ENhancing Exercise With LIGHT to Improve Functioning in PAD

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.