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Effect of Metformin on Vascular and Mitochondrial Function in Type 1 Diabetes (MeT1)

Primary Purpose

Type 1 Diabetes

Status
Completed
Phase
Phase 4
Locations
United States
Study Type
Interventional
Intervention
Metformin
Placebo
Sponsored by
University of Colorado, Denver
About
Eligibility
Locations
Arms
Outcomes
Full info

About this trial

This is an interventional treatment trial for Type 1 Diabetes focused on measuring Diabetes, Insulin, Metformin, Vascular, Vessels, Type 1

Eligibility Criteria

25 Years - 59 Years (Adult)All SexesDoes not accept healthy volunteers

Inclusion Criteria:

  • Age 20-59 years of age,
  • Type 1 diabetes based on antibody-positivity, rapid persistent conversion to insulin requirement after diagnosis, absent C-peptide, or DKA at diagnosis, or a clinical course consistent with T1D,
  • HbA1c 6.0 - 9.5, and
  • Willing and able to commit to two 6 week-long periods of blinded medication followed by hyperinsulinemic euglycemic clamp, vascular testing, and muscle biopsies.

Exclusion Criteria:

  • Any comorbid condition associated with:

    • inflammation,
    • insulin Resistance, or
    • dyslipidemia including:

      1. cancer,
      2. heart failure,
      3. active or end stage liver disease,
      4. kidney disease, or
      5. rheumatological disease;
  • Tobacco use;
  • Pregnancy or women who are breastfeeding;
  • Steroid use;
  • Scheduled strenuous physical activity >3 days a week;
  • Angina, known CAD, or any other cardiovascular or pulmonary disease;
  • A history of COPD or asthma;
  • Presence of systolic blood pressure >190 at rest or >250 with exercise, or diastolic pressure >95 at rest or >105 with exercise;
  • Untreated thyroid disease;
  • Proteinuria (urine protein >200 mg/dl) or a creatinine > 1.5 mg/dl (males) or 1.4 mg/dL (females), suggestive of severe renal disease;
  • Severe Proliferative retinopathy;
  • Niacin treatment;
  • Administration of experimental agent for T1D within 30 days prior to screening;
  • Recent (prior 6 months) or current metformin or thiazolidenedione use;
  • Hypoglycemia unawareness or recurrent severe hypoglycemia (no symptoms of hypoglycemia with FSBS<40 and episodes of this severity >1 per week);
  • Weight instability (weight change >5% in last 6 months);
  • History of any organ transplant, including islet cell transplant;
  • Current or prior infection with HIV, hepatitis B or hepatitis C or hepatic -insufficiency (AST or ALT > 2x the upper limits of normal);
  • Any condition, medical or otherwise that would, in the opinion of the investigator, prevent complete participation in the study, or that would pose a significant hazard to the subject;
  • History of substance abuse within the 12 months prior to screening.

Sites / Locations

  • University of Colorado Denver

Arms of the Study

Arm 1

Arm 2

Arm Type

Experimental

Placebo Comparator

Arm Label

Metformin

Placebo

Arm Description

Outcomes

Primary Outcome Measures

Insulin Sensitivity by Hyperinsulinemic Euglycemic Clamp
Determine the effect of metformin on insulin sensitivity in T1D. Reported measure is glucose infusion rate during hyperinsulinemic euglycemic clamp normalized to total body weight. For this measure, insulin was infused at 40 mU/m2 surface area. Blood sugar wass checked every 5 minutes and glucose infusion adjusted to maintain glucose level at 90 mg/dL for 2 hours. The glucose infusion rate for the final 30 minutes is reported as GIR (aka M-value or glucose disposal rate) in mg glucose/kg*min. A higher value corresponds to greater sensitivity to insulin. There is no strictly defined normal range.
Flow-mediated Brachial Artery Dilation
Measure of endothelial function by brachial ultrasound of the percent dilation after 5 minutes of occlusion.

