Chronic Kidney Diseases, Cognitive Function, Preclinical, Older Adults
Conditions
Keywords
Cognitive function, Kidney Disease, Exercise, Older adults
Brief summary
Chronic kidney disease (CKD), affects over 45% of all individuals over 70 years of age. Patients with moderate CKD have more than a two-fold increased risk of cognitive impairment than those without CKD; furthermore, as many as 20-70% of patients with CKD have established cognitive impairment and overt dementia. The burden of cognitive impairment and dementia leads to functional decline and accelerated loss of independence, contributing to the tremendous individual, societal, and economic burden of CKD (i.e., 20% of Medicare expenditures in adults \>65 years of age). There is no recommended treatment to prevent cognitive decline in CKD patients, and the few medications available for cognitive impairment have only short term modest effects. There is a critical need to evaluate therapies to forestall cognitive impairment, and maintain or improve cognitive functioning in older patients with CKD. To address this need, this study will test the hypothesis that older patients with moderate/severe CKD and pre-clinical cognitive impairment randomized to a 6-month home-based exercise program will improve cognitive function and MRI measured brain structure, compared to a usual care control group. This study will combine an assessment of cognition with MR imaging techniques to fully evaluate brain structure, blood flow, and behavior relationships at a level previously not conducted in this population
Interventions
BEHAVIORALPartially supervised home-based walking exercise
Participants will be asked to exercise at home by walking at a moderate intensity. Each participant will receive an exercise prescription. Participants will receive a heart rate monitor. The heart rate monitors will be used to achieve a desired exercise intensity and to monitor adherence levels. The participants will receive biweekly to weekly phone calls, and monthly in person meetings will be used to address any barriers, provide encouragement, and progress the exercise.
BEHAVIORALControl
Participants will be asked to exercise at home by walking at a moderate intensity. The participants will receive biweekly phone calls, but will not receive a heart rate monitor, individual exercise prescription, or meet with the investigators monthly.
Sponsors
National Institute on Aging (NIA)
University of Illinois at Chicago
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE
Intervention model description
Randomized, controlled design with a 1:1 allocation
Eligibility
Sex/Gender
ALL
Age
60 Years to 80 Years
Healthy volunteers
Yes
Inclusion criteria
* English speaking men and women * diagnosed stage 3-5 CKD (eGFR\<60 to 15 ml/min); * 60-80 years of age, * self-experienced persistent decline in cognitive capacity determined as self-reported cognitive complaint (i.e., answering yes to the question: Do you feel like your memory or thinking skills have gotten worse recently? (before any clinical impairment of cognition has occurred) * ability to undergo an MRI; * no history of major head trauma.
Exclusion criteria
* • current/past diagnosis of neurological/psychiatric disorders; * any medications to improve cognition or mood; * Diagnosed Dementia or a score of \<2 on the mini-cog assessment * Ischemic ulcerations or gangrene on the feet or legs; * Participating in a supervised exercise program with intent to increase fitness levels 3 days/week, * Requires assistive ambulation; * Limited exercise capacity due to conditions other than claudication * unstable angina, * Claudication * severe arthritis, * extreme dyspnea on exertion, * unstable coronary artery disease; * Class III-IV heart failure; * Current uncontrolled sustained arrhythmias, * severe/symptomatic aortic or mitral stenosis, * hypertrophic obstructive cardiomyopathy, * severe pulmonary hypertension, * active myocarditis/pericarditis, * thrombophlebitis, * recent systemic/pulmonary embolus (within 3 months); * Resting systolic BP \>200 mmHg or resting diastolic BP \>110 mmHg; * Revascularization procedures within the previous 6 months; * Any unforeseen illness or disability that would preclude exercise testing or training based on patient provider opinion; * Pregnancy * No diagnosis of CKD * One or more contraindication for MRI * cardiac pacemaker, * aneurysm clip, * cochlear implants, * shrapnel, * history of metal fragments in eyes, * neurostimulators, * diagnosed claustrophobia.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Composite Global Cognitive Function | Change from baseline in composite global cognitive function at 6 months | Determine the effect of a 6-month home-based exercise program on composite global cognitive functioning as determined by principal component analysis of immediate free recall of trials 1-5 on California verbal learning II, long-delay free recall and recognition, and memory discriminability, trail making test part A and part B, digit symbol substitution test, semantic and phonemic fluency, and Digit span subtest in older patients with kidney disease and preclinical cognitive impairment. A composite global cognitive score was created by converting the individual cognitive scores to standardized z scores and then averaging the standardized z scores. An increase in change from baseline to 6 months is considered an improvement. |
