine kinase (U/L), intramuscular CoQ10 (μmol/kg) and plasma CoQ10 (μmol/L), as well as adverse effects of CoQ10. Data collection and analysis The principle investigator and one independent reviewer selected the studies, extracted data and assessed for risk of bias using the Cochrane Collaboration‘s tool for assessing risk of bias. Authors of relevant clinical trials were contacted for additional information. Results Two RCTs were included in the review, totaling 76 participants. A meta-analysis could not be performed, thus the review is narrative. There were an insufficient number of RCTs to confirm whether routine supplementation of CoQ10 improves statin-induced myopathic symptoms. Conclusions More and larger RCTs are required to determine the efficacy of CoQ10 supplementation in statin-induced myopathy. Consensus needs to be reached regarding the definition and measurement instrument/s of myopathy so that results of future studies can easily be compared and synthesized. / AFRIKAANSE OPSOMMING: Agtergrond Statiene is medikasie bekend vir die effektiewe behandeling van hipercholesterolemie. Statien-geïnduseerde miopatie is egter 'n newe-effek wat voorkom in tot 15% van gebruikers, wat 'n vermindering in die voorgeskrewe dosis of staking van die medikasie tot gevolg het. Die presiese meganisme van statien-geïnduseerde miopatie is onbekend, maar die potensiaal van Koënsiem Q10 (CoQ10) is geïdentifiseer as 'n moontlike behandeling aangesien menslike plasma CoQ10 vlakke verlaag na die gebruik van statiene en as gevolg van die rol van CoQ10 in spierfunksie. Doelwitte Hierdie sistematiese literatuuroorsig het die effek van CoQ10 supplementasie bepaal op: die graad van statien-geïnduseerde miopatiese simptome, plasma kreatien kinase vlakke, intra-muskulêre en plasma CoQ10 vlakke, asook die teenwoordigheid van enige newe-effekte van CoQ10 supplementasie soos abdominale pyn, naarheid en braking of hoofpyne. Soektogstrategie Twee soektogte vir studies is uitgevoer in The Cochrane Central Register of Controlled Trials (ontstaan tot Maart 2011 en ontstaan tot November 2011), MEDLINE (ontstaan tot Maart 2011 en ontstaan tot November 2011), Web of Science (ontstaan tot Maart 2011 en ontstaan tot November 2011), Science Direct (ontstaan tot Maart 2011 en ontstaan tot Februarie 2012), Wiley Online Library (ontstaan tot Maart 2011 en ontstaan tot Februarie 2012), Springerlink (ontstaan tot April 2011 en ontstaan tot Februarie 2012), EBSCOhost [Academic Search Premier en CAB abstracts (ontstaan tot Maart 2011 en ontstaan tot Februarie 2012), CINAHL (ontstaan tot Maart 2011 en ontstaan tot November 2011)], Scopus (ontstaan tot Maart 2011 en ontstaan tot November 2011) en Google Scholar (ontstaan tot Maart 2011 en ontstaan tot Februarie 2012). Verwysingslyste van artikels is ook met die hand nagegaan vir relevante kliniese proewe. Slegs kliniese proewe waarvan die volteks beskikbaar was, is ingesluit in die oorsig. Seleksiekriteria Ewekansige gekontroleerde proewe (EGP) is ingesluit met volwasse deelnemers (gemiddeld 18-64.99 jaar) van alle rasse/etniese groepe en geslag op statien-terapie met gerapporteerde miopatie simptome van onbekende oorsaak. Die intervensie was 'n suiwer orale supplement van CoQ10 ongeag die dosis, duurte en frekwensie, en die kontrole 'n plasebo, soortgelyke antioksidant, of geen intervensie. Uitkomste het ingesluit: die graad van miopatie simptome, vlakke van plasma kreatien kinase (U/L), intra-muskulêre CoQ10 (μmol/kg) en plasma CoQ10 (μmol/L), sowel as newe-effekte van CoQ10. Dataversameling en -analise Die hoof ondersoeker en een onafhanklike hersiener het die seleksie van studies en data-ekstraksie onderneem en die risiko vir sydigheid geassesseer deur gebruik te maak van die Cochrane Collaboration’s tool for assessing risk of bias. Outeurs van relevante kliniese proewe is geraadpleeg vir addisionele inligting Resultate Twee EGP is ingesluit in die oorsig met 'n totaal van 76 deelnemers. 'n Meta-analise kon nie uitgevoer word nie, dus is die oorsig beskrywend. Daar was te min EGP om te bewys dat roetine supplementasie van CoQ10 statien-geïnduseerde miopatiese simptome verbeter. Gevolgtrekkings Meer en groter EGP is nodig om die effektiwiteit van CoQ10 supplementasie in statien-geïnduseerde miopatie te bepaal. Konsensus moet bereik word ten opsigte van die definisie en metingsinstrument/e van miopatie sodat die resultate van toekomstige studies makliker vergelyk en verwerk kan word.
476

