Sitagliptin in Cystic Fibrosis-Related Diabetes

Study Overview
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Brief Summary
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The purpose of this study is to determine whether the dipeptidyl peptidase IV (DPPIV) inhibitor sitagliptin is effective in the treatment of cystic fibrosis-related diabetes (CFRD). We hypothesize that sitagliptin will improve meal-stimulated insulin secretion.

Detailed Description
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To date, no clinical trials have been conducted using the DPPIV inhibitor sitagliptin in cystic fibrosis-related diabetes. Cystic fibrosis-related diabetes is characterized initially by post-prandial hyperglycemia, with normal fasting sugars. As the disease progresses, fasting hyperglycemia develops. As sitagliptin augments post-prandial insulin release, while avoiding fasting hypoglycemia, it may be an alternative therapy for cystic fibrosis-related diabetes in individuals who do not yet require basal insulin therapy.

Official Title
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The Effects of the DPPIV Inhibitor Sitagliptin in Cystic Fibrosis-related Diabetes

Conditions
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Cystic Fibrosis

Intervention / Treatment
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* Drug: Sitagliptin
* Drug: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 19 years of age or older Cystic fibrosis-related diabetes with or without fasting hyperglycemia either untreated or using only pre-prandial repaglinide or pre-prandial bolus insulin therapy Exclusion Criteria: Age under 19 years Use of basal insulin therapy Creatinine Clearance < 50 mL/min Active cystic fibrosis exacerbation Pregnancy Women of child-bearing age not using effective contraception Current or prior use of DPPIV inhibitor

Ages Eligible for Study
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Minimum Age: 19 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: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Sitagliptin<br> | Drug: Sitagliptin<br>* 100mg po one dose<br>* Other names: Januvia, MK-0431, Dipeptidyl peptidase IV inhibitor (DPP-4 inhibitor);|
| Placebo Comparator: Placebo<br> | Drug: Placebo<br>* Sugar pill po one dose<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Insulin release | The study protocol is a iv-oral hyperglycemic glucose clamp. We will assess insulin release during the clamp, comparing placebo to sitagliptin. | 180 minutes (during clamp) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Incretin Response | We will assess incretin release [glucoagon-like peptide-1 (GLP-1), gastric inhibitory polypeptide(GIP)] during the glucose clamp. | 180 minutes (during clamp) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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CFRD, sitagliptin, cystic fibrosis-related diabetes, incretins, hyperglycemia, GIP, GLP-1