DiabetesPhase 4PRSNCT06813014
Pharmacogenetics of Response to Sitagliptin (PRS)
A Phase 4 study testing Oral Glucose Tolerance Test in people with Diabetes, run by University of Maryland, Baltimore at 1 site in United States.
Trial summary
This is a research study to find out how different people respond to a medication called sitagliptin. Sitagliptin is an FDA approved medication that is used to treat diabetes. We are asking for healthy, non-diabetic volunteers to participate in this 7-week study. Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Diabetes
- What is being tested?
- Oral Glucose Tolerance Test
- Type of treatment
- Pill or oral medicine, Surgery or procedure
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 400 participants
- Where
- 1 siteUnited States
- Study dates
- Dec 2026to Dec 2032
- Phase
- Phase 4
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- • Age: \>18 years old
- Members of Old Order Amish community in Lancaster, PA
Who cannot join
- • Pregnancy (reproductive age women will undergo pregnancy tests immediately before receiving the drug)
- Diabetes: HbA1c \> 6.5% or fasting plasma glucose \>126 mg/dL
- Estimated glomerular filtration rates (eGFR) \<60 mL/min/1.73 m2
- Anemia: hematocrit \< 35%
- Thyroid status: TSH\<0.4 or TSH\>5.5
- ALT or AST in excess of 2X upper limit of normal
- Drugs that in the physician's judgment would alter response to sitagliptin
- Significant health issues that in the physician's judgment could increase the risk for participants.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Kamah Woelfel contact
United States1 site
University of Maryland Amish Research Clinic
Lancaster, Pennsylvania, 17602
About this study
Official title: Sitagliptin's Effects on Glucose-stimulated Insulin Secretion and Oral Glucose
This is a research study to find out how different people respond to a medication called sitagliptin. Sitagliptin is an FDA approved medication that is used to treat diabetes. We are asking for healthy, non-diabetic volunteers to participate in this 7-week study. If you agree to participate, you will take part in 2 clinic visits that are 4-6 weeks apart. At the clinic visits you will have an oral glucose tolerance test (OGTT) and other blood tests to see how your body processes glucose (sugar). An OGTT is a test in which your drink glucose and then blood samples are taken afterward at specific time points to measure glucose and insulin in your blood. Each clinic visit will last about 5 hours.
- Conditions
- Diabetes
- Being tested
- Oral Glucose Tolerance Test
- Medical subject headings
- Diabetes Mellitus
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Oral Glucose Tolerance TestProcedure or surgery
Three hour glucose tolerance test
| Study group | Role | What they receive |
|---|---|---|
| Sitagliptin | Experimental | Sitagliptin 100 mg given 2 hours prior to the oral glucose tolerance test Receives: Procedure: Oral Glucose Tolerance Test |
| Placebo | Placebo comparator | Placebo given 2 hours prior to the oral glucose tolerance test Receives: Procedure: Oral Glucose Tolerance Test |
What is being measured
The primary outcome is the main question the study is designed to answer.
Sitagliptin-induced enhancement of early insulin secretion
This represents the incretinomimetic effect of sitagliptin, which contributes importantly to the mechanism whereby DPP4is decrease HbA1c in T2D patients. Because histograms for sitagliptin-induced increase in our index of early insulin secretion (T30:T60) demonstrated a skewed distribution, we will apply a logarithmic transformation of data which yields a normal distribution. Thus, the drug effect is defined as: log(T30:T60 ins)sita - log(T30:T60 ins)control.
Measured: 6 weeks
Sitagliptin-induced change in glucose tolerance
Sitagliptin-induced change in glucose tolerance. This is a consequence of enhanced insulin secretion, which reflects most closely the desired effect of the drug to decrease plasma glucose and decrease HbA1c. Because histograms for sitagliptin-induced increase in our index of glucose tolerance (T30:T60) demonstrated a skewed distribution, we will apply a logarithmic transformation of data which yields a normal distribution. Thus, the drug effect is defined as: log(T30:T60 gluc)sita - log(T30:T60 gluc)control.
Measured: 6 weeks
Secondary outcomes (5)
Area under the curve for insulin concentration
Area under the curve of insulin concentration measured from oral glucose tolerance test using trapezoidal rule
Measured: 6 weeks
Area under the curve for glucose concentration
Area under the curve for glucose concentration measured from the oral glucose tolerance test using the trapezoidal rule
Measured: 6 weeks
Area under the curve for intact GIP
Area under the curve for levels of intact GIP during the first hour of the OGTT as calculated by the trapezoidal rule
Measured: 6 weeks
Area under the curve for intact GLP1
Area under the curve for levels of intact GLP1 during the first hour of the OGTT as calculated by the trapezoidal rule
Measured: 6 weeks
Area under the curve for C-peptide levels
Area under the curve for C-peptide levels as a direct index of insulin secretion
Measured: 6 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted6 Feb 2025
- Study startDec 2026 (estimated)
- Primary completionNov 2031 (estimated)
- Study completionDec 2032 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for DiabetesStudies of the same condition, open and under way.
