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

Not Applicable

Completed

• Conditions: Microangiopathy, Diabetic; Vascular Endothelium; Arterial Stiffness; Polyphenol; Optical Tomography; Healthy Participants
• Interventions: Dietary Supplement: Cocoa flavanol; Other: Placebo

• Registration Number: NCT05449782
• Lead Sponsor: University of Surrey

Brief Summary

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.

Detailed Description

Not available

Study Timeline

• Study Start: 2021-05-17
• Study First Submitted: 2021-05-18
• Primary Completion: 2021-06-01
• Status Verified: 2022-05
• Study Completion: 2022-05-17
• Study First Submitted QC: 2022-07-04
• Last Update Submitted: 2022-07-04
• Study First Posted: 2022-07-08
• Last Update Posted: 2022-07-08

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 22

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.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Type 2 diabetes participants: Cocoa flavanol - Placebo	Cocoa flavanol	Participants with type 2 diabetes receiving cocoa flavanols on first study day and placebo on second study day
Type 2 diabetes participants: Cocoa flavanol - Placebo	Placebo	Participants with type 2 diabetes receiving cocoa flavanols on first study day and placebo on second study day
Healthy participant: Placebo - Cocoa flavanol	Cocoa flavanol	Healthy participants receiving placebo on first study day and cocoa flavanols on second study day
Type 2 diabetes participants: Placebo - Cocoa flavanol	Cocoa flavanol	Participants with type 2 diabetes receiving placebo on first study day and cocoa flavanols on second study day
Healthy participants: Cocoa flavanol - Placebo	Cocoa flavanol	Healthy participants receiving cocoa flavanols on first study day and placebo on second study day
Healthy participants: Cocoa flavanol - Placebo	Placebo	Healthy participants receiving cocoa flavanols on first study day and placebo on second study day
Healthy participant: Placebo - Cocoa flavanol	Placebo	Healthy participants receiving placebo on first study day and cocoa flavanols on second study day
Type 2 diabetes participants: Placebo - Cocoa flavanol	Placebo	Participants with type 2 diabetes receiving placebo on first study day and cocoa flavanols on second study day

Primary Outcome Measures

Name	Time	Method
Macrovascular endothelial function	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
Microvascular dilation	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

Secondary Outcome Measures

Name	Time	Method
Blood pressure	Change at 2 hours as compared to baseline after ingestion of cocoa flavanol vs placebo	Upper arm blood pressure measured with Arteriograph
Arterial stiffness	Change at 2 hours as compared to baseline after ingestion of cocoa flavanol vs placebo	Pulse wave velocity (Arteriograph)
Leg perfusion pressure	Change at 2 hours as compared to baseline after ingestion of cocoa flavanol vs placebo	Doppler based perfusion pressure of leg

Trial Locations

Locations (1)

University of Surrey; 🇬🇧 Guildford, United Kingdom