Levels of serum uric acid and risk of myocardial infarction among gout patients

Abdussamad, Abdalla Ali 22 January 2016 (has links)
OBJECTIVE: Our aim in this study to determine if serum uric acid level measured at baseline is a risk factor to develop Myocardial Infarction among people diagnosed with gout. METHOD: This was a retrospective cohort study, which used the THIN (The Health Improvement Network), an electronic medical records database from the UK. Obtained were SUA level at baseline after gout diagnosis and follow-up till time of event. We performed Cox proportional hazard regression models to examine the relation of SUA levels to risk of incident MI for men and women separately, and the multivariable regression model. RESULTS: There were 12,180 individuals included in this study, of them, 70% (n=8539) were men. There were 200 events of MI, 145 in men and 55 in women. SUA were not associated with risk of MI in unadjusted and adjusted multivariable regression model, the crude HR of MI in men were 1.27 (95% CI: 0.70-2.30), 0.97 (95% CI: 0.56-1.69), 0.83 (95% CI: 0.47-1.46), and 1.07 (95% CI: 0.62-1.84), respectively, for each increased SUA categories. No change observed after full adjustment. Similar results were also observed in women. CONCLUSION: There is no association between baseline SUA and risk of MI among gout patients.
477

Exercise in haemodialysis patients : impact on markers of inflammation

Dungey, Maurice January 2015 (has links)
End-stage renal disease patients have a greatly increased risk of cardiovascular disease partly attributed to the elevated levels of systemic inflammation observed in uraemia. One of the key mechanisms underlying inflammation appears to be the immune dysfunction that afflicts almost every aspect of the uraemic immune system. As a consequence patients experience immunosuppression and reduced responsiveness to antigen as well as a simultaneous over-activation leading to a pro-inflammatory environment. In addition, the haemodialysis (HD) treatment itself induces a proinflammatory response but may provide an otherwise opportune time to complete supervised exercise.
478

