Active clinical trials for "Sleep Apnea Syndromes"

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

Venous thromboembolism(VTE) is the third most common cardiovascular complication among hospitalized patients, and can even cause death. VTE often occurs in intensive care patients and there had been many efforts to prevent such complication. The American College of Chest Physicians (ACCP) had published evidence-based clinical practice guideline for VTE prophylaxis. This study focuses on how VTE prophylaxis is being performed in both medical and surgical ICUs in a single University hospital, and sees the differences in such prophylactic patterns.

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.

Elucidating the effects of obstructive sleep apnea (OSA) on cardiovascular outcomes is crucial in risk assessments and therapeutic recommendations for affected individuals. The Sleep and Stent Study is a multi-center observational study investigating the relationships between OSA and cardiovascular outcomes in patients treated with percutaneous coronary intervention (PCI).

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.

Endothelial dysfunction, or abnormal functioning of the lining of blood vessels, appears to be a key process in the development of cardiovascular disease. Endothelial dysfunction appears to be caused by both sleep disordered breathing and obesity. As endothelial dysfunction is among the first clinical marker that predicts future cardiovascular events, understanding molecular mechanisms leading to impairment of endothelial function is very important. Endothelial function requires the proper functioning of endothelial nitric oxide synthase (eNOS). eNOS activity is tightly regulated by caveolin-1, a protein important in the formation of cellular structures called caveolae. Low levels of caveolin-1 facilitate optimal nitric oxide synthesis in endothelial cells as caveolin-1 helps to spatially organize eNOS in close proximity to signaling proteins that are important for eNOS activation. In certain diseases however, the balance of caveolin-1 and eNOS can be disrupted resulting in impaired nitric oxide synthesis and leading to endothelial dysfunction. The investigators therefore seek to characterize levels of caveolin-1, and correlate this with the presence or absence of sleep disordered breathing, obesity, and cardiovascular disease. The current IRB protocol covers the performance of fat biopsies on subjects who have recently completed a sleep study either in the Center for Sleep Medicine or in our sleep laboratory and were found to have sleep disordered breathing or no sleep disordered breathing, subject with sleep disordered breathing who have been treated successfully with continuous positive airway pressure for 3-6 months, and subjects undergoing other studies in our lab who are obese or non-obese and subjects who have known cardiovascular disease and subjects without known cardiovascular disease.

To describe the relationship between OSA and clinical Hypertension (performing ABPM), endothelial dysfunction (performing flowmetry), and its relation at the basic research (determining the β1 subunit in Peripheral Leukocytes in peripheral blood). This relation between OSA and HTA has been evaluated in basal conditions and after modifying the pathophysiological role of OSA applying treatment with positive continues pressure (CPAP) during 3 months.

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.

The purpose of this study is to investigate the effectiveness of CPAP treatment to co-morbidities of sleep apnea by looking the change of the consumption of medication of the co-morbidities before and after starting the CPAP treatment.

Positive airway pressure (PAP) therapy is generally offered to patients with obstructive sleep apnea. The investigators suggest that beneficial effects of PAP therapy is by preventing apneas and therefore reducing cardiac and pulmonary morbidities. The investigators sought to verify this by assessing cardiac and pulmonary function during exercise.