Trial Outcomes & Findings for EMERALD: Effects of Metformin on Cardiovascular Function in Adolescents With Type 1 Diabetes (NCT NCT01808690)

NCT ID: NCT01808690

Last Updated: 2021-09-30

Results Overview

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.

Recruitment status

COMPLETED

Study phase

PHASE3

Target enrollment

52 participants

Primary outcome timeframe

Baseline, Month 3

Results posted on

2021-09-30

Participant Flow

Three (3) enrolled participants decided against participation in the study before randomization occurred.

Participant milestones

Participant milestones
Measure
Metformin
Metformin will be given at a dose of 1000 mg twice a day orally for three months to assess changes in insulin resistance compared to placebo. Metformin
Placebo
Placebo will be given at a dose of 1000 mg twice a day orally for three months to assess changes in insulin resistance compared to metformin. Placebo
Overall Study
STARTED
25
23
Overall Study
COMPLETED
24
21
Overall Study
NOT COMPLETED
1
2

Reasons for withdrawal

Reasons for withdrawal
Measure
Metformin
Metformin will be given at a dose of 1000 mg twice a day orally for three months to assess changes in insulin resistance compared to placebo. Metformin
Placebo
Placebo will be given at a dose of 1000 mg twice a day orally for three months to assess changes in insulin resistance compared to metformin. Placebo
Overall Study
Withdrawal by Subject
1
2

Baseline Characteristics

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

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure
Metformin
n=25 Participants
Metformin will be given at a dose of 1000 mg twice a day orally for three months to assess changes in insulin resistance compared to placebo. Metformin
Placebo
n=23 Participants
Placebo will be given at a dose of 1000 mg twice a day orally for three months to assess changes in insulin resistance compared to metformin. Placebo
Total
n=48 Participants
Total of all reporting groups
Age, Continuous
17.3 years
STANDARD_DEVIATION 2.3 • n=5 Participants
15.9 years
STANDARD_DEVIATION 2.7 • n=7 Participants
16.6 years
STANDARD_DEVIATION 2.5 • n=5 Participants
Sex: Female, Male
Female
14 Participants
n=5 Participants
10 Participants
n=7 Participants
24 Participants
n=5 Participants
Sex: Female, Male
Male
11 Participants
n=5 Participants
13 Participants
n=7 Participants
24 Participants
n=5 Participants
Ethnicity (NIH/OMB)
Hispanic or Latino
3 Participants
n=5 Participants
4 Participants
n=7 Participants
7 Participants
n=5 Participants
Ethnicity (NIH/OMB)
Not Hispanic or Latino
22 Participants
n=5 Participants
19 Participants
n=7 Participants
41 Participants
n=5 Participants
Ethnicity (NIH/OMB)
Unknown or Not Reported
0 Participants
n=5 Participants
0 Participants
n=7 Participants
0 Participants
n=5 Participants
Race (NIH/OMB)
American Indian or Alaska Native
0 Participants
n=5 Participants
0 Participants
n=7 Participants
0 Participants
n=5 Participants
Race (NIH/OMB)
Asian
1 Participants
n=5 Participants
0 Participants
n=7 Participants
1 Participants
n=5 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
0 Participants
n=5 Participants
0 Participants
n=7 Participants
0 Participants
n=5 Participants
Race (NIH/OMB)
Black or African American
0 Participants
n=5 Participants
1 Participants
n=7 Participants
1 Participants
n=5 Participants
Race (NIH/OMB)
White
24 Participants
n=5 Participants
22 Participants
n=7 Participants
46 Participants
n=5 Participants
Race (NIH/OMB)
More than one race
0 Participants
n=5 Participants
0 Participants
n=7 Participants
0 Participants
n=5 Participants
Race (NIH/OMB)
Unknown or Not Reported
0 Participants
n=5 Participants
0 Participants
n=7 Participants
0 Participants
n=5 Participants

PRIMARY outcome

Timeframe: Baseline, Month 3

Population: Metformin group: 1 participant lost to follow-up, 1 IV access problem Placebo group: 2 lost to follow-up, 2 IV access problems

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.

Outcome measures

Outcome measures
Measure
Metformin
n=23 Participants
Metformin will be given at a dose of 1000 mg twice a day orally for three months to assess changes in insulin resistance compared to placebo. Metformin
Placebo
n=19 Participants
Placebo will be given at a dose of 1000 mg twice a day orally for three months to assess changes in insulin resistance compared to metformin. Placebo
Change in Insulin Sensitivity
12.2 (mg/kg/min)/(insulin)
Standard Deviation 3.2
-2.4 (mg/kg/min)/(insulin)
Standard Deviation 3.6

SECONDARY outcome

Timeframe: Baseline, Month 3

Population: 22 participants had both pre/post MRS data

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.

