Active clinical trials for "Apnea"

We intend to study, in depth, the quantitative and qualitative properties of nasal respiration in sleep-disordered breathing and sleep apnea and its relation to (CPAP) treatment with the final goal of improving patient outcome. To do this we will temporarily alter patients' nasal airflow during monitored sleep to lower CPAP air pressure, making CPAP treatment more acceptable to the patient. Additionally we plan to implement highly advanced computerized modelling in collaboration with the OSASMOD research consortium at St. Olavs Hospital/NTNU and SINTEF to predict the results of our alterations and ultimately, to use these predictions to improve both the planning and the outcomes of nasal surgery.

Fluid retention in the legs due to chronic heart failure (CHF) during the daytime may redistribute to neck when with supine positioning at night. A portion of the shifted fluid accumulates in the neck, and narrows the upper airway, predisposing the patient to obstructive sleep apnea (OSA) and central sleep apnea (CSA). However, the mechanism of overnight fluid shift on OSA and CSA remains unclear. The investigators pre-experiment demonstrated there may be a different mechanism of overnight fluid shift on OSA and CSA. The accumulation of water content in neck soft tissue increases neck circumference and leads to pharyngeal resistance, upper airway collapse and causes OSA. The effect of nocturnal fluid shift on CSA may be because of increasing of chemosensitivity (fluctuation of PaCO2), circulation delay and hemodynamic disordered. This study is aimed to explore the different mechanism of overnight fluid shift on OSA and CSA by comparing the changes of upper airway (inside diameter, water content, and pharyngeal resistance), PaCO2, circulation delay (lung-to-finger circulation time) and hemodynamic (loop gain).

Clinical diagnostic of brain death requires a non-reactive coma, absence of brain stem reflex, and absence of spontaneous breathing. The confirmation of absence of spontaneous breathing is established the apnea test (according to the American Academy of Neurology's Guidelines). However this test may lead to complications (acute hypoxemia, ventilatory and cardiocirculatory disorders) and reduces significantly the number of lung transplants. Some data suggest modifying the apnea test : replace the ventilator switching off with continuous positive airway pressure (CPAP) use. These studies showed that this alternative method (CPAP) increased the level of lung harvest but they were not sufficient because these studies were monocentric, non randomized and with little patients,. That why the aim of the present study is to compare the standard strategy and CPAP strategy with a prospective, multicenter, randomized study.

Peripheral vascular function is impaired in people with obstructive sleep apnoea who are untreated compared with age-, weight- and sex-matched healthy controls.

Obstructive sleep apnea (OSA) is the most common type of sleep apnea and is caused by an obstruction of the upper airways. The obstruction results in periods of intermittent hypoxia and re-oxygenation, which lead to increased oxidative stress, increased inflammation, endothelial dysfunction, and insulin resistance. Chronic obstructive pulmonary disease (COPD) is a lung disease that leads to poor airflow. This disease leads to systemic hypoxia, reduced oxidative capacity, and increased inflammation. The direct cause of OSA and COPD is unclear, but OSA and COPD may be linked to other comorbid conditions such as obesity and type II diabetes. Upon onset of OSA and COPD, metabolic disturbances associated with obesity and type II diabetes can be exacerbated. Obesity is a condition characterized by an increase in visceral fat, elevated plasma levels of free fatty acids, inflammation, and insulin resistance. Although the effects of body fat distribution have not been studied in these patients, an increase in both subcutaneous and abdominal fat mass in non-OSA older women was shown to increase morbidity and mortality. Fat/adipose tissue is an active tissue capable of secreting proinflammatory cytokines such as tumor necrosis factor (TNF)-alpha and interleukin (IL)-6, reactive oxygen species and adipokines. Particularly, abdominal fat is a prominent source of pro-inflammatory cytokines, which contributes to a low grade, chronic inflammatory state in these patients. Additionally, an increased inflammatory state is associated with reduced lean body mass, and together with elevated circulating free fatty acids may increase the occurrence of lipotoxicity and insulin resistance. Thus, increased fat deposition is associated with a poor prognosis in OSA and COPD patients and therefore it is of clinical and scientific importance to understand the changes in fat metabolism and digestion as a result of OSA and COPD. It is therefore our hypothesis that fat synthesis and insulin resistance is increased and whole body protein synthesis is decreased in OSA and COPD patients, leading to a poor prognosis.

The purpose of this study is to determine the prevalence of obstructive sleep apnea and associate it with the endothelial function behavior in patients with resistant hypertension. Two groups will be evaluate, one presenting uncontrolled high blood pressure, and other, with controlled blood pressure by drugs.

Polycystic ovary syndrome (PCOS) is one of the most common disease caused by hormonal imbalance and is also associated with overweight and obesity. It affects 5-10% of adolescent girls and women capable of having children. Polycystic ovary syndrome is associated with missed menstrual periods, hormonal imbalance, being overweight, and with a form of diabetes. Girls with polycystic ovary syndrome may have a breathing problem known as "sleep apnea." Sleep apnea may cause a person to stop breathing for short periods of time while sleeping. People with polycystic ovary syndrome are thirty times more likely to develop sleep apnea than those who do not have PCOS. If sleep apnea is not treated, it may lead to daytime sleepiness, poor school performance, high blood pressure, heart disease and diabetes. The purpose of this study is to understand how insulin function is affected in presence of sleep apnea in girls with polycystic ovary syndrome between 13-21 years of age as compared to girls with PCOS without sleep apnea. Insulin is one of the hormones made in your body to convert food into energy. In people with increase weight body cannot use insulin properly. The investigators also want to see if insulin action is also affected by sleep apnea.

Untreated Obstructive Sleep Apnea Syndrome (OSAS) has long-term complications, namely metabolic imbalances (obesity, dislipidemia, type 2 diabetes mellitus). Until now, no molecular markers for this physiopathological connection have been identified. This project aims to determine non-invasive biomarkers that may allow better comprehension of the metabolic consequences of OSAS, as well as assess the effect of Continuous positive airway pressure (CPAP) on these metabolic parameters. This project will integrate the clinical, metabolic, genetic/proteomic and biologic systems to further explore the mechanisms behind OSAS, as well as the effect of the treatment with CPAP.

The investigators will perform a clinical trial comparing mandibular advancement device (MAD) therapy with sleep positional trainer (SPT) and the combination of MAD and SPT in patients with positional sleep apnea using MAD. Patients are invited for 2 consecutive polysomnographies (PSGs) in randomized order: one PSG with SPT, one PSG with SPT and MAD. PSGs are performed at the Antwerp University Hospital.

The purpose of this study is to investigate the correlation between health outcomes associated with the severity of obstructive sleep apnea (OSA) symptomatology, the findings will guide the design of interventional studies.