Gestational DiabetesEarly Phase 1NCT05917587
Metformin for the Treatment of Microvascular Dysfunction After Gestational Diabetes
A Early Phase 1 study testing Metformin Hydrochloride in people with Gestational Diabetes, run by Anna Stanhewicz, PhD at 1 site in United States.
Trial summary
The purpose of this investigation is to examine the mechanisms mediating vascular dysfunction in women who have had gestational diabetes and how metformin may be a valuable treatment tool to improve microvascular function in these women before the onset of disease. Read more about this study
- Who is it for?
- Ages 18 to 45 years, women onlyHealthy volunteers can take part
- Conditions the study is for
- Gestational Diabetes
- What is being tested?
- Metformin Hydrochloride
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 30 participants
- Where
- 1 siteUnited States
- Study dates
- 11 Sep 2024to 30 Jun 2028
- Phase
- Early Phase 1
- 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 to 45 years
- Women only
- Healthy volunteers accepted
- Adult
Who may be able to join
- ≥12 weeks and ≤5 years postpartum
- history of GDM or healthy pregnancy
Who cannot join
- prediabetes or diabetes (HbA1c ≥5.7%)
- current tobacco use
- cardiovascular or metabolic disease
- cardiovascular or metabolic medication
- history of hypertension during pregnancy
- current pregnancy
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
University of Iowa
Iowa City, Iowa, 52242
Anna Stanhewicz, PhD, 319-467-1732, anna-stanhewicz@uiowa.edu
About this study
The purpose of this investigation is to examine the mechanisms mediating vascular dysfunction in women who have had gestational diabetes and how metformin may be a valuable treatment tool to improve microvascular function in these women before the onset of disease.
Read the detailed description
Women with a history of gestational diabetes mellitus (GDM) are at a 2-fold greater risk for the development of overt cardiovascular disease (CVD) following the effected pregnancy. While subsequent development of type II diabetes elevates this risk, prior GDM is an independent risk factor for CVD morbidity, particularly within the first decade postpartum. GDM is associated with impaired endothelial function during pregnancy and decrements in macro- and microvascular function persist postpartum, despite the remission of insulin resistance following delivery. Collectively, while the association between GDM and elevated lifetime CVD risk is clear, and available evidence demonstrates a link between GDM and vascular dysfunction in the decade following pregnancy, the mechanisms mediating this persistent dysfunction remain unexamined.
The purpose of this investigation is to examine the mechanisms mediating vascular dysfunction in women who have had gestational diabetes and how metformin may be a valuable treatment tool to improve microvascular function in these women before the onset of disease. This study will give rise to a new line of research that will center around the goal of improving lifetime cardiovascular outcomes in women with a history of GDM.
In this study, the investigators use the blood vessels in the skin as a representative vascular bed for examining mechanisms of microvascular dysfunction in humans. Using a minimally invasive technique (intradermal microdialysis for the local delivery of pharmaceutical agents) they examine the blood vessels in a dime-sized area of the skin in women who have had GDM. Local heating of the skin at the microdialysis sites is used to explore differences in mechanisms governing microvascular control. As a compliment to these measurements, the investigators also draw blood from the subjects and isolate the inflammatory cells.
- Conditions
- Gestational Diabetes
- Being tested
- Metformin Hydrochloride, placebo
- Keywords
- gestational diabetes, postpartum, vascular
- Medical subject headings
- Diabetes, Gestational
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Metformin HydrochlorideDrug
12 weeks: 850mg metformin once daily for first 7 days then twice daily for the remaining 11 weeks.
placeboOther
12 weeks: placebo tablet once daily for the first 7 days then twice daily for the remaining 11 weeks.
