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Glitazones and Endothelial Function (GATE)

Primary Purpose

Diabetes Mellitus

Status
Terminated
Phase
Phase 3
Locations
Canada
Study Type
Interventional
Intervention
rosiglitazone/placebo
Sponsored by
University of Calgary
About
Eligibility
Locations
Outcomes
Full info

About this trial

This is an interventional treatment trial for Diabetes Mellitus focused on measuring diabetes mellitus, endothelium, thiazolidinediones, atherosclerosis

Eligibility Criteria

18 Years - undefined (Adult, Older Adult)All SexesDoes not accept healthy volunteers

Inclusion Criteria: All patients (both men and women) considered for participation in GATE study have to be non-insulin dependent diabetics (according to Canadian Diabetes Association criteria, namely a fasting serum glucose ≥ 7.0 mmol/L on two occasions, a casual glucose ≥ 11.1 mmol/l with symptoms, or a 2-h post-oral glucose tolerance test glucose of ≥ 11.1 mmol/l) with unsatisfactory glycemic control on oral therapy (HbA1c 6-10%). Exclusion Criteria: Exclusion criteria includes, congestive heart failure (NYHA class III & IV or ejection fraction less than 35%), poorly controlled hypertension (blood pressure > 160/90), hypercholesterolemia (total cholesterol > 6.2 mmol/l), hypertriglyceridemia (triglycerides > 4.0 mmol/l), poor or excellent control of DM (HgA1c <6 % or HbA1c > 10% respectively), known diabetic retinopathy, age at diagnosis of diabetes less than 25 years, current participation in another clinical trial and contraindications to glitazones therapy, including renal (creatinine > 200 micromol/ L) or hepatic (ALT > 2.5 times the upper limit of normal) impairment and/ or known intolerance to glitazones. Patients must be stable on medications that affect endothelial function for more than one month. This includes ACE-inhibitors, angiotensin receptor blockers, statins, calcium channel blockers, hormone replacement therapy and anti-oxidant vitamins, including folates. Patients on insulin will be excluded. Patients in whom it is felt that attainment of better glucose control is required within 3 months will also be excluded. Patients with stable coronary disease will be eligible for the study as long as they are > one month post myocardial infarction, percutaneous intervention or bypass surgery.

Sites / Locations

  • Foothills Medical Centre

Outcomes

Primary Outcome Measures

The primary end-point of the study is the percent change in forearm blood flow to acetylcholine in patients randomized to rosiglitazone compared with placebo.

Secondary Outcome Measures

Secondary end-points include (i) the percent change in forearm blood flow to verapamil and the absolute change to both acetylcholine and verapamil and (ii) the relationship between HOMA-IR, CRP and endothelial function.

Full Information

First Posted
September 13, 2005
Last Updated
October 30, 2008
Sponsor
University of Calgary
Collaborators
GlaxoSmithKline
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1. Study Identification

Unique Protocol Identification Number
NCT00203632
Brief Title
Glitazones and Endothelial Function (GATE)
Official Title
A Trial of the Effect of Rosiglitazone as Add on to Metformin Therapy on Endothelial Function in Subjects With Type II DM
Study Type
Interventional

2. Study Status

Record Verification Date
October 2008
Overall Recruitment Status
Terminated
Why Stopped
Terminated at 50% enrollment due to recent concerns about rosiglitazone
Study Start Date
September 2003 (undefined)
Primary Completion Date
undefined (undefined)
Study Completion Date
October 2007 (Actual)

3. Sponsor/Collaborators

Name of the Sponsor
University of Calgary
Collaborators
GlaxoSmithKline

4. Oversight

Data Monitoring Committee
Yes

5. Study Description

Brief Summary
The purpose of the study is to determine if the addition of rosiglitazone to subjects with fair glucose control on other oral agents improves endothelial function, a surrogate marker of vascular health. It is hypothesized that improving whole body insulin sensitivity with combination therapy including rosiglitazone will restore the vascular actions of insulin and improve endothelium-dependent vasomotion more effectively than placebo in patients with diabetes mellitus.
Detailed Description
The vascular endothelium has emerged as a critical determinant of cardiovascular health and disease, and improving endothelial function is an important target for therapy. Accumulating evidence suggest that insulin resistance in patients with diabetes and the metabolic syndrome may impair endothelial function, uncovering a proinflammatory, and proatherosclerotic vascular phenotype. The GATE study (Glitazones And The Endothelium) is a randomized, double blind study to evaluate the effects of rosiglitazone vs. placebo on endothelial function when employed as an add-on therapy in diabetic patients currently treated with oral therapy. We hypothesize that the PPAR-gamma agonist rosiglitazone, will improve endothelium-dependent vasodilatation, and that this effect will be related to improvements in insulin sensitivity, with concomitant reductions in whole body insulin resistance. Furthermore, the beneficial effects of rosiglitazone will be additive to existing oral therapies that may modulate endothelial function, such as metformin. Since endothelial dysfunction plays a pivotal role in the development and progression of atherosclerosis, these studies may provide the rationale and impetus for aggressive treatment of insulin resistant patients with glitazone therapy.

