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.
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
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
Novel Neuromechanical Measurements Of The Human Upper Airway In Health And Disease
Funder
National Health and Medical Research Council
Funding Amount
$543,728.00
Summary
Obstructive sleep apnea (OSA) is a common condition, in which the upper airway repeatedly collapses during sleep, causing the oxygen concentration in the blood to drop, carbon dioxide to rise, and the person to arouse in order to re-establish adequate oxygen supply. Consequences of OSA include increased daytime sleepiness, increased risk of accidents, and increased risk of cardiovascular diseases. It most commonly affects middle-aged males, but is also seen in the broader population. OSA is asso ....Obstructive sleep apnea (OSA) is a common condition, in which the upper airway repeatedly collapses during sleep, causing the oxygen concentration in the blood to drop, carbon dioxide to rise, and the person to arouse in order to re-establish adequate oxygen supply. Consequences of OSA include increased daytime sleepiness, increased risk of accidents, and increased risk of cardiovascular diseases. It most commonly affects middle-aged males, but is also seen in the broader population. OSA is associated with obesity and specific shapes of the upper airway and facial structure. These anatomical factors can be compensated for while awake but inadequate activity of the muscles surrounding the upper airway during sleep contributes to an increased predisposition of the airway to collapse. Airway collapse occurs when the muscles are unable to withstand the low pressures in the airway and collapse, obstructing the airway. This project will measure the stiffness and motion of the muscles surrounding the airway, in healthy people and those with OSA, to determine how these influence airway collapsibility. We will use two novel non-invasive Magnetic Resonance Imaging (MRI) techniques, MR Elastography, and MR tagging which will allow us to quantify the airway stiffness, or elasticity, and its motion (deformation). These will be the first direct measurements of the upper airway elasticity and deformation in humans. We will also measure how various treatments, such as CPAP therapy and mandibular advancement affect airway elasticity and deformation, so that their mechanisms can be better understood. This may also explain why some patients do not benefit from these therapies. These studies may lead to new diagnostic and treatment modalities, as well as gaining important insights into the basic mechanisms of airway collapse in humans.Read moreRead less
Prediction Of Oral Appliance Treatment Outcome In Obstructive Sleep Apnoea
Funder
National Health and Medical Research Council
Funding Amount
$280,200.00
Summary
Obstructive sleep apnoea (OSA) is a very common disorder, affecting approximately 2% of women and 4% of men in the middle-aged workforce . It is characterised by repetitive, complete or partial closure of the throat passage during sleep, resulting in sleep disturbance and low oxygen levels. OSA is recognised as a serious public health problem. There is growing evidence supporting the use of oral appliances to treat OSA. It is thought that these work by enlarging the throat passage, but this rema ....Obstructive sleep apnoea (OSA) is a very common disorder, affecting approximately 2% of women and 4% of men in the middle-aged workforce . It is characterised by repetitive, complete or partial closure of the throat passage during sleep, resulting in sleep disturbance and low oxygen levels. OSA is recognised as a serious public health problem. There is growing evidence supporting the use of oral appliances to treat OSA. It is thought that these work by enlarging the throat passage, but this remains uncertain. The aim of this project is to gain a better understanding of how such appliances work, so as to be able to predict which patients will particularly benefit from this form of treatment.Read moreRead less
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
Respiratory-control Deficits In A Model Of Sleep Apnoea During Early Development: Mechanisms And Associations
Funder
National Health and Medical Research Council
Funding Amount
$206,717.00
Summary
A recent study showed that it is possible to induce changes in the respiratory control system of piglets after birth. This new study will examine the mechanism of that change, and develop diagnostic tools that can detect whether similar changes have occurred in babies. The results will help to diagnose the complications of respiratory problems in young babies, and will guide research regarding the potential site of the abnormalities that predispose to SIDS. Piglets have very similar development ....A recent study showed that it is possible to induce changes in the respiratory control system of piglets after birth. This new study will examine the mechanism of that change, and develop diagnostic tools that can detect whether similar changes have occurred in babies. The results will help to diagnose the complications of respiratory problems in young babies, and will guide research regarding the potential site of the abnormalities that predispose to SIDS. Piglets have very similar development of the brain and respiratory system to human infants during early development after birth. This study uses piglets to model exposure to factors that occur during infancy, and thus model some of the common respiratory diseases, including risk factors for the sudden infant death syndrome (SIDS). For example, infants may have upper-airway obstruction during sleep, or may get their face trapped in bed clothes so that they breath a mixture of lower oxygen and higher carbon-dioxide than that found in fresh air. We recently found that, during early development of piglets, repeated exposure to these types of gas mixes depressed respiratory responses tested later. Thus, respiratory responses become less vigorous over time, and this finding could explain how the exposures complicate infants' respiratory problems, or increase their risk for SIDS: Less vigorous responses mean the infant does not wake or move, the exposure becomes more severe, and may finally cause death. This study will examine piglets after such repeated exposure to: 1. find out whether heart-rate variability is reduced, in the same way as babies who later died from SIDS 2. develop a new diagnostic tool, to show the site where the abnormality is located 3. determine whether brain chemical alterations could explain the change in breathing 3. find out if exposure to cigarette smoke, known to increase respiratory problems in babies, causes even more severe disturbance of respiratory control in piglets.Read moreRead less