INTRODUÇÃO: A Hipersensibilidade do seio carotídeo (HSC) é a exacerbação do reflexo normal e foi definida como ocorrência de pausa ventricular 3 segundos ou redução da pressão arterial sistólica (PAS) 50 mmHg em resposta à massagem do seio carotídeo (MSC). Fenômeno relacionado à idade, raramente diagnosticado em pacientes com menos de 50 anos, tem recebido especial atenção como causa de síncope e quedas inexplicadas nos idosos, nas últimas décadas, com relatos de taxas de prevalências superiores a 45%. Entretanto, ainda não estão claras as implicações diagnósticas da HSC na síncope, com resultados controversos na literatura. OBJETIVOS: Determinar a prevalência da HSC em pacientes com sintomas de síncope e pré-síncope e comparar com indivíduos assintomáticos. Correlacionar a resposta à MSC com a rigidez aórtica e os parâmetros anatômicos e funcionais carotídeos. MÉTODOS: Foram avaliados em estudo prospectivo 99 pcts sintomáticos, com síncope ou pré-síncope a esclarecer (idade média de 69 anos, 41,4% homens), e 66 pcts assintomáticos para controle (idade média de 73 anos, 34,8% homens). Excluíram-se pacientes com cardiopatia estrutural ou com contraindicações para MSC. A MSC foi realizada no ponto com maior impulsão carotídea por 5 segundos, com o registro contínuo e não invasivo da pressão arterial (PA) e eletrocardiograma, com o paciente em postura ortostática a 70º. Foram consideradas respostas anormais: cardioinibitória (CI): assistolia 3 segundos e vasodepressora (VD): redução da PAS 50 mmHg. O índice da rigidez arterial foi obtido por meio de medida da velocidade de onda de pulso carotídeo-femoral (VOP). As características anatômicas e funcionais da carótida foram determinadas por medidas de diâmetro, espessura íntima-média carotídea (EIMC) e índice de distensibilidade. RESULTADOS: Não foram constatadas diferenças nas respostas obtidas na MSC entre os grupos, com 67,7% e 60,6% de respostas fisiológicas; 24,2% e 25,8% de respostas CI; 8,1% e 13,6% de respostas VD em grupo sintomáticos e assintomáticos, respectivamente (p=0,466). Não foram observadas correlações entre a resposta à MSC, tanto com a VOP como com a EMIC, a distensibilidade e o diâmetro carotídeo. CONCLUSÕES: 1- A prevalência de HSC e resposta hemodinâmica à MSC em pacientes com sintomas de síncope e pré-síncope foram semelhantes a pacientes assintomáticos provenientes da mesma instituição, com características clínicas semelhantes. 2- Não foi observada correlação significativa entre a rigidez arterial, medida por meio da VOP, EIMC, distensibilidade e diâmetro carotídeo e a resposta à MSC / The carotid sinus hypersensitivity (CSH) is the exaggeration of the normal reflex and was defined by occurrence of asystole 3 seconds or fall in systolic BP 50 mmHg in response to carotid sinus massage (CSM). Phenomenon related to age, rarely diagnosed in patients younger than 50 years, has gained importance as a cause of syncope and unexplained falls in the elderly in recent decades with reported prevalence rates above 45%. However, the correlation between CSH and syncope etiology is still controversial. OBJECTIVE: To determine the prevalence of CSH in patients with syncope and near syncope of unknown origin and compare with asymptomatic individuals; to evaluate the correlation between CSM responses and arterial stiffness. METHODS: We studied prospectively 99 symptomatic pts with syncope or near syncope (mean age 69 years, 41.4% men) and 66 asymptomatic controls (mean age 73 years, 34.8% men). Patients with significant structural heart disease or with contraindications to CSM were excluded. The CSM was performed at the point with maximal carotid pulsation, for 5 seconds with continuous and noninvasive blood pressure and electrocardiogram recording at 70° in upright posture. Were considered abnormal responses: cardioinhibitory (CI): asystole 3 seconds and vasodepressor (VD): decrease in systolic BP 50 mmHg. The aortic stiffness was determined by aortic pulse wave velocity (PWV). The anatomical and functional characteristics of the carotid were determined by measurements of diameter, intima-media thickness (IMT) and distensibility index. RESULTS: There were no differences in the responses obtained in the CSM between the groups, being 67.7 % and 60.6% physiological responses, 24.2% and 25.8% CI responses and 8.1% and 13.6% VD responses in symptomatic and asymptomatic groups, respectively (p=0.466). There were no correlations between response to the CSM with VOP, IMT, carotid diameter and distensibility. CONCLUSIONS: The prevalence of CSH in patients with symptoms of syncope and near syncope was similar to asymptomatic patients from the same institution with similar clinical characteristics. There was no significant correlation between arterial stiffness, measured by PWV, IMT, carotid diameter and distensibility with the response to CSM

