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
Alternatives To Polysomnography For Children With Suspected Obstructive Sleep Apnoea.
Funder
National Health and Medical Research Council
Funding Amount
$357,613.00
Summary
Snoring is the cardinal symptom of obstructive sleep apnoea (OSA), a major health issue in childhood with significant impacts on cognition, behaviour and cardiovascular health. Approximately 35% of children snore but only about 10% of those have OSA. Defining OSA in a snoring child requires polysomnography, a technically challenging and expensive test. In this study we will examine a number of simple tests for their predictive power for OSA, developing a tool that will enable clinicians to diagn ....Snoring is the cardinal symptom of obstructive sleep apnoea (OSA), a major health issue in childhood with significant impacts on cognition, behaviour and cardiovascular health. Approximately 35% of children snore but only about 10% of those have OSA. Defining OSA in a snoring child requires polysomnography, a technically challenging and expensive test. In this study we will examine a number of simple tests for their predictive power for OSA, developing a tool that will enable clinicians to diagnose OSA without the need for polysomnography.Read moreRead less
The Influence Of Sleep On The Behaviour Of The Upper Airway Muscles, Genioglossus And Tensor Palatini
Funder
National Health and Medical Research Council
Funding Amount
$295,880.00
Summary
The human airway has limited bone or cartilage support and muscular activity is required to keep the airway open. Central activation of these muscles is reduced during sleep, resulting in the disorder Obstructive Sleep Apnoea. Potential treatments include pharmocological or electrical stimulation of upper airway muscles. However, this is hampered by a lack of understanding of the control of upper airway muscles. This project will study two critical muscles, genioglossus and tensor palatini.
Regulatory Control Of The Upper Airway Muscle Genioglossus During Sleep
Funder
National Health and Medical Research Council
Funding Amount
$329,855.00
Summary
Difficulty breathing during sleep is a major health problem. Obstructive Sleep Apnoea (OSA) is the most frequently occurring of these disorders, being found in approximately 4% of males and 2% of females. In OSA the upper airway (UA) collapses during sleep preventing airflow and causing a fall in oxygen levels in the blood. The airway collapses because during sleep muscles in the UA are unable to offset the negative pressure generated within the airway by the effort of inspiring. If the negative ....Difficulty breathing during sleep is a major health problem. Obstructive Sleep Apnoea (OSA) is the most frequently occurring of these disorders, being found in approximately 4% of males and 2% of females. In OSA the upper airway (UA) collapses during sleep preventing airflow and causing a fall in oxygen levels in the blood. The airway collapses because during sleep muscles in the UA are unable to offset the negative pressure generated within the airway by the effort of inspiring. If the negative pressure is too great and the airway collapses the person has to wake up to reopen the airway. As the UA collapses again on the return of sleep, the cycle becomes repetitive, causing sleep disruption. OSA is a significant health risk causing heart disorders, increased mortality, daytime sleepiness, reduced daytime performance and increased risk of accidents. OSA is due to two interacting factors. First, people with a narrow airway have to generate a greater negative pressure during inspiration. Second, and critically, sleep reduces activity in the UA muscles. The importance of this sleep effect is indicated by the observation that OSA patients do not obstruct while awake. Thus, a respiratory abnormality during sleep is a necessary component of the disorder. However, progress in understanding motor control of UA muscles has been slow. We argue that this is in part because research has concentrated on analysing the activity of the UA muscles, rather than measuring the individual motor units that make up the muscles. In this project we propose to investigate the sleep related activity of individual motor units in the UA muscle, genioglossus (GG). GG plays a critical role in the UA as it keeps the tongue from collapsing backwards into the airway. We anticipate that this approach will provide insights into motor control of the tongue and the role of GG in the development of OSA.Read moreRead less
Impact Of Sleep Disordered Breathing On Cardiovascular, Behavioural And Neurocognitive Function In Preschool Children
Funder
National Health and Medical Research Council
Funding Amount
$425,703.00
Summary
Studies in school age children have shown that disruption to normal sleep patterns resulting from sleep disordered breathing (SDB) has severe consequences for both the cardiovascular system and neurocognition. To date there have been limited investigations of the effects of SDB in pre-school children despite the knowledge that disruptions to breathing during sleep are maximal at this age and the central nervous system which is immature and developing at this time, is most vulnerable to injury.
