Microvascular And Macrovascular Disease In Snoring And Obstructive Sleep Apnoea: A Mechanism For Increased Stroke Risk.
Funder
National Health and Medical Research Council
Funding Amount
$679,744.00
Summary
This project will address the important question of the vascular risk of stroke associated with snoring and obstructive sleep apnoea, by using retinal photography of the eye to directly visualise the vascular changes in the cerebral circulation. Retinal photography may provide a useful clinical tool to help reduce the risk of stroke in patients with snoring and sleep apnoea.
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 VASCULAR CONSEQUENCES OF SNORING AND OBSTRUCTIVE SLEEP APNOEA
Funder
National Health and Medical Research Council
Funding Amount
$476,052.00
Summary
Snoring refers to a condition where the throat narrows significantly during sleep, and allows the soft tissues which surround this part of the airway to vibrate and create the typical snoring noise. Habitual snoring is a very common problem in the adult population, with a prevalence of between 20-40%. More severe forms of snoring are associated with the obstructive sleep apnoea syndrome, which is a condition in which the throat completely blocks behind the tongue and palate during sleep leading ....Snoring refers to a condition where the throat narrows significantly during sleep, and allows the soft tissues which surround this part of the airway to vibrate and create the typical snoring noise. Habitual snoring is a very common problem in the adult population, with a prevalence of between 20-40%. More severe forms of snoring are associated with the obstructive sleep apnoea syndrome, which is a condition in which the throat completely blocks behind the tongue and palate during sleep leading to cessation of breathing for short periods of time. Sleep apnoea is among the commonest chronic disorders of adult males occurring in 5% of men over the age of 45 years. Increasingly, it is now recognised that snoring, without sleep apnoea, may be an independent risk factor for the development of both of these very common and significant medical disorders. However, there have been no studies exploring the mechanisms by which snoring might contribute to the development of stroke and hypertension. In this proposal, 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 leads to disease such as atherosclerosis and hypertension. Our studies will help to prove that this is a common mechanism whereby both snoring and sleep apnoea may contribute to the development of important vascular diseases. Studies will also establish the prevalence of carotid atherosclerosis in snorers (with and without OSA), and the prevalence of habitual snoring and OSA in patients at risk of developoing completed stroke. The recognition of snoring as an independent risk factor for vascular disease will clearly have important and wide ranging implications for the future management of snoring in the prevention of stroke and hypertension.Read moreRead less
The Impact Of CPAP Treatment On Carotid Artery Atherosclerosis In Heavy Snoring And Mild Sleep Disordered Breathing
Funder
National Health and Medical Research Council
Funding Amount
$697,512.00
Summary
Mild sleep disordered breathing, including habitual snoring, is a very common problem in the adult population, with a prevalence of between 20-40%. Increasingly it is now recognised that habitual snoring may be an independent risk factor for the development of stroke. In this proposal we will explore the hypothesis that treatment for snoring will slow or stop the development of carotid artery atherosclerosis.
The Role Of Snoring Vibrations In The Pathogenesis Of Early Carotid Artery Atherosclerosis
Funder
National Health and Medical Research Council
Funding Amount
$593,833.00
Summary
Habitual snoring is a very common problem in the adult population, with a prevalence of between 20-40%. Increasingly it is now recognised that snoring may be an independent risk factor for the development of stroke. In this proposal, we will explore the hypothesis that chronic snoring transmits a pressure wave through the tissues of the neck to the carotid artery which may damage the artery wall and subsequently lead to stroke. This may lead to new strategies to treat habitual snoring.
Examining The Role Of Extracellular Myeloperoxidase In The Pathogenesis, Identification And Treatment Of High-risk Unstable And Ruptured Atherosclerotic Plaque
Funder
National Health and Medical Research Council
Funding Amount
$103,356.00
Summary
Vascular inflammation has emerged as a key driver and therapeutic target for stroke and heart attack. Existing diagnostic techniques and treatments do not target inflammation so that residual inflammatory risk remains. There is a need to identify patients with active inflammation who may benefit from treatment. Myeloperoxidase is an inflammatory enzyme abundant in plaque at risk of rupture and subsequent stroke or heart attack and presents as a potential diagnostic tool and therapeutic target.
Mechanisms Of Gastroesophageal Reflux In Obstructive Sleep Apnoea
Funder
National Health and Medical Research Council
Funding Amount
$462,214.00
Summary
The symptoms of gastroesophageal reflux (heartburn and acid burning) are extremely common in individuals with obstructive sleep apnoea (OSA), especially during sleep (nocturnal reflux). The reasons for this are unclear. This research project will investigate the reasons for this increased occurrence of reflux in OSA.
A Randomised, Controlled Trial Of 10% Dextran 40 In The Prevention Of Stroke Complicating Carotid Endarterectomy
Funder
National Health and Medical Research Council
Funding Amount
$200,667.00
Summary
The operation to remove blockages in the carotid arteries (carotid endarterectomy) is of proven benefit in the prevention of stroke. The procedure itself, however, unfortunately carries approximately a 1 in 20 risk of immediate and early postoperative stroke. Most strokes are caused by blood clots forming at the operation site, breaking off and travelling to the brain (embolism). The up front operative risk is usually accepted by most patients in order to achieve the significantly greater long t ....The operation to remove blockages in the carotid arteries (carotid endarterectomy) is of proven benefit in the prevention of stroke. The procedure itself, however, unfortunately carries approximately a 1 in 20 risk of immediate and early postoperative stroke. Most strokes are caused by blood clots forming at the operation site, breaking off and travelling to the brain (embolism). The up front operative risk is usually accepted by most patients in order to achieve the significantly greater long term benefits of future stroke risk reduction. This study is designed to test a medication (dextran) thought to possibly prevent stroke associated with the operation. Dextran acts in part, by preventing blood clots forming at the operation site . In a pilot study undertaken by the researchers, dextran significantly reduced the downstream shedding of small blood clots (microemboli) detected by monitoring brain arteries using specialised ultrasound techniques. It remains to be proven, however, whether this effect on microemboli actually translates into the prevention of stroke complicating surgery. The DICE (Dextran In Carotid Endarterectomy) Trial aims to assess whether dextran can reduce the risk of stroke associated with carotid surgery by 50% or more. It has important implications for the increasing numbers of Australians being offered this operation (5,000-6,000 each year). If the therapy is proven effective there will be the potential to prevent 350-450 strokes and stroke related deaths each year.Read moreRead less
Dynamic In Vivo Size & Shape Measurement Of The Human Upper Airway Using Endoscopic Long-range Optical Coherence Tomogra
Funder
National Health and Medical Research Council
Funding Amount
$184,250.00
Summary
This project will fund the construction of a clinically deployable prototype device to measure changes in upper airway size and shape in patients with obstructive sleep apnoea. We have recently developed and validated a technique based on endoscopic optical coherence tomography (OCT). Preliminary in vivo studies have been performed in the human upper airway and the results published. To our knowledge, this is the only such system world-wide capable of making these important measurements. The tec ....This project will fund the construction of a clinically deployable prototype device to measure changes in upper airway size and shape in patients with obstructive sleep apnoea. We have recently developed and validated a technique based on endoscopic optical coherence tomography (OCT). Preliminary in vivo studies have been performed in the human upper airway and the results published. To our knowledge, this is the only such system world-wide capable of making these important measurements. The technique has wide commercially applicability as it can be used to measure the internal dimensions of any hollow organ system.Read moreRead less