| Study group | Role | What they receive |
|---|---|---|
| metformin | Active comparator | Not described Receives: Drug: Metformin Hydrochloride |
| placebo | Placebo comparator | Not described Receives: Other: placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
blood flow response to acetylcholine
cutaneous microvascular dilation (cutaneous conductance ; %max) response to acetylcholine
Measured: baseline
blood flow response to acetylcholine
cutaneous microvascular dilation (cutaneous conductance ; %max) response to acetylcholine
Measured: 1 week of treatment
blood flow response to acetylcholine
cutaneous microvascular dilation (cutaneous conductance ; %max) response to acetylcholine
Measured: 6 weeks of treatment
blood flow response to acetylcholine
cutaneous microvascular dilation (cutaneous conductance ; %max) response to acetylcholine
Measured: 12 weeks of treatment
blood flow response to insulin
cutaneous microvascular dilation (cutaneous conductance ; %max) response to insulin
Measured: baseline
blood flow response to insulin
cutaneous microvascular dilation (cutaneous conductance ; %max) response to insulin
Measured: 1 week of treatment
blood flow response to insulin
cutaneous microvascular dilation (cutaneous conductance ; %max) response to insulin
Measured: 6 weeks of treatment
blood flow response to insulin
cutaneous microvascular dilation (cutaneous conductance ; %max) response to insulin
Measured: 12 weeks of treatment
Secondary outcomes (4)
Percentage of nitric oxide-dependent dilation
NO-dependent (%) cutaneous microvascular dilation response to acetylcholine
Measured: baseline
Percentage nitric oxide-dependent dilation
NO-dependent (%) cutaneous microvascular dilation response to acetylcholine
Measured: 1 week of treatment
Percentage of nitric oxide-dependent dilation
NO-dependent (%) cutaneous microvascular dilation response to acetylcholine
Measured: 6 weeks of treatment
Percentage of nitric oxide-dependent dilation
NO-dependent (%) cutaneous microvascular dilation response to acetylcholine
Measured: 12 weeks of treatment
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted26 Jun 2023
- Study start11 Sep 2024
- Primary completion31 Dec 2027 (estimated)
- Study completion30 Jun 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Gestational DiabetesStudies of the same condition, open and under way.
- 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
- Early Phase 1
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind
- Who is masked
- Participant, Investigator, Outcomes assessor
- Enrolment
- 30 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Anna Stanhewicz, PhD
- Sponsor type
- University, hospital or other
- Collaborators
- National Heart, Lung, and Blood Institute (NHLBI)
- Responsible party
- Sponsor-investigator, Anna Stanhewicz, PhD, University of Iowa
- Investigators
- Anna Stanhewicz, PhD, Principal investigator, University of Iowa
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05917587
- Sponsor's protocol ID
- 202303345
- Other IDs
- 1R01HL169201-01
- Status last verified
- Oct 2026
- First submitted
- 6 Jun 2023
- Last updated
- 28 Oct 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Yes: Findings from the primary studies will be published and submitted to PubMed Central in compliance with the NIH public access policy. These findings will also be made public through the clinicaltrial.gov record. The final data set will be stripped of any identifying data prior to release for sharing. We will make the data and any associated documentation available to users only under a data-sharing agreement that provides for: 1) a commitment to using the data only for research purposes and not to identify any one individual participant; 2) a commitment to securing the data using appropriate computer technology; and 3) a commitment to destroying or returning the data after all analyses are completed.
Study at a glance
From the registry record, last updated by the sponsor on 28 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Metformin for the Treatment of Microvascular Dysfunction After Gestational Diabetes
- ClinicalTrials.gov ID
- NCT05917587
- Acronym / sponsor ID
- 202303345
- Conditions
- Gestational Diabetes
- Keywords
- gestational diabetes, postpartum, vascular
- Phase
- Early Phase 1
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 30 participants (estimated)
- Lead sponsor
- Anna Stanhewicz, PhDUniversity, hospital or other
- Collaborators
- National Heart, Lung, and Blood Institute (NHLBI)
- Study start
- 11 Sep 2024 (actual)
- Primary completion
- 31 Dec 2027 (estimated)
- Study completion
- 30 Jun 2028 (estimated)
- First posted
- 26 Jun 2023 (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.
The purpose of this investigation is to examine the mechanisms mediating vascular dysfunction in women who have had gestational diabetes and how metformin may be a valuable treatment tool to improve microvascular function in these women before the onset of disease.
Detailed description
Women with a history of gestational diabetes mellitus (GDM) are at a 2-fold greater risk for the development of overt cardiovascular disease (CVD) following the effected pregnancy. While subsequent development of type II diabetes elevates this risk, prior GDM is an independent risk factor for CVD morbidity, particularly within the first decade postpartum. GDM is associated with impaired endothelial function during pregnancy and decrements in macro- and microvascular function persist postpartum, despite the remission of insulin resistance following delivery. Collectively, while the association between GDM and elevated lifetime CVD risk is clear, and available evidence demonstrates a link between GDM and vascular dysfunction in the decade following pregnancy, the mechanisms mediating this persistent dysfunction remain unexamined.
The purpose of this investigation is to examine the mechanisms mediating vascular dysfunction in women who have had gestational diabetes and how metformin may be a valuable treatment tool to improve microvascular function in these women before the onset of disease. This study will give rise to a new line of research that will center around the goal of improving lifetime cardiovascular outcomes in women with a history of GDM.
