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.
The Role Of Arousal And Diaphragm Displacement In The Pathogenesis Of Obstructive Sleep Apnoea
Funder
National Health and Medical Research Council
Funding Amount
$410,875.00
Summary
Obstructive sleep apnea (OSA) affects 4% of men and causes excessive daytime sleepiness leading to increased accidents, high blood pressure and premature cardiovascular disease e.g. heart attacks and strokes. OSA is characterized by repetitive obstructions of the floppy portion of the throat during sleep with adverse effects on oxygen levels and sleep quality. OSA is strongly associated with obesity and is 2-3 times more common in men than women. How obesity and male gender predispose to OSA is ....Obstructive sleep apnea (OSA) affects 4% of men and causes excessive daytime sleepiness leading to increased accidents, high blood pressure and premature cardiovascular disease e.g. heart attacks and strokes. OSA is characterized by repetitive obstructions of the floppy portion of the throat during sleep with adverse effects on oxygen levels and sleep quality. OSA is strongly associated with obesity and is 2-3 times more common in men than women. How obesity and male gender predispose to OSA is not known. We will investigate two factors that we believe are most likely involved in causing and explaining this gender difference in OSA. We will examine if breathing responses with brief awakening are sufficient to promote OSA patterns of breathing in snorers and if they are greater in male than female OSA patients. We have already shown that healthy men have greater breathing response to arousal compared to women. These brief arousals occur hundreds of times a night in OSA patients, and over-breathing on arousal may increase the probability of upper airway obstruction on falling back to sleep. We will also investigate why even healthy men show greater breathing responses compared to women. Men tend to accumulate fat centrally, particularly in the abdomen, whereas in women fat tends to be distributed more to the hips and thighs. This could be very important in OSA because downward pull exerted on the upper airway by the diaphragm is likely to be reduced in people with more abdominal obesity. This mechanisms has not yet been studied in humans. We will therefore investigate if increased forces placed on the diaphragm during sleep make the upper airway more prone to collapse. We will also investigate these effects during sleep onset, when there may well be important changes in diaphragm position as muscles relax.Read moreRead less
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
The Role Of Respiratory And Upper Airway Neural Control In Sleep Disordered Breathing
Funder
National Health and Medical Research Council
Funding Amount
$346,018.00
Summary
Obstructive Sleep Apnea (OSA) is a disorder associated with snoring. It affects 4% of adult men and causes excessive daytime sleepiness leading to increased accidents, high blood pressure and premature cardiovascular disease eg. heart attacks and strokes. Patients with OSA obstruct the floppy portion of the upper airway (UA) during sleep and consequently experience frequent episodes of oxygen deprivation as well as sleep fragmentation. OSA is at least 2-3 times more common in men than women. Whi ....Obstructive Sleep Apnea (OSA) is a disorder associated with snoring. It affects 4% of adult men and causes excessive daytime sleepiness leading to increased accidents, high blood pressure and premature cardiovascular disease eg. heart attacks and strokes. Patients with OSA obstruct the floppy portion of the upper airway (UA) during sleep and consequently experience frequent episodes of oxygen deprivation as well as sleep fragmentation. OSA is at least 2-3 times more common in men than women. While OSA patients seem, on average, to have smaller upper airways than normal subjects, the cause of OSA cannot be attributed to this factor alone. For example, a small UA cannot explain the male tendency for OSA. Abnormalities in breathing control or the control of upper airway muscles that normally hold the airway open might also be important in OSA. Men have previously been shown to have a greater increase in UA resistance during sleep than women, consistent with the idea that a gender difference in UA muscle control partly explains why more men than women have OSA. We aim to investigate how changes in breathing and UA dilator muscle control might lead to unstable patterns of breathing and to OSA. We propose that protective UA muscle reflexes are reduced during sleep more in men than women, and are reduced by low blood oxygen levels and alcohol (a known aggravator of sleep apnea). We further propose that low blood oxygen levels not only result from OSA but may also aggravate OSA by preferentially reducing the activity of UA dilating muscles, by making breathing patterns overall less stable and by depressing the ability of subjects to arouse from sleep to an airway blockage. We believe that this tendency to decrease UA activity may be exaggerated in OSA patients. We also propose that men are more vulnerable to the deleterious effects of low oxygen than women. We will also examine if men and snorers have exaggerated breathing responses on arousal from sleep.Read moreRead less
Systematic Expansion Of The Clinical Evidence Base In Opioid Prescribing For Refractory Dyspnoea At The End Of Life
Funder
National Health and Medical Research Council
Funding Amount
$414,535.00
Summary
Morphine can relieve breathlessness in the palliative setting. But many important questions remain. What is the best dose, should the dose change over time, do different medications provide the same relief, and how common is dyspnoea in the general population? This three part project will extend our knowledge to answer these questions. Population data will provide critical background to plan best care for future palliative patients distressed by breathlessness.