Alterações das propriedades funcionais e estruturais de grandes artérias são correlacionadas à maior risco cardiovascular em diferentes populações. Recentes diretrizes europeias e brasileiras de hipertensão arterial incluem avaliações da espessura íntima medial (EIM) de carótida e da velocidade de onda de pulso (VOP) aórtica como métodos para avaliação de doença subclínica do paciente hipertenso. Estabelecer valores de referência dos métodos de avaliação da estrutura e da função arteriais e os principais determinantes clínicos e demográficos dos parâmetros obtidos com estes métodos, além de suas correlações, em indivíduos adultos saudáveis, é importante para melhor estratificação dos pacientes. Os objetivos do estudo foram avaliar em indivíduos adultos saudáveis: 1. a distribuição dos valores de VOP aórtica e do diâmetro, da espessura íntima medial e da distensão relativa da artéria carótida, para definir parâmetros de referência. 2. os principais determinantes demográficos e clínicos destes parâmetros e suas correlações.Foram avaliados 210 indivíduos (54% mulheres, idade média 44±13anos) sem história ou evidência de doença cardiovascular atual. A pressão arterial (PA) foi aferida por aparelho automático Omron (HEM 705 CP) com o indivíduo sentado. A medida automática da VOP carótida-femural foi feita pelo aparelho Complior®. As propriedades funcionais e estruturais da carótida (distensão, diâmetro e EIM) foram avaliadas por ultrassom de radiofrequência (WTS®). Todos os indivíduos realizaram avaliação bioquímica.As médias dos valores foram: VOP aórtica (m/s) = 8,7±1,5, diâmetro da carótida (m) = 6617±985, EIM da carótida (m) = 601±131 e distensão relativa da carótida (%) = 5,3±2,1. Não houve diferenças significativas nos parâmetros entre homens e mulheres, assim como entre as raças. Na análise multivariada, os fatores independentemente relacionados aos parâmetros vasculares foram: VOP aórtica = idade (r2 0,22/ p < 0,01), EIM da carótida = idade (r2 0,17 / p < 0,01), diâmetro da carótida = creatinina (r2 0,16 / p = 0,02), distensão relativa da carótida = idade (r2 0,37 / p < 0,01) e pressão arterial diastólica PAD - (r2 0,09 / p < 0,01). Observamos que a VOP teve correlação positiva com EIM (r² - 0,06 / p < 0,01), e correlação inversa com a distensão relativa da carótida (r² - 0,08 / p < 0,01). Em conclusão, em indivíduos saudáveis o principal fator relacionado à medida da rigidez aórtica é a idade, enquanto que a idade e a PAD foram relacionados com a medida funcional da carótida, e o nível de creatinina relacionado ao diâmetro. A estrutura da artéria carótida é diretamente relacionada à medida da rigidez aórtica, que por sua vez é inversamente relacionada à capacidade funcional da artéria carótida / Changes of structural and functional properties of large arteries are correlated with increased cardiovascular risk in different populations. Recent European and Brazilian guidelines for hypertension include assessment of carotid intima-media thickness (IMT) and aortic pulse wave velocity (PWV) for evaluation of subclinical disease in hypertensive patients. Thus, to establish reference values for methods that evaluate arterial properties and the main clinical and demographic determinants of the parameters obtained with these methods, as well as their correlation in healthy adult subjects, it is important for better stratification of patients. The objectives of the study were to evaluate in healthy adult subjects: 1. the distribution of aortic PWV values and of the diameter, intima-media thickness and distension of the carotid artery to obtain reference parameters. 