Peripheral Artery DiseaseLIGHT PADNCT06165016
Far Red Light to Improve Functioning in PAD
A study testing Far red light therapy in people with Peripheral Artery Disease and Peripheral Vascular Disease, run by Northwestern University at 2 sites in United States.
Trial summary
The LIGHT PAD Trial is a Phase II multi-centered randomized clinical trial to collect preliminary data to test whether daily far red light treatment of the lower extremities in people with PAD improves six-minute walk distance, lower extremity perfusion, and ischemia-related damage in gastrocnemius muscle at… 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
- Type of treatment
- Medical device
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 32 participants
- Where
- 2 sitesUnited States
- Study dates
- 14 Feb 2024to 31 Dec 2026
- 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
Show all 18Show fewer
- 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
2 sites in 1 country.
United States2 sites
University of Alabama at Birmingham
Birmingham, Alabama, 35294
Northwestern University
Chicago, Illinois, 60611
About this study
Official title: Far Red Light to Improve Functioning in PAD: The LIGHT PAD Trial
The LIGHT PAD Trial is a Phase II multi-centered randomized clinical trial to collect preliminary data to test whether daily far red light treatment of the lower extremities in people with PAD improves six-minute walk distance, lower extremity perfusion, and ischemia-related damage in gastrocnemius muscle at four-month follow-up, compared to a sham control. Participants will complete 10 minutes of twice daily home treatment with either far red light or a sham light for four months.
Read the detailed description
The LIGHT PAD Trial is a Phase II multi-centered randomized clinical trial to collect preliminary data to test whether daily far red light treatment of the lower extremities in people with PAD improves six-minute walk distance, lower extremity perfusion, and ischemia-related damage in gastrocnemius muscle at four-month follow-up, compared to a sham control. Participants will complete 10 minutes of twice daily home treatment with either far red light or a sham light for four months.
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 daily far red light or sham control for four months. The primary outcome, change in six-minute walk, will be measured at four month follow-up, immediately after the final administration of far red light or sham. In secondary and exploratory aims, investigators will distinguish between acute and chronic effects of far red light on six-minute walk, measure the effects of far red light on patient-reported outcomes, and delineate biologic pathways by which far red light improves walking performance in PAD, by measuring change in plasma nitrite and nitrosothiols, gastrocnemius muscle perfusion (MRI arterial spin labeling) and gastrocnemius muscle health and mitochondrial activity. If the proposed hypotheses are supported by this Phase II trial, results will be used to design a definitive randomized trial of far red light for people with PAD.
To achieve the specific aims, investigators will randomize 32 participants age 50 and older with PAD to one of two groups: far red light therapy or sham therapy. Participants will be followed for four months.
- Being tested
- Far red light therapy, Sham light therapy
- Keywords
- light therapy
- Medical subject headings
- Peripheral Arterial Disease, Peripheral Vascular Diseases, Mobility Limitation
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. A 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. A 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.
| Study group | Role | What they receive |
|---|---|---|
| Far red light therapy | Experimental | Subgroup of participants receiving the 670 nm far red light device Receives: Device: Far red light therapy |
| Sham therapy | Sham comparator | Subgroup of participants receiving 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 |
What is being measured
The primary outcome is the main question the study is designed to answer.
Six-Minute Walk Distance
Four month change in six-minute walk distance
Measured: Measured at baseline and 4 month follow-up
Secondary outcomes (5)
Walking Impairment Questionnaire Distance (WIQ) Score
Four month change in the WIQ distance score. Score range 0-100, 100 is best
Measured: Measured at baseline and 4 month follow-up
Six-Minute Walk Distance
Acute change in six-minute walk distance after first light therapy
Measured: Measured immediately after the first light treatment (within 15 minutes after the first treatment, acute effect)
Six-minute walk distance.
Four month change in 6-minute walk, measured 24 hours after last treatment.
Measured: Measured at 4-month follow-up, 24 hours after the final treatment.
Calf muscle perfusion
Changes in calf muscle perfusion at 3 Tesla measured with arterial spin labeling with MRI and post-cuff occlusion hyperemia
Measured: Measured at baseline and four-month follow up
6-minute walk
Change in 6-minute walk from baseline to 2-month follow-up
Measured: Baseline to 2-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 posted11 Dec 2023
- Study start14 Feb 2024
- Primary completion30 Sep 2026 (estimated)
- Study completion31 Dec 2026 (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
- Investigators will randomize 32 participants age 50 and older with PAD to one of two groups: far red light therapy or sham therapy. Participants will be followed for four months.
