Testosterone Effects on Men With the Metabolic Syndrome
|First Received Date ICMJE||September 26, 2006|
|Last Updated Date||December 4, 2008|
|Start Date ICMJE||May 2006|
|Primary Completion Date||Not Provided|
|Current Primary Outcome Measures ICMJE
|Original Primary Outcome Measures ICMJE||Same as current|
|Change History||Complete list of historical versions of study NCT00382057 on ClinicalTrials.gov Archive Site|
|Current Secondary Outcome Measures ICMJE||Not Provided|
|Original Secondary Outcome Measures ICMJE||Not Provided|
|Current Other Outcome Measures ICMJE||Not Provided|
|Original Other Outcome Measures ICMJE||Not Provided|
|Brief Title ICMJE||Testosterone Effects on Men With the Metabolic Syndrome|
|Official Title ICMJE||Effect of Increasing Testosterone Levels on Insulin Sensitivity in Men With the Metabolic Syndrome|
The metabolic syndrome is a medical condition defined by high levels of cholesterol in the blood, high blood pressure, central obesity (gain in fat around the region of the stomach), and insulin resistance (body responds less well to insulin). This state of impaired insulin resistance can lead to type 2 diabetes mellitus, which is one of the most common metabolic disorders in the U.S. Numerous studies have shown an inverse relationship between insulin resistance and testosterone levels in men, however, causality has not been established. This protocol investigates the role of testosterone in modulating insulin sensitivity in insulin resistant states such as the metabolic syndrome. The hypothesis is that testosterone administration will improve insulin sensitivity.
This protocol will address the impact of three months of testosterone (T) therapy on all components of the metabolic syndrome and the mechanism underlying changes in insulin sensitivity by analyzing changes in body composition, and detailed studies of fat metabolism and skeletal muscle. In addition, this protocol will address the role of estradiol (E2) in mediating the effect of testosterone on insulin sensitivity.
Seventy-two subjects will undergo a screening visit to assess eligibility after which a baseline evaluation will be performed. The baseline metabolic assessment will consist of an intravenous glucose tolerance test (IVGTT) to measure insulin sensitivity, MRI and DEXA scan to assess muscle and body fat distribution, VO2 max test and resting metabolic rate, and a muscle biopsy to look at how the muscle is affected by insulin and testosterone.
Subjects will then be randomized to one of three 12-week treatment arms, 1) Group 1 (Placebo); 2) Group 2 (Depot GnRH agonist (Zoladex) + T + placebo); or 3) Group 3 (Zoladex + T + aromatase inhibitor (anastrozole)). The rationale for this study design is as follows. Under normal physiological conditions, administration of T leads to a concomitant increase in E2 levels due to endogenous conversion by the aromatase enzyme system. Therefore, in order to dissect the relative roles of T and E2 on insulin sensitivity, one group of subjects will receive T in conjunction with the aromatase inhibitor, anastrozole.
At 13 weeks, the entire baseline evaluation including IVGTT, resting metabolic rate and VO2 max, body composition assessment by DEXA and MRI, and muscle biopsy will be repeated. Subjects will return for a follow up visit four weeks later to measure CBC, T and PSA levels, to ensure levels are within the normal range.
|Study Type ICMJE||Interventional|
|Study Phase||Phase 2|
|Study Design ICMJE||Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Primary Purpose: Treatment
|Condition ICMJE||Metabolic Syndrome|
|Study Arm (s)||Not Provided|
|Publications *||Not Provided|
* Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline.
|Recruitment Status ICMJE||Withdrawn|
|Estimated Enrollment ICMJE||72|
|Estimated Completion Date||March 2011|
|Primary Completion Date||Not Provided|
|Eligibility Criteria ICMJE||
|Ages||50 Years to 75 Years|
|Accepts Healthy Volunteers||No|
|Contacts ICMJE||Contact information is only displayed when the study is recruiting subjects|
|Location Countries ICMJE||Not Provided|
|NCT Number ICMJE||NCT00382057|
|Other Study ID Numbers ICMJE||5 K23 DK02858-1526, 5 K23 DK02858-02 6/15/05|
|Has Data Monitoring Committee||Not Provided|
|Responsible Party||Not Provided|
|Study Sponsor ICMJE||Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)|
|Collaborators ICMJE||Not Provided|
|Information Provided By||Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)|
|Verification Date||November 2008|
ICMJE Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP