Type 2 DiabetesInsITENCT00786019
Influence of Endothelial Function on Central and Peripheral Causes Of Exercise Impairment in Type 2 Diabetes
A study testing Exercise program and Ascorbic Acid (Vitamin C) in people with Type 2 Diabetes, run by University of Colorado, Denver at 1 site in United States.
Trial summary
This study will evaluate the effects of impaired blood flow regulation on exercise. It will also determine whether the effects are more important in the heart or in the skeletal muscle tissue during exercise. Read more about this study
- Who is it for?
- Ages 30 to 55 yearsHealthy volunteers can take part
- Conditions the study is for
- Type 2 Diabetes
- What is being tested?
- Exercise program and Ascorbic Acid (Vitamin C)
- Type of treatment
- Injection or infusion, Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 47 participants
- Where
- 1 siteUnited States
- Study dates
- May 2008to Oct 2011
- Phase
- Interventional
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
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 30 to 55 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Men and women with uncomplicated Type 2 Diabetes
- Healthy men and women without Type 2 Diabetes
- Patients with Type 2 Diabetes may be taking metformin or sulfonylurea drugs to treat diabetes
- Persons with history of hypercholesteremia if controlled with statins and/or diet
- Patients who are moderately overweight (BMI 25-37.5)
- Must be sedentary (defined as regular exercise < 2 times a week at a low to moderate level).
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- Patients with Hemoglobin A1c (HBA1C) <8%
- Patients between the ages of 30 to 55 years
- Premenopausal women.
- Former smokers who have quit smoking for at least one year
- Absence of comorbid conditions
- Mild neuropathy is O.K. as long as it will not hamper exercise performance.
- Resting systolic blood pressure (SBP) < 140, Resting diastolic blood pressure (DBP) < 90
- Total Cholesterol < 205 Triglycerides < 250 low density lipoprotein (LDL) < 130
- Control subjects with a normal A1C and fasting glucose
Who cannot join
- People with T2DM taking oral medications, other than metformin or sulfonylurea drugs to control their diabetes.
- Persons treated with insulin will be excluded
- People who are currently smoking or have not quit for at least one year
- Controls who have immediate family history of T2DM
- Peri-menopausal or post-menopausal women.
- Peripheral neuropathy
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- Total cholesterol > 205
- Regional wall motion abnormalities
- LV wall thickness ≥1.1 cm
- Decreased contractility (fractional shortening <30%)
- Ischemic heart disease (abnormal resting or exercise ECG)
- Presence of angina that would limit exercise performance
- Pulmonary problems that would limit exercise performance
- Systolic blood pressure >140 mmHg at rest or >250 mmHg with exercise or diastolic pressure >90 mmHg at rest or >105 mmHg with exercise
- Persons with autonomic insufficiency, assessed by measuring variation in RR intervals with cycled breathing and by presence of a >20 mm fall in upright blood pressure without a change in heart rate
- Proteinuria (urine protein >200 mg/dl) or a creatinine > 2 mg/dl
- Renal disease
Trial locations and contacts
1 site in 1 country.
United States1 site
University of Colorado Denver
Aurora, Colorado, 80045
About this study
Official title: Influence Of Endothelial Function On Central and Peripheral Causes Of Exercise Impairment In Type 2 Diabetes
This study will evaluate the effects of impaired blood flow regulation on exercise. It will also determine whether the effects are more important in the heart or in the skeletal muscle tissue during exercise. In addition, this study will decide whether temporarily reversing these problems will improve blood flow control, improve heart and muscle tissue function and help improve exercise capacity in person with type 2 diabetes. This study will do so using two methods: (1) by giving vitamin C intravenously (IV) and (2) a three month exercise training program. Up to 100 subjects will be enrolled in this study.
Read the detailed description
The investigators have found that persons with type 2 diabetes have an impaired ability to perform exercise even without clinically apparent complications. The reasons for this marked abnormality are unknown but are important as the decreased ability to exercise could contribute to the decreased expenditure of physical activity frequently observed in this population and may potentially constitute an early marker of cardiovascular disease.
The investigators wish to evaluate the effects of impaired blood flow regulation on exercise capacity and whether the effects are more important in the heart or in the skeletal muscle tissue during exercise. In addition, the investigators are determining whether correcting these abnormalities by two methods of improving blood flow regulation (acutely infusing Vitamin C or three months of chronic exercise training) leads to improved blood flow regulation, improved heart and skeletal muscle tissue function and hence to better exercise capacity in person with type 2 diabetes. This information will provide a more mechanistic understanding of causes of abnormal exercise responses observed in person with type 2 diabetes as well as whether and to what degree responses are modifiable. Interventions that reverse the exercise defect may facilitate patient adherence to prescribed physical activity programs and potentially decrease cardiovascular mortality in this large segment of the population.
