Grant Abstract: COCOA to improve walking performance in Peripheral Artery Disease: the COCA-PAD Study

Grant Number: 5R21AG050897-02
PI Name: McDermott
Project Title: COCOA to improve walking performance in Peripheral Artery Disease: the COCA-PAD Study

Abstract: Older people with lower extremity peripheral artery disease (PAD) have greater functional impairment and faster functional decline than those without PAD. PAD-related functional limitations are associated with increased morbidity and mortality, increased health care costs, and loss of independence. Yet few medical therapies improve functioning or prevent mobility loss in older people with PAD.
Cocoa is the dried and fermented seed from theobroma cacao, from which chocolate is made.
Epicatechin, a major ingredient of cocoa, has therapeutic effects on vasculature and skeletal muscle that may improve functioning in people with PAD. Our COCOA-PAD Study (R21-AG050897) is a funded pilot randomized clinical trial designed to gather preliminary data to test our hypothesis that epicatechin-rich cocoa improves six-minute walk performance at 6-month follow-up in 44 people with PAD age 65 and older.
We now request supplemental funding through PA 16-319 to add novel biomarkers to our funded
COCOA-PAD-Study, to determine whether epicatechin-rich cocoa increases calf skeletal muscle perfusion, reduces calf muscle oxidative stress, and promotes calf skeletal muscle regeneration in older people with PAD. We propose three additional outcomes at baseline and follow-up to our funded COCOA-PAD clinical trial: a) MRI-measured calf muscle perfusion; b) calf muscle biopsy muscle regeneration measures and c) calf muscle oxidative stress measures. These measures can be obtained for a relatively small marginal cost and without disrupting the parent study. The calf muscle biopsy procedure is already included in our funded COCOA-PAD Study. Our newly proposed skeletal muscle measures will require an additional 50 mg of muscle that can be obtained at the time of the muscle biopsy. Participants will be asked to undergo an MRI perfusion test at one of their already scheduled baseline and follow-up visits. Costs of recruitment, intervention, and the muscle biopsy procedure are funded by the parent R21.
This request for supplemental funding is responsive to the purpose of PA 16-319 because it stimulates dietary supplement research in a population of older PAD patients, where supplement research is lacking. Our request for supplemental funding allows us to keep the originally funded study intact while expanding the originally funded study’s impact with the additionally proposed outcome measures. Results will improve understanding of the role of dietary supplements in human health and prevention of disability for the large and growing number of people with PAD.

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