Trial · NCT01808690

EMERALD: Effects of Metformin on Cardiovascular Function in Adolescents With Type 1 Diabetes

NCT01808690, Phase 3, Completed, University of Colorado, Denver; results first posted 2020-02-05

3 sourcestrials-2026-11-12-0.5.0

Cite this record

ConductScience Library. EMERALD: Effects of Metformin on Cardiovascular Function in Adolescents With Type 1 Diabetes. Trials, record NCT01808690. Release trials-2026-11-12-0.5.0, 12 Nov 2026. https://conductscience.org/library/trials/NCT01808690

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Trial

As registered on ClinicalTrials.gov, in the graph's capture of the registry.

Title: EMERALD: Effects of Metformin on Cardiovascular Function in Adolescents With Type 1 Diabetes
NCT number: NCT01808690
Status: Completed
Phases: Phase 3
Enrollment: 52 participants, actual
Lead sponsor: University of Colorado, Denver
Conditions: Type 1 Diabetes
Interventions: Metformin, Placebo
First posted: 2013-03-11
Last updated: 2021-09-30
Results first posted: 2020-02-05
Limitations and caveats: Results may not apply to prepubertal youth. Treatment duration limited to 3 months. MRI unavailable during scanner replacement. Lacked measure to monitor BGs during vascular assessments. Not all females studied in traditional follicular phase.

Source ClinicalTrials.gov

Registered outcomes7

Each outcome the trial registered, primary first, in ClinicalTrials.gov's words.

List	Outcome	Time frame	Description
Primary	Change in Insulin Sensitivity	Baseline, Month 3	Hypothesis 1: Metformin will improve insulin function in Type 1 Diabetes. Insulin function will be measured using a euglycemic-hyperinsulinemic clamp procedure at both baseline and after 3 months of treatment. A clamp measures insulin sensitivity. A higher number indicates a better outcome; a lower number indicates a worse outcome.
Secondary	Change in ADP Time Constant	Baseline, Month 3	Hypothesis 1b: Metformin will improve mitochondrial function in Type 1 Diabetes. 31Phosphorus magnetic resonance spectroscopy (MRS) was used before, during, and after 90 seconds of near-maximal isometric exercise of the calf muscle for post-exercise muscle mitochondrial function. ADP time constant is the time for conversion of ADP → ATP and is a measure of muscle mitochondrial health (energy metabolism). A faster recovery is a better outcome; a slower recovery is a worse outcome.
Secondary	Change in Pulse Wave Velocity (PWV)	Baseline, Month 3	Hypothesis 2a: Metformin will improve central vascular function in Type 1 Diabetes via pulse wave velocity (PWV) by MRI. PWV is a measure of central arterial stiffness. A lower value indicates a better outcome.
Secondary	Change in Central Arterial Intimal Medial Thickness (cIMT)	Baseline, Month 3	Hypothesis 2a: Metformin will improve central vascular function in Type 1 Diabetes via central arterial intimal medial (cIMT) thickness by carotid ultrasound. cIMT is a measure used to diagnose the extent of carotid atherosclerotic vascular disease. The test measures the thickness of the inner two layers of the carotid artery-the intima and media. A lower result is a better outcome.
Secondary	Change in Mitral Valve E/A Ratio by Echocardiogram	Baseline, Month 3	Hypothesis 2b: Metformin will improve cardiac function in Type 1 Diabetes by echocardiogram. Mitral Valve E/A ratio is the ratio of early (E) to late (A) ventricular filling velocities. Ideal myocardial tissue relaxation is indicated by a ratio of \>0.8 and \<2.0.
Secondary	Change in Aortic Wall Sheer Stress (WSS)	Baseline, Month 3	Hypothesis 2a: Metformin will improve central vascular function in Type 1 Diabetes via Aortic Wall Sheer Stress (WSS) by MRI. WSS is a measure of central arterial stiffness. A lower value indicates a better outcome.
Other	Change in Brachial Artery Distensibility	Baseline, Month 3	Hypothesis 2a: Metformin will improve peripheral arterial stiffness in Type 1 Diabetes via Dynapulse. Peripheral arterial stiffness is measured by the distensibility of the arterial wall. Increased arterial stiffness results from reduced elasticity of the arterial wall. A higher result is a better outcome.

Source ClinicalTrials.gov

Outcomes7

Each outcome the trial posted results for, in ClinicalTrials.gov's words.

Type	Outcome	Time frame	Population	Units	Measured as
PRIMARY	Change in Insulin Sensitivity	Baseline, Month 3	Metformin group: 1 participant lost to follow-up, 1 IV access problem Placebo group: 2 lost to follow-up, 2 IV access problems	(mg/kg/min)/(insulin)	MEAN
SECONDARY	Change in ADP Time Constant	Baseline, Month 3	22 participants had both pre/post MRS data	seconds (s)	MEDIAN
SECONDARY	Change in Pulse Wave Velocity (PWV)	Baseline, Month 3	Number of participants analyzed differs from participant flow numbers because the institution's MRI scanner was unavailable during replacement.	m/s	MEAN
SECONDARY	Change in Central Arterial Intimal Medial Thickness (cIMT)	Baseline, Month 3	Metformin: 1 lost to follow-up Placebo: 2 lost to follow-up	mm	MEAN
SECONDARY	Change in Mitral Valve E/A Ratio by Echocardiogram	Baseline, Month 3	Metformin: 2 lost to follow-up Placebo: 2 lost to follow-up, 1 echocardiogram not performed	ratio	MEAN
SECONDARY	Change in Aortic Wall Sheer Stress (WSS)	Baseline, Month 3	Number of participants analyzed differs from participant flow numbers because the institution's MRI scanner was unavailable during replacement.	dyne/cm2	MEAN
OTHER_PRE_SPECIFIED	Change in Brachial Artery Distensibility	Baseline, Month 3	Metformin: 1 lost to follow-up Placebo: 2 lost to follow-up	%/mmHg	MEAN

Source ClinicalTrials.gov

Results by group14

Each measurement the trial posted, group by group, in the words and numbers it posted.