Secondary Outcome Measures

Arterial Stiffness by PWV
Pulse wave velocity by Sphygmacor as a measure of aortic stiffness in m/sec.
Arterial Stiffness by AI@75
Augmentation index by Sphygmacor is a measure of aortic arterial stiffness. AI@75 is the ratio of augmented pressure/pulse pressure adjusted to a heart rate of 75.
Mitochondrial Measures: Oxygen Consumption
Oxygen consumption rate with various substrates and max uncoupled O2 consumption. Measure is performed on permeabilized muscle fibers from biopsy tissue from the vastus lateralis using the Oroboros OxygraphO2k high resolution respirometer. State 3 is full coupled oxygen flux using PMG or PMGS (pyruvate, malate, glutamate, +/- succinate) or OCMS (octanyl carnitine, malate, +/- succinate) as substrates. state 4 is after addition of oligomycin to inhibit the ATP synthase and thus corresponds to the maximum leak state where O2 consumption is limited by the buildup of the proton gradient and can only proceed as fast as the protons can leak back across the membrane. FCCP is added as an uncoupler, allowing free leakage of protons across the inner membrane, and thus measures maximum possible O2 flux. There are no defined normal ranges, but higher state 3 and uncoupled flux indicate better mitochondrial function, while state 4 is needed to correct state 3 to the fully coupled flux.
Mitochondrial Measures: Protein Expression Levels of Electron Transport Chain Complexes
Mito content by Western Blotting of electron transport chain complexes I, II, III, and V. complex 1 utilizes NADH from pyruvate/malate/glutamate while complex II utilizes FADH from succinate. complex III is the cytochrome c reductase while complex V is the ATP synthase.
Inflammatory Marker: hsCRP
hsCRP (mg/L) by Beckman Coulter assay
Heart Rate Variability
measure of autonomic function: ratio of fastest to slowest heart rate during valsalva maneuver
Continuous Glucose Monitor Measures of Mean Glucose
Mean Glucose & Glucose Standard Deviation (Glycemic Variability) by Dexcom CGM
Continuous Glucose Monitor Measures of Hypoglycemia
Percent of time less than 70 mg/dL during the final week of each phase by Dexcom CGM.
Metabolic Markers: Glucagon
Glucagon (pg/ml); baseline on AM of each phase final study visit.
Metabolic Markers: Glucose, Triglycerides, Cholesterol
Glucose (mg/dL), triglycerides (mg/dL), cholesterol (mg/dL) at baseline after each phase
Metabolic Markers: Fatty Acids
fatty acids (microeq/L) at baseline after each phase in the AM of the final visit
Metabolic Markers: Glycerol
glycerol (micromol/L) at baseline after each phase in the AM of the final phase visit
Metabolic Markers: Insulin
insulin (microIU/ml) at baseline after each phase in the AM of the final phase visit
Metabolic Markers: Lactate
lactate (mmol/L) at baseline after each phase in the AM of the final phase visit
Metabolic Markers: Adiponection
adiponection (microg/ml) at baseline after each phase in the AM of the final phase visit
Vascular Markers: Endothelin-1 (pg/ml)
endothelin-1 at baseline after each phase in the AM of the final phase visit by peninsula labs radioimmunoassay
In Vivo Mitochondrial Function: Ratio of the Amount of ATP Generated Per Unit of Oxygen Consumed
Measured by 31P-mass spec. This ratio measures mitochondrial efficiency. The higher the ratio, the more efficiently the individual converts metabolic substrates into ATP, with the ATP then available for energy-demanding cellular processes such as protein synthesis and biomass production
In Vivo Mitochondrial Function: Time Constants
Measured by 31P-mass spec. ADP time constant and phosphocreatine time constant. ADP time constant is a measure of the time required to convert 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. Similarly for phosphocreatine.
In Vivo Mitochondrial Function: QMax, VPCr
Measured by 31P-mass spec. For each measure, a higher value indicates better mitochondrial function. All re calculated from multiple measures from the MRS spectra. These are relatively new research measures and normal values are not known or generally accepted. QMax is theoretical maximum activity. VPCr measures the rate at which PCr is regenerated.
In Vivo Mitochondrial Function: Oxidative Phosphorylation
Measured by 31P-mass spec. A higher value indicates better mitochondrial function. All re calculated from multiple measures from the MRS spectra. These are relatively new research measures and normal values are not known or generally accepted. Oxidative Phosphorylation measures the rate at which electron transport activity generates phosphorylated energy sources (ATP and PCr)
In Vivo Mitochondrial Function:AnGly
Measured by 31P-mass spec. Anaerobic glycolysis measures the amount of anaerobic ATP generation for energy. It is generally felt that a higher value here reflects impaired mitochondrial function necessitating greater reliance on anaerobic metabolism.
Cardiac Function
Cardiac output

Full Information

First Posted
September 28, 2012
Last Updated
December 21, 2021
Sponsor
University of Colorado, Denver
Collaborators
US Department of Veterans Affairs
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1. Study Identification

