diagnostic sleep research (medical head Sleep Disorders Center UZA-UA) treatment sleep apnoea
AbstractObstructive sleep apnea (OSA) is a prevalent public health issue with an attributable risk of cardio- and cerebrovascular morbidity and mortality. Furthermore, OSA is related to a high socioeconomic burden due to its clinical daytime consequences such as excessive daytime sleepiness, impaired cognitive performance and reduced quality of life. Oral appliances that protrude the mandible, the mandibular advancement devices (MAD), significantly reduce OSA severity in the majority of patients. However, in a third of patients, the efficacy is not medically appropriate to reduce the long-term consequences of OSA. Furthermore, the efficacy of MAD therapy is inconsistent among patients. Therefore, a high need exists for upfront prediction of treatment outcome in the individual OSA patient. There is no validated method that can achieve upfront selection of candidates for MAD therapy in an accurate and reliable way. Nowadays, it is increasingly recognized that OSA is a multifactorial disease. In the proposed research project, a prospective prediction model with a combination of different pathophysiological traits will be assessed. Furthermore, up to now, our understanding of MAD therapy relies on relatively small studies lacking power. Therefore, we will evaluate this predictive model, as well as the long-term effectiveness, morbidity and mortality in a large international cohort of patients treated with MAD.
- Promotor: Vanderveken Olivier
- Co-promotor: Braem Marc
- Co-promotor: Verbraecken Johan
- Fellow: Dieltjens Marijke
AbstractEctosense devloped a miniaturized, comfortable and clinically accurate home sleep test for the diagnosis of sleep apnea, based on 'Perhipheral Arterial Tonometry' (PAT). In this research, we would like to evaluate i) the underlying physiological phenomena which explain this performance but also limitations, ii) which technologies can be complementary used via incorporation or extension of the current technology, iii) how these technologiees can fit in new care paths.
- Promotor: Verbraecken Johan
AbstractStudy of the vascular wall by means of functional imaging in patients with sleep apnea Obstructive sleep apnea (OSA) is a disorder with a high prevalence, which is present in 5 to 10% of the general population, depending on its severity. Untill recently sleepiness during the daytime, fatigue and concentration problems are considered as the most important consequences of the disease. These symptoms are often present and disappear quickly after the start of adequate treatment with CPAP (1). The last decennium it has become clear that sleep apnea, which is characterized by repetitive oxygen desaturation, with inherent reoxygenation, is an important source of oxidative stress and systemic inflammation. More recently these changes have been associated with increasing vascular pathology. Indeed, sleep apnea is associated with hypertension and an increasing cardiovascular morbidity and mortality. The link between severe OSA and cardiovascular burden has been shown convincingly by a very significant reduction of cardiovascular morbidity in patients with adequate nCPAP therapy compared to untreated OSA patients (2). OSA can lead to cardiovascular pathology by an incrase in sympathetic tone, but probably also by complex inflammatory processes and oxidative stress at the vascular wall (3). Therefore it is extremely important to describe in a very sensitive and adequate manner the changes in the structure of the vascular wall in OSA patients. The structural changes in the larger vessels can only be detected by means of a threedimensional reconstruction. Moreover, it is of interest to calculate the vascular resistance. Only recently, an analysis method has become available which makes it able to calculate resistances in geometries, when boundary conditions like pressure and flow are known. This method is known as 'computational fluid dynamics' or CFD. There is already some experience with biomedical applications of CFD in both the cardiovascular (4) and respiratory field (5). In the current research project we will study patients with different degrees of sleep apnea, before and after adequate treatment, with focus on the structure of the vascular wall, using CFD. The treatments which will be considered are antioxidants and anti-inflammatory drugs compared to CPAP. Also the effect of combination therapies will be evaluated. References 1. McMahon, J. P., B. H. Foresman, and R. C. Chisholm. 2003. The influence of CPAP on the neurobehavioral performance of patients with obstructive sleep apnea hypopnea syndrome: a systematic review. WMJ. 102:36-43. 2. Marin, J. M., S. J. Carrizo, E. Vicente, and A. G. Agusti. 2005. Long-term cardiovascular outcomes in men with obstructive sleep apnoea-hypopnoea with or without treatment with continuous positive airway pressure: an observational study. Lancet 365:1046-1053. 3. Lavie, L. 2004. Sleep apnea syndrome, endothelial dysfunction, and cardiovascular morbidity. Sleep 27:1053-1055. 4. Eloot, S., Y. D'Asseler, P. De Bondt, and R. Verdonck. 2005. Combining SPECT medical imaging and computational fluid dynamics for analyzing blood and dialysate flow in hemodialyzers. Int.J Artif.Organs 28:739-749. 5. De Backer, J., O. Vanderveken, W. Vos, A. Devolder, S. Verhulst, J. Verbraecken, P. Parizel, M. Braem, P. Van de Heyning, W. De Backer. 2007. Functional imaging using computational fluid dynamics to predict treatment success of mandibular advancement devices in sleep-disordered breathing. J Biomechanics 40:16: 3708-3714.
AbstractWe spend approximately one third of our lives sleeping, while a synergy of psychological, physiological and physical conditions affects the quality of sleep. These conditions should not be considered apart from each other, since physical factors can influence the mental quality of sleep and vice versa. Furthermore, physiological reactions of the human body are often a response to the physical condition of the body in its environment. Due to the considerably complex and multidisciplinary character of this interaction, however, sleep is generally considered as a black box, while passing over the underlying determinants and relations. It is quite a surprise to find out that scientists have only recently (last 50 years) started to study this phenomenon, and that few communications (e.g. by media) are scientifically founded. To our knowledge, this project is the first to quantify and to gain insight into the complex and multidisciplinary character of the interaction between environmental variables and the quality of sleep. SCIENTIFIC AND TECHNOLOGICAL AIMS This project aims at opening the black box in four phases, where the first two are rather scientifically oriented, while the last two are technologically oriented:
- Promotor: Verbraecken Johan