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

Sponsor

University of Aarhus (Other)

Overall Status

Completed

CT.gov ID

NCT00337298

Collaborator

Velux Fonden (Other)

Enrollment

Location

Arm

31.1

Duration (Months)

0.8

Patients Per Site Per Month

Study Details

Study Description

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.

Condition or Disease	Intervention/Treatment	Phase
Type 1 Diabetes Diabetic Retinopathy Eye Diseases Diabetes Complications	Drug: Amlodipine Drug: Lisinopril	N/A

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.

Study Design

Study Type:

Interventional

Actual Enrollment :

25 participants

Allocation:

Randomized

Intervention Model:

Crossover Assignment

Masking:

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

Official Title:

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.

Study Start Date :

Jul 1, 2006

Actual Primary Completion Date :

Feb 1, 2009

Actual Study Completion Date :

Feb 1, 2009

Arms and Interventions

Arm	Intervention/Treatment
Experimental: 1 Crossover design. Arm is same all the way	Drug: Amlodipine 1 (5mg) tablet daily, given 14 days totally before measure of outcome. Drug: Lisinopril Lisinopril 10 mg given daily for 14 days and then outcome was measured.

Arm

Intervention/Treatment

Experimental: 1

Crossover design. Arm is same all the way

Drug: Amlodipine

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

Drug: Lisinopril

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

Outcome Measures

Primary Outcome Measures

Vessel diameter changes in arbitrary units as measured with the Retinal Vessel Analyzer [120,240,360,480,600,720 and at 840secs]

Secondary Outcome Measures

Blood pressure (mmHG) [120,240,360,600,720,840 secs]
24 hour ambulatory blood pressure (mmHg) [24 hours]

Eligibility Criteria

Criteria

Ages Eligible for Study:

18 Years to 35 Years

Sexes Eligible for Study:

All

Accepts 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

Contacts and Locations

Locations

	Site	City	State	Country	Postal Code
1	Aarhus university hospital	Aarhus		Denmark	8000

Sponsors and Collaborators

University of Aarhus
Velux Fonden

Investigators

Principal Investigator: Toke Bek, MD, PhD, Aarhus university hospital, Dep. of ophthalmology
Principal Investigator: Per L Poulsen, MD, PhD, Aarhus University hospital, Dep. of endocrinology (M)