Unique Protocol Identification Number
NCT01813929
Brief Title
Effect of Metformin on Vascular and Mitochondrial Function in Type 1 Diabetes
Acronym
MeT1
Official Title
Effect of Metformin on Vascular and Mitochondrial Function in Type 1 Diabetes
Study Type
Interventional

2. Study Status

Record Verification Date
December 2021
Overall Recruitment Status
Completed
Study Start Date
June 2011 (undefined)
Primary Completion Date
March 24, 2017 (Actual)
Study Completion Date
March 24, 2017 (Actual)

3. Sponsor/Collaborators

Responsible Party, by Official Title
Sponsor
Name of the Sponsor
University of Colorado, Denver
Collaborators
US Department of Veterans Affairs

4. Oversight

Data Monitoring Committee
No

5. Study Description

Brief Summary
Insulin resistance (IR) is an important contributor to increased cardiovascular disease risk in type 1 diabetes (T1D). The purpose of this study is to measure the effect of metformin on insulin sensitivity, vascular function and compliance, and mitochondrial function in T1D. The long term goal is to identify novel non-glycemic approaches to managing cardiovascular disease risk in T1D. The results of this study may validate a novel approach to T1D treatment that could significantly improve current management of cardiovascular disease risk in this high risk population.

6. Conditions and Keywords

Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
Type 1 Diabetes
Keywords
Diabetes, Insulin, Metformin, Vascular, Vessels, Type 1

7. Study Design

Primary Purpose
Treatment
Study Phase
Phase 4
Interventional Study Model
Crossover Assignment
Masking
ParticipantInvestigator
Allocation
Randomized
Enrollment
23 (Actual)

