Diabetic RetinopathyRAASNCT02119689
Vascular Reparative Mechanism in Diabetes
An observational study of Diabetic Retinopathy, run by University of Alabama at Birmingham at 1 site in United States.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Diabetic Retinopathy
- What is being tested?
- Diabetic Patients
- How many people
- 78 participants
- Where
- 1 siteUnited States
- Study dates
- 30 Oct 2011to 31 Dec 2026
- How long will I take part?
- 4 Years
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Study population: Ophthalmology and Primary Care Clinics
Who may be able to join
- 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
Who cannot join
- Current pregnancy as evidence by a urine pregnancy test as the blood from a pregnant female will influence the results of the laboratory tests
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Vascular Reparative Mechanism by ACE2/Ang-(1-7) 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.
- Conditions
- Diabetic Retinopathy
- Being tested
- Diabetic Patients, Healthy Controls
- Keywords
- Diabetes, Retinopathy
- Medical subject headings
- Diabetic Retinopathy, Diabetes Mellitus, Retinal Diseases
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Diabetic PatientsOther
measuring CD34 cell function in relation to diabetic retinopathy status
Healthy ControlsOther
measuring CD34 cell function
| Study group | Role | What they receive |
|---|---|---|
| Diabetic Patients | Mild, Moderate and Severe Retinopathy Receives: Other: Diabetic Patients | |
| Healthy Controls | Age and sex matched Healthy Controls Receives: Other: Healthy Controls |
What is being measured
The primary outcome is the main question the study is designed to answer.
The ACE/ACE2 ratio within EPC's
Peripheral blood of 150cc, approximately 8-10 tablespoons will be collected from a vein in the arm of both diabetic and healthy control patients.
Measured: up to 216 weeks
Secondary outcomes (1)
The balance of the RAS (renin-angiotensin system) within EPCs
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
Measured: up to 216 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted22 Apr 2014 (estimated)
- Study start30 Oct 2011
- Primary completion31 Dec 2026 (estimated)
- Study completion31 Dec 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Diabetic RetinopathyStudies of the same condition, open and under way.
- More trials run by University of Alabama at BirminghamThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 78 participants (estimated)
- Target duration
- 4 Years
Sponsor and investigators
- Lead sponsor
- University of Alabama at Birmingham
- Sponsor type
- University, hospital or other
- Collaborators
- National Heart, Lung, and Blood Institute (NHLBI)
- Responsible party
- Principal investigator, Maria Grant, University of Alabama at Birmingham
- Investigators
- Maria B Grant, MD, Principal investigator, University of Alabama at Birmingham
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT02119689
- Sponsor's protocol ID
- 1308798827
- Other IDs
- R01HL110170
- Acronym
- RAAS
- Status last verified
- Dec 2025
- First submitted
- 14 Apr 2014
- Last updated
- 23 Dec 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Publications
Reddy SK, Devi V, Seetharaman ATM, Shailaja S, Bhat KMR, Gangaraju R, Upadhya D. Cell and molecular targeted therapies for diabetic retinopathy. Front Endocrinol (Lausanne). 2024 Jun 14;15:1416668. doi: 10.3389/fendo.2024.1416668. eCollection 2024.
PubMed 38948520
Study at a glance
From the registry record, last updated by the sponsor on 23 Dec 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Vascular Reparative Mechanism by ACE2/Ang-(1-7) in Diabetes
- ClinicalTrials.gov ID
- NCT02119689
- Acronym / sponsor ID
- RAAS / 1308798827
- Conditions
- Diabetic Retinopathy
- Keywords
- Diabetes, Retinopathy
- Study type
- Observational
- Recruitment status
- Active, not recruiting
- Enrolment
- 78 participants (estimated)
- Lead sponsor
- University of Alabama at BirminghamUniversity, hospital or other
- Collaborators
- National Heart, Lung, and Blood Institute (NHLBI)
- Study start
- 30 Oct 2011 (actual)
- Primary completion
- 31 Dec 2026 (estimated)
- Study completion
- 31 Dec 2026 (estimated)
- First posted
- 22 Apr 2014 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Target follow-up
- 4 Years
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Diabetic Patients | – | Other: Diabetic PatientsMild, Moderate and Severe Retinopathy |
| Healthy Controls | – | Other: Healthy ControlsAge and sex matched Healthy Controls |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
- Study population
- Ophthalmology and Primary Care Clinics
Key inclusion criteria (6 listed)
- 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
Key exclusion criteria (1 listed)
- Current pregnancy as evidence by a urine pregnancy test as the blood from a pregnant female will influence the results of the laboratory tests
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Diabetic Patientsmeasuring CD34 cell function in relation to diabetic retinopathy status | Other | Diabetic Patients |
| Healthy Controlsmeasuring CD34 cell function | Other | Healthy Controls |
Primary outcome
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.
1 secondary outcome
The balance of the RAS (renin-angiotensin system) within EPCs
Time frame: up to 216 weeks
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 23 Dec 2025.
- Derived from this study: PubMed 38948520Reddy SK, Devi V, Seetharaman ATM, Shailaja S, Bhat KMR, Gangaraju R, Upadhya D. Cell and molecular targeted therapies for diabetic retinopathy. Front Endocrinol (Lausanne). 2024 Jun 14;15:1416668. doi: 10.3389/fendo.2024.1416668. eCollection 2024.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Maria B Grant, MD principal investigator
University of Alabama at Birmingham
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Diabetic Retinopathy, run by University of Alabama at Birmingham at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: under way, not looking for participants, as of the sponsor's last update on 23 Dec 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
The ACE/ACE2 ratio within EPC's (time frame: up to 216 weeks). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT02119689, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 23 Dec 2025.