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Metabolic SyndromeNCT00433173

Insulin Sensitivity in Men With the Metabolic Syndrome

A study testing intravenous glucose tolerance test, testosterone and anastrozole in people with Metabolic Syndrome, run by National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) at 2 sites in United States.

Suspended

Paused. Enrolment is on hold for now and may resume.

Official record
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Trial summary

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). Read more about this study

Who is it for?
Ages 50 to 75 years, men only
Conditions the study is for
Metabolic Syndrome
What is being tested?
intravenous glucose tolerance test, testosterone and anastrozole
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
72 participants
Where
2 sitesUnited States
Study dates
May 2006to Mar 2011
Phase
Interventional
Are there results?
None posted in the registry

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 50 to 75 years
  • Men only
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • Age 50-75 yr
  • Diagnosis of the metabolic syndrome defined by the American Heart Association/National Heart, Lung, and Blood Institute guidelines as the presence of three or more of the following:
  • Waist circumference > 102 cm
  • Serum triglycerides > 150 mg/dL
  • HDL cholesterol < 40 mg/dL
  • Blood pressure > 130 mm Hg systolic or 85 mm Hg diastolic, or treatment with anti-hypertensives
Show all 10Show fewer
  • Fasting serum glucose > 100 mg/dL
  • Plasma total testosterone level less than 300 ng/dL (1 SD below the mean for young healthy men)
  • Stable weight for previous three months (no weight change greater than or equal to +/-10 lbs)
  • Normal TSH, prolactin and prostate specific antigen (PSA) levels (<2.5 ng/mL)

Who cannot join

  • New diagnosis of type 2 diabetes as defined by the ADA criteria: fasting glucose greater than 126 mg/dL or random blood glucose greater than 200 mg/dL on two occasions, or on oral hypoglycemic agents
  • Contraindication to stress testing
  • Contraindication to MRI scanning (Central nervous system aneurysm clips; Implanted neural stimulator; Implanted cardiac pacemaker or defibrillator; Cochlear implant; Ocular foreign body (e.g. metal shavings); Insulin pump; Metal shrapnel or bullet)
  • History of testicular disorders (i.e. cryptorchidism)
  • History of bleeding disorders (i.e. thrombocytopenia) or baseline hemoglobin levels less than 12g/dL
  • History of metabolic bone disease (osteoporosis, osteomalacia)
Show all 21Show fewer
  • History of prostate cancer
  • History of sleep apnea (subjects will also be excluded if at their baseline assessment they admit to heavy snoring, restless sleep, and/or excessive daytime somnolence)
  • Symptoms of urinary outflow obstruction (i.e. benign prostatic hypertrophy)
  • Illicit drug use or heavy alcohol use (>4 drinks/day)
  • Allergic disorders
  • Current medications (must exclude individuals taking the following medications):
  • Testosterone,
  • Cimetidine,
  • Spironolactone,
  • Ketoconazole,
  • Finasteride,
  • DHEA,
  • Androstenedione,
  • Oral steroids,
  • GnRH analogs

Trial locations and contacts

2 sites in 1 country.

United States2 sites
  • Johns Hopkins Bayview Medical Center

    Baltimore, Maryland, 21224

  • Massachusetts General Hospital

    Boston, Massachusetts, 02114

Other trials in United States

About this study

Official title: Effect of Increasing Testosterone 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.

Read the detailed description

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 be enrolled. Study subjects will undergo a screening visit to assess eligibility after which a baseline metabolic assessment will be performed including a a fasting oral glucose tolerance test (OGTT) to measure normal glucose and insulin metabolism, 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 (T).

Subjects will then be randomized to one of three 12-week treatment arms, 1) Group 1 (Placebo); 2) Group 2 (Depot GnRH agonist (Zoladex) + Testosterone + placebo); or 3) Group 3 (Zoladex + Testosterone + 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 estradiol (E2) levels due to endogenous conversion by the aromatase enzyme system. Therefore, in order to understand 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 OGTT, 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.

Being tested
intravenous glucose tolerance test, testosterone, anastrozole, goserelin acetate implant, aerobic capacity (VO2 Max)
Keywords
testosterone, insulin sensitivity, insulin resistance, metabolic disorders
Medical subject headings
Metabolic Syndrome, Insulin Resistance, Metabolic Diseases

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • intravenous glucose tolerance testProcedure or surgery

    Also called IVGTT

    The IVGTT (70) is a 4 hour study with baseline sampling for insulin and glucose, followed by the administration of 0.3 mg/kg infusion of glucose, and subsequent frequent samples through 180 minutes. At 20 minutes, subjects will receive a 0.03 U/kg infusion of regular human insulin over 45 seconds to enhance the insulin level to better help us assess the impact of insulin on glucose uptake and to facilitate minimal model analysis. The IVGTT will be administered at baseline and after 3 months.

