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
Quantifying The Ventilatory Control Contribution To Obstructive Sleep Apnoea Using Clinical Polysomnography
Funder
National Health and Medical Research Council
Funding Amount
$196,995.00
Summary
Obstructive sleep apnoea is a highly prevalent condition with limited treatment options. New research shows that many patients have sleep apnoea because of a hypersensitive control of breathing (instability). Yet there is no way to measure instability and target it clinically. We aim to refine and apply a powerful new method to measuring breathing instability using a conventional sleep study, to allow treatments for sleep apnoea to be targeted at those patients who will respond most effectively.
A-Prof Wheatley is a respiratory and sleep disorders physician investigating the pathogenesis, health consequences and management of sleep breathing disorders, including sleep apnoea and snoring.
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.
Pressures Exerted On Upper Airway Walls By Surrounding Tissue Structures
Funder
National Health and Medical Research Council
Funding Amount
$426,500.00
Summary
The obstructive sleep apnoea syndrome (OSA) refers to a condition in which throat blockage occurs during sleep leading to breathing difficulties, including cessation of breathing for short periods of time. OSA effects both men and women but is amongst the commonest of chronic disorders of adult males, occurring in 5% of men over the age of 45 years. In the proposed studies we will examine the effect of the pressure in the tissues surrounding the throat on the ability of the throat to stay open a ....The obstructive sleep apnoea syndrome (OSA) refers to a condition in which throat blockage occurs during sleep leading to breathing difficulties, including cessation of breathing for short periods of time. OSA effects both men and women but is amongst the commonest of chronic disorders of adult males, occurring in 5% of men over the age of 45 years. In the proposed studies we will examine the effect of the pressure in the tissues surrounding the throat on the ability of the throat to stay open and allow breathing. The major outcome of the animal studies is increased knowledge concerning mechanisms whereby collapsing forces are applied to the upper airway. This will give insights into potential factors influencing upper airway collapse during sleep in OSA patients. Of particular importance will be our studies on the effects of jaw position on the pressure exerted on the walls of the throat since the use of an intra-oral device to hold the jaw forward during sleep is one of the treatments used to prevent throat blockage during sleep. The studies in humans will examine, for the first time, the notion that the mass (weight) of the neck has a direct effect on the severity of sleep disordered breathing. If neck mass has a substantive influence on sleep disordered breathing then strategies aimed at reducing neck mass (fat) may provide a new therapeutic approach to the management of OSA patients.Read moreRead less
Most deaths from non-illicit drugs are caused by prescribed opioids and are nearly always due to respiratory arrest during sleep. However, no study has assessed the effect of opioids on vital respiratory drives during sleep. In addition, sleep apnea has been identified as a major risk factor for postoperative morbidity and mortality, while no study investigated how to identify those sleep apnea patients most at risk of opioids. Our proposed studies aim to address these gaps in knowledge.
THE BAROREFLEX IN SNORING AND THE OBSTRUCTIVE SLEEP APNOEA HYPOPNOEA SYNDROME
Funder
National Health and Medical Research Council
Funding Amount
$436,261.00
Summary
The obstructive sleep apnoea hypopnoea syndrome (OSAHS) refers to a condition in which throat blockage occurs during sleep leading to breathing difficulties, including snoring and cessation of breathing for short periods of time. OSAHS is amongst the commonest of chronic disorders of adult males, occuring in 5% of men over the age of 45 years. It is now recognised that one of the major complications of OSAHS is the development of high blood pressure and heart disease. In the proposed studies, we ....The obstructive sleep apnoea hypopnoea syndrome (OSAHS) refers to a condition in which throat blockage occurs during sleep leading to breathing difficulties, including snoring and cessation of breathing for short periods of time. OSAHS is amongst the commonest of chronic disorders of adult males, occuring in 5% of men over the age of 45 years. It is now recognised that one of the major complications of OSAHS is the development of high blood pressure and heart disease. In the proposed studies, we will examine the proposal that snoring alone, without significant associated OSAHS, can also lead to high blood pressure in habitual snorers both awake and asleep. In particular, we will explore the hypothesis that chronic snoring transmits a pressure wave through the tissues of the neck to the carotid artery which is the main blood supply to the brain. We propose that the chronic vibration of this artery can alter pressure sensors in the artery wall, which then results in the persistance of high blood pressure. Our studies will help to prove that this is a mechanism whereby both snoring and OSAHS may contribute to the development of high blood pressure. The recognition of snoring as an independent risk factor for high blood pressure will clearly have important and wide ranging implications for the future management of snoring in the prevention of high blood pressure.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.
Surface Tension Of Upper Airway Lining Liquid: Role In Obstructive Sleep Apnoea Hyponoea Syndrome
Funder
National Health and Medical Research Council
Funding Amount
$494,833.00
Summary
The obstructive sleep apnoea hypopnoea syndrome (OSAHS) refers to a condition in which throat blockage occurs during sleep leading to breathing difficulties, including cessation of breathing for short periods of time. OSAHS affects both men and women but is amongst the commonest of chronic disorders of adult males, occurring in 5% of men over the age of 45 years. In the proposed studies we will examine the effect that the liquid layer that lines the throat, has on the ability of the airway to st ....The obstructive sleep apnoea hypopnoea syndrome (OSAHS) refers to a condition in which throat blockage occurs during sleep leading to breathing difficulties, including cessation of breathing for short periods of time. OSAHS affects both men and women but is amongst the commonest of chronic disorders of adult males, occurring in 5% of men over the age of 45 years. In the proposed studies we will examine the effect that the liquid layer that lines the throat, has on the ability of the airway to stay open during sleep. In particular we will examine whether coating the throat with a substance that decreases stickiness will help to prevent the occurrence of episodes of throat blockage during sleep in persons with OSAHS. We will also explore the role of saliva production and swallowing during sleep in maintaining a low stickiness of the throat and whether this liquid lining is abnormal in OSAHS patients. These studies will establish the potential usefulness of decreasing the stickiness of the liquid lining the throat as a treatment for OSAHS.Read moreRead less
Prof McEvoy a respiratory physician researching the causes and consequences of sleep breathing disorders. He has a particular research interest in the link between sleep apnea and cardiovascular disease and in increasing access to care for sleep apnea sufferers through the development of new, simplified methods of diagnosis and management.