7 Clinical Trials for Various Conditions
Cognitive dysfunction in the aging Veteran population is a growing health concern in the Veterans Health System. It is not known whether OSA coexisting with COPD will enhance the risk for cognitive dysfunction. The investigators sought to investigate whether these two highly prevalent diseases, that often co-exist as the 'Overlap Syndrome', combine to enhance cognitive impairment in the elderly Veteran population. Thus, the investigators will study whether elderly patients with Overlap syndrome have increased cognitive deficits compared with OSA or COPD alone. Additionally, treatment of OSA with positive airway pressure (PAP) has been shown to improve neurocognitive function in moderate-to-severe OSA while cognitive decline in COPD may be reversible through treatment with long-term oxygen therapy. The investigators will also study whether treatment with positive airway pressure (PAP) and supplemental oxygen vs PAP alone will improve cognitive function and improve quality of life of elderly Veterans.
Major progress has been made in the area of cardiovascular disease, but we believe that further progress will involve mechanistically addressing underlying respiratory causes including chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea (OSA). The most common cause of death in COPD is cardiovascular, although mechanisms are unknown. OSA has been associated with major neurocognitive and cardiovascular sequelae, the latter likely a function of autonomic nervous system abnormalities, oxidative stress, inflammation, and other pathways. Recent data suggest that individuals with OVS die preferentially of cardiovascular disease compared to OSA or COPD alone, although mechanisms are again unclear. The combination of OSA and COPD may lead to profound hypoxemia. Individuals with COPD can develop pulmonary hypertension via disturbances in gas exchange and parenchymal injury leading to loss of pulmonary vasculature. OSA has been associated with mild to moderate pulmonary hypertension, but the situation may be worse if combined with parenchymal lung disease. The biological response to sustained hypoxemia has been carefully studied as has the topic of intermittent hypoxemia; however, to our knowledge, very little research has occurred regarding the combination of sustained plus intermittent hypoxia as seen in OVS. For example, we do not really know whether individuals with OVS develop coronary disease, right or left heart failure, dysrhythmias or some combination of abnormalities predisposing them to cardiovascular death. Thus, design of interventional studies is challenging as causal pathways are poorly understood despite our considerable preliminary data addressing these issues. The purpose of this study is to examine vascular mechanisms in individuals with COPD/OSA overlap syndrome (OVS) compared with matched individuals with obstructive sleep apnea (OSA) alone or chronic obstructive pulmonary disease (COPD) alone and to perform a phase II pilot mechanistic clinical trial in OVS to examine the effect size of nocturnal bi-level positive airway pressure (PAP) vs. nocturnal oxygen therapy in cardiovascular outcomes.
The term "Overlap Syndrome" (OS) is used to describe the presence of both chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea (OSA) in a single patient. Due to premature aging, patients with OS are prone to developing functional decline up to 20 years earlier than the general population. The International Classification of Functioning, Disability and Health (ICF) evaluates functional status in chronic pulmonary disease globally in 5 domains. The investigators propose to study validated outcomes in 3 of these domains: 1) participation in life situations; 2) physical activity; and 3) cardiovascular health. The investigators long-term goal is to develop an exercise strategy tailored to Veterans with OS which will reduce the risk of functional decline through increased PA.
The coexistence of chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea (OSA) in the same patient has been termed overlap syndrome, affecting 1% of the U.S. population.The investigators propose to conduct this study that aims: (1) to compare right and left ventricular hemodynamic parameters using cardiac magnetic resonance imaging (MRI) in overlap syndrome vs. COPD only and OSA only; (2) to compare the effects of bi-level positive airway pressure (BPAP) vs. nocturnal oxygen therapy (NOT) on right ventricular (RV) hemodynamics in overlap syndrome. This study will allow us to test the hypothesis: (1) Patients with overlap syndrome have more RV dysfunction than those with COPD only or OSA only; (2) treatment of both hypoxemia and hypercapnia during sleep will improve RV hemodynamics compared with treatment of hypoxemia alone in patients with overlap syndrome.
Patients with both sleep apnea and COPD have overlap syndrome, but their optimal management is not known. We plan to conduct a randomized trial of of bi-level PAP vs. night time oxygen to asses the impact of intervention on cardiac MRI and biomarkers.
The purpose of study is to evaluate the physiologic effects of pulmonary tissue/structural changes associated with COPD and upper airway inflammation on upper airway collapsibility. Upper airway collapsibility is closely associated with development of obstructive sleep apnea (OSA), which is a common disease characterized by repetitive collapse of upper airway during sleep, leading to hypoxemia and arousal. OSA has important neurocognitive and cardiovascular consequences, especially in patients with COPD. Participants in this research study will undergo two overnight sleep studies (PSGs), pulmonary function test, and CT scan of the upper airway and chest. The first sleep study will evaluate the sleep breathing disorder and the second sleep study will measure the upper airway collapsibility, called critical closing pressure (Pcrit). Pcrit is measured by a modified continuous positive airway pressure (CPAP) machine which can provide a wide range of pressures between 20 and -20 cmH2O in order to modify upper airway pressure.
The purpose of this study is to determine if Bipap should assume a standard-of-care role in the management of overlap syndrome.