View clinical trials related to Vascular Function.
Filter by:Obese people have a disturbed postprandial metabolism and thereby a decreased postprandial vascular function. Nitric oxide plays an important role in the postprandial vascular function. Multiple studies already focused on various nutritional compounds to improve the postprandial vascular function by increasing the nitric oxide bioactivity. However, the vast majority of the trials has been performed with relatively high doses of the individual components, which are problematic to convert into daily food measures, thereby preventing translation of these findings. Well-designed trails studying the effect of feasible amounts of nutritional supplements on the bioactivity of nitric oxide and vascular function are missing.
The purpose of this study will be to examine the acute effect of commercially available energy products on endothelial function, arterial stiffness and thrombosis in healthy young males.
Vascular function decreases following the intake of a mixed meal in some, but not all studies. Differences in the relative amounts of dietary fat, carbohydrates and protein present in the mixed-meal challenges may have contributed to these apparently inconsistent results. Well-designed trials - comparing under rigorously standardized conditions - on the effects of macronutrients on postprandial vascular function are missing. The primary objective of the current study is thus to evaluate in overweight and slightly obese men the effects of the three macronutrients (fat, carbohydrates, and protein) on postprandial vascular function, as assessed by brachial artery flow-mediated vasodilation (FMD). Secondary objectives are to examine postprandial effects on other markers reflecting vascular function, plasma markers for low-grade systemic inflammation and endothelial dysfunction, blood pressure, and serum lipid and plasma glucose metabolism.
The study will explore the benefit of tea for microcirculation. Subjects will consume tea ar a placebo matched for taste and appearance in a blinded cross over design.
Research indicate that people who regularly drink tea have a reduced risk of stroke or heart disease. In a number of studies in which people that normally do not drink showed that their blood vessels function improved when the drunk tea. The current study tests whether a specific black tea improves vessel function in non-tea drinking hypertensive subjects.
Rationale: The incidence of obesity and type 2 diabetes (T2D) is increasing rapidly and accounts for a considerable part of health care costs. Herbal supplements are used in many cultures for the prevention and treatment of many different conditions. Due to lack of scientific proof, the application in western cultures are minimal. Animal studies have shown that many constituents of such herbal supplements may have beneficial effects on several important parameters known to be affected in T2D. Still, no scientific proof in humans is available. We therefore aim to investigate the effect of 4-week herbal supplementation on glucose metabolism, lipid metabolism, vascular function and inflammation in subjects with increased fasting glucose levels or a decreased glucose tolerance. Objective: The primary objectives are to investigate if 4-week herbal supplementation in subjects with increased fasting glucose levels or a decreased glucose tolerance has a positive effect on blood glucose levels and glucose tolerance. The secondary objectives are to investigate if 4-week herbal supplementation in subjects with increased fasting glucose levels or a decreased glucose tolerance has a positive effect on triglycerides (TG), total cholesterol (TC), low density lipoprotein (LDL), high density lipoprotein (HDL) levels, inflammation, adipose tissue and white blood cell gene-expression and AIX both fasted and during an OGTT test. Study design: This study is a randomized, double-blind, placebo controlled cross-over trial in which two different treatments will be evaluated e.g. an intervention with the herbal mixture and a placebo. Each person will obtain both treatments in random order for four weeks with a wash out period of four weeks in-between. Fasting blood samples will be collected and subjects will receive a OGTT, paralleled by a PWA before and after 4-week supplementation. Furthermore, after 4-week supplement intake we will collect a urine sample and collect an adipose tissue biopsy. The whole trial will last three months. Study population: 26 overweight males and females 50-75yrs old with an increased fasting glucose or with an impaired glucose tolerance. Intervention: Two intervention periods of 4-weeks in which participants will take three times a day a supplement of 500mg herbal or placebo. Main study parameters/endpoints: Fasting blood glucose levels, glucose tolerance as determined by an oral glucose tolerance test (OGTT), AIX, triglycerides (TG), total cholesterol (TC), low density lipoprotein (LDL), high density lipoprotein (HDL) levels, PWA, adipose tissue an white blood cell gene expression and markers of inflammation . Nature and extent of the burden and risks associated with participation, benefit and group relatedness: Subjects that will participate in the study will invest a total of 16.5 hours. Blood collection by vena punctures/insertion of the venflon and the collection of an adipose tissue biopsy can occasionally cause a local hematoma or bruise and some participants may report pain or discomfort. The herbal supplements contain small amounts St. John's wort, which may affect the function of liver enzymes. We will therefore monitor liver function parameters during the supplementation period. Furthermore, subjects are excluded if they use medication known to be affected by St. John's wort. Participant will donate 284ml of blood, dispersed over 12 weeks.