Cardiovascular, Neurophysiological And Neurocognitive Assessments To Define Sleep Disordered Breathing In Children
Funder
National Health and Medical Research Council
Funding Amount
$324,008.00
Summary
Disruptions to breathing during sleep (snoring), known as sleep disordered breathing occurs in up to 27% of children and forms a continuum of symptoms ranging from mild to severe. It has previously been thought that only severe disruptions to breathing, as occurs in obstructive sleep apnoea (OSA), were of clinical significance requiring intervention, however recent studies have shown that even snoring with no currently used signs of altered blood oxygenation levels or sleep disruption can have a ....Disruptions to breathing during sleep (snoring), known as sleep disordered breathing occurs in up to 27% of children and forms a continuum of symptoms ranging from mild to severe. It has previously been thought that only severe disruptions to breathing, as occurs in obstructive sleep apnoea (OSA), were of clinical significance requiring intervention, however recent studies have shown that even snoring with no currently used signs of altered blood oxygenation levels or sleep disruption can have a significant impact on daytime functioning and school performance. It is also known that cardiovascular disease is a long-term consequence of untreated sleep disordered breathing in adults, however the long-term effects on the cardiovascular system in children are unknown. This study will examine both the neurocognitive and cardiovascular effects of a range of severities of sleep disordered breathing in children and will identify new more sensitive markers of sleep disruption in order to predict neurocognitive dysfunction. In order to address this most important issue, this project will combine the expertise of scientists and clinicians in the fields of paediatric sleep, cardiovascular control and neuropsychological assessment from Monash and Melbourne Universities, and the Monash Medical Centre and Royal Children's Hospital.Read moreRead less
Sleep Disordered Breathing In Pregnancy: Frequency And Impact.
Funder
National Health and Medical Research Council
Funding Amount
$607,034.00
Summary
Sleep disordered breathing (SDB)affects up to 15% of women during pregnancy. There is some evidence that it may have adverse effects on both mother and baby, particularly it may be associated with a 7-8 fold increase risk of developing hypertension during pregnancy. This study aims to measure breathing during sleep in pregnant women to determine its role in pregnancy-related hypertension and diabetes, then treat the SDB to assess its effect on maternal and foetal outcomes.
Neurobiological Effects Of Sleep Apnea And Sleepiness
Funder
National Health and Medical Research Council
Funding Amount
$320,437.00
Summary
Sleep apnea affects over one million Australians. It not only affects the quality of a persons sleep and the oxygen supply to their brain, but can cause sleepiness during the day which can in turn affect the ability of the person to conduct their normal activities. Over 30,000 sleep studies are conducted annually in Australia and current therapies result in significant improvements in the quality of life of the patient. However, the data analysis during these studies does not give a clear indica ....Sleep apnea affects over one million Australians. It not only affects the quality of a persons sleep and the oxygen supply to their brain, but can cause sleepiness during the day which can in turn affect the ability of the person to conduct their normal activities. Over 30,000 sleep studies are conducted annually in Australia and current therapies result in significant improvements in the quality of life of the patient. However, the data analysis during these studies does not give a clear indication of the degree to which individual patients may have problems with performing their normal tasks during the day. Tasks like driving vehicles are of particular interest due to the potential for accidents through fatigue or a lack of concentration. This research is designed to investigate the impact of sleep apnea on brain function and daytime performance using certain new techniques - more sophisticated analysis of the brain's activity, detection of brain chemicals and metabolism using a specific form of brain scan called MR spectroscopy, a special monotonous computer based driving simulator, an other tests of performance. We will assess a large group of patients with sleep apnea to determine how the impact of sleep apnea on performance may be differ throughout the population and how this may be affected by the current standard treatment for sleep apnea. We will examine the impact on brain function and performance of removing the current standard therapy in a group of patients previously diagnosed with sleep apnea (as this is a common occurrence in the community). We will also repeat some specific measurements on a control group without any symptoms of sleep apnea for the purpose of comparison. We plan to show a relationship between the effects of sleep apnea and the ability of a person to carry out activities such as driving and thinking. We will then be able to better assess the risk a patient may face and the most appropriate way to treat them.Read moreRead less
The Role Of Arousal And Respiratory Control Factors In The Pathogenesis Of Obstructive Sleep Apnoea
Funder
National Health and Medical Research Council
Funding Amount
$567,924.00
Summary
Sleep apnoea (OSA) is a very common breathing disorder in sleep characterized by repetitive closure of the collapsible portion of the throat with serious effects on sleep quality and health. Basic causes of OSA are still largely unknown. We will investigate waking responses to breathing load and related respiratory control factors that we believe may be fundamental causes of OSA, and potentially explain many features of OSA including worsening in light sleep and with increasing age.