IA Trial Radar | ||
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O estudo clínico NCT03803904 para Envelhecimento está ativo, não recrutando. Consulte a visualização em cartões do Radar de Estudos Clínicos e as ferramentas de descoberta de IA para ver todos os detalhes. Ou pergunte qualquer coisa aqui. | ||
Aerobic Exercise and Cerebrovascular Function
Research over the last few decades have driven the continual promotion of exercise as one of the most impactful interventions of central nervous system health and function. At the forefront of much of this research is the use of task-based fMRI BOLD to quantify beneficial changes in cortical function following aerobic exercise. While transformative, the true impact of this research is limited in scope until the investigators can define the influence of cerebrovascular function on the well-documented beneficial change in BOLD response. The investigators do know that older adults who are physically active have improved vascular health but do not know the full impact of an exercise intervention on cerebrovascular health. If the hypotheses of improved perfusion and CVR is supported it would inform current intervention strategies and would add important additional information about the potential of exercise to improve brain health in aging. This would have implications for aging Veterans at risk for neurodegenerative disease brought on by cerebrovascular dysfunction.
Graded Intensity Aerobic Exercise to Improve Cerebrovascular Function and Performance in Aged Veterans
- E2825-R
Fase III
brain health
| Grupo de participantes/Braço | Intervenção/Tratamento |
|---|---|
ExperimentalSpin The intervention will take place three times a week for 12 weeks and will be led by a qualified instructor (an Exercise Physiologist with five years of experience conducting the intervention). The duration of each session will be increased by 1-2 minutes to a maximum time of 45 minutes per session based on the progression of the participants and the recommendation of the instructor. Because participants are initially sedentary and detrained, exercise intensity will begin at low levels (50% of maximal heart rate reserve, HRR) but will be increased by 5% every week (if deemed necessary by the instructor) to a maximum of 75% maximal HRR. | Spin The intervention will take place three times a week for 12 weeks and will be led by a qualified instructor (an Exercise Physiologist with five years of experience conducting the intervention). The duration of each session will be increased by 1-2 minutes to a maximum time of 45 minutes per session based on the progression of the participants and the recommendation of the instructor. Because participants are initially sedentary and detrained, exercise intensity will begin at low levels (50% of maximal heart rate reserve, HRR) but will be increased by 5% every week (if deemed necessary by the instructor) to a maximum of 75% maximal HRR. |
Comparador ativoControl Participants in the control group will be equalized (frequency and duration) to the Spin group for contact and monitoring. As such they will report to the same facility and interact with the same experienced interventionist; however instead of progressive Spin exercise they will participate in sessions focused on balance and stretching. Similar to the aerobic intervention, these exercises will take place in a group setting and heart rate will be consistently monitored during each session to verify heart rate does not reach 50% HRR. | Spin The intervention will take place three times a week for 12 weeks and will be led by a qualified instructor (an Exercise Physiologist with five years of experience conducting the intervention). The duration of each session will be increased by 1-2 minutes to a maximum time of 45 minutes per session based on the progression of the participants and the recommendation of the instructor. Because participants are initially sedentary and detrained, exercise intensity will begin at low levels (50% of maximal heart rate reserve, HRR) but will be increased by 5% every week (if deemed necessary by the instructor) to a maximum of 75% maximal HRR. |
| Medida de desfecho | Descrição da medida | Prazo |
|---|---|---|
Arterial Spin Labeling (ASL) to Measure Cerebral Blood Flow Change | ASL is a robust, sensitive and specific, non-invasive technique used for determining the amount of arterial blood flow to the whole brain or a particular ROI.47,48 In ASL, arterial blood water is magnetically labeled at the ROI by applying a 180 degree radiofrequency inversion pulse, resulting in magnetization of the blood water. The labeled water exchanges with tissue water, which alters the tissue magnetization and the image intensity creating a "tag" image. This process is repeated without magnetically labeling the arterial blood water, thus creating a "control" image. Subtracting the control and tag images produces the perfusion imaging which reflects the amount of arterial blood delivered to each voxel within the region of interest, termed difference signal. | At the Pre-intervention assessment and 12-weeks following at the Post intervention assessment |
| Medida de desfecho | Descrição da medida | Prazo |
|---|---|---|
Cerebrovascular reactivity (CVR) using a hypercapnic CO2 response test change | CVR will be assessed using 5% CO2 challenge while continuously acquiring MR images. This method has been extensively used and is the most suitable vasoactive stimulus.33,34 Briefly, the CO2 air (5% CO2, 21% O2 and 74% N2) will be administered via an air bag with a valve to switch between room air and CO2 air in the bag. A mouth piece and a nose clip will be used to achieve mouth-only breathing. A research staff member will be inside the magnet room throughout the experiment to switch the valve and to monitor the subject. Physiologic parameters, including end-tidal (Et) CO2 and breathing rate will be monitored and recorded during the experiments. | At the Pre-intervention assessment and 12-weeks following at the Post intervention assessment |
Adults aged 65-80 who do not regularly exercise
- defined as exercising less than 20 minutes twice per week
Are willing and able to cooperate with assessments and interventions
Participant will be quantified at or below the "poor" range for cardiovascular fitness as assessed by a volume of oxygen (VO2) test
- 26.0 ml/kg/min for males
- 21.0 ml/kg/min for females)
26 on the MoCA to meet the criteria for cognitively intact
Participants will be free from diseases affecting cognition or that would interfere with their ability to engage in aerobic exercise - including but not limited to:
- chronic heart
- liver
- kidney disease
Free from diseases/injuries directly affecting brain functions - including but not limited to:
- significant closed head injury
- open intracranial wounds
- stroke
- epilepsy
- degenerative diseases of the nervous system
All subjects will speak English as a primary language and will have at minimum a high school diploma so that behavioral/cognitive measures reflect effects of aging and aerobic exercise and not unfamiliarity with the English language or a lack of education
Potential participants with major psychiatric disorder - including but not limited to:
- psychosis
- major depression
- bipolar disorder
Individuals with ongoing drug or alcohol abuse and severe hypertension (systolic BP > 200 or diastolic BP > 110 mm Hg or subjects taking three or more antihypertensive medications
Participants must not have conditions incompatible with MRI - including but not limited to:
- ferrous metal implants
- cardiac pacemakers or similar devices
- claustrophobia
- morbid obesity
Persons engaging in significant skilled manual movements regularly will be excluded so that behavioral/motor measures reflect the effects of age and aerobic exercise and not the effects of frequent practice
VA Office of Research and DevelopmentGeorgia