Hypoxia-induced Suppression Of Respiratory Sensations And Reflexes
Funder
National Health and Medical Research Council
Funding Amount
$276,750.00
Summary
Many diseases that effect the respiratory system have their primary effect on the lungs and airway themselves but in some conditions, such as obstructive sleep apnea (OSA) and asthma, increased breathing load can induce periods of low blood oxygen which could further contribute to morbidity in these diseases. OSA is a disorder associated with snoring. Patients experience periods of sleep fragmentation and oxygen deprivation due to obstruction of the floppy portion of the upper airway (pharynx) d ....Many diseases that effect the respiratory system have their primary effect on the lungs and airway themselves but in some conditions, such as obstructive sleep apnea (OSA) and asthma, increased breathing load can induce periods of low blood oxygen which could further contribute to morbidity in these diseases. OSA is a disorder associated with snoring. Patients experience periods of sleep fragmentation and oxygen deprivation due to obstruction of the floppy portion of the upper airway (pharynx) during sleep. It affects 4% of men and 2% of women and causes excessive daytime sleepiness leading to increased risk of accidents, high blood pressure and premature cardiovascular disease. Asthma produces airway inflamation and narrowing and affects a wide range of people. Both OSA and asthma are associated with episodes of impaired breathing and reduced levels of oxygen in the blood. Low levels of oxygen in the blood (hypoxia) is well known to impair functioning of the central nervous system. We have recently found that hypoxia blunts sensations of increased breathing load in healthy people and in asthmatics. Hypoxia might therefore contribute to worsening of attacks in these diseases. This study aims to investigate how changes in blood oxygen levels affect brain processing of respiratory signals, how this translates to perception of sensations and the physiological adaptations that people make to cope with increased breathing load. We will also investigate whether the inhibitory effects of hypoxia on central nervous system function extend to other vital protective respiratory reflexes such as cough, awakening from sleep to increased breathing load and upper airway reflexes that are important for maintaining an open airway.Read moreRead less
Optimising Lung Surfactant Protein Production In The IUGR Fetus At Risk Of Preterm Delivery
Funder
National Health and Medical Research Council
Funding Amount
$463,853.00
Summary
Pregnant women at risk of preterm labour after 24 weeks gestation are increasingly administered glucocorticoids in Australian hospitals in order to promote fetal lung maturation and a successful transition to extrauterine life. Antenatal glucocorticoid treatment reduces overall neonatal mortality, the risk of respiratory distress syndrome and the need for respiratory support. Babies that are born small may not benefit from this treatment in the same way that average size babies benefit.
Addressing Therapeutic Challenges In Sleep Disorders
Funder
National Health and Medical Research Council
Funding Amount
$851,980.00
Summary
The aim of this fellowship is to improve the health and well-being of Australians by reducing the burden of sleep and disorders that disrupt the body clock such as shift work. My program will involve different fields of research combining their efforts together to understand more about sleep apnea and insomnia, the two most common sleep disorders. By this strategy, better treatment for sleep disorders will be found with particular impact on our aging population
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
The Role Of Hypoxia Inducible Factor 1a In Beta-Cell Function And Diabetes
Funder
National Health and Medical Research Council
Funding Amount
$362,303.00
Summary
HIF1a is a gene which our preliminary data shows is needed for normal beta-cell function and insulin secretion. When beta-cells cannot release enough insulin, blood sugar levels rise, and diabetes develops. This research plan will look at the effects of deletion of HIF1a and of increasing HIF1a to see how this affects function of beta-cells and - or diabetes development. This work may show that HIF1a is a potential therapeutic target for the treatment of diabetes in humans.
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