2. the main demographic and clinical determinants of these parameters and their correlations. We evaluated 210 subjects (54% women, mean age 44 ± 13anos) with no history or current evidence of cardiovascular disease. Blood pressure (BP) was measured by automatic device Omron (HEM 705 CP) with the subject in a sitting position. The automatic measurement of carotid-femoral PWV was performed by Complior® device. The functional and structural properties of the carotid artery (distension, diameter and IMT) were assessed by ultrasound radiofrequency (WTS®). All subjects underwent biochemical evaluation. The mean values were: aortic PWV (m / s) = 8.7±1.5, carotid diameter (m) = 6617±985, carotid IMT (m) = 601±131 and distension on carotid (% ) = 5.3±2.1. There were no significant differences in parameters according gender or race. In multivariate analysis, the independent factors related to arterial parameters were: aortic PWV = age (r2 - 0.22 / p -< 0.01), carotid IMT = age (r2 - 0.17 / p <0.01 ), carotid diameter = creatinine (r2 - 0.16 / p = 0.02), carotid distension = age (r2 - 0.37 / p < 0.01) and diastolic blood pressure - DBP - (r2 - 0.09 / p< 0.01). We also found that aortic PWV was positively correlated with IMT (r² - 0.06 / p < 0.01) and inversely correlated with the relative distension of the carotid (r² - 0.08 / p < 0.01). In conclusion, in healthy subjects the main factor related to aortic stiffness is age, whereas age and DBP were related to functional measurement of the carotid artery, and creatinine levels related to the diameter. The structure of the carotid artery is directly related to the aortic stiffness, which in turn is inversely related to the functional capacity of the carotid artery.

No description available.

Bakgrund: Ateroskleros är en känd bakomliggande orsak till hjärt-och kärlsjukdomar. Progressionen av ateroskleros är en långsam process som börjar redan i unga år. En accepterad subklinisk markör för utvecklingen av ateroskleros är carotis intima-media tjockleken. Syfte: Syftet med studien var att undersöka om det föreligger en statistisk signifikant skillnad på carotis intima-media tjockleken mellan unga kvinnor och män utan någon känd kardiovaskulär riskfaktor. Metod: I studien undersöktes 38 friska studiedeltagare med medelåldern 24,5 år. Carotis intima-media tjockleken undersöktes med ultraljud. Resultat: Resultatet påvisade ingen statistisk signifikant skillnad på carotis intima-media tjockleken mellan unga kvinnor och män. Diskussion: Resultatet kan påverkas av liten provstorlek och för att kunna dra mer generella slutsatser bör en större population undersökas. / Background: Atherosclerosis is a known underlying cause of cardiovascular disease. The progression of atherosclerosis is a slow process that begins at an early age. An accepted subclinical marker for the development of atherosclerosis is carotid intima media thickness. Purpose: The purpose of the study was to investigate whether there is a statistically significant difference in intima-media thickness in the carotid artery between young women and men without any known cardiovascular risk factor. Method: The study examined 38 healthy participants with a mean age of 24.5 years. Carotid intima-media thickness was measured by ultrasound. Results: The results showed no statistically significant difference in carotid intima-media thickness between young women and men. Discussion: The result can be affected by the small sample size and in order to be able to draw more general conclusions, a larger population should be examined.

This study examined racial/ethnic differences in pre-clinical disease, social support, and tested whether social support was a moderator of racial/ethnic differences in subclinical atherosclerosis. Participants were NHWs, NHBs, and Latinos (n = 283) from the baseline and cross-sectional sample of the North Texas Heart Study. Results from unadjusted models showed no significant racial/ethnic differences for common or bifurcation intima-media thickness (cIMT). However, unadjusted models for cIMT showed a main effect for race/ethnicity F(2, 229) = 3.12, p = .046, partial η2 = .027, with Latinos demonstrating significantly greater internal cIMT compared to NHB but not NHWs. In minimally adjusted models, there was a main effect for race/ethnicity, F(2, 227) = 3.10, p = .047, partial η2 = .027, with significantly greater internal cIMT in Latinos compared to NHBs but not NHWs. In fully adjusted models, racial/ethnic differences in cIMT were attenuated. Contrary to study hypotheses, no racial/ethnic differences in social support were found and social support was not a moderator of racial/ethnic differences in subclinical disease. In the North Texas Heart Study, few racial/ethnic differences emerged, with fully adjusted risk factor models accounting for these differences.