Epidemiological studies indicate that regular consumption of three cups of black tea per day reduces the risk of stroke or myocardial infarction. In a number of previous nutrition intervention studies tea has been shown to improve vascular function as assessed by Flow Mediated Dilation (FMD).
Emergency Service Professionals have an increased risk of death from heart attacks when compared to the general public. All the emergency professions share similar responsibilities such as emergency call-outs and shift work. Heart disease is the commonest cause of on-duty death amongst fire-fighters accounting for 45% and compared with 22% in police officers and 15% in the general population. The unique risk to fire-fighters is likely to reflect a combination of factors including extreme physical exertion, mental stress, heat and pollutant exposure. In this study the investigators will assess healthy career fire-fighters and age-matched healthy police officer control subjects following a sedentary period. The investigators will take blood samples to measure platelet activity (platelets are the particles in blood that help blood clot) and will examine how blood clots outside of the body. The investigators will then perform studies placing small needles in the arm to assess how the blood vessels respond following these duties. The investigators hypothesise that fire-fighters do not have pre-existing impairment of heart, blood or blood vessel function as a cumulative effect of their occupation, but rather these are acute and transitory effects following distinct fire-fighter duties. We therefore expect similar results in both occupational groups.
Fire-fighters are at increased risk of death from heart attacks when compared to other emergency service professionals whose jobs involve similar components such as emergency call-outs and shift work. The unique risk to fire-fighters is likely to reflect a combination of factors including extreme physical exertion, mental stress, heat and pollutant exposure. In the largest analysis of cause of death amongst on-duty fire-fighters, fire-fighter deaths were classified according to the duty performed during the onset of symptoms or immediately prior to any sudden death. The majority of deaths due to a cardiovascular cause (i.e. heart attack) occurred during fire-suppression whilst this activity represented a relatively small amount of a fire-fighters professional time. Fire simulation training centers offer a unique opportunity to assess the heart, blood and blood vessel response to fire suppression in a controlled environment. In this study the investigators will assess healthy career fire-fighters on two occasions: following a fire-suppression training exercise in a purpose built real-fire training center, and following a sedentary period as a control. The investigators will take blood samples to measure platelet activity (platelets are the particles in blood that help blood clot) and will examine how blood clots outside of the body. The investigators will then perform studies placing small needles in the arm to assess blood vessel function following fire suppression. By undertaking this comprehensive assessment of blood, blood vessel and heart function we hope to understand the mechanisms whereby the risk of a heart attack is influenced by fire suppression. The investigators hypothesize that following the fire-suppression exercise firefighters blood will clot more readily and their blood vessels will not relax properly which are two of the main processes in the development of a heart attack.
Firefighters are at increased risk of death from heart attacks when compared to other emergencyy service professionals whose jobs involve similar components such as emergency call-outs and shift work. In the largest analysis of cause of death amongst on-duty firefighters, firefighter deaths were classified according to the duty performed during the onset of symptoms or immediately prior to any sudden death. The majority of deaths due to a cardiovascular cause (i.e. heart attack) occurred during fire suppression whilst this activity represented a relatively small amount of a firefighters professional time. There was also a risk of death associated with other duties such as emergency non-fire response and physical exertion. The investigators hypothesize that participation in active fire-fighting duties impairs blood vessel function and increases blood clot formation when compared with non-fire-fighting activities. In this study, healthy career firefighters will be assessed after three periods of duty: fire-suppression, emergency response without fire suppression and following a sedentary shift. The investigators will take blood samples to measure platelet activity (platelets are the particles in blood that help blood clot) and will examine how blood clots outside of the body. The investigators will then perform studies placing small needles in the arm to assess blood vessel function following these duties. By undertaking this comprehensive assessment of blood, blood vessel and heart function the investigators hope to understand the mechanisms whereby the risk of a heart attack, fatal or otherwise, is posed throughout these distinct duties that firefighters undertake on a daily basis.