- Conditions
- Type 2 Diabetes
- Being tested
- Exercise program, Ascorbic Acid (Vitamin C)
- Keywords
- Type, 2, Diabetes, Blood, Vessel, Function, Exercise, Program, Intervention, Vitamin, C, Men, Women, Blood vessel function
- Medical subject headings
- Diabetes Mellitus, Type 2, Limb-girdle muscular dystrophy, type 2C, Diabetes Mellitus, Motor Activity, Multiple Endocrine Neoplasia Type 1
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Exercise programBehavioural
Also called Exercise Training
Three month exercise program located at the Anschutz Medical Campus at I-225 and Colfax. The program runs three times per week for about an hour each session. Gym is open Monday - Saturday during specific hours (morning, noon, evening).
Ascorbic Acid (Vitamin C)Drug
Also called Ascorbic Acid, Vitamin C
During one exercise study visit, 0.06 grams of Vitamin C per kilogram fat-free mass per 100 milliliters (mL) of normal saline administered; Subjects will receive a bolus of 100mL Vitamin C solution given at 5ml/minute over 20 minutes followed by a "drip-infusion" given at 1.7ml/minute.
| Study group | Role | What they receive |
|---|---|---|
| Ascorbic acid | Experimental | All study subjects have ascorbic acid infusion during one exercise visit as well as a three month exercise training intervention. Receives: Behavioral: Exercise program; Drug: Ascorbic Acid (Vitamin C) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Percent Change in Circumferential Strain Before and After Exercise at Baseline, After Vitamin C Infusion, and After Exercise Training
Characterize the purported cardiac dysfunction during exercise in people with type 2 diabetes (T2D). In a normal patient when measuring circumferential strain, results are negative with downward tracing (as strain is a relative change in length). Circumferential strain is a measurement of ventricular circumference within the heart vessels, measured via echocardiography.
Measured: 7 months; Measures are made at rest and after exercise for baseline, at rest and after infusion for Vitamin C administration, and at rest and after exercise following the exercise training
Ejection Fraction: Percentage of Blood Leaving the Heart Before and After Exercise at Baseline, After a Vitamin C Infusion, and After Exercise Training
Evaluate potential changes in cardiac function by echocardiography following 2 interventions: Three months of exercise training and acute vitamin C administration. Ejection fraction (EF) is a measurement of the percentage of blood leaving your heart each time it contracts, typically measure by echocardiography. Numbers listed are absolute EF values.
Measured: 7 months; Measures are made at rest for baseline, at rest for Vitamin C administration, and at rest following the exercise training
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted5 Nov 2008 (estimated)
- Study startMay 2008
- Primary completionOct 2011
- Study completionOct 2011
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Type 2 DiabetesStudies of the same condition, open and under way.
- More trials run by University of Colorado, DenverThe 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 N/A
- Primary purpose
- Health services research
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 47 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Colorado, Denver
- Sponsor type
- University, hospital or other
- Collaborators
- American Diabetes Association, National Institutes of Health (NIH)
- Responsible party
- Sponsor
- Investigators
- Judith G Regensteiner, PhD, Principal investigator, University of Colorado, Denver
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT00786019
- Sponsor's protocol ID
- 07-1152
- Other IDs
- UL1TR000154
- Acronym
- InsITE
- Status last verified
- Jul 2023
- First submitted
- 4 Nov 2008
- Last updated
- 12 Jul 2023
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- Yes
Publications
Scalzo RL, Bauer TA, Harrall K, Moreau K, Ozemek C, Herlache L, McMillin S, Huebschmann AG, Dorosz J, Reusch JEB, Regensteiner JG. Acute vitamin C improves cardiac function, not exercise capacity, in adults with type 2 diabetes. Diabetol Metab Syndr. 2018 Feb 14;10:7. doi: 10.1186/s13098-018-0306-9. eCollection 2018.
PubMed 29456629
Study at a glance
From the registry record, last updated by the sponsor on 12 Jul 2023. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Influence Of Endothelial Function On Central and Peripheral Causes Of Exercise Impairment In Type 2 Diabetes
- ClinicalTrials.gov ID
- NCT00786019
- Acronym / sponsor ID
- InsITE / 07-1152
- Conditions
- Type 2 Diabetes
- Keywords
- Type, 2, Diabetes, Blood, Vessel, Function, Exercise, Program
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 47 participants (actual)
- Lead sponsor
- University of Colorado, DenverUniversity, hospital or other
- Collaborators
- American Diabetes Association, National Institutes of Health (NIH)
- Study start
- May 2008
- Primary completion
- Oct 2011 (actual)
- Study completion
- Oct 2011 (actual)
- First posted
- 5 Nov 2008 (estimated)
- Results
- Posted 11 Sep 2018
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study will evaluate the effects of impaired blood flow regulation on exercise. It will also determine whether the effects are more important in the heart or in the skeletal muscle tissue during exercise. In addition, this study will decide whether temporarily reversing these problems will improve blood flow control, improve heart and muscle tissue function and help improve exercise capacity in person with type 2 diabetes. This study will do so using two methods: (1) by giving vitamin C intravenously (IV) and (2) a three month exercise training program. Up to 100 subjects will be enrolled in this study.
Detailed description
The investigators have found that persons with type 2 diabetes have an impaired ability to perform exercise even without clinically apparent complications. The reasons for this marked abnormality are unknown but are important as the decreased ability to exercise could contribute to the decreased expenditure of physical activity frequently observed in this population and may potentially constitute an early marker of cardiovascular disease.
