Cerebral Circulation In Sleep: Impact Of Endothelial Dysfunction
Funder
National Health and Medical Research Council
Funding Amount
$313,026.00
Summary
Prolonged, repetitive episodes of obstructed breathing during sleep (known as obstructive sleep apnoea syndrome or OSA) is a common medical problem that afflicts both children and adults. As many as 200,000 Australian adults and 300,000 children are affected. OSA has major medical consequences, amongst the most serious being cognitive deficits in children and vascular disease and stroke in adults. This experimental study investigates blood flow to the brain in normal sleep, and in sleep disrupte ....Prolonged, repetitive episodes of obstructed breathing during sleep (known as obstructive sleep apnoea syndrome or OSA) is a common medical problem that afflicts both children and adults. As many as 200,000 Australian adults and 300,000 children are affected. OSA has major medical consequences, amongst the most serious being cognitive deficits in children and vascular disease and stroke in adults. This experimental study investigates blood flow to the brain in normal sleep, and in sleep disrupted OSA, as many of the problems associated with OSA may have their origin in disturbance of blood flow to the brain.Read moreRead less
Developmental Changes In Cerebral Oxygenation After Term And Preterm Birth
Funder
National Health and Medical Research Council
Funding Amount
$445,306.00
Summary
Approximately 10% of all births are preterm and the numbers of infants surviving are increasing. We have previously found that infants born preterm have lower blood pressure over the first 6 months after term equivalent age than infants born at term. We will use new technology to examine how preterm birth affects brain oxygenation and how this is altered with gestational age, sleep states and sleeping position, to provide insights into their increased risk for SIDS.
Foetal Determinants Of Sleep Disordered Breathing In Infants
Funder
National Health and Medical Research Council
Funding Amount
$174,691.00
Summary
Obstructive sleep apnea (OSA) has been identified and recorded in infants, however the factors that lead to the development of OSA and its prevalence in infants is unknown. We have recorded OSA in some infants and we demonstrated that the severity of apnea was at its peak at approximately 2 months of age and then resolved by 1 year. We hypothesised that these infants possibly had a maturational delay of breathing control during sleep. This project is designed to examine the development and preva ....Obstructive sleep apnea (OSA) has been identified and recorded in infants, however the factors that lead to the development of OSA and its prevalence in infants is unknown. We have recorded OSA in some infants and we demonstrated that the severity of apnea was at its peak at approximately 2 months of age and then resolved by 1 year. We hypothesised that these infants possibly had a maturational delay of breathing control during sleep. This project is designed to examine the development and prevalence of sleep and breathing disorders in infants. The prenatal factors that possibly influence development of sleep and breathing disorders in infants, in particular, the effects of maternal smoking will be determined. Pregnant women will be recruited for the study during their third trimester. The foetal movements, foetal breathing movements, heart rate and sleep state will be monitored continuously overnight in the patients home between 32 and 36 weeks gestation using a newly developed foetal movement monitor. The infants will be subsequently studied using overnight polysomnography at 2 months of age to assess their breathing, sleep patterns, arousal behaviour, and the presence and severity of central and obstructive apnea. A group from these infants will be selected and studied longitudinally to examine the development of sleep and breathing disorders more closely. These infants will undergo overnight sleep studies during the first week of life, then at 2 and 6 months of age. A detailed medical history will also be collected regarding the pregnancy, the perinatal history of the infant, exposure to cigarette smoke during pregnancy and postnatally, and the medical history of other family members. We will examine the quality and quantity of foetal movements and its association with the development of OSA. The occurrence of sleep and breathing disorders in the infants will be correlated with the foetal behaviour and, the prenatal and postnatal factors.Read moreRead less
Impact Of An Infant Sleep Intervention On Infant Sleep And Maternal Wellbeing: A Cluster Controlled Trial
Funder
National Health and Medical Research Council
Funding Amount
$205,500.00
Summary
Infant sleep problems and postnatal depression are common in the Australian community. Over a third of Australians report a problem with their infant's sleep in the second six months of life whilst 10-15% of Australian women will experience an episode of depression in the first year after their child is born. Both infant sleep problems and postnatal depression have been associated with serious outcomes including child abuse, child behaviour problems, maternal physical and emotional problems, fam ....Infant sleep problems and postnatal depression are common in the Australian community. Over a third of Australians report a problem with their infant's sleep in the second six months of life whilst 10-15% of Australian women will experience an episode of depression in the first year after their child is born. Both infant sleep problems and postnatal depression have been associated with serious outcomes including child abuse, child behaviour problems, maternal physical and emotional problems, family stress and family breakdown. This study builds on previous work conducted by researchers at the Centre for Community Child Health, Royal Children's Hospital, Melbourne. In this work, a brief behavioural intervention significantly decreased infant sleep problems and symptoms of maternal depression, particularly for depressed mothers. The intervention consisted of controlled crying and removal of sleep associations such as a dummy which the infant had become dependent upon to fall asleep. Mothers who received the intervention reported 20% fewer sleep problems and a 45% reduction in depression symptoms compared with mothers who did not receive the intervention. The interention also improved maternal sleep quality and quantity and reduced the need for professional sleep services. It was acceptable to mothers, of low cost and was minimally disruptive to families - in contrast to many current strategies directed primarily at postnatal depression. This trial aims to determine whther a similar intervention delivered by Victorian Maternal and Child health nurses within their usual practice settings can replicate these important benefits.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
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
Upper Airway Dilator Muscle Activity During Sleep Onset.
Funder
National Health and Medical Research Council
Funding Amount
$211,320.00
Summary
Disorders of breathing during sleep are recognised as a major health problem. Of these, Obstructive Sleep Apnoea is the most prevalent, occurring in approximately 4% of the male and 2% of the female population. In this disorder the upper airway collapses during sleep causing cessation of airflow and subsequent oxygen desaturation. The airway is thought to occlude because dilator muscles are unable to sustain patency in the face of the negative pressures generated by inspiratory effort. In order ....Disorders of breathing during sleep are recognised as a major health problem. Of these, Obstructive Sleep Apnoea is the most prevalent, occurring in approximately 4% of the male and 2% of the female population. In this disorder the upper airway collapses during sleep causing cessation of airflow and subsequent oxygen desaturation. The airway is thought to occlude because dilator muscles are unable to sustain patency in the face of the negative pressures generated by inspiratory effort. In order for patency of the airway to be re-established some form of arousal from sleep must occur . As the UA is likely to collapse on the resumption of sleep, the cycle becomes repetitive, causing significant sleep disruption. OSA is a significant health risk, being associated with increased risk of cardiovascular disorders, increased mortality, excessive daytime sleepiness, reduced daytime performance and increased risk of accidents. In previous work we have demonstrated that normal sleep related changes in the activity of upper airway dilator muscles result in a reduction in the calibre of the airway at sleep onset. This exposes some individuals, such as those with narrow airways, to airway obstruction during sleep. We have also reported that elderly men have larger reductions in upper airway muscle activity at sleep onset than younger men, suggesting one reason why they may have a higher prevalence for Obstructive Sleep Apnea. The aim of the present project is to determine what causes the larger reductions in upper airway muscle activity in older males. The answer to this question will contribute to understanding why this group is so susceptible to Obstructive Sleep Apnea and will elucidate the mechanisms leading to the disorder.Read moreRead less