Peripheral Artery DiseaseENLIGHTEN PADNCT06399900
ENhancing Exercise With LIGHT to Improve Functioning in PAD
A study testing Far red light therapy and Home-based walking exercise in people with Peripheral Artery Disease and Peripheral Vascular Disease, run by Northwestern University at 1 site in United States.
Trial summary
The ENLIGHTEN PAD Trial will collect preliminary data to test whether daily 660 nm light treatment of the lower extremities immediately before home-based walking exercise sessions improves six-minute walk distance at 4-month follow-up, compared to sham light, in people with lower extremity peripheral artery disease… Read more about this study
- Who is it for?
- Ages 50 years and older
- Conditions the study is for
- Peripheral Artery Disease, Peripheral Vascular Disease, Aging
- What is being tested?
- Far red light therapy and Home-based walking exercise
- Type of treatment
- Medical device, Lifestyle or therapy programme
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 32 participants
- Where
- 1 siteUnited States
- Study dates
- 12 Aug 2024to 31 Jan 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 50 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- First, all participants will be age 50 and older. Second, all participants will have PAD. PAD will be defined as:
- An ABI <= 0.90 at baseline.
- Vascular lab evidence of PAD (such as a toe brachial pressure <= 0.70 or an ankle brachial index less than or equal to 0.90), or angiographic evidence of PAD defined as at least 70% stenosis of an artery supplying the lower extremities.
- An ABI of >0.90 and <= 1.00 who experience a 20% or greater drop in ABI in either leg after the heel-rise test.
Who cannot join
- Above- or below-knee amputation
- Critical limb ischemia defined as an ABI <0.40 with symptoms of rest pain
- Wheelchair confinement or requiring a walker to ambulate
- Walking is limited by a symptom other than PAD
- Current foot ulcer on bottom of foot
- Failure to successfully complete the study run-in
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- Planned major surgery, coronary or leg revascularization during the next four months
- Major surgery, coronary or leg revascularization or major cardiovascular event in the previous three months
- Major medical illness including lung disease requiring oxygen, Parkinson's disease, a life-threatening illness with life expectancy less than six months, or cancer requiring treatment in the previous two years. [NOTE: potential participants may still qualify if they have had treatment for an early stage cancer in the past two years and the prognosis is excellent, unless the cancer is located in the lower extremities. Participants who require oxygen only at night may still qualify.]
- Mini-Mental Status Examination (MMSE) score < 23
- Non-English speaking
- Participation in or completion of a clinical trial in the previous three months. [NOTE: after completing a stem cell or gene therapy intervention, participants will become eligible after the final study follow-up visit of the stem cell or gene therapy study so long as at least six months have passed since the final intervention administration. After completing a supplement or drug therapy (other than stem cell or gene therapy), participants will be eligible after the final study follow-up visit as long as at least three months have passed since the final intervention of the trial.]
- Visual impairment that limits walking ability.
- Six-minute walk distance of <400 feet or >1700 feet.
- Participation in a supervised treadmill exercise program or a cardiac rehabilitation program in previous three months or planning to begin a supervised treadmill exercise program or a cardiac rehabilitation program in the next five months.
- Unwilling to avoid red light therapy outside of study participation.
- Baseline blood pressure <100/45.
- In addition to the above criteria, investigator discretion will be used to determine if the trial is unsafe or not a good fit for the potential participant.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
Northwestern University
Chicago, Illinois, 60611
Mary McDermott, MD, 312-503-6419, mdm608@northwestern.edu
About this study
Official title: ENhancing Exercise With LIGHT to Improve Functioning in PAD: the ENLIGHTEN PAD Trial
The ENLIGHTEN PAD Trial will collect preliminary data to test whether daily 660 nm light treatment of the lower extremities immediately before home-based walking exercise sessions improves six-minute walk distance at 4-month follow-up, compared to sham light, in people with lower extremity peripheral artery disease (PAD).