For most children, occult vascular damage is minimal and has a slow rate of progression likely due to the existence of healthy lifestyles and the prevalence of preventative behaviours. However, there is evidence to suggest a marked increase in the prevalence of traditional and emerging cardiovascular risk factors in children with chronic inflammatory conditions due to the common aetiology pathways of inflammation and atherosclerosis. In the current cross-sectional study, a comprehensive vascular assessment was conducted on 21 children with various chronic inflammatory conditions including juvenile idiopathic arthritis (JIA), cystic fibrosis (CF), type I diabetes mellitus (T1DM) and inflammatory bowel disease (IBD) (CIC, 12.7 ± 2.3 years) compared to 9 healthy, age and sex- matched controls (CON, 13.1 ± 1.8 years). B-mode ultrasound images were used to assess carotid artery intima media thickness (cIMT) as well as local arterial stiffness through measurement of compliance and distensibility with the use of concurrent applanation tonometry. Whole-body arterial stiffness was measured by assessing pulse wave velocity (PWV) between the carotid and dorsalis pedis arteries. A brachial flow mediated dilation (FMD) test was implemented to assess endothelial function of the brachial artery. Twelve hour-fasted blood samples were collected and analyzed for blood lipids and an acute inflammatory marker, C-reactive protein (CRP). There were no group differences in cIMT (p=0.18), distensibility (p=0.40), compliance (p=0.88), whole body PWV (p=0.74) or LDL- cholesterol (p=0.99). The CIC group demonstrated significantly lower FMD when iii compared to CON (p=0.01). There were no group differences in inflammatory levels, as indicated by concentration of CRP (p=0.63). Sub-analyses revealed similar cIMT, distensibility, compliance, PWV and LDL levels between children with JIA (n=11, 12.6 ± 2.9 years), CON (n=9, 13.1 ± 1.8 years) and the other inflammatory conditions (INFL, n=10, 12.4 ± 1.7 years). Both JIA and INFL reported lower FMD when compared to CON (p=0.04). INFL had lower BMI compared to JIA and CON (p=0.02). The primary findings from this study suggest that arterial structure is similar between children with a CIC and their healthy peers; however, arterial function, as indicated by FMD (%), was reduced in the CIC group. This finding is essential in that it helps to identify an area for targeted intervention and/or prevention of future CV events as endothelial dysfunction is known to be an early event in the pathophysiology of atherosclerosis. / Thesis / Master of Science (MSc)

Motivation - The burden of cardiovascular diseases (CVD) is increasing in developing countries worldwide, but even more so in sub-Saharan Africa. Due to rapid urbanisation, black populations experience lifestyle changes (e.g. unhealthy diet, increased access to alcohol and tobacco) that predispose them to increased obesity and cardiovascular risk. In this study, attention will be given to cardiovascular alterations, specifically arterial calcification, in lean and overweight/obese women nearing or already experiencing menopause. These include elevated blood pressure, large artery stiffness (indicated by increased central pulse pressure (cPP)) and carotid intima-media thickness (CIMT). Other factors linked to arterial calcification include the level of obesity as well as low bone mineral density. Ectopic calcification plays a significant role in cardiovascular morbidity and mortality, especially in renal failure patients, osteoporotic and elderly women. Factors contributing to the development and progression of arterial calcification include calciotropic hormones and altered bone metabolism, particularly in older postmenopausal women. This is due to the lack of protective effects of oestrogen against vascular alterations and bone loss after menopause. Previous studies have shown that increased bone resorption indicated by elevated levels of c-telopeptide of type I collagen (CTX), parathyroid hormone (PTH), low 25- hydroxycholecalciferol (25(OH)D3) and parathyroid hormone to 25-hydroxycholecalciferol ratio (PTH:25(OH)D3) are independently linked to arterial stiffening, CIMT and vascular calcification. Knowledge on the contribution of altered bone metabolism and associated calciotropic hormones on cardiovascular health in Africans is limited. Previous studies on ectopic calcification in South Africans focused on men and renal failure patients. This study will explore the possible role of altered calcium regulation and bone metabolism in the development of arterial calcification and CVD in older African women. Aim - The aim of this study was to investigate the associations of brachial and central pressures and CIMT with PTH, PTH:25(OH)D3 