Effect of Glucose on Ocular Blood Flow

March 18, 2024 updated by: University Hospital, Basel, Switzerland

Influence of Plasma Glucose Levels on Retinal Vascular Diameter and Choroidal Blood Flow in Vasospastic Subjects

The primary objective is to assess the effect of glucose on retinal vascular diameter in otherwise healthy vasospastic subjects compared to non-vasospastic controls.

The secondary objective is to compare the effect of glucose also on choroidal blood flow in otherwise healthy vasospastic subjects with non-vasospastic controls.

Study Overview

Status

Completed

Conditions

Detailed Description

It is known that a glucose load can induce an increase in ocular blood flow. Acute hyperglycemia increases retinal vessel diameters in animals and humans. The purpose of this study is to compare the effect of glucose on the ocular blood flow in vasospastics and nonvasospastics. Body core temperature depends on basal metabolism. Peripheral vasoconstriction is a physiological way to preserve core temperature of the body. The etiology of primary vasospastic syndrome is unknown and potentially represents simply a reaction to a defective metabolism. Based on this hypothesis, vasospastics are expected to show a different vascular reaction to glucose.

On both study days, after an overnight fast, the subjects will be seated for 30 minutes in the Lab and local tropicamide will be applied for pupil dilatation. After stabilisation of blood pressure Retinal vessel diameter and choroidal blood flow will be assessed. Baseline blood glucose levels will be measured. Afterwards study substance (75 gram of Glucose or Aspartate) will be applied in 3 dl of water. One and a half hour later, the vascular measurements will be repeated. Ath the end of hemodynamic assessments, blood sugar level will be measured again.

Study Type

Observational

Enrollment (Actual)

24

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Switzerland
    • BS
      • Basel, BS, Switzerland, 4031
        • University Hospital Basel, Eye Clinic

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 85 years (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Sampling Method

Probability Sample

Study Population

healthy vasospastic subjects, healthy non-vasospastic subjects

Description

Inclusion Criteria:

  • No history of the following problems: ocular or systemic disease; chronic or current systemic or topical medication; or of drug or alcohol abuse
  • normal blood pressure (100-140 / 60-90 mmhg)
  • best corrected visual acuity above 20/25 in both eyes
  • no pathological findings upon a slit-lamp examination and indirect fundoscopy
  • ametropia within -3 to +3 diopters of spherical equivalent
  • less than 1 diopter astigmatism
  • IOP < 20 mmHg in both eyes
  • Subjects will be classified as vasospastic if they relate a clear history of frequent cold hands (answering yes to the questions: "do you have always cold hands, even during summer time?" and "do other people tell you that you have cold hands?") and as normals if they deny such a history
  • Vasospastic propensity will also be assessed by capillaroscopy

Exclusion Criteria:

  • Subjects describing "sometimes cold hands"
  • if the test substance cannot be ingested
  • not obtainable ocular blood flow measurements
  • abnormally high levels of glucose at any point in time

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Observational Models: Case-Control
  • Time Perspectives: Prospective

Cohorts and Interventions

Group / Cohort
1
healthy vasospastic subjects
2
healthy non-vasospastic subjects

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University Hospital, Basel, Switzerland

Investigators

  • Study Director: Selim Orgül, MD, University Hospital, Basel, Switzerland

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

December 1, 2002

Primary Completion (Actual)

February 1, 2003

Study Completion (Actual)

February 1, 2003

Study Registration Dates

First Submitted

July 7, 2006

First Submitted That Met QC Criteria

July 7, 2006

First Posted (Estimated)

July 10, 2006

Study Record Updates

Last Update Posted (Actual)

March 19, 2024

Last Update Submitted That Met QC Criteria

March 18, 2024

Last Verified

March 1, 2024

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 005-ZAC-2004-002

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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