Cardiovascular disease, type 2 diabetes and carotid ultrasound

Robertson, Christine Mary January 2015 (has links)
Cardiovascular disease contributes significantly to global morbidity and mortality and is particularly prevalent among individuals with Type 2 diabetes, which is thought to in part be due to the association between diabetes and the metabolic syndrome. Traditional cardiovascular risk prediction scores perform well in the general population but their use in people with Type 2 diabetes is limited as they are thought to underperform in high risk groups. Indeed, the use of any risk prediction in people with Type 2 diabetes is a point of discussion among clinicians as people with diabetes are thought by some to be at immediate high risk of CVD, whereas others view them as having a degree of modifiable risk which can be addressed using risk prediction. In the general population, novel markers such as cIMT and carotid plaque, as well as other potential biomarkers of cardiovascular risk, have been explored as possible adjuncts to risk scores in the prediction of cardiovascular disease. The evidence for their use in general populations has been established, although there have been no firm conclusions with regard to recommendations for their use, which is partly due to the high degree of variability in cIMT measurement. However, the evidence for their use in people with Type 2 diabetes is sparse, despite the use of such markers as surrogate CV endpoints in clinical trials. This thesis aimed to describe the frequency, distribution and change of cIMT and carotid plaque, as well as to explore the relationship of cIMT and carotid plaque with cardiovascular risk factors, prevalent cardiovascular disease and future cardiovascular events in older people with Type 2 diabetes. The association between cIMT, carotid plaque and other novel risk markers was also explored. The analysis was performed using data from the Edinburgh Type 2 Diabetes Study (ET2DS). This study is a large, prospective cohort study of 1066 men and women with Type 2 diabetes, aged 60-75 years at recruitment, living in Edinburgh and the Lothians. cIMT and carotid plaque were measured at year 1 follow up of the study. Variables concerning cardiovascular risk factors used in this thesis were obtained from the data collection performed at baseline and year 1. A mean of 3.5 years of follow up was available for analysis and is complete for the baseline cohort as data linkage was performed. Mean values of cIMT in the ET2DS were comparable with other studies of cIMT in people with Type 2 diabetes and may indeed be higher than cIMT in the general population. Measurement of cIMT by the sonographer was comparable with computer aided measurements. Increasing cIMT was independently associated (although only modestly) with increasing age, male sex and raised systolic blood pressure. Mean cIMT was associated with prevalent vascular disease and was predictive of incident global cardiovascular events and coronary artery events (but not stroke) over and above UKPDS risk factors, although the clinical impact of this on the reclassification of vascular risk (as demonstrated by net reclassification index (NRI)) was limited. There was a high prevalence of carotid plaque, and in particular “high risk” plaque, in the ET2DS. Different measures of carotid plaque were independently associated with several cardiovascular risk factors. Carotid plaque thickness was independently associated, albeit modestly, with increasing age, male sex, duration of diabetes and hypertension, plaque score with increasing age, hypertension, smoking and low BMI, and high risk plaque with hypertension and low BMI. All measures of carotid plaque were associated with prevalent vascular disease. However, despite these associations, carotid plaque did not have any additional predictive value for incident cardiovascular events over and above UKPDS risk factors. Finally, measures of cIMT and carotid plaque in the ET2DS were associated with the biomarkers ankle brachial index (ABI) and NTproBNP. In addition these markers were significantly higher in those individuals with prevalent vascular disease, suggesting a more extensive exploration of the association of these markers in relation to cardiovascular disease in the ET2DS may be warranted. cIMT and carotid plaque are modestly associated with traditional cardiovascular risk