Sitagliptin and Endothelial Dysfunction

Study Overview
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Brief Summary
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Over the years, numbers of cardioprotective drugs have been evaluated to attenuate lethal ischemia-reperfusion (IR) injuries. There is little study whether sitagliptin protects against endothelial dysfunction induced by IR injury in humans.

Detailed Description
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Glucagon-like peptide-1 (GLP-1) is a novel insulinotropic peptide which is rapidly degraded by the enzyme dipeptidyl peptidase-4 (DPP-4). In addition to its attractive merit in type 2 diabetes, interest in the cardioprotective effects of GLP-1 has been increased with various reports and evidence. Previously, the investigators could show exenatide, GLP-1 receptor agonist protects ischemic/reperfusion injury-induced endothelial dysfunction through opening of KATP (ATP-sensitive potassium) channels in human ischemic/reperfusion injury model. But, recent clinical studies showed 2 different DPP-4 inhibitors, alogliptin and saxagliptin, did not decrease major adverse cardiovascular events even though improving glycemic control. The investigators will investigate the role of sitagliptin in human ischemic/reperfusion (IR) injury model of forearm conductance vessels as previous described method.

Official Title
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Preventive Effects of Sitagliptin on Endothelial Dysfunction Induced by Forearm Ischemia-Reperfusion Injury Model

Conditions
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Healthy

Intervention / Treatment
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* Drug: Sitagliptin


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: healthy volunteer age 20 to 40 years non-smoker Exclusion Criteria: High blood pressure (>140/90 mmHg) or any antihypertensive medications diabetes any cardiovascular disease kidney disease thyroid disease cerebrovascular disease liver disease (bilirubin level >2 mg/dl) pregnancy body mass index >25 kg/m2

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 40 Years

Sexes Eligible for Study
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All

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: Prevention
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Sitagliptin<br>All participant will exam brachial artery endothelium-dependent flow-mediated dilatation (FMD). After then, pneumatic cuff wiil be inflated to 200 mmHg for 15 minutes to induce brachial artery ischemia. At the end of ischemia, 15 minutes of reperfusion was performed to induce reperfusion injury. After ischemia-reperfusion (IR) injury, brachial artery FMD will be measured again. After randomization, sitagliptin group will be treated by single dose of sitagliptin (Januvia) 50mg. In 2 hours later, brachial artery FMD measurement, IR injury and brachial artery FMD measurement will be measured again. | Drug: Sitagliptin<br>* The brachial FMD before and after IR injury will be assessed. After randomization, study medication will be treated. In 2 hours later, the brachial FMD before and after IR injury will be assessed again. All volunteers had a wash-out period of 7 days. Seven days later, the subjects returned to crossover study medication (ie, sitagliptin or placebo), and the protocol described above was repeated.<br>* Other names: Januvia;|
| Placebo Comparator: Placebo<br>After brachial artery FMD measurement, IR injury for each 15 minutes will be performed, and brachial artery FMD will be measured again. After randomization, placebo group will be treated by nothing. In 2 hours later, brachial artery FMD measurement, IR injury and brachial artery FMD measurement will be measured again. | |
| Other: Sitagliptin and glibenclimide<br>If sitagliptin treatment show preventive effects of IR injury, the investigator will perform additional experiment to explore the mechanism (Protocol 2 study). Additional 15 healthy volunteers will be treated 5 mg of glibenclamide (Euglucon) 1 hour before administration of 50 m g of sitagliptin. In 2 hours after sitagliptin administration, FMD measurement before and after IR injury will be performed as described above. | Drug: Sitagliptin<br>* The brachial FMD before and after IR injury will be assessed. After randomization, study medication will be treated. In 2 hours later, the brachial FMD before and after IR injury will be assessed again. All volunteers had a wash-out period of 7 days. Seven days later, the subjects returned to crossover study medication (ie, sitagliptin or placebo), and the protocol described above was repeated.<br>* Other names: Januvia;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The difference of FMD [brachial artery endothelium-dependent flow-mediated dilatation] after IR injury (brachial FMD before and after IR injury will be assessed) |  | 2 hours after study drug treatment | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The difference of FMD after IR injury in co-treatment of glibenclimide and sitagliptin ((brachial FMD before and after IR injury will be assessed) |  | 3.5 hours after study drug treatment | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Sitagliptin, Endothelium, Ischemia-Reperfusion Injury, human