Healthy Age-dependent Reference Values for Microvascular Structure and Function

Study Overview
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Brief Summary
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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. How healthy ageing affects the smallest blood vessels (microcirculation) and 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. We have developed an automated software (OCTAVA) to determine metrics to characterise the microcirculation on the layers of density, diameter and tortuosity. In the current study we aim at providing reference values of these metrics in hands and feet of healthy people according to age together with macrovascular function in arms and legs.

Official Title
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Assessing Age-dependent Reference Values for Microvascular Structure and Function in Healthy Participant Together With Macrovascular Function With Optical Coherence Tomography Angiography

Conditions
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Vascular Endothelium, Microvascular Circulation, Arterial Stiffness, Healthy Ageing

Intervention / Treatment
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* Other: Age


Participation Criteria
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Eligibility Criteria
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Inclusion criteria: Healthy, 20-70 years, BMI 20-30 kg/m^2 Exclusion criteria: Diabetes mellitus, symptoms of acute infection, cardiac arrhythmias, 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.

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 70 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Healthy<br>Healthy people age 20-70 years | Other: Age<br>* Determination of age-dependence<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Microvascular density | Density of skin microvasculature of hand and foot with OCTA at rest and after 5 min distal occlusion | 1 day (One timepoint during single visit) | 
| Microvascular diameter | Diameter of skin microvasculature of hand and foot with OCTA at rest and after 5 min distal occlusion | 1 day (One timepoint during single visit) | 
| Microvascular turtuosity | Turtuosity of skin microvasculature of hand and foot with OCTA at rest and after 5 min distal occlusion | 1 day (One timepoint during single visit) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Blood pressure | Upper arm blood pressure and leg systolic blood pressure | 1 day (One timepoint during single visit) | 
| Endothelial function | Flow-mediated dilation of brachial and common femoral artery with ultrasound | 1 day (One timepoint during single visit) | 
| Arterial stiffness | Pulse wave velocity measured at upper arm (Arteriograph) | 1 day (One timepoint during single visit) | 
| Arterial stiffness | Pulse wave velocity measured with photoplethysmography sensors at hand and foot | 1 day (One timepoint during single visit) |