  • testosteroneDrug

    Also called Androgel 1%

    transdermal 7.5 g/per day for 3 months

  • anastrozoleDrug

    Also called arimidex, IND# 76,878

    tablet (per oral) 10.0 mg/ daily 3 months

  • goserelin acetate implantDrug

    Also called Zoladex

    single depot injection 10.8 mg 3 months

  • aerobic capacity (VO2 Max)Procedure or surgery

    This test is employed to assess VO2max in all subjects. O2 and CO2 will be collected and measured from the expired air during the exercise stress test and used to calculate VO2max. This test will be administered at baseline and after 3 months.

  • MRIProcedure or surgery

    1H-MR spectroscopy will be performed to measure IMCL at baseline and after 3 months.

  • muscle biopsyProcedure or surgery

    Biopsies (20-50mg) will be obtained from the vastus lateralis muscle under local anesthesia (1% lidocaine) using a 5 mm Bergström needle (65) with suction applied. The muscle biopsy will be performed at baseline and after 3 months.

  • measurement of resting metabolic rate (energy expenditure)Procedure or surgery

    Energy expenditure in the form of resting metabolic rate (RMR) will be measured via a metabolic monitor at baseline and after 3 months.

  • Dual energy x-ray absorptiometryProcedure or surgery

    Also called DEXA

    Total and regional percent body fat, fat mass, lean tissue mass and bone mineral content will be determined by DEXA (Lunar Prodigy version 8.50). DEXA provides an in vivo assessment of body composition with minimal requirements for subject cooperation and will be employed at baseline and after 3 months.

  • Fasting oral glucose tolerance testProcedure or surgery

    Also called OGTT

    To examine glucose and insulin metabolism a standard 75g OGTT will be conducted at baseline and after 3 months.

Study groups in NCT00433173
Study groupRoleWhat they receive
1Placebo comparator1) Group 1: Placebo
Receives: Procedure: intravenous glucose tolerance test; Procedure: aerobic capacity (VO2 Max); Procedure: MRI; Procedure: muscle biopsy; Procedure: measurement of resting metabolic rate (energy expenditure); Procedure: Dual energy x-ray absorptiometry; Procedure: Fasting oral glucose tolerance test
2Active comparator2) Group 2: Depot GnRH agonist (Zoladex) + Testosterone + placebo
Receives: Procedure: intravenous glucose tolerance test; Drug: testosterone; Drug: goserelin acetate implant; Procedure: aerobic capacity (VO2 Max); Procedure: MRI; Procedure: muscle biopsy; Procedure: measurement of resting metabolic rate (energy expenditure); Procedure: Dual energy x-ray absorptiometry; Procedure: Fasting oral glucose tolerance test
3Active comparator3) Group 3: (Zoladex + Testosterone + aromatase inhibitor (anastrozole)
Receives: Procedure: intravenous glucose tolerance test; Drug: testosterone; Drug: anastrozole; Drug: goserelin acetate implant; Procedure: aerobic capacity (VO2 Max); Procedure: MRI; Procedure: muscle biopsy; Procedure: measurement of resting metabolic rate (energy expenditure); Procedure: Dual energy x-ray absorptiometry; Procedure: Fasting oral glucose tolerance test

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. insulin sensitivity

    Measured: at baseline and after 3 months

Secondary outcomes (5)
  1. glucose metabolism

    Measured: at baseline and after 3 months

  2. body composition VO2 max; resting metabolic rate; muscle biopsy analysis

    Measured: at baseline and after 3 months

  3. VO2 max

    Measured: at baseline and after 3 months

  4. resting metabolic rate

    Measured: at baseline and after 3 months

  5. muscle biopsy analysis

    Measured: at baseline and after 3 months

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted9 Feb 2007 (estimated)
  2. Study startMay 2006
  3. Primary completionFeb 2011 (estimated)
  4. Study completionMar 2011 (estimated)

Why it stopped: Primary investigator is taking a leave of absence

Resources

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
Treatment
Allocation
Randomised
Intervention model
Parallel groups
Masking
Triple blind
Who is masked
Participant, Care provider, Investigator
Enrolment
72 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT00433173
Sponsor's protocol ID
DK71168 (suspended)
Other IDs
NIDDK # 1 RO1 DK071168-01A2
Status last verified
Mar 2010
First submitted
8 Feb 2007
Last updated
2 Mar 2010
Results posted
No
Data monitoring committee
Yes

Publications

  • Caronia LM, Dwyer AA, Hayden D, Amati F, Pitteloud N, Hayes FJ. Abrupt decrease in serum testosterone levels after an oral glucose load in men: implications for screening for hypogonadism. Clin Endocrinol (Oxf). 2013 Feb;78(2):291-6. doi: 10.1111/j.1365-2265.2012.04486.x.

    PubMed 22804876

Questions about this trial

What is this clinical trial studying?

A study testing intravenous glucose tolerance test, testosterone and anastrozole in people with Metabolic Syndrome, run by National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) at 2 sites 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 10 inclusion and 21 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: paused, as of the sponsor's last update on 2 Mar 2010. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 2 sites 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. Some participants in this study may receive a placebo. 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?

Results are not available in the source record.

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?

insulin sensitivity (time frame: at baseline and after 3 months). 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 NCT00433173, 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 2 Mar 2010.

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