The investigators wish to evaluate the effects of impaired blood flow regulation on exercise capacity and whether the effects are more important in the heart or in the skeletal muscle tissue during exercise. In addition, the investigators are determining whether correcting these abnormalities by two methods of improving blood flow regulation (acutely infusing Vitamin C or three months of chronic exercise training) leads to improved blood flow regulation, improved heart and skeletal muscle tissue function and hence to better exercise capacity in person with type 2 diabetes. This information will provide a more mechanistic understanding of causes of abnormal exercise responses observed in person with type 2 diabetes as well as whether and to what degree responses are modifiable. Interventions that reverse the exercise defect may facilitate patient adherence to prescribed physical activity programs and potentially decrease cardiovascular mortality in this large segment of the population.
Study design
- Primary purpose
- Health services research
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Ascorbic acid | Experimental | Behavioral: Exercise program, Drug: Ascorbic Acid (Vitamin C)All study subjects have ascorbic acid infusion during one exercise visit as well as a three month exercise training intervention. |
Who may qualify
- Ages
- 30 to 55 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (15 listed)
- Men and women with uncomplicated Type 2 Diabetes
- Healthy men and women without Type 2 Diabetes
- Patients with Type 2 Diabetes may be taking metformin or sulfonylurea drugs to treat diabetes
- Persons with history of hypercholesteremia if controlled with statins and/or diet
- Patients who are moderately overweight (BMI 25-37.5)
Key exclusion criteria (17 listed)
- People with T2DM taking oral medications, other than metformin or sulfonylurea drugs to control their diabetes.
- Persons treated with insulin will be excluded
- People who are currently smoking or have not quit for at least one year
- Controls who have immediate family history of T2DM
- Peri-menopausal or post-menopausal women.
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 |
|---|---|---|
| Exercise programAlso: Exercise TrainingThree month exercise program located at the Anschutz Medical Campus at I-225 and Colfax. The program runs three times per week for about an hour each session. Gym is open Monday - Saturday during specific hours (morning, noon, evening). | Behavioural | Ascorbic acid |
| Ascorbic Acid (Vitamin C)Also: Ascorbic Acid, Vitamin CDuring one exercise study visit, 0.06 grams of Vitamin C per kilogram fat-free mass per 100 milliliters (mL) of normal saline administered; Subjects will receive a bolus of 100mL Vitamin C solution given at 5ml/minute over 20 minutes followed by a "drip-infusion" given at 1.7ml/minute. | Drug | Ascorbic acid |
Primary outcome
Percent Change in Circumferential Strain Before and After Exercise at Baseline, After Vitamin C Infusion, and After Exercise Training
Time frame: 7 months; Measures are made at rest and after exercise for baseline, at rest and after infusion for Vitamin C administration, and at rest and after exercise following the exercise training
Characterize the purported cardiac dysfunction during exercise in people with type 2 diabetes (T2D). In a normal patient when measuring circumferential strain, results are negative with downward tracing (as strain is a relative change in length). Circumferential strain is a measurement of ventricular circumference within the heart vessels, measured via echocardiography.
Ejection Fraction: Percentage of Blood Leaving the Heart Before and After Exercise at Baseline, After a Vitamin C Infusion, and After Exercise Training
Time frame: 7 months; Measures are made at rest for baseline, at rest for Vitamin C administration, and at rest following the exercise training
Evaluate potential changes in cardiac function by echocardiography following 2 interventions: Three months of exercise training and acute vitamin C administration. Ejection fraction (EF) is a measurement of the percentage of blood leaving your heart each time it contracts, typically measure by echocardiography. Numbers listed are absolute EF values.
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 12 Jul 2023.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Derived from this study: PubMed 29456629Scalzo RL, Bauer TA, Harrall K, Moreau K, Ozemek C, Herlache L, McMillin S, Huebschmann AG, Dorosz J, Reusch JEB, Regensteiner JG. Acute vitamin C improves cardiac function, not exercise capacity, in adults with type 2 diabetes. Diabetol Metab Syndr. 2018 Feb 14;10:7. doi: 10.1186/s13098-018-0306-9. eCollection 2018.
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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. This study is not recruiting at the moment.
Judith G Regensteiner, PhD principal investigator
University of Colorado, Denver
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Exercise program and Ascorbic Acid (Vitamin C) in people with Type 2 Diabetes, run by University of Colorado, Denver 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 15 inclusion and 17 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: finished, as of the sponsor's last update on 12 Jul 2023. 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. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
Yes. Results are posted in the registry (first posted 11 Sep 2018). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Percent Change in Circumferential Strain Before and After Exercise at Baseline, After Vitamin C Infusion, and After Exercise Training (time frame: 7 months; Measures are made at rest and after exercise for baseline, at rest and after infusion for Vitamin C administration, and at rest and after exercise following the exercise training). 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?
On the ClinicalTrials.gov record for NCT00786019, which also lists 1 linked publication.
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 12 Jul 2023.