In this study, the investigators use the blood vessels in the skin as a representative vascular bed for examining mechanisms of microvascular dysfunction in humans. Using a minimally invasive technique (intradermal microdialysis for the local delivery of pharmaceutical agents) they examine the blood vessels in a dime-sized area of the skin in women who have had GDM. Local heating of the skin at the microdialysis sites is used to explore differences in mechanisms governing microvascular control. As a compliment to these measurements, the investigators also draw blood from the subjects and isolate the inflammatory cells.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind (participant, investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| metformin | Active comparator | Drug: Metformin Hydrochloride |
| placebo | Placebo comparator | Other: placebo |
Who may qualify
- Ages
- 18 to 45 years
- Sex
- Female only
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (2 listed)
- ≥12 weeks and ≤5 years postpartum
- history of GDM or healthy pregnancy
Key exclusion criteria (6 listed)
- prediabetes or diabetes (HbA1c ≥5.7%)
- current tobacco use
- cardiovascular or metabolic disease
- cardiovascular or metabolic medication
- history of hypertension during pregnancy
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 |
|---|---|---|
| Metformin Hydrochloride12 weeks: 850mg metformin once daily for first 7 days then twice daily for the remaining 11 weeks. | Drug | metformin |
| placebo12 weeks: placebo tablet once daily for the first 7 days then twice daily for the remaining 11 weeks. | Other | placebo |
Primary outcome
blood flow response to acetylcholine
Time frame: baseline
cutaneous microvascular dilation (cutaneous conductance ; %max) response to acetylcholine
blood flow response to acetylcholine
Time frame: 1 week of treatment
cutaneous microvascular dilation (cutaneous conductance ; %max) response to acetylcholine
blood flow response to acetylcholine
Time frame: 6 weeks of treatment
cutaneous microvascular dilation (cutaneous conductance ; %max) response to acetylcholine
blood flow response to acetylcholine
Time frame: 12 weeks of treatment
cutaneous microvascular dilation (cutaneous conductance ; %max) response to acetylcholine
blood flow response to insulin
Time frame: baseline
cutaneous microvascular dilation (cutaneous conductance ; %max) response to insulin
blood flow response to insulin
Time frame: 1 week of treatment
cutaneous microvascular dilation (cutaneous conductance ; %max) response to insulin
blood flow response to insulin
Time frame: 6 weeks of treatment
cutaneous microvascular dilation (cutaneous conductance ; %max) response to insulin
blood flow response to insulin
Time frame: 12 weeks of treatment
cutaneous microvascular dilation (cutaneous conductance ; %max) response to insulin
4 secondary outcomes
Percentage of nitric oxide-dependent dilation
Time frame: baseline
Percentage nitric oxide-dependent dilation
Time frame: 1 week of treatment
Percentage of nitric oxide-dependent dilation
Time frame: 6 weeks of treatment
Percentage of nitric oxide-dependent dilation
Time frame: 12 weeks of treatment
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 28 Oct 2026.
- Individual participant dataSharing planned: Yes. Findings from the primary studies will be published and submitted to PubMed Central in compliance with the NIH public access policy. These findings will also be made public through the clinicaltrial.gov record. The final data set will be stripped of any identifying data prior to release for sharing. We will make the data and any associated documentation available to users only under a data-sharing agreement that provides for: 1) a commitment to using the data only for research purposes and not to identify any one individual participant; 2) a commitment to securing the data using appropriate computer technology; and 3) a commitment to destroying or returning the data after all analyses are completed.
Related trials for Gestational Diabetes
Active, not recruiting
Effect of Probiotics on Insulin Sensitivity in Overweight and Obese Pregnancy
Obesity & Overweight, Gestational Diabetes Mellitus (GDM)
Not yet recruitingObservational study
Ultrasound Assessment Of Gastric Volume In Pregnant Women Undergoing Elective Cesarean Section
Gestational Diabetes Mellitus (GDM), Obstetric Anesthesia
Active, not recruitingPhase 2
Effectiveness Study of a Lifestyle Intervention Versus Metformin in Mothers With Recent Gestational Diabetes
Weight Loss, Gestational Diabetes Mellitus in Pregnancy
Not yet recruiting
STRONG: SMART Trial
Gestational Diabetes Mellitus (GDM)
Not yet recruiting
A Study to Lower Blood Pressure One Year After Childbirth in Women Who Had Preeclampsia
Adverse Pregnancy Outcomes, Cardiovascular Diseases
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.
Anna Stanhewicz, PhD principal investigator
University of Iowa
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Early Phase 1 study testing Metformin Hydrochloride in people with Gestational Diabetes, run by Anna Stanhewicz, PhD 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 6 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: looking for participants now, as of the sponsor's last update on 28 Oct 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?
Early Phase 1 (sometimes called Phase 0) studies give a very small amount of a treatment to a few people, mainly to see how the body handles it.
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 Anna Stanhewicz, PhD (3194671732, anna-stanhewicz@uiowa.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
blood flow response to acetylcholine (time frame: baseline). The study lists 8 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 28 Oct 2026.