Obstructive Sleep Apnea And Androgen Dysregulation
Funder
National Health and Medical Research Council
Funding Amount
$537,041.00
Summary
Obstructive Sleep Apnea (OSA) is a serious public health problem associated with increased sleepiness, heart disease and metabolic dysfunction. Obesity and male gender are important predisposing factors for OSA. This study will determine if short-term testosterone therapy can help improve OSA in men who are also dieting and exercising. It will also determine the genetic mechanisms by which testosterone might influence breathing during sleep and obesity.
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
A Randomised Controlled Trial Of A Simplified Management Strategy Versus Standard Care In Moderate To Severe OSA
Funder
National Health and Medical Research Council
Funding Amount
$561,400.00
Summary
Currently breathing difficulties during sleep known as obstructive sleep apnea (OSA) are undertreated in our community. This reflects an inability of the current diagnostic and treatment strategies to deal with the high clinical burden of OSA. As a result, in particular in rural and remote areas, many have long waits for treatment, or no access to therapy at all. The purpose of this project is to evaluate a simplified protocol for the management of OSA. This will be done using diagnostic devices ....Currently breathing difficulties during sleep known as obstructive sleep apnea (OSA) are undertreated in our community. This reflects an inability of the current diagnostic and treatment strategies to deal with the high clinical burden of OSA. As a result, in particular in rural and remote areas, many have long waits for treatment, or no access to therapy at all. The purpose of this project is to evaluate a simplified protocol for the management of OSA. This will be done using diagnostic devices and treatment strategies that are more widely available than the current approaches to the diagnosis and management of obstructive sleep apnea. This will involve measurement of the numbers of falls in oxygen levels in a patient via a device to measure oxygen levels called an oximeter. These falls in oxygen levels correlate well with breath holding episodes during sleep characteristic of OSA. Treatment can be commenced in the patient's home depending on these results. We intend to compare these new approaches with the current best practice in OSA. If the outcomes are good these stategies could be applied to reduce the waiting times for to diagnose and manage OSA and make therapy more widely available throughout the community.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
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.
Mechanisms Of Apnea And Periodic Breathing In The Newborn.
Funder
National Health and Medical Research Council
Funding Amount
$381,100.00
Summary
Breathing pauses referred to as apnea or periodic breathing occur frequently in the preterm infant, and often require intensive clinical vigilance to ensure survival. And yet the mechanisms that produce and terminate apnea are not understood. This study will investigate the mechanisms underlying infantile apnea and periodic breathing and the effectiveness of drugs and techniques currently used to control apnea by using a combination of infant animal model studies, mathematical modelling studies ....Breathing pauses referred to as apnea or periodic breathing occur frequently in the preterm infant, and often require intensive clinical vigilance to ensure survival. And yet the mechanisms that produce and terminate apnea are not understood. This study will investigate the mechanisms underlying infantile apnea and periodic breathing and the effectiveness of drugs and techniques currently used to control apnea by using a combination of infant animal model studies, mathematical modelling studies and studies in human preterm infants to improve our understanding of breathing control in infancy.Read moreRead less
Role Of Load Detection And Compensation In Pathogenesis Of Obstructive Sleep Apnea.
Funder
National Health and Medical Research Council
Funding Amount
$340,867.00
Summary
This proposal will use novel techniques to explore how defective responses to the threat posed by a collapsing upper airway contribute to the Obstructive Sleep Apnea syndrome, a disease involving repetitive collapse of the upper airway in sleep. Responses to small increases in the resistance to inspiratory airflow will be examined by measuring the small electrcal responses in the brain to these loads, and the response of the muscles responsible for maintaining airway patency to the collapsing fo ....This proposal will use novel techniques to explore how defective responses to the threat posed by a collapsing upper airway contribute to the Obstructive Sleep Apnea syndrome, a disease involving repetitive collapse of the upper airway in sleep. Responses to small increases in the resistance to inspiratory airflow will be examined by measuring the small electrcal responses in the brain to these loads, and the response of the muscles responsible for maintaining airway patency to the collapsing forces induced by these loads, in both wakefulness and sleep. The brain's response to resistive loads will also be evaluated using the techique of functional magnetic resonance imaging, which demonstrates areas of the brain activated by a stimulus.Read moreRead less
The Diagnosis Of Obstructive Sleep Apnea In Primary Care
Funder
National Health and Medical Research Council
Funding Amount
$295,075.00
Summary
The gold standard method for diagnosis of sleep apnea is the overnight sleep study. These tests are expensive, have long waiting lists and are hard to access outside larger cities. We aim to determine if general practitioners can combine information from questionnaires and a simple home diagnostic test, to confirm or rule out sleep apnea. The results of this study will eventually lead to more accessible and efficient diagnosis and treatment of this common condition.
Ageing, Obstructive Sleep Apnea (OSA) and obesity are becoming more common in the community. Each is associated with increased heart disease and metabolic disorders. Understanding how androgen dysregulation exacerbates OSA, obesity and ageing and how androgen treatments alter these conditions may lead to reduced cardiometabolic dysfunction and improved health.