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.

Status

Completed

Phases

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT00337298

Enrollment

Registered

2006-06-15

Start date

2006-07-31

Completion date

2009-02-28

Last updated

2009-06-23

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Diabetes Complications, Diabetic Retinopathy, Eye Diseases, Type 1 Diabetes

Keywords

Diabetes, Retinopathy, Blood Pressure, Amlodipine, Lisinopril

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.

Interventions

DRUGAmlodipine

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

DRUGLisinopril

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

Study design

Allocation

RANDOMIZED

Intervention model

CROSSOVER

Masking

QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)

Eligibility

Sex/Gender

ALL

Age

18 Years to 35 Years

Healthy volunteers

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

Design outcomes

Primary

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

Measure	Time frame
Blood pressure (mmHG)	120,240,360,600,720,840 secs
24 hour ambulatory blood pressure (mmHg)	24 hours

Countries

Denmark

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026