Dissecting The Pseudoexfoliation Syndrome With Complementary Genetic, Proteomic And Biophysical Strategies
Funder
National Health and Medical Research Council
Funding Amount
$490,352.00
Summary
Pseudoexfoliation syndrome (PEX) is an eye condition in which flaky material deposits in the eye, greatly increasing the risk of cataract and glaucoma which can lead to blindness. PEX is also associated with heart disease, strokes and aneurysms. Cataract surgery in PEX patients has a higher rate of complications. In this project we will determine the nature of PEX material and why it forms. This knowlege will facilitate better diagnosis and treatment of PEX preventing associated blindness.
An Examination Of The Relationship Between Alcohol-related Injury (ARI) And Licensed Premises
Funder
National Health and Medical Research Council
Funding Amount
$78,686.00
Summary
There is growing interest in acute alcohol-related problems, and especially injuries. These are often experienced by young people, frequently as a consequence of intoxication or drinking in unsafe settings. Little work has been undertaken in Australia to systematically examined alcohol-related injuries (ARIs). This study will examine ARIs, identify the frequency with which such problems present to a local hospital, record the nature of the injuries, details of the person sustaining it, and the d ....There is growing interest in acute alcohol-related problems, and especially injuries. These are often experienced by young people, frequently as a consequence of intoxication or drinking in unsafe settings. Little work has been undertaken in Australia to systematically examined alcohol-related injuries (ARIs). This study will examine ARIs, identify the frequency with which such problems present to a local hospital, record the nature of the injuries, details of the person sustaining it, and the drinking location. Characteristics of drinking locations and drinking settings, in particular licensed premises, will be examined to determine their association with ARIs. Then an intervention will be undertaken in conjunction with local police, to address the conditions of the drinking environment with the aim of reducing ARIs and other alcohol-related problems stemming from licensed premises. The intervention will form part of a randomised controlled trial where licensed premises, identified through monthly police data as hot spots, receive either an intervention or act as a control. In the following month, controls receive the intervention (a cross-over design). The intervention was established in 1998 by Gold Coast police and involves police, fire and liquor licensing officers undertaking an on-site inspection and taking prescribed actions. It is hypothesised that this action should result in a decreased level of ARIs being generated from premises which receive the intervention, compared to those that do not. This is an intersectoral, collaborative project aimed at improving community safety through a concerted effort by police, health and the licensees.Read moreRead less
Investigating The Role Of The UPF3B Gene And Nonsense Mediated RNA Decay (NMD) Process In Mental Retardation.
