Active clinical trials for "Sleep Apnea Syndromes"

Apart from obesity, craniofacial factors are well recognized in the pathogenesis of obstructive sleep apnea (OSA) and are likely to play an important role in influencing the response to weight loss. The prevalence of OSA syndrome is as common among the middle-aged Hong Kong Chinese populations as the Caucasians, despite our Chinese patients having much lower body mass index (BMI). From previous work on ethnic comparison, for the same degree of OSA severity, Caucasians were more overweight, whereas Chinese exhibited more craniofacial bony restriction. Cephalometric measurements based on lateral radiograph of the upper airway have shown that a shorter distance between maxillary projection from the cranial base, a smaller posterior airway space, less mandibular protrusion, a narrower space between the hard palate and cranial base, and a more caudally placed hyoid bone predispose to a higher apnea-hypopnea index (AHI). A recent study shown that a shorter mandibular length as measured by lateral cephalometry was associated with a greater fall in AHI after weight loss. Another study using craniofacial computed tomography (CT) scans to evaluate the maxillomandibular bony volume found that craniofacial restriction influenced the relationship between weight loss and OSA improvement. Collectively, these studies suggest that the effect on AHI with weight loss is likely to be more pronounced in those with a smaller craniofacial skeleton. However, the effect of the craniofacial restriction on the degree of rebound in OSA following weight gain after the weight loss intervention is unknown. The study aims to investigate the change in weight and OSA severity following cessation of a lifestyle modification program (LMP) and examine the relationship between craniofacial restriction and the degree of OSA reoccurrence.

The investigators will perform a diagnostic accuracy study comparing tracheal breath sound recordings in awake individuals to the STOP-Bang screening questionnaire, using the apnea-hypopnea index (AHI) score determined by polysomnography as the gold standard.

This is a prospective double blinded randomized crossover controlled trial aiming at validating the measurement of laryngopharyngeal mechanosensitivity in patients with suspected OSA using a recently developed laryngopharyngeal endoscopic esthesiometer and rangefinder (LPEER). Subjects will be recruited from patients with suspected OSA referred for baseline polysomnography to a university hospital sleep laboratory. Intra- and inter-rater reliability will be evaluated using the Bland-Altman's limits of agreement plot, the intraclass correlation coefficient, and the Pearson or Spearman correlation coefficient, depending on the distribution of the variables. Diagnostic accuracy will be evaluate plotting Receiver-operating-characteristic-curves (ROC-curves) using as reference standard basal polysomnogram. The sensory threshold values for patients with mild, moderate, and severe OSA, will be determined and compared using ANOVA or Kruskal Wallis test, depending on the distribution of the variables.

Obstructive sleep apnoea (OSA) is a condition that affects around one in 20 children. In children with OSA, repeated episodes of airway obstruction can severely disturb and fragment sleep, leading to subsequent cognitive and behavioural problems . Epilepsy affects 60,000 children in the UK and up to 30% of children with epilepsy have learning problems. Evidence suggests that OSA is more common in children with epilepsy, such that sleep disturbance could account for some of the learning problems they experience. The aim of this study is to determine the prevalence of OSA in children with epilepsy. The investigators plan carry out detailed sleep studies in children with epilepsy and healthy controls to determine if children with epilepsy are more likely to have OSA than healthy children of the same age. OSA is almost always treatable and the benefits of detecting and treating the condition in healthy children are well-established. If OSA proves to be a common finding in children with epilepsy, it will be important to carry out further studies to see if treating the condition has beneficial effects on learning and behaviour. This project could lead doctors to target sleep-disordered breathing as a way of improving learning outcomes in children with epilepsy.