factors and prevalent cardiovascular disease in older adults with Type 2 diabetes. cIMT has been shown to be predictive of incident events while carotid plaque was not, in people with Type 2 diabetes, over and above traditional cardiovascular risk factors, although its impact on risk reclassification may only be small. Further evidence is required from the longer follow up of the ET2DS before firm conclusions can be drawn on the usefulness of cIMT and carotid plaque as risk markers in people with Type 2 diabetes. In addition, large collaborative studies could be used to further explore the relationship of carotid plaque, and change in cIMT with incident cardiovascular events, as well as exploring the additive effect of cIMT and plaque on risk prediction.
479

Efeito agudo da ingestão de álcool sobre a função endotelial em homens jovens / Acute effect of alcohol on endothelial function in young males

Bau, Paulo Fernando Dotto January 2004 (has links)
A disfunção endotelial, avaliada através da vasodilatação mediada pelo fluxo (FMD) e não mediada pelo fluxo (NFMD), está associada à ocorrência de eventos cardiovasculares. Enquanto o consumo moderado de bebidas alcoólicas está associado com baixo risco para doenças cardiovasculares, a ingestão de doses mais altas predispõe a arritmias cardíacas, acidente vascular encefálico e outros eventos, que têm maior incidência no período da manhã. A investigação dos efeitos do álcool sobre a função endotelial pode trazer um melhor entendimento para esta associação. O presente estudo tem por objetivo avaliar, em uma amostra homogênea, o efeito de uma dose relativamente elevada de álcool sobre parâmetros vasculares e de função endotelial. O diâmetro da artéria braquial (DAB), a FMD e a NFMD foram mensurados em três horários (17h, 22h e 7h), em 100 indivíduos do sexo masculino, hígidos, com idades entre 18 e 25 anos (média de 20,74 anos), por ecodoppler da artéria braquial (segundo o protocolo da International Brachial Artery Reactivity Task Force). Os indivíduos foram randomizados para ingerir uma bebida contendo álcool ou uma bebida similar não alcoólica, às 18h. O grupo que consumiu álcool apresentou um aumento no DAB entre as 17h (4,03 mm) e 22h (4,41 mm). Ocorreu uma redução da FMD para 2,43% e da NFMD para 6,30% às 22h, quando comparados com os valores anteriores à ingestão (FMD = 4,22% e NFMD = 13,7%). Foi constatado um efeito bifásico para a pressão arterial sistólica (PAS) e diastólica (PAD), com redução às 22h (PAS = 105,18 mmHg; PAD = 60,14 mmHg), seguida de elevação às 7h (PAS = 117,50 mmHg; PAD = 70,98 mmHg). Conclui-se que, após um período inicial de vasodilatação, a ingestão aguda de álcool não afeta a função endotelial, comparado ao placebo. / The endothelial function evaluated by endothelium dependent flow-mediated dilatation (FMD) and endothelium independent nitroglycerin-mediated dilatation (NFMD) is associated to the risk of cardiovascular events. While the moderate consumption of alcoholic beverages is associated with a lower risk of cardiovascular disease, the ingestion of higher doses predispose to cardiac arrhythmias, stroke and other events that have a higher incidence in the morning. The investigation of the effects of alcohol on endothelial function may help to clarify this association. This study aims to evaluate in a homogeneous sample the effect of a relatively high dose of alcohol on vascular and endothelial function parameters. The diameter of brachial artery (DBA), FMD and NFMD were measured in three moments (5 pm, 10 pm and 7 am) in 100 healthy males aged 18 to 25 years (mean of 20.74) by brachial artery ecodoppler (following the International Brachial Artery Reactivity Task Force protocol). Subjects were randomized to drink either an alcohol containing drink or a similar non-alcoholic beverage at 6 pm. The alcohol-drinking group presented a DBA increase between 5 pm (4.03 mm) and 10 pm (4.41 mm). FMD decreased to 2,43% and NFMD to 6,30% at 10 pm from the basal values (FMD = 4.22%; NFMD = 13.7%). Alcohol induced a biphasic effect on systolic (SBP) and diastolic blood pressure (DBP), with a decrease at 10 pm (SBP = 105.18 mmHg; DBP = 60.14 mmHg) followed by an increase at 7 am (SBP = 117.50 mmHg; DBP = 70.98 mmHg). We conclude that after an initial period of vasodilatation, the acute ingestion of alcohol does not affect endothelial function compared to placebo.
480