and CTX, a marker of bone resorption, in lean and overweight/obese African women older than 46 years. Methodology - This sub-study forms part of the Prospective Urban Rural Epidemiology (PURE) study. A total of 434 urban and rural women older than 46 years were included in the study. Women infected with the human immunodeficiency virus (HIV) were excluded from the study. The study was reviewed and approved by the Ethics Committee of the North-West University (Potchefstroom campus) and all participants signed an informed consent form prior to enrolment into the project. Field workers administered demographic, general health and physical activity questionnaires in the participants’ home language. Anthropometric measurements included weight, height and waist circumference, while body mass index (BMI) was calculated in kg/m2. Cardiovascular measurements included brachial and central systolic blood pressure (SBP), brachial diastolic blood pressure (DBP), brachial and central pulse pressure (PP) as well as CIMT and carotid cross-sectional wall area (CSWA). Blood pressure measurements were performed on the right arm with the participant in the sitting position. Blood was drawn after an overnight fasting period. We performed biochemical analyses from serum and plasma samples for follicle stimulating hormone (FSH), PTH, 25(OH)D3, and CTX. HIV testing was performed according to standardised procedures. Since interactions existed for BMI with regards to associations of CIMT and cPP with PTH:25(OH)D3, the study population was divided into the lean (BMI <25 kg/m2) and overweight/obese (BMI ≥25 kg/m2) groups. We performed independent T-tests to compare means and used the chi-square test to compare proportions. Single and multiple regression analyses were performed to investigate the associations of markers of vascular structure and function with CTX and calciotropic hormones. Results - In this study, 90% of the women displayed an FSH concentration exceeding the cut-off value of 35 mIu/mL, indicating a postmenopausal state. When comparing lean and overweight/obese African women, we found that lean women had higher levels of CTX and 25(OH)D3 (both p<0.001), while the overweight/obese group was older (p=0.007) and presented with higher PTH and PTH:25(OH)D3 levels (both p<0.001). Brachial and central pressures did not differ between the groups (p≥0.23), except for DBP being higher in the overweight/obese group (p=0.017). Overweight/obese women had higher CIMT (p<0.001) and CSWA (p=0.001) as compared to their lean counterparts. A larger proportion of lean women smoked (63%) and self-reported on alcohol use (37%) than overweight/obese women (41% and 18%, respectively) (both p<0.001). Forty-one percent of overweight/obese women used antihypertensive medication, opposed to 25% in the lean group (p=0.001). In multivariate regression analyses, an independent positive association existed between CIMT and PTH:25(OH)D3 (R2=0.22; β=0.26; p=0.003) in lean women. In the overweight/obese group independent positive associations were confirmed between brachial SBP and PTH (p=0.013) and CTX (p=0.038), and between DBP and PTH (p=0.030). Brachial PP and central SBP remained positively associated with CTX (p=0.016 and p=0.024, respectively), while cPP was independently associated with PTH:25(OH)D3 (R2=0.20; β=0.17; p=0.017) and CTX (R2=0.20; β=0.17; p=0.025). Conclusion - Our results indicate that in older African women, large artery structure and function are associated with calciotropic hormones and bone resorption, suggesting that altered bone metabolism and associated calciotropic hormones play a role in the development of vascular calcification. The different associations in lean and overweight/obese women suggest different mechanisms at work regarding arterial calcification in states of low and high adiposity. These findings need confirmation in larger prospective and experimental studies. / MSc (Physiology), North-West University, Potchefstroom Campus, 2014

Motivation - The burden of cardiovascular diseases (CVD) is increasing in developing countries worldwide, but even more so in sub-Saharan Africa. Due to rapid urbanisation, black populations experience lifestyle changes (e.g. unhealthy diet, increased access to alcohol and tobacco) that predispose them to increased obesity and cardiovascular risk. In this study, attention will be given to cardiovascular alterations, specifically arterial calcification, in lean and overweight/obese women nearing or already experiencing menopause. These include elevated blood pressure, large artery stiffness (indicated by increased central pulse pressure (cPP)) and carotid intima-media thickness (CIMT). Other factors linked to arterial calcification include the level of obesity as