Active clinical trials for "Sleep Apnea Syndromes"

The aim of this study is to clarify the influence of obstructive sleep apnea syndrome on left ventricular function using echocardiographic parameters including the myocardial performance index (Tei-index), and to determine the short-term effects of nCPAP on them.

The purpose of this research is to determine the effect of adenotonsillectomy surgery (removal of tonsils and adenoids) on obstructive sleep apnea syndrome (OSAS) in children. OSAS can cause health problems including poor growth, high blood pressure, diabetes and behavioral and learning difficulties. Although adenotonsillectomy is the usual treatment for children with OSAS, it is not known with any certainty if the child's OSAS symptoms improve afterwards. This study will help determine if improvement occurs or if it does not. It will also look at whether certain groups, such as children who are overweight or of different ethnicities, are helped by the surgery.

The purpose of this study is to determine whether respiratory muscle training by means of normocapnic hyperpnea leads to clinical and polysomnographical improvements in patients with mild to intermediate sleep apnea syndrome.

Between 2%-4% of adult population suffers from obstructive sleep apnea (OSAS)(1), which is characterized by obstructive snoring, repetitive apnea and hypopnea in sleep, repetitive cyclic oxygen saturation, as a result from sleep fragmentation related to the arousals in sleeping profile and clinical consequences like day drowsiness, neuropsychological deficits, raised danger of accidents and cardiovascular disease. (1-6). The therapy of choice is the application of nasal continuous positive airway pressure (CPAP) (7-9). Increasing relevance obtain the combined sleep-related breathing disturbances, where the patient shows an obstructive sleep apnea syndrome and some central breathing disturbances in the polysomnography at night. Those patients frequently present with cardiovascular diseases. These combined night breathing disturbances are frequently insufficient to be mitigated exclusively with a CPAP therapy. Some modifications of nCPAP therapy were developed in order to optimize the therapy-compliance and the effectiveness of the therapy. Bi-level-CPAP-devices produce two pressure levels: one for inspiration and another for expiration, so that the patients are able expire against a constant low pressure. An increase in the use of this application in comparison between the conventional or the automatic CPAP therapy could not be proved in early studies. (12, 13) The principle of the automatic nCPAP therapy is to recognize the patient's current need of pressure and to alter the pressure within a set range by applying different algorithms. Some studies have shown that this therapy increased compliance and comfort (14-16), while other studies could not confirm these results. (17, 18) The result of the current study should prove if the treatment of a new algorithm therapy based on an automatic bi-level-system for patients with sleep-related respiratory disorders is as effectively and subjective more comfortable as the conventional CPAP therapy. Patients with a particularly high need of pressure should experience a clear expiratory pressure relief and a higher comfort. Therefore a better compliance is to expect. In the same way patients with additional central respiratory disturbances should obtain a benefit from the bi-level modus. This new treatment would help particularly such "critical patients", who are not responding well to the CPAP therapy or find it uncomfortable.

The investigators hypothesize that obstructive sleep apnea (OSA) contributes to impaired glucose homeostasis and associated vasculopathy, and nCPAP treatment of OSA should improve glycemic control and vascular function in OSA patients with type II diabetes mellitus. This study aims to investigate the therapeutic effects of nCPAP on glycemic control and vascular function in patients with OSA and type II diabetes mellitus.

Obstructive sleep apnea syndrome (OSAS) has been linked to resistant hypertension, but the effect of treatment of OSAS on the resistant hypertension have no been established. In a double-blind randomized clinical trial patients with resistant hypertension with at least moderate sleep apnea will be randomized to receive therapeutic CPAP or Placebo CPAP for eight weeks in an ambulatory set. The investigators want to determine any difference on hypertension control between the 2 management strategies.

Nasal resistance presents considerable variations during night[8]. Additionally, Oral and oro-nasal breathing epochs exhibit strong correlation with the number of apnoea/hypopnoeas [7].The hypothesis that the present study aims to test is whether the pharmacological prevention of increased nasal resistance during night could alter breathing route pattern and lead to a decrease in the number of apnoea/hypopnoeas in OSA patients with normal nasal resistance.

The investigators' overall goal is to compare the effect of CPAP treatment on intermediate cardiovascular risk measures in obese versus lean patients with obstructive sleep apnea (OSA). The overall hypothesis is that, adjusting for OSA severity and obtaining normative data from non-OSA subjects with comparable amounts of visceral adiposity, the two OSA groups will have comparable improvements in daytime sleepiness, but that the cardiovascular and metabolic improvements following CPAP therapy will be decreased in OSA patients with increased visceral adipose tissue. The investigators anticipate that, although there will be a greater absolute change in markers of sympathetic activity, inflammation and oxidative stress in obese compared to lean OSA patients following CPAP treatment, the levels will still be abnormally high in the obese patients resulting in the decreased improvements in insulin resistance, arterial blood pressure, and vascular health in obese versus lean OSA patients.

The main objective of this study is to evaluate the evolution of memory deficit (verbal episodic memory, procedural memory, working memory, short-term memory) in Sleep Apnea Obstructive Syndrome (SAOS) patients after treatment by Continuous Positive Airway Pressure treatment (CPAP). For thus, we will compare memory tests in two separate groups of SAOS patients with "effective " versus "ineffective" ( or sham) CPAP, before and 6 weeks after the beginning of the treatment. Thus we will assess the evolution of memory deficit, the effectiveness of the treatment on the evolution of memory deficit before and 6 weeks after the beginning of the treatment by "effective " versus "ineffective" CPAP. We feel the results of the tests of memory will show greater memory disorders in patients with SAOS before beginning the treatment rather than six weeks afterwards. Thus we hypothesise that, after the treatment by "effective" CPAP, the patients with SAOS will have greater improvement of their memory disorders than those treated by "sham CPAP".

The main objective of the study is to compare the decrease of mean arterial blood pressure over 24 hours in patients having obstructive sleep apnea syndrome and weak or moderate hypertension, treated by Valsartan 160mg per day versus continuous Positive Airway Pressure.