Effects of Pulse Varieties on Blood Vessel Function in Peripheral Artery Disease

Effects of Pulse Varieties on Blood Vessel Function in Individuals With Peripheral Artery Disease (PAD)

Consumption of a diet containing pulse crops provides flavonoid compounds that will improve vascular function and glycemic control in individuals with Peripheral Artery Disease.

This is a single site, randomized, controlled, food intervention study designed to explore the effects of pulse types and varieties on blood vessel function in individuals with Peripheral Artery Disease.

Phase One(Acute): To identify relative potency of pulse types (beans,peas, lentils,and chickpeas) for vascular activity in healthy participants and participants with Peripheral Artery Disease. Healthy participants (10) and participants with Peripheral Artery Disease (10) will be asked to consume (in random order) one test food per in-person visit over 5 visits scheduled a minimum of 6 days apart. Vascular responsiveness will be monitored non-invasively by peripheral arterial tonometry before consumption of the test food and 2 hours post food consumption. Blood samples will be collected at the same time intervals for analyses, of vascular, inflammatory, and metabolic markers as well as flavonoids present in the pulses.

Phase Two(Chronic): Chronic 8-week study using mixed beans (pinto, kidney, black, and navy) to determine improvements in vascular function, cardiovascular risk factors, and glycemic control in participants with Peripheral Artery Disease (N=75, 25/group). Participants will be randomly assigned to one of the following three groups: i) foods containing 0.6 cup mixed beans/day consumed 5 days per week (total amount is 3 cups mixed beans per week); or, ii) foods containing 0.3 cup mixed beans/day for 5 days per week); or, iii) pulse-free foods (control) consumed 5 days/week. A total of 3 in-person visits for screening, baseline and final will be required during the 8-week study schedule. Assessments of vascular function, cognitive function, food dietary intake and preferences, flavonoid levels and cardiovascular risk markers in blood and urine, glycemic control, and anthropometrics will be completed at baseline and at 8 weeks.

Phase Three(Follow-Up: An 8-week follow-up assessment with a subset of participants (n=10/group, 3 groups) with Peripheral Artery Disease will be done at 2, 4, and at 8 weeks. Assessments of vascular function, cognitive function, food dietary intake, flavonoid levels and cardiovascular risk markers in blood and urine, glycemic control, and anthropometrics will be completed. These assessments will enable us to determine the length of time the benefits of the pulse consumption are retained.

Inclusion Criteria:

Healthy Participants, Acute Phase:

• Healthy volunteers, male or female, >33 years of age, age matched with PAD participants ± 7 years;
• BMI 18-30;
• Glycated hemoglobin < 6.5%;
• Fasting serum total cholesterol < 4 mmol/L and triglycerides < 2.5 mmol/L;
• Blood pressure < 140/90 mm Hg;
• Ankle-brachial Index (ABI) >0.9;
• Willing to comply with the protocol requirements;
• Willing to provide informed consent.

Inclusion Criteria, Participants with Peripheral Artery Disease (Acute Phase and Chronic Phase):

• Male or female, > 40 years of age;
• Documented Peripheral Artery Disease including those with claudication as defined by an ankle brachial Index of ≤ 0.90; or asymptomatic carotid stenosis of > 50% or confirmed by imaging; or having had a previous intervention for Peripheral Artery Disease or carotid disease;
• Stable medication profile with no changes required for the past 3 months;
• Willing to comply with the protocol requirements;
• Willing to provide informed consent.

Exclusion Criteria:

Healthy Participants, Acute Phase:

• Currently smoking, or smoking within the last 6 months;
• Clinically diagnosed disease affecting the heart, liver, kidneys, lungs, gastrointestinal, endocrine or blood/immune systems that requires medical treatment;
• Taking any prescribed medication with the exception of birth control and hormone (estrogen) replacement therapy;
• Pregnancy;
• Amputation of upper or lower extremity on both sides;
• History of severe gastrointestinal reactions or allergies to pulses or ingredients used to prepare the pulse-containing and pulse-free foods.

Exclusion Criteria, Participants with Peripheral Artery Disease (Acute Phase and Chronic Phase):

• Currently smoking, or smoking within the last 6 months;
• Type 1 diabetes;
• Renal failure requiring dialysis;
• Acute cardiovascular event or medical illness within the past 3 months precluding study participation;
• Hormone (estrogen) replacement therapy;
• Amputation of upper or lower extremity on both sides;
• History of severe gastrointestinal reactions or allergies to pulses or ingredients used to prepare the pulse-containing and pulse-free foods;
• Currently participating in or having participated in a food study within the last 3 months unless randomized to a control group and consumed no study foods;
• High pulse consumption (greater or equal to 2 servings per week);
• Inability to adhere to a regular diet;
• Additional intake of pulses other than the requirements outlined in the study.