Outcome	Group	Value	Spread	Units
Change in Insulin Sensitivity	Metformin	12.2	Standard Deviation 3.2	(mg/kg/min)/(insulin)
Change in Insulin Sensitivity	Placebo	-2.4	Standard Deviation 3.6	(mg/kg/min)/(insulin)
Change in ADP Time Constant	Metformin	0.46	Inter-Quartile Range -5.62 to 7.72	seconds (s)
Change in ADP Time Constant	Placebo	-0.47	Inter-Quartile Range -1.55 to 0.34	seconds (s)
Change in Pulse Wave Velocity (PWV)	Metformin	-1.1	Standard Deviation 1.2	m/s
Change in Pulse Wave Velocity (PWV)	Placebo	4.1	Standard Deviation 1.6	m/s
Change in Central Arterial Intimal Medial Thickness (cIMT)	Metformin	-0.04	Standard Deviation 0.01	mm
Change in Central Arterial Intimal Medial Thickness (cIMT)	Placebo	0.00	Standard Deviation 0.10	mm
Change in Mitral Valve E/A Ratio by Echocardiogram	Metformin	1.55	Standard Deviation 0.42	ratio
Change in Mitral Valve E/A Ratio by Echocardiogram	Placebo	1.72	Standard Deviation 0.34	ratio

1 to 10 of 14Source ClinicalTrials.gov

See all 14 results by group

Participant flow6

How many started, completed or left each group, period by period.

Period	Milestone	Group	Participants
Overall Study	STARTED	Metformin	25
Overall Study	STARTED	Placebo	23
Overall Study	COMPLETED	Metformin	24
Overall Study	COMPLETED	Placebo	21
Overall Study	NOT COMPLETED	Metformin	1
Overall Study	NOT COMPLETED	Placebo	2

Source ClinicalTrials.gov

Adverse events2

Each adverse event the trial posted, group by group: the participants affected out of those at risk.

Type	Event	Organ system	Group	Affected	At risk	Events
other	Gastrointestinal Side Effects	Gastrointestinal disorders	Metformin	10	25
other	Gastrointestinal Side Effects	Gastrointestinal disorders	Placebo	2	23

Source ClinicalTrials.gov

Adverse event totals6

The totals the trial posted for each group.

Total	Group	Affected	At risk
Total, all-cause mortality	Metformin	0	25
Total, all-cause mortality	Placebo	0	23
Total, other adverse events	Metformin	10	25
Total, other adverse events	Placebo	2	23
Total, serious adverse events	Metformin	0	25
Total, serious adverse events	Placebo	0	23

Source ClinicalTrials.gov

Papers2

The papers the trial lists on ClinicalTrials.gov.

PMID	Listed as	Source
30566007	DERIVED	PubMed
33402367	DERIVED	PubMed

Grants1

The grants NIH RePORTER links to the trial, newest funded first: NIH's, and some of AHRQ's, CDC's, FDA's and VA's. Each shows its title, principal investigators, organization and funder in its newest year.

Project	Title	Principal investigators	Organization	Funder	Fiscal years
R56DK078645	Regulation of Maternal Fuel Supply and Neonatal Adiposity	BARBOUR, LINDA ANNE	UNIVERSITY OF COLORADO DENVER	NATIONAL INSTITUTE OF DIABETES AND DIGESTIVE AND KIDNEY DISEASES	2007 to 2008

Source NIH RePORTER

Trial comparisons2

Comparisons of the trial's two groups, calculated by ConductScience from the counts it posted.

Comparison	Source
Metformin vs Placebo: deaths from any cause	Trial comparisons
Metformin vs Placebo: serious adverse events	Trial comparisons

Tests0

The ConductCognition tests this trial's registered outcomes name, as ScienceGraph matched them in trial-tests-2026-11-12-0.2.1.

None in this release.

Data dates

The day each source was copied for this release.

ClinicalTrials.gov: 2026-11-12; ClinicalTrials.gov
Results, from AACT: 2026-03-23; AACT
NIH grant links: 2026-11-13; NIH RePORTER

Sources 3

ClinicalTrials.gov's posted results, through CTTI's AACTFreely available. Acknowledgement requested
ClinicalTrials.govNo license stated
NIH RePORTER's clinical studies and project filesPublic domain

Each source's terms

ClinicalTrials.gov's posted results, through CTTI's AACTClinicalTrials.gov data via Aggregate Analysis of ClinicalTrials.gov (AACT), CTTI. CTTI makes its materials freely available and requests acknowledgement. https://aact.ctti-clinicaltrials.org/documentation/299
ClinicalTrials.govnone stated
NIH RePORTER's clinical studies and project filesPublic domain (NIH RePORTER)

ClinicalTrials.gov's data carry an international copyright outside the United States: https://clinicaltrials.gov/about-site/terms-conditions.

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