- More trials run by University of Maryland, BaltimoreThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 4
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 400 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Maryland, Baltimore
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Amber Beitelshees, University of Maryland, Baltimore
- Investigators
- Amber L Beitelshees, PharmD, MPH, Principal investigator, University of Maryland, BaltimoreSimeon I Taylor, MD, PhD, Principal investigator, University of Maryland, Baltimore
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06813014
- Sponsor's protocol ID
- HP-00111892
- Acronym
- PRS
- Status last verified
- Feb 2026
- First submitted
- 3 Feb 2025
- Last updated
- 18 Feb 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Undecided: Given that the Amish are a unique founder population, they are more easily identified and at-risk for stigmatization. Therefore, we must consult with the community in order to address this plan to share individual level data.
Study at a glance
From the registry record, last updated by the sponsor on 18 Feb 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Sitagliptin's Effects on Glucose-stimulated Insulin Secretion and Oral Glucose
- ClinicalTrials.gov ID
- NCT06813014
- Acronym / sponsor ID
- PRS / HP-00111892
- Conditions
- Diabetes
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 400 participants (estimated)
- Lead sponsor
- University of Maryland, BaltimoreUniversity, hospital or other
- Study start
- Dec 2026 (estimated)
- Primary completion
- Nov 2031 (estimated)
- Study completion
- Dec 2032 (estimated)
- First posted
- 6 Feb 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This is a research study to find out how different people respond to a medication called sitagliptin. Sitagliptin is an FDA approved medication that is used to treat diabetes. We are asking for healthy, non-diabetic volunteers to participate in this 7-week study. If you agree to participate, you will take part in 2 clinic visits that are 4-6 weeks apart. At the clinic visits you will have an oral glucose tolerance test (OGTT) and other blood tests to see how your body processes glucose (sugar). An OGTT is a test in which your drink glucose and then blood samples are taken afterward at specific time points to measure glucose and insulin in your blood. Each clinic visit will last about 5 hours.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind (participant)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Sitagliptin | Experimental | Procedure: Oral Glucose Tolerance TestSitagliptin 100 mg given 2 hours prior to the oral glucose tolerance test |
| Placebo | Placebo comparator | Procedure: Oral Glucose Tolerance TestPlacebo given 2 hours prior to the oral glucose tolerance test |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (2 listed)
- • Age: \>18 years old
Key exclusion criteria (8 listed)
- • Pregnancy (reproductive age women will undergo pregnancy tests immediately before receiving the drug)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Oral Glucose Tolerance TestThree hour glucose tolerance test | Procedure or surgery | Placebo, Sitagliptin |
Primary outcome
Sitagliptin-induced enhancement of early insulin secretion
Time frame: 6 weeks
This represents the incretinomimetic effect of sitagliptin, which contributes importantly to the mechanism whereby DPP4is decrease HbA1c in T2D patients. Because histograms for sitagliptin-induced increase in our index of early insulin secretion (T30:T60) demonstrated a skewed distribution, we will apply a logarithmic transformation of data which yields a normal distribution. Thus, the drug effect is defined as: log(T30:T60 ins)sita - log(T30:T60 ins)control.
Sitagliptin-induced change in glucose tolerance
Time frame: 6 weeks
Sitagliptin-induced change in glucose tolerance. This is a consequence of enhanced insulin secretion, which reflects most closely the desired effect of the drug to decrease plasma glucose and decrease HbA1c. Because histograms for sitagliptin-induced increase in our index of glucose tolerance (T30:T60) demonstrated a skewed distribution, we will apply a logarithmic transformation of data which yields a normal distribution. Thus, the drug effect is defined as: log(T30:T60 gluc)sita - log(T30:T60 gluc)control.
5 secondary outcomes
Area under the curve for insulin concentration
Time frame: 6 weeks
Area under the curve for glucose concentration
Time frame: 6 weeks
Area under the curve for intact GIP
Time frame: 6 weeks
Area under the curve for intact GLP1
Time frame: 6 weeks
Area under the curve for C-peptide levels
Time frame: 6 weeks
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 18 Feb 2026.
- Individual participant dataSharing planned: Undecided. Given that the Amish are a unique founder population, they are more easily identified and at-risk for stigmatization. Therefore, we must consult with the community in order to address this plan to share individual level data.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Kamah Woelfel contact
Amber L Beitelshees, PharmD, MPH principal investigator
University of Maryland, Baltimore
Simeon I Taylor, MD, PhD principal investigator
University of Maryland, Baltimore
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 4 study testing Oral Glucose Tolerance Test in people with Diabetes, run by University of Maryland, Baltimore at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 18 Feb 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Amber L Beitelshees (14107060118, abeitels@som.umaryland.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Sitagliptin-induced enhancement of early insulin secretion (time frame: 6 weeks). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 18 Feb 2026.