Aptidão física relacionada à saúde cardiovascular : proposição de pontos de corte para escolares brasileiros

Bergmann, Gabriel Gustavo January 2009 (has links)
As doenças cardiovasculares (DCV) são as principais causas de morte no mundo. Estas doenças se originam e se desenvolvem a partir de uma série de fatores de risco durante os anos da infância e adolescência. Dois componentes da aptidão física relacionada á saúde apresentam associação com estes fatores de risco; a aptidão cardiorrespiratória (ApC) e a composição corporal. Indivíduos jovens com baixos níveis de ApC e níveis elevados do componente de gordura da composição corporal (sobrepeso/obesidade) têm maiores probabilidades de portarem estes fatores de risco. É neste contexto que se insere este estudo, que tem como principais objetivos: 1) identificar a capacidade de triagem de crianças e adolescentes com maior probabilidade de portarem fatores de risco para DCV dos pontos de corte disponíveis na literatura para a ApC e para indicadores antropométricos de sobrepeso e obesidade (IASO), e; b) propor novos pontos de corte para a ApC e IASO de escolares brasileiros de 7 a 12 anos de idade. A amostra do tipo aleatória por conglomerados foi constituída por 1.413 escolares de 7 a 12 anos de idade. A ApC foi medida através do teste de corrida/caminhada de 9 minutos. Os IASO utilizados foram o índice de massa corporal (IMC), o somatório de dobras cutâneas triciptal e subescapular (TRI+SUB) e triciptal e da panturrilha (TRI+PAN), a circunferência da cintura (CC), e o índice de conicidade (IC). O colesterol total (monitor portátil Roche Diagnostics) e as pressões arterial sistólica e diastólica (método auscultatório) foram medidas e através delas foram criadas referências de fatores de risco para DCV. Através da curva Receiver Operating Characteristic (ROC) entre a ApC e os IASO, com as referências de fatores de risco para DCV foram identificados os valores dos pontos de corte que corresponderam ao melhor ajustamento entre sensibilidade e especificidade. A sensibilidade e a especificidade dos pontos de corte disponíveis na literatura e os propostos por nosso estudo foram calculadas a partir de tabelas de contingência com as referências de fatores de risco para DCV. Adicionalmente foi utilizada a regressão logística binária para identificar o quanto os indivíduos que não atenderam aos pontos de corte propostos tinham a mais de probabilidade de apresentar fatores de risco para DCV em relação àqueles que atenderam. Os resultados indicaram que os pontos de corte disponíveis na literatura para a ApC não apresentam bom ajustamento entre sensibilidade e especificidade, não sendo adequados para a avaliação da ApC. Os pontos de corte disponíveis na literatura para os IASO por outro lado, no geral, apresentaram aceitáveis ajustamentos entre sensibilidade e especificidade. Os pontos de corte propostos no presente estudo para ApC e para os IASO mostraram-se adequados para a identificação de escolares com maiores probabilidades de portarem fatores de risco para DCV, com ajustamentos entre sensibilidade e especificidade melhores que os apresentados pelos pontos de corte disponíveis na literatura. Estes resultados ficam reforçados quando as análises da regressão logística binária indicam que a probabilidade de escolares que não atenderam aos pontos de corte propostos em nosso estudo é maior que a probabilidade de escolares que não atenderam aos pontos de corte propostos na literatura de portarem fatores de risco para DCV em relação aos escolares que atenderam aos pontos de corte. Dentre os IASO o IMC e o TRI+SUB foram os que apresentaram melhor capacidade de identificar escolares com maior probabilidade de apresentar fatores de risco para DCV. Contudo, os demais IASO, com exceção do IC, também mostraram adequada capacidade. Frente aos resultados encontrados ficam evidências de que indivíduos com baixos valores de ApC e elevados de IASO possuem maior probabilidade de apresentar fatores de risco para DCV em comparação com aqueles com valores mais apropriados. Além disto, os pontos de corte propostos pelo presente estudo mostraram-se mais adequados que àqueles disponíveis na literatura para a identificação de escolares com maior probabilidade de portarem fatores de risco para DCV. Desta forma, sugerimos as medidas de ApC pela corrida/caminhada de nove minutos e dos IASO estudados, com exceção do IC, e a avaliação pelos pontos de corte propostos no presente estudo para triagem de escolares com risco aumentado para apresentarem fatores de risco para DCV. / The cardiovascular diseases (CVD) are the mainly death cause in the world. These diseases begin and development during childhood and adolescent years by a serial of risk factors. Two components of health related physical fitness show association with these risk factors; cardiorespiratory fitness (CF) end body composition. Young individuals with low level of CF and high level of fat component of body composition (overweight/obesity) have more probability to carry on these risk factors. The aims of this study are: 1) to identify the sort capacity of children and adolescents with more probability to carry on the CVD risk factors of the CF and overweight/obesity anthropometric indicators (OOAI) cut offs available at literature, end; b) to propose new cut offs to CF and OOAI of brazilian scholars of 7 to 12 years old. The sample was compound for 1.413 scholars of 07 to 12 years old, selected of aleatory by conglomerated way. The CF was measured by the 9 minutes run/walk test. The OOAI utilized were the body mass index (BMI), the sum of triciptal and subescapular skinfold (TRI+SUB) and triciptal and calf (TRI+CAL), waist circumference (WC), and conicity index (CI). The total cholesterol (portable monitor Roche Diagnostics) and systolic and diastolic blood pressure (auscultation method) were measured and were created CVD risk factors references. By the Receiver Operating Characteristic curve between CF and the OOAI, with the CVD risk factors references were identified the cut offs values that correspond to the best balance between sensibility and specificity. The sensibility and specificity of the cut offs available at literature ant those proposed by our study were calculated by contingency tables with the CVD risk factors references. Supplementary was utilized the binary logistic regression to identify how the individual that did not attend the cut offs had more probability to show CVD risk factors than those individuals that did. The results indicated that the CF cut off's available at literature do not show good balance between sensibility and specificity. The OOAI literature available CUT off's by other side, in general, showed acceptable balance between sensibility and specificity. The cut offs proposed at present study for CF and OOAI showed appropriated values to identify scholars with more probability to carry on CVD risk factors with best balance between sensibility and specificity than those showed by cut offs available at literature. These results get reinforced when the binary logistic regression results indicate that the probability of scholars that did not attend the cut offs proposed in the our study is greater than the probability of scholars that did not attend to literature available cut off's to carry on CVD risk factors in relation those scholars that attended the cut offs Among the OOAI the BMI and the TRI+SUB were those that showed the best capacity to identify scholars with greater probability to carry on CVD risk factors. However, the others OOAI, exception CI, show adequate capacity too. These results show that individuals with poor level of CF and great level of OOAI have more probability to carry on CVD risk factors than those individuals with appropriated levels. Besides, the cut offs proposed at our study showed to be more appropriated than those available in the literature to identify scholars with more probability to carry on CVD risk factors. Thus, we suggest the CF by 9 minutes run/walk test and OOAI measured studied, exception CI, and the evaluation by the cut offs proposed at the present study to the sorting of the scholars with more probability to carry on CVD risk factors.

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