Read the detailed description
The ENLIGHTEN PAD Trial will collect preliminary data to test whether daily 660 nm light treatment of the lower extremities immediately before home-based walking exercise sessions improves six-minute walk distance at 4-month follow-up, compared to sham light, in people with lower extremity peripheral artery disease (PAD) (Primary Aim #1). In Primary Aim #2, the investigators will measure the acute effect of the first treatment of 660 nm light on six-minute walk distance and on walking intensity (measured with the ActiGraph accelerometer) during the six-minute walk. In secondary and exploratory aims, the investigators will delineate biologic pathways by which 660 nm light enhances the benefits of home-based walking exercise, by measuring the effects of 660 nm light on exercise intensity during the exercise intervention and by measuring the effects of 660 nm light on plasma nitrosothiols, leg perfusion, and gastrocnemius muscle health and mitochondrial activity. Exercise intensity will be measured by the well validated ActiGraph accelerometer.
The ENLIGHTEN PAD Trial is a Phase II multi-centered randomized clinical trial. Thirty-two participants with PAD will be randomized at one of two centers: Northwestern University (PI: MM McDermott, MD) and the University of Alabama (PI: Nicole Lohr MD, PhD) to either 660 nm light + home-based exercise or sham light + home-based exercise for four months. Both groups of participants will receive the same home-based high intensity walking exercise intervention.
- Being tested
- Far red light therapy, Sham light therapy, Home-based walking exercise
- Keywords
- light therapy, peripheral artery disease, exercise
- Medical subject headings
- Peripheral Arterial Disease, Peripheral Vascular Diseases, Mobility Limitation, Motor Activity
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Far red light therapyDevice
All participants will receive one far red light device per leg. Participants will be asked to use their two light devices daily, exposing their bare legs to the devices for 10 minutes twice per day. An unblinded study coordinator will deliver the light devices to each participant's home, positioning the devices 15 cm behind the participant's heels, using tape on the floor to mark where the light and feet should be positioned. Twice each day, the participant flips a switch on the device to begin each session. A timer will turn off the device after 10 minutes. A power meter will measure the total time that the device was turned on. Participants will also record use of the light in a log.
Sham light therapyDevice
All participants will receive one sham device per leg. Participants will be asked to use their two light devices daily, exposing their bare legs to the devices for 10 minutes twice per day. An unblinded study coordinator will deliver the light devices to each participant's home, positioning the devices 15 cm behind the participant's heels, using tape on the floor to mark where the light and feet should be positioned. Twice each day, the participant flips a switch on the device to begin each session. A timer will turn off the device after 10 minutes. A power meter will measure the total time that the device was turned on. Participants will also record use of the light in a log.
Home-based walking exerciseBehavioural
This study involves a 16 week intervention where participants will walk at home for exercise with guidance from a study coach. Participants will have 4 in-person visits in the first four weeks and then have weekly phone calls in the last 12 weeks of the intervention with their coach.
| Study group | Role | What they receive |
|---|---|---|
| Far red light therapy + home-based walking exercise | Experimental | Subgroup of participants receiving home-based walking exercise and the 670 nm far red light device Receives: Device: Far red light therapy; Behavioral: Home-based walking exercise |
| Sham therapy + home-based walking exercise | Sham comparator | Subgroup of participants receiving home-based walking exercise and the sham light device, far red light device covered with blue filter paper to block 670 nm light, resulting in mean power generated of 0.24 mW/cm2, compared to 26.3 mW/cm2 for the intervention, a 100-fold difference. Receives: Device: Sham light therapy; Behavioral: Home-based walking exercise |
What is being measured
The primary outcome is the main question the study is designed to answer.
Six-Minute Walk Distance
Change in six-minute walk distance
Measured: Measured at baseline and 4-month follow-up
Six-Minute Walk Distance
Change in six-minute walk distance (acute effect)
Measured: Measured immediately after the first light treatment (within 15 minutes after the first treatment, acute effect)
Secondary outcomes (7)
Six-Minute Walk Distance
Change in six-minute walk distance (chronic effect)
Measured: Measured at 4-month follow-up, 24 hours after the final treatment
Gastrocnemius Perfusion
Changes in calf perfusion at 3 Tesla measured with arterial spin labeling with MRI and post-cuff occlusion hyperemia
Measured: Measured at baseline and 4-month follow-up
Minutes of High Intensity Exercise
Change in minutes of high intensity exercise/week (measured by the ActiGraph activity monitor)
Measured: Measured at baseline and 4-month follow-up
Mean Exercise Intensity
Change in mean exercise intensity (measured by the ActiGraph activity monitor)
Measured: Measured at baseline and 4-month follow-up
Mean Exercise Intensity During Six-Minute Walk
Change in mean exercise intensity during the six-minute walk (measured by the ActiGraph activity monitor)
Measured: Measured at baseline and 4-month follow-up
Walking Impairment Questionnaire Distance Score
Participant report of difficulty walking increasingly longer distances. Score range 0-100, 100 is best
Measured: Measured at baseline and 4-month follow-up
PROMIS Mobility Score
PROMIS mobility score from administered PROMIS questionnaire. Score range is from zero to infinity and a higher score means a better outcome.
