Improving Age-Related Cognitive Decline With Exercise in Hypertensive Older Adults: A Pilot Study to Investigate A Retinal Microvascular Biomarker and the Role of IGF
Overview
- Phase
- N/A
- Intervention
- Not specified
- Conditions
- Hypertension
- Sponsor
- University of Alabama at Birmingham
- Enrollment
- 11
- Locations
- 1
- Primary Endpoint
- Changes in graded exercise stress test
- Status
- Completed
- Last Updated
- 8 months ago
Overview
Brief Summary
The investigator aims to assess the extent to which a brief exercise intervention improves systemic growth factor concentrations, reverses loss of systemic vascular networks and hypertension, and by extension, improves neurocognition. To test the investigator's hypothesis that increased cardiovascular fitness will correlate with improved vascular density, the investigator proposes the innovative use of retinal density scans.
Investigators
Ronald M. Lazar, PhD
Professor of Neurology
University of Alabama at Birmingham
Eligibility Criteria
Inclusion Criteria
- •adults between 55-75 years of age
- •essential hypertension (as determined by referring physicians)
- •engages in less than 150 minutes of moderate intensity exercise/week (as determined by CHAMPS Questionnaire)
- •physically able to exercise
- •access to an upright cycle ergometer at home or via gym access
- •access to smart device (iOS or Android phone or tablet with ability to install and use Polar Beat and Polar FlowTM applications).
Exclusion Criteria
- •diagnosis of dementia
- •resting systolic blood pressure \<120, or \>180 mm Hg
- •disease or condition that would preclude exercise
- •untreated depression or anxiety disorders
- •severe respiratory disease
- •disease of the eye
- •refractive error \> 6 diopters or +6 diopters (as assessed by 1st retinal scan).
Outcomes
Primary Outcomes
Changes in graded exercise stress test
Time Frame: 16 weeks
This test will measure participants' maximal oxygen utilization and will be done once before and once after exercise intervention. The investigator will use a graded exercise test on a stationary cycle. The test will continue to maximum, and expired gases will be collected (via a spirometer) throughout the test to monitor oxygen consumption and carbon dioxide expiration. The investigator defines maximum or test termination as either voluntary exhaustion by the participant, or by two of three physiologic criteria: 1) heart rate = 220 minus age; 2) respiratory exchange ratio \> 1.15; 3) Stabilization of oxygen consumption with increasing workload. The participant's effort is monitored at each test stage via the standard 6-20 rating of a perceived exertion scale. Lactate levels will also be collected by finger prick to help determine maximum.
Retinal microvascular density changes
Time Frame: 16 weeks
Standardized Optical Coherence Tomography Angiography (OCT-A) scans will occur twice before and once after exercise intervention to measure retinal microvascular density changes. A fractal analysis will be used to uniquely analyze the retinal microvascular network so that global changes of the vascular system can be quantified.
Cognitive changes
Time Frame: 16 weeks
Standardized neuropsychological tests will be completed twice before and once after exercise intervention. These are designed to assess global functions of processing speed, memory, attention, and executive function, which have been shown to be sensitive to diffuse effects of cardiogenic, cerebral hypoperfusion. All tests have published, aged-adjusted norms. Specific tests include: Trail making A \& B, Digit Span; Rey Complex Figure (RCFT); Digit Symbol; Controlled Oral Word Association (verbal fluency); Hopkins Verbal Learning Test (HVLT); Boston Naming Test; Center for Epidemiologic Studies-Depression Scale (CES-D), and the Brief Visual Memory Test (BVMT). At each time point, the Z scores for all measures will be aggregated and divided by 9 to arrive at the total cognitive Z-score. In addition, we will calculate composite scores for separate cognitive domains using the same approach and compare each time point to measure total cognitive changes.
Serum growth factor changes
Time Frame: 16 weeks
Approximately 2 teaspoons (10 mL) of venous blood draw will occur twice before and once after exercise intervention to measure serum growth factor changes.