The Effect of Amlodipine and Lisinopril on Retinal Autoregulation in Type 1 Diabetes

Lack of Effect of Antihypertensive Treatment With Amlodipine and Lisinopril on Retinal Autoregulation in Patients With Type 1 Diabetes and Mild Diabetic Retinopathy. A Prospective Randomized Clinical Trial.


Lead Sponsor: University of Aarhus

Collaborator: Velux Fonden

Source University of Aarhus
Brief Summary

The purpose of this study is to compare the effect of two antihypertensive drugs on retinal vessel diameter in young type 1 diabetics. The retinal vessel analyzer (RVA) was used to investigate how the drugs affected vessel diameter, when the subjects were exposed to an increase in blood pressure, induced by isometric muscle contraction and when they were stimulated by flickering light.

Detailed Description

Diabetes is a leading cause of blindness in the western part of the world. Diabetic patients develop diabetic retinopathy which can progress to blindness. Diabetic retinopathy is associated with an increase of blood flow in the retinal vessels, ischaemia in the periphery and macular oedema. It has been shown in previous trials, that the pressure and metabolic autoregulation is disturbed in patients with diabetes, and it is believed to contribute to the development of diabetic retinopathy.

In healthy subjects the retinal arterioles will contract during an increase in blood pressure, but trials have shown that this response is impaired in diabetics. When the retina is exposed to flickering lights, the metabolism increase and the arterioles in healthy subjects dilates. In diabetics this dilation is impaired. In this trial we want to investigate if an ACE-inhibitor (lisinopril) or calcium channel blocker (amlodipine) influence this response in subjects exposed to increased blood pressure vs increased retinal metabolism.

Overall Status Completed
Start Date July 2006
Completion Date February 2009
Primary Completion Date February 2009
Phase N/A
Study Type Interventional
Primary Outcome
Measure Time Frame
Vessel diameter changes in arbitrary units as measured with the Retinal Vessel Analyzer 120,240,360,480,600,720 and at 840secs
Secondary Outcome
Measure Time Frame
Blood pressure (mmHG) 120,240,360,600,720,840 secs
24 hour ambulatory blood pressure (mmHg) 24 hours
Enrollment 25

Intervention Type: Drug

Intervention Name: Amlodipine

Description: 1 (5mg) tablet daily, given 14 days totally before measure of outcome.

Arm Group Label: 1

Intervention Type: Drug

Intervention Name: Lisinopril

Description: Lisinopril 10 mg given daily for 14 days and then outcome was measured.

Arm Group Label: 1



Inclusion Criteria:

- Type 1 diabetes

- 18-35 years of age

- Simplex retinopathy at last screening (Less than 10 retinal haemorrhages at the nearest ordinary screening examination)

- normotensive (BP not above 160 mmHg systolic or 100 mmHg diastolic)

Exclusion Criteria:

- Pregnancy

- Systolic Bloodpressure above 160 mmHg

- Diastolic bloodpressure above 100 mmHg

- Retinopathy grade higher than simplex retinopathy

- Prior retinal laser photocoagulation

Gender: All

Minimum Age: 18 Years

Maximum Age: 35 Years

Healthy Volunteers: No

Overall Official
Facility: Aarhus university hospital
Location Countries


Verification Date

June 2009

Responsible Party

Name Title: Toke Bek/Professor

Organization: Aarhus University Hospital

Has Expanded Access No
Condition Browse
Number Of Arms 1
Arm Group

Label: 1

Type: Experimental

Description: Crossover design. Arm is same all the way

Study Design Info

Allocation: Randomized

Intervention Model: Crossover Assignment

Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)