6. Conditions and Keywords

Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
Diabetes Mellitus
Keywords
diabetes mellitus, endothelium, thiazolidinediones, atherosclerosis

7. Study Design

Primary Purpose
Treatment
Study Phase
Phase 3
Interventional Study Model
Parallel Assignment
Masking
ParticipantCare ProviderInvestigatorOutcomes Assessor
Allocation
Randomized
Enrollment
40 (Actual)

8. Arms, Groups, and Interventions

Intervention Type
Drug
Intervention Name(s)
rosiglitazone/placebo
Primary Outcome Measure Information:
Title
The primary end-point of the study is the percent change in forearm blood flow to acetylcholine in patients randomized to rosiglitazone compared with placebo.
Secondary Outcome Measure Information:
Title
Secondary end-points include (i) the percent change in forearm blood flow to verapamil and the absolute change to both acetylcholine and verapamil and (ii) the relationship between HOMA-IR, CRP and endothelial function.

10. Eligibility

Sex
All
Minimum Age & Unit of Time
18 Years
Accepts Healthy Volunteers
No
Eligibility Criteria
Inclusion Criteria: All patients (both men and women) considered for participation in GATE study have to be non-insulin dependent diabetics (according to Canadian Diabetes Association criteria, namely a fasting serum glucose ≥ 7.0 mmol/L on two occasions, a casual glucose ≥ 11.1 mmol/l with symptoms, or a 2-h post-oral glucose tolerance test glucose of ≥ 11.1 mmol/l) with unsatisfactory glycemic control on oral therapy (HbA1c 6-10%). Exclusion Criteria: Exclusion criteria includes, congestive heart failure (NYHA class III & IV or ejection fraction less than 35%), poorly controlled hypertension (blood pressure > 160/90), hypercholesterolemia (total cholesterol > 6.2 mmol/l), hypertriglyceridemia (triglycerides > 4.0 mmol/l), poor or excellent control of DM (HgA1c <6 % or HbA1c > 10% respectively), known diabetic retinopathy, age at diagnosis of diabetes less than 25 years, current participation in another clinical trial and contraindications to glitazones therapy, including renal (creatinine > 200 micromol/ L) or hepatic (ALT > 2.5 times the upper limit of normal) impairment and/ or known intolerance to glitazones. Patients must be stable on medications that affect endothelial function for more than one month. This includes ACE-inhibitors, angiotensin receptor blockers, statins, calcium channel blockers, hormone replacement therapy and anti-oxidant vitamins, including folates. Patients on insulin will be excluded. Patients in whom it is felt that attainment of better glucose control is required within 3 months will also be excluded. Patients with stable coronary disease will be eligible for the study as long as they are > one month post myocardial infarction, percutaneous intervention or bypass surgery.
Overall Study Officials:
First Name & Middle Initial & Last Name & Degree
Todd J Anderson, MD
Organizational Affiliation
University of Calgary
Official's Role
Principal Investigator
First Name & Middle Initial & Last Name & Degree
Subodh Verma, MD, PhD
Organizational Affiliation
University of Toronto
Official's Role
Study Chair
Facility Information:
Facility Name
Foothills Medical Centre
City
Calgary
State/Province
Alberta
ZIP/Postal Code
T2N 2T9
Country
Canada

12. IPD Sharing Statement

Citations:
PubMed Identifier
15614340
Citation
Hubacek J, Verma S, Shewchuk L, Ross SJ, Edwards A, Anderson TJ. Rationale and design of the Glitazones and the Endothelium (GATE) study: evaluation of rosiglitazone on endothelial function in patients with diabetes. Can J Cardiol. 2004 Dec;20(14):1449-53.
Results Reference
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Glitazones and Endothelial Function (GATE)

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