Aging and Exercise Impacts on Glymphatic Function

The purpose of this research study is to understand how the human brain removes amyloid beta (Aβ) protein which can lead to Alzheimer's disease (AD), using non-invasive magnetic resonance imaging (MRI) techniques. Participants will first go through screening including health survey and blood draw. Depending on their age, enrolled participants will take neuropsychological assessment, sleep and quality-of-life survey, exercise testing, MRI and positron emission tomography (PET) scans. Depending on individual age, the study may include up to three separate visits, a blood draw, an MRI visits and a PET scan visit. The greatest risks of this study include the possibility of injury during the exercise testing, MRI and PET scans, and loss of confidentiality.

Inclusion criteria

• age 25-75 years old
• cognitively unimpaired (CU)
• Mini-Mental State Examination (MMSE) score ≥27 at enrollment screening
• matched gender
• all racial/ethnic groups

Exclusion criteria

• pregnant women
• history of stroke or other major cerebrovascular disease;
• diagnosis of Alzheimer's disease (AD) or other types of dementia;
• diagnosis of major neurologic and psychiatric disorders (e.g., Parkingson's disease, major depression);
• history of prior head trauma, significant autoimmune disorders,
• sleep apnea;
• major systemic illness likely to affect the central nervous system, e.g., uncontrolled diabetes, severe cardiovascular disease, cancer, etc.;
• prior or current alcoholism or drug abuse;
• resistant hypertension (SBP ≥140 or DBP ≥ 90 mmHg despite 3 antihypertensive drugs at maximal doses);
• orthostatic hypotension defined as the third standing systolic blood pressure (SBP) < 100mmHg; any contraindications to having a MRI, e.g., claustrophobia, pacemaker or other medical device of metal;
• any conditions judged by the investigators to be medically inappropriate, risky or likely to cause poor study compliance.