| Composite Executive Function | Change from baseline in composite executive function at 6 months | A composite executive functioning score was created by converting 4 individual executive cognitive scores (verbal fluency FAS and animal summary score, digit span backward subtest, and TMT-B) to standardized z scores and then averaging the standardized z scores. A larger change in Z score is considered an improvement. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| White Matter Integrity | Change from baseline white matter integrity fractional anisotropy at 6 months | Whole brain white matter integrity was created by averaging the fractional anisotropy of 80 tracts using region of interest analysis. An increased change from baseline to 6 months in fractional anisotropy (a measure of directionality, 0 = no principle direction, 1 = one principle direction) is considered an improvement. |
| Hippocampal Volume - Right | Change from baseline hippocampal volume at 6 months. | Determine the effect of a 6-month exercise program on hippocampal volume. An increased change from baseline to 6 months in right hippocampal volume in cubic millimeters is considered an improvement. |
| Cerebral Blood Flow | Change from baseline in cerebral blood flow at 6 months. | Determine the effect of a 6-month exercise program on cerebral blood flow. Change in global cerebral blood measured in mL/100g/min from baseline to 6 months. An larger change is considered an improvement. |
| Vascular Health - Young's Elastic Modulus | Change from baseline in vascular health indices at 6 months | Vascular health was assessed by Young's Elastic Modulus (YEM) at the carotid artery. A larger negative change in YEM (measured in kilo pascal, stiffer artery=higher number) from baseline to 6 months is considered an improvement. |
| Cognitive Function - Total Cognition | Mean change from baseline to 6 months. | Determine the effect of a 6-month exercise program on cognitive function via the NIH toolbox This composite includes: Flanker, Dimensional Change Card Sort, Picture Sequence Memory, List Sorting and Pattern Comparison. This composite score is derived by averaging the standard scores of each of the measures, and then deriving standard scores based on this new distribution. An Age-Corrected Standard Score was used. Scale runs 140 to 23, a higher score means a better outcome. An increased change from baseline to 6 months is considered an improvement |
| Motor Function - Grip Strength | Change from baseline in NIH toolbox motor function indices at 6 months | Determine the effect of a 6-month exercise program on motor function via the NIH toolbox. Age corrected grip strength on a standard scale. Standard scale 140-23, higher score is better. An increased change from baseline to 6 months is considered an improvement. |
| Motor Function - Dexterity | 6 Months | Determine the effect of a 6-month exercise program on motor function via the NIH toolbox. Hand dexterity was determine using age corrected standard scale in the dominant hand. A larger change from baseline to 6 months is considered an improvement. Standard scale range 140-23, higher score is better. |
| Vascular Health - Augmentation Index | 6 Months | Vascular function indices of vascular health was assessed using augmentation index at the carotid artery (in percentage, higher percent=more stiff artery). A larger negative change from baseline to 6 months is considered an improvement. |
| Cognitive Function - Fluid Cognition | Mean change from baseline to 6 months. | Determine the effect of a 6-month exercise program on cognitive function via the NIH toolbox. Fluid cognition. This composite includes: Flanker, Dimensional Change Card Sort, Picture Sequence Memory, List Sorting and Pattern Comparison. This composite score is derived by averaging the standard scores of each of the measures, and then deriving standard scores based on this new distribution. An Age-Corrected Standard Score was used. A larger change from baseline to 6 months is considered an improvement. Scale runs 140 to 23, a higher score means a better outcome. |
| Cognitive Function - Crystalized Cognition | Mean change from baseline to 6 months. | Change from baseline in NIH toolbox cognitive function indices at 6 months. Crystalized cognition. This composite includes : Flanker, Dimensional Change Card Sort, Picture Sequence Memory, List Sorting and Pattern Comparison. This composite score is derived by averaging the standard scores of each of the measures, and then deriving standard scores based on this new distribution. An Age-Corrected Standard Score was used. An larger change from baseline to 6 months is considered an improvement. Scale runs 140 to 23, a higher score means a better outcome. |