Funder
National Health and Medical Research Council
Funding Amount
$572,710.00
Summary
Intellectual disability is a frequent and important medical problem. Genetic and environmental factors contribute about equally to the aetiology of intellectual disability. Estimated 1-3% of population suffer from a form of intellectual disability. Among the genetic factors contributing to intellectual disability are genes, and their mutations, on one of the human chromosomes, chromosome X. We have been studying human X-chromosome genes for many years and discovered in excess of 20 novel genes c ....Intellectual disability is a frequent and important medical problem. Genetic and environmental factors contribute about equally to the aetiology of intellectual disability. Estimated 1-3% of population suffer from a form of intellectual disability. Among the genetic factors contributing to intellectual disability are genes, and their mutations, on one of the human chromosomes, chromosome X. We have been studying human X-chromosome genes for many years and discovered in excess of 20 novel genes causing various forms of intellectual disability. Surprisingly the number of genes, in which mutations cause various forms of intellectual disability is unexpectedly high. Just on the human X-chromosome we expect in excess of 200 such genes, which is nearly 30% of the gene content of this chromosome. We propose to study a novel gene, UPF3B, we recently identified to be mutated in a form of intellectual disability. The normal function of this gene and its protein is known to a certain extent. The UPF3B protein plays a role of a guardian of other genes in human (and also other species) cells. The role of the UPF3B protein is to prevent erroneous genetic information to be used for the building of proteins with potentially toxic effects to the organism. In our patients this process clearly malfunctions as a consequence of the damaged UPF3B gene. We propose to shed some more light in to the molecular intricacies of this process with the aim to better understand the mechanics of the process. Families, which participate in our studies and have this gene involved will benefit from the availability of direct test. Multiple other families around the world are also likely to benefit, now or in the future.Read moreRead less
MICROFABRICATED DEVICES: A SIGNIFICANT ADVANCE FOR THE DETECTION AND MOLECULAR ANALYSES OF CIRCULATING CANCER CELLS?
Funder
National Health and Medical Research Council
Funding Amount
$422,107.00
Summary
Using advanced microfabrication concepts, this project aims to develop a platform technology able to capture tumour cells circulating in the blood of cancer patients. Although present only in extremely small numbers, these cells provide invaluable insights into the pathophysiology of the disease and consequently provide vital diagnostic and prognostic information. Molecular analyses of these cancer cells could ultimately enable the design of improved and personalized cancer treatment.
Randomised Double-blind Controlled Trial Of Oxygen Versus Air To Palliate Intractable End-of-life Dyspnoea When Pa02 >55
Funder
National Health and Medical Research Council
Funding Amount
$463,318.00
Summary
Shortness of breath at the end-of-life is one of the most feared symptoms. Unlike most other symptoms, it worsens as death approaches. Despite the fact that more than 50,000 Australian will die an expected death in the next year, of whom the majority will have breathlessness toward the end-of-life, we know little about how best to treat this symptom. Oxygen is frequently introduced but we have not identified whether it is more effective than medical air, and, if it is more effective, which patie ....Shortness of breath at the end-of-life is one of the most feared symptoms. Unlike most other symptoms, it worsens as death approaches. Despite the fact that more than 50,000 Australian will die an expected death in the next year, of whom the majority will have breathlessness toward the end-of-life, we know little about how best to treat this symptom. Oxygen is frequently introduced but we have not identified whether it is more effective than medical air, and, if it is more effective, which patients would most benefit from it. Because of this lack of evidence, oxygen is only funded in Australia in community settings for people who have severely low oxygen levels in their blood. Palliative oxygen is provided on a compassionate basis at times but this is on an ad hoc basis and does not ensure equitable access for people at the end of life who experience shortness of breath. This multi-centre study will compare oxygen and air, with neither the participant nor caring clinicians knowing which treatment they will receive. After careful explanation, volunteers who agree to participate will be asked to use the oxygen machine for at least 15 hours each day for 7 days and fill out a diary twice each day. Five centres across Australia are planning to enroll 240 participants in this study. Outcomes will include whether the sensation of breathlessness has improved, the overall quality of life while being treated, the ability to perform activities of daily living and any side effects experienced. This study is eagerly awaited by clinicians and health planners not only in Australia but in North America and Europe. This study will provide data in a long-standing international debate about the role of oxygen in people with relatively normal levels of oxygen in their blood who suffer from shortness of breath at the end-of-life.Read moreRead less