Measured: Measured at baseline and 4-month follow-up
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted6 May 2024
- Study start12 Aug 2024
- Primary completion30 Sep 2026 (estimated)
- Study completion31 Jan 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Peripheral Artery DiseaseStudies of the same condition, open and under way.
- More trials run by Northwestern UniversityThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Thirty-two participants with PAD will be randomized to either 660 nm light + home-based exercise or sham light + home-based exercise for four months. Both groups will receive the same home-based high intensity walking exercise intervention.
- Masking
- Triple blind
- Who is masked
- Participant, Care provider, Outcomes assessor
- Enrolment
- 32 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Northwestern University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Mary McDermott, Northwestern University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06399900
- Sponsor's protocol ID
- STU00219103
- Acronym
- ENLIGHTEN PAD
- Status last verified
- Apr 2026
- First submitted
- 30 Apr 2024
- Last updated
- 15 Apr 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 15 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- ENhancing Exercise With LIGHT to Improve Functioning in PAD: the ENLIGHTEN PAD Trial
- ClinicalTrials.gov ID
- NCT06399900
- Acronym / sponsor ID
- ENLIGHTEN PAD / STU00219103
- Keywords
- light therapy, peripheral artery disease, exercise
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 32 participants (estimated)
- Lead sponsor
- Northwestern UniversityUniversity, hospital or other
- Study start
- 12 Aug 2024 (actual)
- Primary completion
- 30 Sep 2026 (estimated)
- Study completion
- 31 Jan 2027 (estimated)
- First posted
- 6 May 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The ENLIGHTEN PAD Trial will collect preliminary data to test whether daily 660 nm light treatment of the lower extremities immediately before home-based walking exercise sessions improves six-minute walk distance at 4-month follow-up, compared to sham light, in people with lower extremity peripheral artery disease (PAD).
Detailed description
The ENLIGHTEN PAD Trial will collect preliminary data to test whether daily 660 nm light treatment of the lower extremities immediately before home-based walking exercise sessions improves six-minute walk distance at 4-month follow-up, compared to sham light, in people with lower extremity peripheral artery disease (PAD) (Primary Aim #1). In Primary Aim #2, the investigators will measure the acute effect of the first treatment of 660 nm light on six-minute walk distance and on walking intensity (measured with the ActiGraph accelerometer) during the six-minute walk. In secondary and exploratory aims, the investigators will delineate biologic pathways by which 660 nm light enhances the benefits of home-based walking exercise, by measuring the effects of 660 nm light on exercise intensity during the exercise intervention and by measuring the effects of 660 nm light on plasma nitrosothiols, leg perfusion, and gastrocnemius muscle health and mitochondrial activity. Exercise intensity will be measured by the well validated ActiGraph accelerometer.
The ENLIGHTEN PAD Trial is a Phase II multi-centered randomized clinical trial. Thirty-two participants with PAD will be randomized at one of two centers: Northwestern University (PI: MM McDermott, MD) and the University of Alabama (PI: Nicole Lohr MD, PhD) to either 660 nm light + home-based exercise or sham light + home-based exercise for four months. Both groups of participants will receive the same home-based high intensity walking exercise intervention.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind (participant, care provider, outcomes assessor)
- Number of arms
- 2
- Model description
- Thirty-two participants with PAD will be randomized to either 660 nm light + home-based exercise or sham light + home-based exercise for four months. Both groups will receive the same home-based high intensity walking exercise intervention.
