The Electroretinogram in Healthy and Glucose Intolerant Young Men

Study Overview
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Brief Summary
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The purpose is to investigate the electroretinogram (ERG) in young, healthy men in the normoglycaemic and hyperglycaemic state before and after intervention with corticosteroids treatment, high calorie diet and exercise restraint.

Detailed Description
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The subjects will be fasting from midnight the day before the experiment. Standard procedures (including pupil dilation, dark adaptation, and local anaesthetics) are carried out to allow the ERG to be obtained. After electrophysiology, the subject will be clamped at a plasma glucose level of 10 mM ( 180 mg/dL) and after a stabilisation period the ERG protocol is repeated. Each subject is examined twice on two different days. The first day the subjects are normoglycaemic in the morning (first examination) and hyperglycaemic (clamped to 10 mM) throughout the second examination. The second day subjects are also normoglycaemic and hyperglycaemic but shows up after 7-12 days of daily intake of prednisolone, high calorie diet, and exercise restraint.

Official Title
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Electroretinographic Changes in Healthy Young Men Before and After Induction of Glucose Intolerance by Glucocorticoids Treatment, Hyperphagia and Lack of Exercise

Conditions
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Electroretinography

Intervention / Treatment
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* Drug: Prednisolone
* Behavioral: Lifestyle change


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Caucasians without type 2 diabetes mellitus Normal OGTT (75 g glucose dissolved in 250 mL water) according to WHO's criteria BMI 20-30 Haemoglobin > 8,0 mM Exclusion Criteria: Nephropathy (s-creatinin > 130 µM or albuminuria) Relatives (parents or sibling with T2DM) Medical treatment which cannot be paused for 12 hours

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 35 Years

Sexes Eligible for Study
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Male

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Non-Randomized
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Intervention<br>Medical and behavioural intervention | Drug: Prednisolone<br>* 12 days of corticosteroids treatment (prednisolone 37,5 mg/day)<br>* Other names: Prednisolon DAK, Nycomed, Zurich, Switzerland;Behavioral: Lifestyle change<br>* High calorie diet (130 % of recommended daily energy intake) and relative physical inactivity (no exercise and at least 8 hours of rest/day)<br>* Other names: Behavioral regimen;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| ERG | Characteristics of the scotopic ERG at normo-/hyperglycaemia before vs. after prednisolone treatment | 12 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Retinal Vessel Caliber | Measurement of retinal vessel caliber from fundus photographs before and after treatment with glucocorticoids. | 12 days | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Retina, Electroretinography, Diabetes Mellitus, Glucose Intolerance, Physiology