well as low bone mineral density. Ectopic calcification plays a significant role in cardiovascular morbidity and mortality, especially in renal failure patients, osteoporotic and elderly women. Factors contributing to the development and progression of arterial calcification include calciotropic hormones and altered bone metabolism, particularly in older postmenopausal women. This is due to the lack of protective effects of oestrogen against vascular alterations and bone loss after menopause. Previous studies have shown that increased bone resorption indicated by elevated levels of c-telopeptide of type I collagen (CTX), parathyroid hormone (PTH), low 25- hydroxycholecalciferol (25(OH)D3) and parathyroid hormone to 25-hydroxycholecalciferol ratio (PTH:25(OH)D3) are independently linked to arterial stiffening, CIMT and vascular calcification. Knowledge on the contribution of altered bone metabolism and associated calciotropic hormones on cardiovascular health in Africans is limited. Previous studies on ectopic calcification in South Africans focused on men and renal failure patients. This study will explore the possible role of altered calcium regulation and bone metabolism in the development of arterial calcification and CVD in older African women. Aim - The aim of this study was to investigate the associations of brachial and central pressures and CIMT with PTH, PTH:25(OH)D3 and CTX, a marker of bone resorption, in lean and overweight/obese African women older than 46 years. Methodology - This sub-study forms part of the Prospective Urban Rural Epidemiology (PURE) study. A total of 434 urban and rural women older than 46 years were included in the study. Women infected with the human immunodeficiency virus (HIV) were excluded from the study. The study was reviewed and approved by the Ethics Committee of the North-West University (Potchefstroom campus) and all participants signed an informed consent form prior to enrolment into the project. Field workers administered demographic, general health and physical activity questionnaires in the participants’ home language. Anthropometric measurements included weight, height and waist circumference, while body mass index (BMI) was calculated in kg/m2. Cardiovascular measurements included brachial and central systolic blood pressure (SBP), brachial diastolic blood pressure (DBP), brachial and central pulse pressure (PP) as well as CIMT and carotid cross-sectional wall area (CSWA). Blood pressure measurements were performed on the right arm with the participant in the sitting position. Blood was drawn after an overnight fasting period. We performed biochemical analyses from serum and plasma samples for follicle stimulating hormone (FSH), PTH, 25(OH)D3, and CTX. HIV testing was performed according to standardised procedures. Since interactions existed for BMI with regards to associations of CIMT and cPP with PTH:25(OH)D3, the study population was divided into the lean (BMI <25 kg/m2) and overweight/obese (BMI ≥25 kg/m2) groups. We performed independent T-tests to compare means and used the chi-square test to compare proportions. Single and multiple regression analyses were performed to investigate the associations of markers of vascular structure and function with CTX and calciotropic hormones. Results - In this study, 90% of the women displayed an FSH concentration exceeding the cut-off value of 35 mIu/mL, indicating a postmenopausal state. When comparing lean and overweight/obese African women, we found that lean women had higher levels of CTX and 25(OH)D3 (both p<0.001), while the overweight/obese group was older (p=0.007) and presented with higher PTH and PTH:25(OH)D3 levels (both p<0.001). Brachial and central pressures did not differ between the groups (p≥0.23), except for DBP being higher in the overweight/obese group (p=0.017). Overweight/obese women had higher CIMT (p<0.001) and CSWA (p=0.001) as compared to their lean counterparts. A larger proportion of lean women smoked (63%) and self-reported on alcohol use (37%) than overweight/obese women (41% and 18%, respectively) (both p<0.001). Forty-one percent of overweight/obese women used antihypertensive medication, opposed to 25% in the lean group (p=0.001). In multivariate regression analyses, an independent positive association existed between CIMT and PTH:25(OH)D3 (R2=0.22; β=0.26; p=0.003) in lean women. In the overweight/obese group independent positive associations were confirmed between brachial SBP and PTH (p=0.013) and CTX (p=0.038), and between DBP and PTH (p=0.030). Brachial PP and central SBP remained positively associated with CTX (p=0.016 and p=0.024, respectively), while cPP was independently associated with PTH:25(OH)D3 (R2=0.20; β=0.17; p=0.017) and CTX (R2=0.20; β=0.17; p=0.025). Conclusion - Our results indicate that in older African women, large artery structure and function are associated with calciotropic hormones and bone resorption, suggesting that altered bone metabolism and associated calciotropic hormones play a role in the development of vascular calcification. The different associations in lean and overweight/obese women suggest different mechanisms at work regarding arterial calcification in states of low and high adiposity. These findings need confirmation in larger prospective and experimental studies. / MSc (Physiology), North-West University, Potchefstroom Campus, 2014

