Skip to main content
OpenTrials
Active, Not Recruiting

NCT Number: NCT02119689

Vascular Reparative Mechanism in Diabetes

The purpose of this research study is to study blood stem cells in diabetic patients and normal patients. We would like to better understand if these cells, called endothelial precursor cells (EPCs), are not working as expected in people with diabetes. We would like to see if the function of these cells can predict the development of diabetic retinopathy.

Diabetic retinopathy is an eye disease associated with diabetes in which the cells of the retina are damaged. It can cause blurred vision, vision loss, blindness or possible bleeding in the retina. Even with current treatments, the quality of life for people with diabetic retinopathy is much reduced.

Active, Not Recruiting

This study is active but is not currently recruiting participants.

Key information

Conditions

Diabetic Retinopathy Cardiovascular Diseases Diabetes Complications Diabetes Mellitus Diabetic Angiopathies Endocrine System Diseases Eye Diseases Glucose Metabolism Disorders Metabolic Diseases Nutritional and Metabolic Diseases Retinal Diseases Vascular Diseases

Age range

18 year and older

Sex eligibility

All sexes

Study type

Observational

Primary location

University of Alabama

Birmingham, Alabama, 35294, United States

Who can participate

Healthy volunteers accepted: Yes

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

Inclusion criteria

  • Men or women 18 years or older
  • 39 type 1 or type 2 diabetic patients
  • 13 with mild retinopathy
  • 13 with moderate retinopathy
  • 13 with severe, nonproliferative retinopathy
  • 39 age and sex matched healthy controls

Exclusion criteria

  • Current pregnancy as evidence by a urine pregnancy test as the blood from a pregnant female will influence the results of the laboratory tests

Treatment and study plan

Diabetic Patients

Other

measuring CD34 cell function in relation to diabetic retinopathy status

Healthy controls

Other

measuring CD34 cell function

Primary outcomes

  1. The ACE/ACE2 ratio within EPC's

    Time frame: up to 216 weeks

    Peripheral blood of 150cc, approximately 8-10 tablespoons will be collected from a vein in the arm of both diabetic and healthy control patients.

Secondary outcomes

  1. The balance of the RAS (renin-angiotensin system) within EPCs

    Time frame: up to 216 weeks

    The Endo-PAT2000 will be used to obtain this measurement. This is a 15-minute office-based test where a blood-pressure cuff is placed around the arm, inflated and measurements are obtained from a small fingertip monitor

Other outcomes

  1. Photography findings

    Time frame: up to 216 weeks

    The findings from eye photographs will be collected and evaluated from both the diabetic patients and the heallthy control patients. This will be done at either the patient's yearly visit or at their 6 week follow-up visit.

  2. Fluorescein angiogram findings

    Time frame: up to 216 weeks

    The findings from eye photographs will be collected and evaluated from both the diabetic patients and the heallthy control patients. This will be done at either the patient's yearly visit or at their 6 week follow-up visit.

Sponsors and collaborators

Lead sponsor

University of Alabama at Birmingham

Other

Collaborators

  • National Heart, Lung, and Blood Institute (NHLBI)

Registry information

Official study title

Vascular Reparative Mechanism by ACE2/Ang-(1-7) in Diabetes

Acronym: RAAS

Important dates

Study start
2011
Primary completion
2026
Study completion
2026
First posted
Apr 22, 2014
Registry last updated
Dec 23, 2025

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.

Related clinical trials

Published trials that share one or more normalized conditions with this study.