| Arm | Type | Receives |
|---|---|---|
| Far red light therapy + home-based walking exercise | Experimental | Device: Far red light therapy, Behavioral: Home-based walking exerciseSubgroup of participants receiving home-based walking exercise and the 670 nm far red light device |
| Sham therapy + home-based walking exercise | Sham comparator | Device: Sham light therapy, Behavioral: Home-based walking exerciseSubgroup of participants receiving home-based walking exercise and the sham light device, far red light device covered with blue filter paper to block 670 nm light, resulting in mean power generated of 0.24 mW/cm2, compared to 26.3 mW/cm2 for the intervention, a 100-fold difference. |
Who may qualify
- Ages
- 50 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- First, all participants will be age 50 and older. Second, all participants will have PAD. PAD will be defined as:
- An ABI <= 0.90 at baseline.
- Vascular lab evidence of PAD (such as a toe brachial pressure <= 0.70 or an ankle brachial index less than or equal to 0.90), or angiographic evidence of PAD defined as at least 70% stenosis of an artery supplying the lower extremities.
- An ABI of >0.90 and <= 1.00 who experience a 20% or greater drop in ABI in either leg after the heel-rise test.
Key exclusion criteria (18 listed)
- Above- or below-knee amputation
- Critical limb ischemia defined as an ABI <0.40 with symptoms of rest pain
- Wheelchair confinement or requiring a walker to ambulate
- Walking is limited by a symptom other than PAD
- Current foot ulcer on bottom of foot
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Far red light therapyAll participants will receive one far red light device per leg. Participants will be asked to use their two light devices daily, exposing their bare legs to the devices for 10 minutes twice per day. An unblinded study coordinator will deliver the light devices to each participant's home, positioning the devices 15 cm behind the participant's heels, using tape on the floor to mark where the light and feet should be positioned. Twice each day, the participant flips a switch on the device to begin each session. A timer will turn off the device after 10 minutes. A power meter will measure the total time that the device was turned on. Participants will also record use of the light in a log. | Device | Far red light therapy + home-based walking exercise |
| Sham light therapyAll participants will receive one sham device per leg. Participants will be asked to use their two light devices daily, exposing their bare legs to the devices for 10 minutes twice per day. An unblinded study coordinator will deliver the light devices to each participant's home, positioning the devices 15 cm behind the participant's heels, using tape on the floor to mark where the light and feet should be positioned. Twice each day, the participant flips a switch on the device to begin each session. A timer will turn off the device after 10 minutes. A power meter will measure the total time that the device was turned on. Participants will also record use of the light in a log. | Device | Sham therapy + home-based walking exercise |
| Home-based walking exerciseThis study involves a 16 week intervention where participants will walk at home for exercise with guidance from a study coach. Participants will have 4 in-person visits in the first four weeks and then have weekly phone calls in the last 12 weeks of the intervention with their coach. | Behavioural | Far red light therapy + home-based walking exercise, Sham therapy + home-based walking exercise |
Primary outcome
Six-Minute Walk Distance
Time frame: Measured at baseline and 4-month follow-up
Change in six-minute walk distance
Six-Minute Walk Distance
Time frame: Measured immediately after the first light treatment (within 15 minutes after the first treatment, acute effect)
Change in six-minute walk distance (acute effect)
7 secondary outcomes
Six-Minute Walk Distance
Time frame: Measured at 4-month follow-up, 24 hours after the final treatment
Gastrocnemius Perfusion
Time frame: Measured at baseline and 4-month follow-up
Minutes of High Intensity Exercise
Time frame: Measured at baseline and 4-month follow-up
Mean Exercise Intensity
Time frame: Measured at baseline and 4-month follow-up
Mean Exercise Intensity During Six-Minute Walk
Time frame: Measured at baseline and 4-month follow-up
Walking Impairment Questionnaire Distance Score
Time frame: Measured at baseline and 4-month follow-up
PROMIS Mobility Score
Time frame: Measured at baseline and 4-month follow-up
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 15 Apr 2026.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Far red light therapy and Home-based walking exercise in people with Peripheral Artery Disease and Peripheral Vascular Disease, run by Northwestern University at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 18 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 15 Apr 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Mary McDermott, MD (13125036419, mdm608@northwestern.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Six-Minute Walk Distance (time frame: Measured at baseline and 4-month follow-up). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 15 Apr 2026.