| Motor Function - Balance | 6 Months | Determine the effect of a 6-month exercise program on motor function via the NIH toolbox. Change in balance age corrected standard score from baseline to 6-months (23-140, higher score is better). A larger change is considered an improvement. |
| Hippocampal Volume - Left | Change from baseline at 6 Months | Determine the effect of a 6-month exercise program on hippocampal volume. An larger change from baseline to 6 months in left hippocampal volume (cubic millimeters) is considered an improvement. |
| Vascular Health - Pulse Wave Velocity | 6 Months | Vascular function indices of vascular health was assessed using pulse wave velocity of the aorta in meters/second (higher number =more stiff aorta). A larger negative change from baseline to 6 months is considered an improvement. |
| Resting Global Connectivity | Change from baseline at 6 months | Resting global connectivity measured and averaged across 132 regions. A larger change from baseline to 6 months is considered an improvement. Connectivity is a correlation (increased connectivity=higher correlation) |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Home-based Walking Exercise Home-based exercise program: The exercise training group will participate in an educational session on exercise for CKD. Participants will receive a packet of information with an exercise prescription and a heart rate monitor that monitors the exercise. Participants will be asked to exercise (a brisk walk) at home, 3 times per week, for 30-60 minutes for 24 weeks. Participants will be contacted via phone biweekly or more frequently if they are behind the exercise routine, and the investigators will meet with them monthly to provide encouragement and progression of exercise, and to download the heart rate monitor.
Partially supervised home-based walking exercise: Participants will be asked to exercise at home by walking at a moderate intensity. Each participant will receive an exercise prescription. Participants will receive a heart rate monitor. The heart rate monitors will be used to achieve a desired exercise intensity and to monitor adherence levels. The participants will receive biweekly to weekly phone calls, and monthly in person meetings will be used to address any barriers, provide encouragement, and progress the exercise. | 22 |
| Control The control group will receive standard instructions on exercise for patients with kidney disease similar to what is commonly done in clinical practice. The control group will not receive an exercise prescription or heart rate monitor. Participants will be contacted via phone biweekly to answer any questions and ensure continued study participation. The control group will not meet with the investigators monthly.
Control: Participants will be asked to exercise at home by walking at a moderate intensity. The participants will receive biweekly phone calls, but will not receive a heart rate monitor, individual exercise prescription, or meet with the investigators monthly. | 17 |
| Total | 39 |
Baseline characteristics
| Characteristic | Home-based Walking Exercise | Control | Total |
|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 11 Participants | 12 Participants | 23 Participants |
| Age, Categorical Between 18 and 65 years | 11 Participants | 5 Participants | 16 Participants |
| Age, Continuous | 66.68 Years STANDARD_DEVIATION 4.4 | 68.76 Years STANDARD_DEVIATION 5.7 | 67.6 Years STANDARD_DEVIATION 5 |
| Ethnicity (NIH/OMB) Hispanic or Latino | 3 Participants | 3 Participants | 6 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 19 Participants | 14 Participants | 33 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Asian | 1 Participants | 0 Participants | 1 Participants |
| Race (NIH/OMB) Black or African American | 14 Participants | 14 Participants | 28 Participants |
| Race (NIH/OMB) More than one race | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) White | 7 Participants | 3 Participants | 10 Participants |
| Region of Enrollment United States | 22 participants | 17 participants | 39 participants |
| Sex: Female, Male Female | 14 Participants | 12 Participants | 26 Participants |
| Sex: Female, Male Male | 8 Participants | 5 Participants | 13 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 22 | 0 / 17 |
| other Total, other adverse events | 14 / 22 | 10 / 17 |
| serious Total, serious adverse events | 1 / 22 | 0 / 17 |
Outcome results
Primary
Composite Executive Function
A composite executive functioning score was created by converting 4 individual executive cognitive scores (verbal fluency FAS and animal summary score, digit span backward subtest, and TMT-B) to standardized z scores and then averaging the standardized z scores. A larger change in Z score is considered an improvement.