Outcome measures

Outcome measures
Measure
Metformin
n=12 Participants
Metformin will be given at a dose of 1000 mg twice a day orally for three months to assess changes in insulin resistance compared to placebo. Metformin
Placebo
n=10 Participants
Placebo will be given at a dose of 1000 mg twice a day orally for three months to assess changes in insulin resistance compared to metformin. Placebo
Change in ADP Time Constant
0.46 seconds (s)
Interval -5.62 to 7.72
-0.47 seconds (s)
Interval -1.55 to 0.34

SECONDARY outcome

Timeframe: Baseline, Month 3

Population: Number of participants analyzed differs from participant flow numbers because the institution's MRI scanner was unavailable during replacement.

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.

Outcome measures

Outcome measures
Measure
Metformin
n=20 Participants
Metformin will be given at a dose of 1000 mg twice a day orally for three months to assess changes in insulin resistance compared to placebo. Metformin
Placebo
n=17 Participants
Placebo will be given at a dose of 1000 mg twice a day orally for three months to assess changes in insulin resistance compared to metformin. Placebo
Change in Pulse Wave Velocity (PWV)
-1.1 m/s
Standard Deviation 1.2
4.1 m/s
Standard Deviation 1.6

SECONDARY outcome

Timeframe: Baseline, Month 3

Population: Metformin: 1 lost to follow-up Placebo: 2 lost to follow-up

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.

Outcome measures

Outcome measures
Measure
Metformin
n=24 Participants
Metformin will be given at a dose of 1000 mg twice a day orally for three months to assess changes in insulin resistance compared to placebo. Metformin
Placebo
n=21 Participants
Placebo will be given at a dose of 1000 mg twice a day orally for three months to assess changes in insulin resistance compared to metformin. Placebo
Change in Central Arterial Intimal Medial Thickness (cIMT)
-0.04 mm
Standard Deviation 0.01
0.00 mm
Standard Deviation 0.10

SECONDARY outcome

Timeframe: Baseline, Month 3

Population: Metformin: 2 lost to follow-up Placebo: 2 lost to follow-up, 1 echocardiogram not performed

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.

Outcome measures

Outcome measures
Measure
Metformin
n=23 Participants
Metformin will be given at a dose of 1000 mg twice a day orally for three months to assess changes in insulin resistance compared to placebo. Metformin
Placebo
n=20 Participants
Placebo will be given at a dose of 1000 mg twice a day orally for three months to assess changes in insulin resistance compared to metformin. Placebo
Change in Mitral Valve E/A Ratio by Echocardiogram
1.55 ratio
Standard Deviation 0.42
1.72 ratio
Standard Deviation 0.34

SECONDARY outcome

Timeframe: Baseline, Month 3

Population: Number of participants analyzed differs from participant flow numbers because the institution's MRI scanner was unavailable during replacement.

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.

Outcome measures

Outcome measures
Measure
Metformin
n=20 Participants
Metformin will be given at a dose of 1000 mg twice a day orally for three months to assess changes in insulin resistance compared to placebo. Metformin
Placebo
n=17 Participants
Placebo will be given at a dose of 1000 mg twice a day orally for three months to assess changes in insulin resistance compared to metformin. Placebo
Change in Aortic Wall Sheer Stress (WSS)
-0.3 dyne/cm2
Standard Deviation 0.4
1.5 dyne/cm2
Standard Deviation 0.5

OTHER_PRE_SPECIFIED outcome

Timeframe: Baseline, Month 3

Population: Metformin: 1 lost to follow-up Placebo: 2 lost to follow-up

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.

Outcome measures

Outcome measures
Measure
Metformin
n=24 Participants
Metformin will be given at a dose of 1000 mg twice a day orally for three months to assess changes in insulin resistance compared to placebo. Metformin
Placebo
n=21 Participants
Placebo will be given at a dose of 1000 mg twice a day orally for three months to assess changes in insulin resistance compared to metformin. Placebo
Change in Brachial Artery Distensibility
0.23 %/mmHg
Standard Deviation 0.19
0.16 %/mmHg
Standard Deviation 0.20

Adverse Events

Metformin

Serious events: 0 serious events
Other events: 10 other events
Deaths: 0 deaths

Placebo

Serious events: 0 serious events
Other events: 2 other events
Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Other adverse events
Measure
Metformin
n=25 participants at risk
Metformin will be given at a dose of 1000 mg twice a day orally for three months to assess changes in insulin resistance compared to placebo. Metformin
Placebo
n=23 participants at risk
Placebo will be given at a dose of 1000 mg twice a day orally for three months to assess changes in insulin resistance compared to metformin. Placebo
Gastrointestinal disorders
Gastrointestinal Side Effects
40.0%
10/25 • 3 months
8.7%
2/23 • 3 months

Additional Information

Dr. Kristen J Nadeau

University of Colorado Denver/Children's Hospital Colorado

Phone: 720-777-2855

Results disclosure agreements

  • Principal investigator is a sponsor employee
  • Publication restrictions are in place