The mechanical properties of the arterial wall are of great importance for blood pressure regulation and cardiac load. With increasing age, large arteries are affected by increased wall stiffness. Furthermore, atherosclerotic manifestations may increase the stiffness even further, both processes acting as independent cardiovascular risk factors affecting the arterial system in a heterogeneous way. The aims of this thesis was to characterize the local mechanical properties of brachial artery (BA) with the aid of ultrasound technique and to evaluate the influence of 1) age, gender, sympathetic stimulation and examination site; 2) type 1 diabetes (DM) and its association to circulatory biomarkers; and 3) to evaluate the general properties of the arterial system with the aid of pulse wave velocity (PWV) as well as pulse wave analysis (PWA) in systemic lupus erythematosus (SLE) and correlate the findings to disease activity and circulatory biomarkers. In the most proximal arterial segment of the upper arm a pronounced age-related decrease in wall distensibility, increase in intima-media thickness (IMT), and a slight increase in diameter were seen. Sympathetic stimulation had no influence on wall mechanics. More distally in BA, no change in diameter, and only minor increase in IMT and decrease in distensibility were seen. No gender differences were found. These findings suggest that the principle transit zone between elastic and muscular artery behaviour is located in the proximal part of the upper arm. Women with uncomplicated insulin-dependent DM had similar diameter, IMT and distensibility in their distal BA as controls, whereas flow-mediated dilatation (FMD) was slightly, and nitrate mediated dilatation (NMD) markedly reduced. NMD was negatively correlated with higher HbA1c levels. Vascular smooth muscle cell function seems to be an early manifestation of vascular disease in women with DM, influenced by long-term hyperglycaemia. Women with SLE had increased aortic PWV compared to controls, a finding positively associated with increased levels of complement factor 3 (C3), but not with disease activity. The increased stiffness of central arteries may be one factor contributing to the increased cardiovascular risk seen in SLE.

<p>S obzirom na visoku prevalencu metaboličkog sindroma (10-40% u svetskoj populaciji) i na činjenicu da prisustvo metaboličkog sindroma duplira rizik od nastanka aterosklerotske bolesti kardiovaskularnog sistema jasna je potreba za identifikacijom indivudualnih parametara koji doprinose njenom razvoju. Metabolički sindrom je klaster faktora rizika metaboličkog porekla koji je udružen sa povećanim rizikom za nastanak aterosklerotske bolesti kardiovaskularnog sistema i dijabetes melitusa tipa 2. Insulinska rezistencija, abdominalna gojaznost, aterogena dislipidemija, hipertenzija, proinflamatorno i protrombotično stanje su faktori koji su u osnovi metaboličkog sindroma a često su i praćeni nagomilavanjem masti u jetri. Cilj rada je bio da se utvrdi odnos između markera disfunkcije hepatocita (AST, ALT, GGT), serumskog nivoa inflamatornih biomarkera (broj leukocita, elektroforeza serumskih proteina, CRP, fibrinogen, TNF-&alpha;), biomarkera endotelne disfunkcije (ADMA i homocistein), kao i nivoa serumskih adipokina (leptin i adiponektin) i debljine intima-medija kompleksa (IMT) karotidne arterije kao pokazatelja prisustva aterosklerotskog procesa. Ispitivanje je dizajnirano kao studija preseka. U ispitivanje je uključeno 58 ispitanika oba pola sa karakteristikama metaboličkom sindroma (NCEP:ATP III kriterijumi). Odabir ispitanika je vr&scaron;en u Odeljenju za pravilnu ishranu i zdravstvenu bezbednost hrane, Instituta za javno zdravlje Vojvodine. Kontrolnu grupu su sačinjavale 30 klinički i biohemijski zdravih ispitanika nepu&scaron;ača koji su prema polnoj i dobnoj strukturi odgovarali ispitivanim grupama bolesnika. Iz ispitivanja su isključene osobe koje konzumiraju vi&scaron;e od 20g/dan alkohola, pu&scaron;ači, koji imaju dijagnostikovan virusni hepatitis B ili C ili pozitivan Hbs antigen, anti-Hbs antitela i anti-HCV antitela, osobe koje imaju verifikovana