- Masking
- Triple blind
- Who is masked
- Participant, Care provider, Outcomes assessor
- Enrolment
- 32 participants (actual)
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
- NCT06165016
- Sponsor's protocol ID
- STU00218660
- Acronym
- LIGHT PAD
- Status last verified
- Jun 2026
- First submitted
- 19 Nov 2023
- Last updated
- 4 Jun 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 4 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Far Red Light to Improve Functioning in PAD: The LIGHT PAD Trial
- ClinicalTrials.gov ID
- NCT06165016
- Acronym / sponsor ID
- LIGHT PAD / STU00218660
- Keywords
- light therapy
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 32 participants (actual)
- Lead sponsor
- Northwestern UniversityUniversity, hospital or other
- Study start
- 14 Feb 2024 (actual)
- Primary completion
- 30 Sep 2026 (estimated)
- Study completion
- 31 Dec 2026 (estimated)
- First posted
- 11 Dec 2023 (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 LIGHT PAD Trial is a Phase II multi-centered randomized clinical trial to collect preliminary data to test whether daily far red light treatment of the lower extremities in people with PAD improves six-minute walk distance, lower extremity perfusion, and ischemia-related damage in gastrocnemius muscle at four-month follow-up, compared to a sham control. Participants will complete 10 minutes of twice daily home treatment with either far red light or a sham light for four months.
Detailed description
The LIGHT PAD Trial is a Phase II multi-centered randomized clinical trial to collect preliminary data to test whether daily far red light treatment of the lower extremities in people with PAD improves six-minute walk distance, lower extremity perfusion, and ischemia-related damage in gastrocnemius muscle at four-month follow-up, compared to a sham control. Participants will complete 10 minutes of twice daily home treatment with either far red light or a sham light for four months.
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 daily far red light or sham control for four months. The primary outcome, change in six-minute walk, will be measured at four month follow-up, immediately after the final administration of far red light or sham. In secondary and exploratory aims, investigators will distinguish between acute and chronic effects of far red light on six-minute walk, measure the effects of far red light on patient-reported outcomes, and delineate biologic pathways by which far red light improves walking performance in PAD, by measuring change in plasma nitrite and nitrosothiols, gastrocnemius muscle perfusion (MRI arterial spin labeling) and gastrocnemius muscle health and mitochondrial activity. If the proposed hypotheses are supported by this Phase II trial, results will be used to design a definitive randomized trial of far red light for people with PAD.
To achieve the specific aims, investigators will randomize 32 participants age 50 and older with PAD to one of two groups: far red light therapy or sham therapy. Participants will be followed for four months.
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
- Investigators will randomize 32 participants age 50 and older with PAD to one of two groups: far red light therapy or sham therapy. Participants will be followed for four months.
| Arm | Type | Receives |
|---|---|---|
| Far red light therapy | Experimental | Device: Far red light therapySubgroup of participants receiving the 670 nm far red light device |
| Sham therapy | Sham comparator | Device: Sham light therapySubgroup of participants receiving 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. A 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 |
| 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. A 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 |
Primary outcome
Six-Minute Walk Distance
Time frame: Measured at baseline and 4 month follow-up
Four month change in six-minute walk distance
5 secondary outcomes
Walking Impairment Questionnaire Distance (WIQ) Score
Time frame: Measured at baseline and 4 month follow-up
Six-Minute Walk Distance
Time frame: Measured immediately after the first light treatment (within 15 minutes after the first treatment, acute effect)
Six-minute walk distance.
Time frame: Measured at 4-month follow-up, 24 hours after the final treatment.
Calf muscle perfusion
Time frame: Measured at baseline and four-month follow up
6-minute walk
Time frame: Baseline to 2-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 4 Jun 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. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
2 sites 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 in people with Peripheral Artery Disease and Peripheral Vascular Disease, run by Northwestern University at 2 sites 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: under way, not looking for participants, as of the sponsor's last update on 4 Jun 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites 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?
The record lists no contact. The official record names the sponsor, who can be asked directly. 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). 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 4 Jun 2026.