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NCT Number: NCT05449782

Macro- and Microvascular Response to Cocoa Flavanols in Healthy and Type 2 Diabetes

The greatest challenge in our ageing society are cardiovascular diseases such as stroke, heart attack, peripheral artery disease of the legs with non-healing wounds (ulcers), or diabetes. Specific diets with high polyphenol content are associated with lower incidence of cardiovascular disease and can improve macrovascular function when consumed acutely and chronically. Which role the smallest blood vessels (microcirculation) play in this and if the microcirculation responds to therapies is not well understood. One reason for this is that no generally available medical instrument has the resolution to study the microcirculation. The recently developed optical coherence tomography angiography (OCTA), currently mainly used by eye doctors, is able to visualise the microcirculation.

The current randomised controlled cross-over proof-of-concept study will test the acute effect of a cocoa flavanol intervention on cutaneous microvascular structure and function of hands and feet together with macrovascular function of upper and lower extremities in healthy and type 2 diabetes participants. It is the hypothesis that cocoa flavanol intervention as compared to placebo can acutely increase microvascular vasodilation and macrovascular endothelial function in arms and legs together with arterial stiffness in both healthy and type 2 diabetes participants.

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Key information

Conditions

Microangiopathy, Diabetic Arterial Stiffness Cardiovascular Diseases Diabetes Complications Diabetes Mellitus Diabetic Angiopathies Endocrine System Diseases Healthy Participants Optical Tomography Polyphenol Vascular Diseases Vascular Endothelium

Age range

20 year–70 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

University of Surrey

Guildford, GU2 7XH, United Kingdom

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Healthy:

Inclusion criteria

  • Healthy, 20-70 years
  • BMI 20-30 kg/m^2

Exclusion criteria

  • Diabetes mellitus
  • Symptoms of acute infection
  • Cardiac rhythm other than sinus
  • Active malignancy
  • Clinical signs or symptoms of cardiovascular disease (coronary artery disease, lower extremity artery disease, cerebrovascular disease): angina pectoris, dyspnea, palpitation, syncope, claudication
  • Active vasoactive medication.

Type 2 Diabetes:

Inclusion criteria

  • Type 2 diabetes mellitus
  • 20-70 years
  • BMI 20-30 kg/m^2

Exclusion criteria

  • Symptoms of acute infection
  • Cardiac rhythm other than sinus
  • Active malignancy
  • Clinical signs or symptoms of cardiovascular disease (coronary artery disease, lower extremity artery disease, cerebrovascular disease): angina pectoris, dyspnea, palpitation, syncope, claudication
  • Active vasoactive medication.

Treatment and study plan

Cocoa flavanol

Dietary Supplement

Commercially available Cocoa Via Brand capsules containing 1350 mg cocoa flavanols (6 capsules)

Placebo

Other

Capsules identical to ccocoa flavanol capsules filled with calorically matched brown sugar (6 capsules)

Primary outcomes

  1. Microvascular dilation

    Time frame: Change at 2 hours as compared to baseline after ingestion of cocoa flavanol vs placebo

    Microvascular diameter increase in response to 5 min limb occlusion on hands and feet

  2. Macrovascular endothelial function

    Time frame: Change at 2 hours as compared to baseline after ingestion of cocoa flavanol vs placebo

    Flow-mediated dilation determined with ultrasound in brachial and common femoral artery

Secondary outcomes

  1. Arterial stiffness

    Time frame: Change at 2 hours as compared to baseline after ingestion of cocoa flavanol vs placebo

    Pulse wave velocity (Arteriograph)

  2. Blood pressure

    Time frame: Change at 2 hours as compared to baseline after ingestion of cocoa flavanol vs placebo

    Upper arm blood pressure measured with Arteriograph

  3. Leg perfusion pressure

    Time frame: Change at 2 hours as compared to baseline after ingestion of cocoa flavanol vs placebo

    Doppler based perfusion pressure of leg

Other outcomes

  1. Photoplethysmography (PPG) based pulse wave velocity (PWV)

    Time frame: Change at 2 hours as compared to baseline after ingestion of cocoa flavanol vs placebo

    PWV velocity calculated based on PPG sensor at hand and foot

  2. Photoplethysmography (PPG) blood flow

    Time frame: Change at 2 hours as compared to baseline after ingestion of cocoa flavanol vs placebo

    Based on PPG signals on hand and foot

Sponsors and collaborators

Lead sponsor

University of Surrey

Other

Registry information

Official study title

Proof-of-concept Study to Investigate Hand and Foot Microvascular Response to Cocoa Flavanols in Healthy and Type 2 Diabetes Participant

Important dates

Study start
2021
Primary completion
2021
Study completion
2022
First posted
Jul 8, 2022
Registry last updated
Jul 8, 2022

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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