I am a physiologist working in the area of paediatric sleep and its disorders to elucidate mechanisms involved in Sudden Infant Death Syndrome, the consequences of preterm birth for later development of cardiovascular compromise and the consequences of sleep disordered breathing in children for disturbance of the cardiovascular system.
Does Maladaptive Remodelling Of The Heart And Vasculature In Response To Preterm Birth Lead To Long-term Cardiovascular Risk?
Funder
National Health and Medical Research Council
Funding Amount
$535,086.00
Summary
Being born prematurely is linked to the development of high blood pressure (a major risk factor for cardiovascular disease) later in life. In this project we will examine whether injury to the cells lining the cardiovascular system and/or structural changes in the wall of the arteries and the heart, as a result of being born early, lead to an elevation in blood pressure and heart dysfunction in adulthood.
Being Born Small Is Not Good For The Heart:early Detection Of Cardiovascular Risk
Funder
National Health and Medical Research Council
Funding Amount
$486,757.00
Summary
Intra uterine growth restriction(IUGR) is linked to adult onset of cardiovascular disease. However, little is known about the mechanism(s) which underlie this link or which babies are most at risk. This study aims to assess cardiovascular function in infants and children who were growth restricted. Early identification of cardiovascular dysfunction may aid in new opportunities for monitoring and therapeutic targets to ultimately reduce later onset of cardiovascular morbidity in this population.
Does Adenotonsillectomy Change Vascular Function In Children With Sleep Breathing Disorders?
Funder
National Health and Medical Research Council
Funding Amount
$522,105.00
Summary
Sleep breathing disorders affect 10% of all children and when severe, obstruction in the upper airways causes serious deficits in growth, development, brain function and heart health. But even mild snoring (without obstruction) may also cause poor health in the arteries that supply blood to the brain and heart, as well as the smaller arteries in the arms and legs. In both adults and children with conditions like diabetes and obesity, poor blood vessel health has been shown to greatly increase th ....Sleep breathing disorders affect 10% of all children and when severe, obstruction in the upper airways causes serious deficits in growth, development, brain function and heart health. But even mild snoring (without obstruction) may also cause poor health in the arteries that supply blood to the brain and heart, as well as the smaller arteries in the arms and legs. In both adults and children with conditions like diabetes and obesity, poor blood vessel health has been shown to greatly increase the future risk of heart attacks, angina and strokes. Children with severe sleep breathing disorders (such as sleep apnoea syndrome) are currently treated by removal of the tonsils and adenoids, which typically resolves snoring and improves sleep, but it is not yet known whether there are any benefits for blood vessel health. The earliest signs of blood vessel disease in children are abnormal function of the lining of the blood vessels (endothelial dysfunction) and thickening of the lining of blood vessels (intima media thickness). They precede the adult diseases of atherosclerosis - which causes heart attacks and strokes, and diabetic kidney and eye disease. These changes can be measured accurately and non-invasively using ultrasound imaging of arteries in the neck and arm. Our primary aim is to assess whether changes in blood vessel health occur in children with sleep breathing disorders across the range of severity, with a secondary aim to measure any changes in cardiovascular control during both sleep (when snoring occurs). Most importantly, by assessing children before and after surgery, we will be able to see for the first time whether treatment of childhood snoring improves blood vessel health. This study may have major implications for the clinical management of snoring children, who may require treatment at an earlier age to prevent poor blood vessel health and an increased risk of cardiovascular diseases later in life.Read moreRead less
DEVELOPMENT OF CARDIOVASCULAR CONTROL DURING SLEEP IN HUMAN INFANTS AFTER PRETERM BIRTH
Funder
National Health and Medical Research Council
Funding Amount
$358,537.00
Summary
Infants spend the major part of their life in sleep, and the period between birth and 6 months of age sees dramatic changes in their sleep organisation. Coincidently, there are dramatic developmental changes in the infant's heart and blood pressure control systems, and the ability to compensate for stress such as falls of blood pressure (hypotension) or in the level of oxygen in the blood (hypoxaemia). In infants born preterm, the risks of hypoxaemia, and even death are significantly greater dur ....Infants spend the major part of their life in sleep, and the period between birth and 6 months of age sees dramatic changes in their sleep organisation. Coincidently, there are dramatic developmental changes in the infant's heart and blood pressure control systems, and the ability to compensate for stress such as falls of blood pressure (hypotension) or in the level of oxygen in the blood (hypoxaemia). In infants born preterm, the risks of hypoxaemia, and even death are significantly greater during sleep than during wakefulness, but why this is so is uncertain. This study will examine the ability of infants to respond to stress during sleep. Four groups of infants will be examined: healthy infants born at normal gestation; healthy infants born prematurely (preterm); preterm infants who have experienced mild hypoxaemia soon after birth; and preterm infants who have suffered more severe hypoxaemia because of lung disease. Infants will be studied in a sleep laboratory during day-time sleep, and their ability to control blood pressure will be determined. By contrasting the effectiveness of blood pressure control between the infant groups we aim to determine whether preterm infants have lasting problems as a result of their premature birth, or their exposure to hypoxaemia. By contrasting infants in sleep and wakefulness, we aim to assess whether the risks of poorer blood pressure control are greater in sleep.Read moreRead less
Previous research has shown that SIDS victims have a number of subtle abnormalities that set them apart from the normal population. These include the occurrence of upper airway obstruction in sleep, a reduced ability to awaken from sleep and abnormalities of the automatic control of heart rate and blood pressure in sleep. These body functions are controlled by a component of the brain called the autonomic nervous system which controls the heart and other internal functions by means of nerves cal ....Previous research has shown that SIDS victims have a number of subtle abnormalities that set them apart from the normal population. These include the occurrence of upper airway obstruction in sleep, a reduced ability to awaken from sleep and abnormalities of the automatic control of heart rate and blood pressure in sleep. These body functions are controlled by a component of the brain called the autonomic nervous system which controls the heart and other internal functions by means of nerves called the parasymmpathetic and sympathetic systems. The purpose of this project is to undertake studies of the autonomic system in normal infants and in those infants who are considered to be at risk for SIDS. As SIDS occurs almost exclusively in sleep it is important to study the infant?s heart rate and blood pressure responses to various challenges whilst asleep. All infants (both controls and subjects) enrolled in the protocol will therefore undergo overnight sleep studies during which their automatic responses to a variety of stimuli will be measured. Once we have established the normal response to these stimuli we can then compare them to the results of the at risk group. If, as we anticipate, there is a difference between our at risk group and the normal controls in automatic function then we will measure some of the stress hormones in the body which reflect the function of the autonomic nervous system. If there is a difference in the levels of these hormones between the normal and the at risk groups which correlates with the expected subtle abnormalities in function we may be able to devise an accessible and quantifiable measure for those infants at risk of SIDSRead moreRead less