Measurement of Eye Blood Flow and Renal Function in Healthy and Diabetic Patients

Study Overview
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Brief Summary
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The purpose of this study is to the determine the effect of salt intake and Captopril on the ophthalmic artery (OA) blood supply of individuals with Type 2 Diabetes Mellitus.

Detailed Description
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The overall objective of this study is to ascertain if salt intake affects ophthalmic artery (OA) blood flow. In addition, we will study both the eye and kidney response to ACE inhibition compared to placebo while controlling salt intake in subjects with Type 2 diabetes mellitus. We hypothesize that salt intake will affect OA blood flow. We will initially look at both eye and renal response to subjects on a low salt diet (10mEq Na/day) followed by response to high salt diet (200mEq Na/day). In addition, we may look at eye response while subjects consume their regular diet.

Official Title
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Eye Blood Flow and the Kidney

Conditions
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Type 2 Diabetes Mellitus

Intervention / Treatment
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* Drug: Captopril
* Drug: placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Type 2 Diabetes Mellitus Exclusion Criteria: Type 1 Diabetes Mellitus Heart Attack or Stroke within the last 6 months Pregnant or lactating females

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Arm A<br>Captopril 25 mg (Admission 1, Day 1, low salt diet) Matched Placebo (Admission 1, Day 2, low salt diet) Captopril 25 mg (Admission 2, Day 1, high salt diet) Matched Placebo (Admission 2, Day 2, high salt diet) | Drug: Captopril<br>* 25mg Captopril<br>Drug: placebo<br>* placebo<br>|
| Placebo Comparator: Captopril<br>Matched Placebo (Admission 1, Day 1, low salt diet) Captopril 25 mg (Admission 1, Day 2, low salt diet) Matched Placebo (Admission 2, Day 1, high salt diet) Captopril 25 mg (Admission 2, Day 2, high salt diet) | Drug: Captopril<br>* 25mg Captopril<br>Drug: placebo<br>* placebo<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in ophthalmic artery blood flow from baseline | Eye blood flow will be measured at baseline and post drug time points (3 total) | 1 hour post drug, 2 hours post drug, 3 hours post drug | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in blood pressure from baseline | Blood pressure will be monitored throughout the study starting at baseline | Every 15 minutes for 3 hours | 
| Change in renal plasma flow (RPF) from baseline | Renal Plasma Flow (to measure kidney function) will be measured at baseline and post drug time points (3 total) | 1 hour post drug, 2 hours post drug, 3 hours post drug |