Time frame: Change from baseline in composite executive function at 6 months
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Home-based Walking Exercise | Composite Executive Function | 0.21 Z score | Standard Deviation 0.47 |
| Control | Composite Executive Function | -.01 Z score | Standard Deviation 0.47 |
Primary
Composite Global Cognitive Function
Determine the effect of a 6-month home-based exercise program on composite global cognitive functioning as determined by principal component analysis of immediate free recall of trials 1-5 on California verbal learning II, long-delay free recall and recognition, and memory discriminability, trail making test part A and part B, digit symbol substitution test, semantic and phonemic fluency, and Digit span subtest in older patients with kidney disease and preclinical cognitive impairment. A composite global cognitive score was created by converting the individual cognitive scores to standardized z scores and then averaging the standardized z scores. An increase in change from baseline to 6 months is considered an improvement.
Time frame: Change from baseline in composite global cognitive function at 6 months
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Home-based Walking Exercise | Composite Global Cognitive Function | .15 Z-score | Standard Deviation 0.37 |
| Control | Composite Global Cognitive Function | .02 Z-score | Standard Deviation 0.33 |
Secondary
Cerebral Blood Flow
Determine the effect of a 6-month exercise program on cerebral blood flow. Change in global cerebral blood measured in mL/100g/min from baseline to 6 months. An larger change is considered an improvement.
Time frame: Change from baseline in cerebral blood flow at 6 months.
Population: Of the total sample of 39 participants, 31 participants were able to undergo MRI scans. Of these, four participants did not complete the study. Good quality data, without motion distortion, were available in 25 participants (two participants were excluded due to motion distortion) at baseline and follow-up and were included in the analysis (11 intervention participants and 14 control participants).
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Home-based Walking Exercise | Cerebral Blood Flow | 1.6 mL/100gm/min | Standard Deviation 9.8 |
| Control | Cerebral Blood Flow | 0.3 mL/100gm/min | Standard Deviation 12.2 |
Secondary
Cognitive Function - Crystalized Cognition
Change from baseline in NIH toolbox cognitive function indices at 6 months. Crystalized cognition. This composite includes : Flanker, Dimensional Change Card Sort, Picture Sequence Memory, List Sorting and Pattern Comparison. This composite score is derived by averaging the standard scores of each of the measures, and then deriving standard scores based on this new distribution. An Age-Corrected Standard Score was used. An larger change from baseline to 6 months is considered an improvement. Scale runs 140 to 23, a higher score means a better outcome.
Time frame: Mean change from baseline to 6 months.
Population: Data was collected in a sub-sample (n=12) to provide pilot data on the NIH-toolbox as part of an administrative supplement. Of the 12 participants that were part of the sub-sample, two did not complete the study. Baseline and follow-up data was available in 10 participants (6=intervention, 4=control).
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Home-based Walking Exercise | Cognitive Function - Crystalized Cognition | 7.7 Score on a scale | Standard Deviation 7.5 |
| Control | Cognitive Function - Crystalized Cognition | 8.3 Score on a scale | Standard Deviation 7.1 |
Secondary
Cognitive Function - Fluid Cognition
Determine the effect of a 6-month exercise program on cognitive function via the NIH toolbox. Fluid cognition. This composite includes: Flanker, Dimensional Change Card Sort, Picture Sequence Memory, List Sorting and Pattern Comparison. This composite score is derived by averaging the standard scores of each of the measures, and then deriving standard scores based on this new distribution. An Age-Corrected Standard Score was used. A larger change from baseline to 6 months is considered an improvement. Scale runs 140 to 23, a higher score means a better outcome.
Time frame: Mean change from baseline to 6 months.
Population: Data was collected in a sub-sample (n=12) to provide pilot data on the NIH-toolbox as part of an administrative supplement. Of the 12 participants that were part of the sub-sample, two did not complete the study. Baseline and follow-up data was available in 10 participants (6=intervention, 4=control).
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Home-based Walking Exercise | Cognitive Function - Fluid Cognition | 5.2 Score on a scale | Standard Deviation 12.2 |
| Control | Cognitive Function - Fluid Cognition | 11 Score on a scale | Standard Deviation 8.9 |
Secondary
Cognitive Function - Total Cognition
Determine the effect of a 6-month exercise program on cognitive function via the NIH toolbox This composite includes: Flanker, Dimensional Change Card Sort, Picture Sequence Memory, List Sorting and Pattern Comparison. This composite score is derived by averaging the standard scores of each of the measures, and then deriving standard scores based on this new distribution. An Age-Corrected Standard Score was used. Scale runs 140 to 23, a higher score means a better outcome. An increased change from baseline to 6 months is considered an improvement
Time frame: Mean change from baseline to 6 months.