8. Arms, Groups, and Interventions

Arm Title
Metformin
Arm Type
Experimental
Arm Title
Placebo
Arm Type
Placebo Comparator
Intervention Type
Drug
Intervention Name(s)
Metformin
Other Intervention Name(s)
glucophage
Intervention Description
Six week intervention: Study drug/placebo will be given in a forced uptitration with 500 mg once daily for one week, 500 mg twice daily for one week, 500/1000 for one week, and then 1000mg twice daily for the remainder of the 6 week intervention. If uptitration is not tolerated, max dose will be max tolerated dose of at least 500 mg twice daily.
Intervention Type
Drug
Intervention Name(s)
Placebo
Intervention Description
Six-week intervention: Study drug/placebo will be given in a forced uptitration with 500 mg once daily for one week, 500 mg twice daily for one week, and then the higher dose (850 mg) for the remainder of the 6 week intervention.
Primary Outcome Measure Information:
Title
Insulin Sensitivity by Hyperinsulinemic Euglycemic Clamp
Description
Determine the effect of metformin on insulin sensitivity in T1D. Reported measure is glucose infusion rate during hyperinsulinemic euglycemic clamp normalized to total body weight. For this measure, insulin was infused at 40 mU/m2 surface area. Blood sugar wass checked every 5 minutes and glucose infusion adjusted to maintain glucose level at 90 mg/dL for 2 hours. The glucose infusion rate for the final 30 minutes is reported as GIR (aka M-value or glucose disposal rate) in mg glucose/kg*min. A higher value corresponds to greater sensitivity to insulin. There is no strictly defined normal range.
Time Frame
End of each 6 week intervention period
Title
Flow-mediated Brachial Artery Dilation
Description
Measure of endothelial function by brachial ultrasound of the percent dilation after 5 minutes of occlusion.
Time Frame
End of each 6 week intervention period
Secondary Outcome Measure Information:
Title
Arterial Stiffness by PWV
Description
Pulse wave velocity by Sphygmacor as a measure of aortic stiffness in m/sec.
Time Frame
End of each 6 week intervention period
Title
Arterial Stiffness by AI@75
Description
Augmentation index by Sphygmacor is a measure of aortic arterial stiffness. AI@75 is the ratio of augmented pressure/pulse pressure adjusted to a heart rate of 75.
Time Frame
End of each 6 week intervention period
Title
Mitochondrial Measures: Oxygen Consumption
Description
Oxygen consumption rate with various substrates and max uncoupled O2 consumption. Measure is performed on permeabilized muscle fibers from biopsy tissue from the vastus lateralis using the Oroboros OxygraphO2k high resolution respirometer. State 3 is full coupled oxygen flux using PMG or PMGS (pyruvate, malate, glutamate, +/- succinate) or OCMS (octanyl carnitine, malate, +/- succinate) as substrates. state 4 is after addition of oligomycin to inhibit the ATP synthase and thus corresponds to the maximum leak state where O2 consumption is limited by the buildup of the proton gradient and can only proceed as fast as the protons can leak back across the membrane. FCCP is added as an uncoupler, allowing free leakage of protons across the inner membrane, and thus measures maximum possible O2 flux. There are no defined normal ranges, but higher state 3 and uncoupled flux indicate better mitochondrial function, while state 4 is needed to correct state 3 to the fully coupled flux.
Time Frame
End of each 6 week intervention period
Title
Mitochondrial Measures: Protein Expression Levels of Electron Transport Chain Complexes
Description
Mito content by Western Blotting of electron transport chain complexes I, II, III, and V. complex 1 utilizes NADH from pyruvate/malate/glutamate while complex II utilizes FADH from succinate. complex III is the cytochrome c reductase while complex V is the ATP synthase.
Time Frame
End of each 6 week intervention period
Title
Inflammatory Marker: hsCRP
Description
hsCRP (mg/L) by Beckman Coulter assay
Time Frame
End of each 6 week intervention period
Title
Heart Rate Variability
Description
measure of autonomic function: ratio of fastest to slowest heart rate during valsalva maneuver
Time Frame
End of each 6 week intervention period
Title
Continuous Glucose Monitor Measures of Mean Glucose
Description
Mean Glucose & Glucose Standard Deviation (Glycemic Variability) by Dexcom CGM
Time Frame
Last Week of each 6 Week Intervention Period (over 7 days)
Title
Continuous Glucose Monitor Measures of Hypoglycemia
Description
Percent of time less than 70 mg/dL during the final week of each phase by Dexcom CGM.
Time Frame
Last Week of each 6 Week Intervention Period (over 7 days)
Title
Metabolic Markers: Glucagon
Description
Glucagon (pg/ml); baseline on AM of each phase final study visit.
Time Frame
End of each 6 week intervention period
Title
Metabolic Markers: Glucose, Triglycerides, Cholesterol
Description
Glucose (mg/dL), triglycerides (mg/dL), cholesterol (mg/dL) at baseline after each phase
Time Frame
End of each 6 week intervention period
Title
Metabolic Markers: Fatty Acids
Description
fatty acids (microeq/L) at baseline after each phase in the AM of the final visit
Time Frame
End of each 6 week intervention period
Title
Metabolic Markers: Glycerol
Description
glycerol (micromol/L) at baseline after each phase in the AM of the final phase visit
Time Frame
End of each 6 week intervention period
Title
Metabolic Markers: Insulin
Description
insulin (microIU/ml) at baseline after each phase in the AM of the final phase visit
Time Frame
End of each 6 week intervention period
Title
Metabolic Markers: Lactate
Description
lactate (mmol/L) at baseline after each phase in the AM of the final phase visit
Time Frame
End of each 6 week intervention period
Title
Metabolic Markers: Adiponection
Description
adiponection (microg/ml) at baseline after each phase in the AM of the final phase visit
Time Frame
End of each 6 week intervention period
Title
Vascular Markers: Endothelin-1 (pg/ml)
Description
endothelin-1 at baseline after each phase in the AM of the final phase visit by peninsula labs radioimmunoassay
Time Frame
End of each 6 week intervention period
Title
In Vivo Mitochondrial Function: Ratio of the Amount of ATP Generated Per Unit of Oxygen Consumed
Description
Measured by 31P-mass spec. This ratio measures mitochondrial efficiency. The higher the ratio, the more efficiently the individual converts metabolic substrates into ATP, with the ATP then available for energy-demanding cellular processes such as protein synthesis and biomass production
Time Frame
End of each 6 week intervention period
Title
In Vivo Mitochondrial Function: Time Constants
Description
Measured by 31P-mass spec. ADP time constant and phosphocreatine time constant. ADP time constant is a measure of the time required to convert 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. Similarly for phosphocreatine.
Time Frame
End of each 6 week intervention period
Title
In Vivo Mitochondrial Function: QMax, VPCr
Description
Measured by 31P-mass spec. For each measure, a higher value indicates better mitochondrial function. All re calculated from multiple measures from the MRS spectra. These are relatively new research measures and normal values are not known or generally accepted. QMax is theoretical maximum activity. VPCr measures the rate at which PCr is regenerated.
Time Frame
End of each 6 week intervention period
Title
In Vivo Mitochondrial Function: Oxidative Phosphorylation
Description
Measured by 31P-mass spec. A higher value indicates better mitochondrial function. All re calculated from multiple measures from the MRS spectra. These are relatively new research measures and normal values are not known or generally accepted. Oxidative Phosphorylation measures the rate at which electron transport activity generates phosphorylated energy sources (ATP and PCr)
Time Frame
End of each 6 week intervention period
Title
In Vivo Mitochondrial Function:AnGly
Description
Measured by 31P-mass spec. Anaerobic glycolysis measures the amount of anaerobic ATP generation for energy. It is generally felt that a higher value here reflects impaired mitochondrial function necessitating greater reliance on anaerobic metabolism.
Time Frame
End of each 6 week intervention period
Title
Cardiac Function
Description
Cardiac output
Time Frame
End of each 6 week intervention period
Other Pre-specified Outcome Measures:
Title
Vascular Markers: PAI-1
Description
PAI-1 exploratory thromobotic marker.
Time Frame
End of each 6 week intervention period
Title
Vascular Markers: Exploratory
Description
ICAM
Time Frame
End of each 6 week intervention period
Title
Oxidative Stress Markers
Description
TBARs, GSSG:GSH ratio
Time Frame
End of each 6 week intervention period
Title
Mitochondrial Measures: Oxidant Generation
Description
oxidant generation
Time Frame
End of each 6 week intervention period
Title
Inflammatory Markers: Exploratory
Description
IL6, TNF alpha
Time Frame
End of each 6 week intervention period
Title
Mitochondrial Oxidant Generation
Description
exploratory measure looking at H2O2 production. not performed due to equipment not available.
Time Frame
after each 6 week intervention

