Haemodynamic Determinants Of HYpertension In Children And Young People And Role Of The Sympathetic Nervous System: HY CYP

大约三分之一的成年人患有高血压（医学上称为“高血压”）。如果不及时治疗，高血压是心脏病发作或中风的主要危险因素。这些疾病加在一起，每年在世界上造成的死亡人数最多。人们对成人高血压患者体内发生的变化进行了大量研究，但对导致儿童高血压的原因却知之甚少。越来越多的孩子被诊断出患有高血压，部分原因是医生检查得越来越多，但也因为这是一个伴随着超重而出现的常见问题。不幸的是，随着时间的推移，儿童和年轻人变得越来越超重。这意味着找出导致儿童和年轻人高血压的原因变得越来越重要，这样我们才能提供最好的治疗方法。这也很重要，因为儿童高血压往往会导致成人高血压。高血压可能是由于心脏跳动太快或太用力而不能满足身体的需要（心脏过度活动），或者是由于将血液从心脏输送出去的血管变得僵硬或变窄。以前的研究表明高血压主要是由血管的改变引起的。最近的一些证据，包括我们小组的研究表明，年轻人的主要问题是心脏跳动得更快更快。我们希望对此进行更详细的研究，并试图确定我们发现的任何心脏过度活动的原因。我们怀疑患有高血压的年轻人增加了“战斗或逃跑”活动（称为交感神经系统活动），我们将使用呼吸练习和药物来尝试阻止这种活动，看看这对患有高血压的儿童和年轻人的血压有什么不同。目的：该项目将使用最先进的血压测量和心脏扫描来测量患有高血压的儿童和青少年的心脏和血管中的血液流量，并将其与无高血压的儿童和青少年进行比较。我们还将操纵来自大脑的一些信息来控制心脏和血管。目的：我们将使用先进的成像技术（超声和磁共振成像技术或MRI）来详细研究高血压和正常血压的年轻人在心脏和血管中的血流变化。-我们将使用呼吸练习来降低心率和每次心跳时的泵血量，看看这对高血压年轻人和血压正常的年轻人有更大的影响。我们将使用两种以不同方式降低血压的药物，并评估这些药物对心脏泵血和血液流经血管的方式的影响。影响：如果我们证实了我们的假设，即患有高血压的儿童和年轻人心脏活动增加，而不是血管阻力增加，这将导致我们对儿童和年轻人高血压的看法发生转变。我们使用的许多药物针对血管，因此可能不是年轻人使用的最佳药物。我们希望这项研究将导致一项临床试验，比较不同类型的降压药在这个年龄段的患者中效果如何。这项研究也将是第一个使用核磁共振成像来研究这个年龄组高血压血流量的研究之一，也是第一个在不使用侵入性和痛苦技术的情况下操纵儿童“战斗或逃跑”反应的研究。

BackgroundAround a third of the adult population suffers from high blood pressure (medically known as "hypertension"). If left untreated, hypertension is a major risk factor for having a heart attack or a stroke. Put together these cause the largest number of deaths each year in the world. A lot of research has been conducted into the changes that take place in the body in adults with hypertension but not much is known about what causes hypertension in children. More and more children are being diagnosed with high blood pressure - partly because doctors are checking for it more, but also because it is a common problem that develops alongside being overweight. Children and young people are unfortunately becoming more overweight over time. This means it is becoming increasingly important to find out what causes hypertension in children and young people so we can offer the best treatment. It is also important because hypertension in children often leads on to hypertension in adults.Hypertension can be caused either by the heart pumping too fast or too hard for the body's needs (cardiac overactivity), or by the blood vessels that carry the blood away from the heart becoming stiff or narrowed. Old studies suggest that hypertension is caused mainly by alterations in blood vessels. Some more recent evidence, including work from our group suggests that it is the heart beating harder and faster that is the main problem in young people. We would like to look at this in more detail and try to ascertain the cause of any cardiac overactivity we find. We suspect that young people with hypertension have increased "fight or flight" activity (called sympathetic nervous system activity) and we will use breathing exercises and medication to try and block this activity to see what difference this makes to blood pressure in children and young adults with hypertension.Aims: This project will use state of the art blood pressure measurements and heart scans to measure the flow of blood in the heart and blood vessels of children and young people with hypertension and compare it to those without hypertension. We will also manipulate some of the messages getting from the brain to control the heart and blood vessels.Objectives: - We will use sophisticated imaging techniques (ultrasound and magnetic resonance imaging technology or MRI) to study in detail how the flow of blood through the heart and the blood vessels varies between young people with hypertension and with normal blood pressure. - We will use breathing exercises to reduce the heart rate and volume of blood pumped during each heartbeat and see whether this has a greater effect in young people with hypertension or young people with normal blood pressure. - We will use two medicines that work to reduce blood pressure in different ways and assess what effect these medications have on how the heart pumps and how the blood flows through the blood vessels. ImpactIf we confirm our hypothesis that children and young people with high blood pressure have increased cardiac activity and not increased resistance in their blood vessels, it would lead to a shift in the way we think about high blood pressure in children and young adults. Many of the medications we use target the blood vessels and may therefore not be the best medications to use in young people. We hope this research will lead to a clinical trial comparing how well different types of blood pressure medication work in this age group of patients. This research will also be one of the first studies to use MRI to study blood flows in hypertension in this age group, and the first study to manipulate the "fight or flight" response for children without using invasive and painful techniques.