Population: Data was collected in a sub-sample (n=12) to provide pilot data on the NIH-toolbox as part of an administrative supplement. Of the 12 participants that were part of the sub-sample, two did not complete the study. Baseline and follow-up data was available in 10 participants (6=intervention, 4=control).
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Home-based Walking Exercise | Cognitive Function - Total Cognition | 8 Score on a scale | Standard Deviation 7.4 |
| Control | Cognitive Function - Total Cognition | 11 Score on a scale | Standard Deviation 7.6 |
Secondary
Hippocampal Volume - Left
Determine the effect of a 6-month exercise program on hippocampal volume. An larger change from baseline to 6 months in left hippocampal volume (cubic millimeters) is considered an improvement.
Time frame: Change from baseline at 6 Months
Population: Of the total sample of 39 participants, 31 participants were able to undergo MRI scans. Of these, four participants did not complete the study. Good quality data, without motion distortion, were available in 21 participants (four participants were excluded due to motion distortion) at baseline and follow-up and were included in the analysis (9 intervention participants and 12 control participants).
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Home-based Walking Exercise | Hippocampal Volume - Left | -.0001 Cubic millimeters | Standard Deviation 0.0002 |
| Control | Hippocampal Volume - Left | .0 Cubic millimeters | Standard Deviation 0.0001 |
Secondary
Hippocampal Volume - Right
Determine the effect of a 6-month exercise program on hippocampal volume. An increased change from baseline to 6 months in right hippocampal volume in cubic millimeters is considered an improvement.
Time frame: Change from baseline hippocampal volume at 6 months.
Population: Of the total sample of 39 participants, 31 participants were able to undergo MRI scans. Of these, four participants did not complete the study. Good quality data, without motion distortion, were available in 21 participants (four participants were excluded due to motion distortion) at baseline and follow-up and were included in the analysis (9 intervention participants and 12 control participants).
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Home-based Walking Exercise | Hippocampal Volume - Right | .003 Cubic millimeters | Standard Deviation 0.0002 |
| Control | Hippocampal Volume - Right | .003 Cubic millimeters | Standard Deviation 0.003 |
Secondary
Motor Function - Balance
Determine the effect of a 6-month exercise program on motor function via the NIH toolbox. Change in balance age corrected standard score from baseline to 6-months (23-140, higher score is better). A larger change is considered an improvement.
Time frame: 6 Months
Population: Data was collected in a sub-sample (n=12) to provide pilot data on the NIH-toolbox as part of an administrative supplement. Of the 12 participants that were part of the sub-sample, two did not complete the study. Baseline and follow-up data was available in 10 participants (6=intervention, 4=control).
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Home-based Walking Exercise | Motor Function - Balance | -6 Score on a scale | Standard Deviation 8.5 |
| Control | Motor Function - Balance | -8 Score on a scale | Standard Deviation 25 |
Secondary
Motor Function - Dexterity
Determine the effect of a 6-month exercise program on motor function via the NIH toolbox. Hand dexterity was determine using age corrected standard scale in the dominant hand. A larger change from baseline to 6 months is considered an improvement. Standard scale range 140-23, higher score is better.
Time frame: 6 Months
Population: Data was collected in a sub-sample (n=12) to provide pilot data on the NIH-toolbox as part of an administrative supplement. Of the 12 participants that were part of the sub-sample, two did not complete the study. Baseline and follow-up data was available in 10 participants (6=intervention, 4=control).
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Home-based Walking Exercise | Motor Function - Dexterity | 1.2 Score on a scale | Standard Deviation 4.5 |
| Control | Motor Function - Dexterity | 1.8 Score on a scale | Standard Deviation 15.5 |
Secondary
Motor Function - Grip Strength
Determine the effect of a 6-month exercise program on motor function via the NIH toolbox. Age corrected grip strength on a standard scale. Standard scale 140-23, higher score is better. An increased change from baseline to 6 months is considered an improvement.