10. Eligibility

Sex
All
Minimum Age & Unit of Time
25 Years
Maximum Age & Unit of Time
59 Years
Accepts Healthy Volunteers
No
Eligibility Criteria
Inclusion Criteria: Age 20-59 years of age, Type 1 diabetes based on antibody-positivity, rapid persistent conversion to insulin requirement after diagnosis, absent C-peptide, or DKA at diagnosis, or a clinical course consistent with T1D, HbA1c 6.0 - 9.5, and Willing and able to commit to two 6 week-long periods of blinded medication followed by hyperinsulinemic euglycemic clamp, vascular testing, and muscle biopsies. Exclusion Criteria: Any comorbid condition associated with: inflammation, insulin Resistance, or dyslipidemia including: cancer, heart failure, active or end stage liver disease, kidney disease, or rheumatological disease; Tobacco use; Pregnancy or women who are breastfeeding; Steroid use; Scheduled strenuous physical activity >3 days a week; Angina, known CAD, or any other cardiovascular or pulmonary disease; A history of COPD or asthma; Presence of systolic blood pressure >190 at rest or >250 with exercise, or diastolic pressure >95 at rest or >105 with exercise; Untreated thyroid disease; Proteinuria (urine protein >200 mg/dl) or a creatinine > 1.5 mg/dl (males) or 1.4 mg/dL (females), suggestive of severe renal disease; Severe Proliferative retinopathy; Niacin treatment; Administration of experimental agent for T1D within 30 days prior to screening; Recent (prior 6 months) or current metformin or thiazolidenedione use; Hypoglycemia unawareness or recurrent severe hypoglycemia (no symptoms of hypoglycemia with FSBS<40 and episodes of this severity >1 per week); Weight instability (weight change >5% in last 6 months); History of any organ transplant, including islet cell transplant; Current or prior infection with HIV, hepatitis B or hepatitis C or hepatic -insufficiency (AST or ALT > 2x the upper limits of normal); Any condition, medical or otherwise that would, in the opinion of the investigator, prevent complete participation in the study, or that would pose a significant hazard to the subject; History of substance abuse within the 12 months prior to screening.
Overall Study Officials:
First Name & Middle Initial & Last Name & Degree
Irene Schauer, MD, PhD
Organizational Affiliation
University of Colorado, Denver
Official's Role
Principal Investigator
Facility Information:
Facility Name
University of Colorado Denver
City
Aurora
State/Province
Colorado
ZIP/Postal Code
80045
Country
United States

12. IPD Sharing Statement

Learn more about this trial

Effect of Metformin on Vascular and Mitochondrial Function in Type 1 Diabetes

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