Clinical Research Studies

The purpose of this research study is to test whether racial differences exist in markers of brain loss in Alzheimer's disease and if Obstructive Sleep Apnea influences this process among African-Americans when compared to Caucasians (hereafter referred to as 'whites'). African-Americans (AAs) have a higher risk of both Alzheimer's disease (AD) and vascular risk factors for Alzheimer's disease, such as diabetes and high blood pressure, when compared to whites. Sleep characteristics vary between AAs and whites. AAs take longer to fall asleep, have shorter sleep duration, lower sleep quality and less slow wave sleep (SWS) duration than whites. Obstructive Sleep Apnea (OSA) is more common in AA's, increases AD risk, and is associated with markers of AD pathology even in persons with normal cognition. OSA may be a physiologic race-dependent biologic mechanism increasing AD-risk in AA's. Notably, AA's seem to have a higher degree of brain loss and less tau (i.e. brain loss marker) in the spinal fluid, for the same levels of amyloid (i.e. AD pathology marker). This may lead to possible AD underdiagnoses in AA's. This study will investigate this tau differences via neuroimaging and examine whether OSA influences this process.