Time frame: Change from baseline in NIH toolbox motor function indices at 6 months
Population: Data was collected in a sub-sample (n=12) to provide pilot data on the NIH-toolbox as part of an administrative supplement. Of the 12 participants that were part of the sub-sample, two did not complete the study. Baseline and follow-up data was available in 10 participants (6=intervention, 4=control).
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Home-based Walking Exercise | Motor Function - Grip Strength | 3 Score on a scale | Standard Deviation 6.2 |
| Control | Motor Function - Grip Strength | -2.5 Score on a scale | Standard Deviation 7.2 |
Secondary
Resting Global Connectivity
Resting global connectivity measured and averaged across 132 regions. A larger change from baseline to 6 months is considered an improvement. Connectivity is a correlation (increased connectivity=higher correlation)
Time frame: Change from baseline at 6 months
Population: Resting global connectivity was collected in a sub-sample (n=12) to provide pilot data. Of the 12 participants that were part of the sub-sample, two did not complete the study. Good quality data without motion distortion at baseline and follow-up was available in 10 participants (5=intervention, 5=control).
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Home-based Walking Exercise | Resting Global Connectivity | .0047 Z-score | Standard Deviation 0.0356 |
| Control | Resting Global Connectivity | -.0310 Z-score | Standard Deviation 0.019 |
Secondary
Vascular Health - Augmentation Index
Vascular function indices of vascular health was assessed using augmentation index at the carotid artery (in percentage, higher percent=more stiff artery). A larger negative change from baseline to 6 months is considered an improvement.
Time frame: 6 Months
Population: Of the 39 participants enrolled, four did not complete the study. Good quality data without motion distortion at baseline and follow-up was available in 34 participants (18=intervention, 16=control).
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Home-based Walking Exercise | Vascular Health - Augmentation Index | -2.6 Percentage | Standard Deviation 12.1 |
| Control | Vascular Health - Augmentation Index | 3.3 Percentage | Standard Deviation 16.6 |
Secondary
Vascular Health - Pulse Wave Velocity
Vascular function indices of vascular health was assessed using pulse wave velocity of the aorta in meters/second (higher number =more stiff aorta). A larger negative change from baseline to 6 months is considered an improvement.
Time frame: 6 Months
Population: Of the 39 participants that were enrolled, four did not complete the study. Good quality data without motion distortion at baseline and follow up was available in 30 participants (15=intervention, 15=control).
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Home-based Walking Exercise | Vascular Health - Pulse Wave Velocity | -.01 Meters per second | Standard Deviation 1.1 |
| Control | Vascular Health - Pulse Wave Velocity | .21 Meters per second | Standard Deviation 0.92 |
Secondary
Vascular Health - Young's Elastic Modulus
Vascular health was assessed by Young's Elastic Modulus (YEM) at the carotid artery. A larger negative change in YEM (measured in kilo pascal, stiffer artery=higher number) from baseline to 6 months is considered an improvement.
Time frame: Change from baseline in vascular health indices at 6 months
Population: Of the total sample of 39 participants, four participants did not complete the study. Good quality data, without motion distortion, were available in 33 participants (two participants were excluded due to motion distortion) at baseline and follow-up and were included in the analysis (17 intervention participants and 16 control participants).
| Arm | Measure | Value (MEAN) |
|---|---|---|
| Home-based Walking Exercise | Vascular Health - Young's Elastic Modulus | -3,175 Kilo pascals |
| Control | Vascular Health - Young's Elastic Modulus | 1,279 Kilo pascals |
Secondary
White Matter Integrity
Whole brain white matter integrity was created by averaging the fractional anisotropy of 80 tracts using region of interest analysis. An increased change from baseline to 6 months in fractional anisotropy (a measure of directionality, 0 = no principle direction, 1 = one principle direction) is considered an improvement.
Time frame: Change from baseline white matter integrity fractional anisotropy at 6 months
Population: Of the total sample of 39 participants, 31 participants were able to undergo MRI scans. Of these, four participants did not complete the study. Good quality data, without motion distortion , were available in 25 participants (two participants were excluded due to motion distortion) at baseline and follow-up and were included in the analysis (11 intervention participants and 14 control participants).
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Home-based Walking Exercise | White Matter Integrity | -.002 units on a scale | Standard Deviation 0.02 |
| Control | White Matter Integrity | .003 units on a scale | Standard Deviation 0.01 |