oboljenja kardiovaskularnog sistema, bubrega, CNS-a, infektivna, maligna i autoimuna oboljenja kao i druga oboljenja jetre i žučnih puteva, osobe koje su pod medikamentoznom terapijom koja može uticati na nivo serumskih biomarkera endotelne disfunckije, lipidni i lipoproteinski status, glikoregulaciju kao i menstruacioni ciklus. Sve laboratorijske analize su urađene u Centru za laboratorijsku medicinu, Kliničkog centra Vojvodine. Doppler ultrasonografski pregled karotidnih arterija i ultrazvuk abdomena i jetre je urađen u Centru za radiologiju Kliničkog centra Vojvodine. Signifikantna pozitivna korelacija niskog stepena je utvrđena između IMT zajedničke karotidne arterije i serumskih koncentracija GGT, hsCRP i leptina kao i odnosa neutrofili/limfociti. Prema prvom konstruisanom regresionom modelu u kojem je zavisna varijabla bila IMT preko 0,09 cm statistički značajan uticaj na predviđanje debljine IMT zajedničke karotidne arterije imaju hsCRP (Exp (B) 1,112 i glikemija (Exp (B) 1,973). Prema modelu neuronske mreže sa istom zavisnom varijablom najveću mogućnost predviđanja IMT imaju glikemija, AST i fibrinogen. Prema drugom konstruisanom regresionom modelu gde su zavisne varijable bile IMT zajedničke karotidne arterije preko 0,09 cm i prisutnost hepatične steatoze najveću mogućnost predviđanja imaju leptin Exp (B) 1,1022 i ALT Exp (B) 1,053. Prema modelu neuronske mreže sa istom zavisnom varijablom najveću mogućnost predviđanja IMT imaju ALT, ADMA i leptin.</p> / <p>Given the high prevalence of metabolic syndrome (10-40% in the world population) and the fact that the presence of metabolic syndrome doubles the risk of atherosclerotic disease of the cardiovascular system, there is a clear need to identify individual parameters that contribute to its development. Metabolic syndrome is a cluster of the risk factors of metabolic origin that is associated with an increased risk for the onset of atherosclerotic disease of the cardiovascular system and type 2 diabetes mellitus. Insulin resistance, abdominal obesity, atherogenic dyslipidemia, hypertension, proinflammatory and prothrombotic conditions are the factors at the base of the metabolic syndrome and are often accompanied by fat accumulation in the liver. The aim of this work was to determine the relation between markers of hepatic dysfunction (AST, ALT and GGT), serum levels of inflammatory biomarkers (white blood cell count, electrophoresis of serum proteins, CRP, fibrinogen, TNF-&alpha;), biomarkers of endothelial dysfunction (ADMA and homocysteine) as well as levels of serum adipokines (leptin and adiponectin) and intima-media thickness of carotid artery as indicators of atherosclerotic process in the patients with metabolic syndrome. Study was cross-sectional. It included 58 participants with metabolic syndrome (NCEP:ATP III criteria) as well as 30 clinically and biochemically healthy nonsmokers, age and gender matched controls. Participants were selected in the Department for Nutrition and Food Safety, Center of Hygiene and Human Ecology Institute of Public Health of Vojvodina. Patients that consumed alcohol more than 20g/day were excluded. Participants with positive HBsAg, anti-HBs-antibodies or anti- HCV antibodies were excluded also. Smokers were also excluded. Patients with cardiovascular diseases, renal diseases, infective, hepatic, malignant and autoimmune diseases were excluded from this study. Subjects which used drugs that could affect biomarker levels of endothelial dysfunction, lipid metabolism, glucose metabolism and menstrual cycle were also excluded. All laboratory analyzes were done in Centre for Laboratory Medicine, Clinical Centre of Vojvodina. Doppler ultrasonography of carotid arteries and ultrasound of abdomen and liver were done in Centre for Radiology, Clinical Centre of Vojvodina. Significant positive correlation of low degree was determined between IMT of common carotid artery and serum concentrations between GGT, hsCRP and leptin and relationship neutrophils/lymphocytes. According to the first constructed regression model where dependent variable was IMT of common carotid artery above 0.09 cm statistically significant influence on foreseeing IMT of common carotid artery have hsCRP (Exp (B) 1.112 and glycaemia (Exp (B) 1.973). According to the neuronal network with the same dependent variable greatest probability for foreseeing IMT have glycaemia, AST and fibrinogen. According to the second constructed regression model where dependent variable was IMT above 0.09 cm and present hepatic steatosis greatest probability for foreseeing IMT have leptin Exp (B) 1.1022 and ALT Exp (B) 1.053. According to the neuronal network with the same dependent variable greatest probability for foreseeing IMT have ALT, ADMA and leptin.</p>