Sleep disordered breathing (SDB) insidiously worsens metabolic function, heightens insulin resistance (IR), and in pregnancy is thought to precipitate gestational diabetes, preterm birth, growth restriction, gestational hypertension, and preeclampsia. Despite the fact that sleep disturbances are common during pregnancy, SDB remains under-recognized, under-diagnosed, and poorly understood, particularly in pregnancies affected by obesity. Sixty percent of pregnancies are now affected by obesity, yet the relationship between SDB, patterns of glycemia, and insulin resistance (IR) in obese pregnant women is a neglected area with major therapeutic implications to improve maternal and infant health. Using a prospective design in which diet and gestational age are highly controlled, the investigators propose to measure SDB (apneas/hypopneas) in obese pregnant women using an ambulatory sleep monitoring system. In parallel, robust patterns of glycemia will be measured with a continuous glucose monitoring system (CGMS), followed by a 75g oral glucose tolerance test to measure insulin action. The investigators global hypothesis is that worse SDB in part accounts for higher 24-hour patterns of glycemia in obese normal glucose tolerant (NGT) pregnant women in their 3rd trimester. The Investigators will test the hypothesis that: 1) In obese NGT pregnant women at 32-34 weeks gestation on a controlled eucaloric diet, higher apnea hypopnea index (AHI) will be positively associated with 24-hour glycemia measured by a CGMS and that, 2) Higher AHI in obese NGT pregnant women at 32-34 weeks gestation on a eucaloric controlled diet will be associated with higher insulin resistance measured by a 75g oral glucose tolerance test (Matsuda Model). Early identification and treatment has the potential to decrease long-term maternal cardiovascular morbidity and mortality.

Background Maxillomandibular advancement surgery (MMA) has demonstrated high success rates, improving both the apnea-hypopnea index and associated patient' quality of life (QOL), in patients diagnosed with obstructive sleep apnea syndrome (OSAS). However, clinical relapse has been described in the target population, especially when associated with significant weight gain. Literature reporting the long-term impact of MMA for OSAS is lacking. The surgeons of the Division of Maxillofacial Surgery already started to perform this type of surgery in 1995. Objectives The investigators aim to evaluate the long-term (minimum 15 years post-surgery) biologic and QOL impact of MMA in patients with OSAS. The biologic impact refers to the stability of hard and soft tissues and polysomnographic results. Study design Retrospective study Both pre- en postoperative clinical imaging, polysomnography and quality of life questionnaires will be retrieved from all patients that were surgically treated with an MMA by one surgeon (CDC) between 01/11/1995 and 01/12/1999. Conclusion Short-term data have shown high success rates for MMA in OSAS patients. However, long-term data are lacking. This retrospective study might provide us with more information about the incidence of clinical relapse fifteen to twenty years after surgery.

This is a prospective multipart clinical performance study to compare the ability of the SnoreSounds algorithm with polysomnography (PSG) and a type III Home Sleep Testing (HST) device to identify patients with obstructive sleep apnea (OSA).

The sole objective in this study is to evaluate if routine amounts of opioids given for tonsillectomy in children have greater amounts of respiratory depression in children with documented obstructive sleep apnea when compared with patients that do not have obstructive sleep apnea

Negative expiratory pressure is a technique that has been the focus of many studies in the last few years. Airway response to the application of a negative expiratory pressure (NEP) can be used to detect the presence of upper airway collapsibility. In normal subjects, an increase in expiratory flow is observed while in patients with collapsible upper airway, the flow will show a transient decrease due to airway collapse. The objectives of this study will be initially to investigate the diagnostic utility of this technique as a noninvasive measurement of the stability of the upper airway in sleep-related breathing disorders. Secondly, we aim to see the sites of airway obstructions, discovered by NEP, through nasal endoscopy. Finally, we aim at testing the utility of NEP technique in the evaluation of therapeutic response. For this purpose, we will apply it in patients before and after airway stabilization interventions like ENT surgery, oropharyngeal exercises, orthodontic mandibular advancement electrical stimulation of the hypoglossal nerve.

Sleep apnea (SA) affects more than 4% from general population and is largely underdiagnosed. SA can increase the occurrence of cardiovascular, endocrine and metabolic events (particularly stroke, diabetes & obesity). CPAP is currently the Gold Standard treatment of SA and to prevent these events, with a major clinical benefit, long term adherence to CPAP is a significant problem where a significant rate of rejection and abundance after 6 months of treatment.