The Effect of 5-Alpha Reductase on Testosterone in Men

The recruitment status of this study is unknown because the information has not been verified recently.

Verified October 2003 by Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD). Recruitment status was Recruiting

First Received on October 7, 2003. Last Updated on November 4, 2005 History of Changes

Sponsor:	Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)
Information provided by:	Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)
ClinicalTrials.gov Identifier:	NCT00070733

Purpose

The enzyme 5-alpha reductase is present in small amounts in muscle and converts testosterone to dihydrotestosterone (DHT). Testosterone affects lean body tissue, muscle size, muscle strength, and sexual function in men. This study will evaluate how 5-alpha reductase influences the effects of testosterone in young healthy men.

Condition	Intervention	Phase
Sex Disorders	Drug: testosterone enanthate Drug: duastride	Phase III

Study Type:	Interventional
Study Design:	Allocation: Randomized Endpoint Classification: Safety/Efficacy Study Intervention Model: Parallel Assignment Masking: Double-Blind Primary Purpose: Treatment
Official Title:	The Role of 5-Alpha Reductase in Mediating Testosterone Actions

Resource links provided by NLM:

Drug Information available for: Testosterone Propionate Methyltestosterone Testosterone Oxymesterone Testosterone enanthate Testosterone undecanoate

U.S. FDA Resources

Further study details as provided by Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD):

Estimated Enrollment:	184
Study Start Date:	August 2003
Estimated Study Completion Date:	June 2005

Detailed Description:

Testosterone, the predominant circulating androgen in men, serves as the active hormone in some target tissues; however, testosterone effects in other target organs require its conversion to two active metabolites, estradiol 17-beta and DHT. The role of 5-alpha reductase in mediating testosterone's effects on muscle and sexual function remains unclear. This study will determine whether 5-alpha reduction of testosterone to DHT is necessary for mediating effects on fat-free mass, muscle size, muscle strength, and leg power in men. The study will also evaluate the necessity of 5-alpha reductase for maintenance of androgen effects on sexual function (sexual desire, overall sexual activity, nocturnal penile tumescence [NPT], response to visual erotic stimulus, and penile rigidity) in men.

Participants in this study will be treated with a drug to suppress endogenous testosterone production. Participants will then be randomly assigned to receive either testosterone and placebo or testosterone and the 5-alpha reductase inhibitor dutasteride. Testosterone will be administered weekly; dutasteride and placebo will both be administered daily. Diet and exercise will be standardized across both groups. Participants will be assessed at study entry and Week 20. Assessments will include measurements such as a DEXA scan, MRI scan, and muscle performance and sexual function tests. Participants will also have blood tests for safety monitoring; blood tests will include measures of hematocrit, liver enzymes (AST and ALT), prostate specific antigen (PSA), and cholesterol.

Eligibility

Ages Eligible for Study:	21 Years to 40 Years
Genders Eligible for Study:	Male
Accepts Healthy Volunteers:	Yes

Criteria

Inclusion Criteria

General good health and capable of undergoing strength testing
Normal testosterone (300-1100 ng/dL), LH, and FSH levels

Exclusion Criteria

Currently participating in competitive sports
Mental state that would preclude complete understanding of the protocol and compliance
Disorder known to cause or be associated with hypogonadism (e.g., pituitary tumors, hyperprolactinemia, HIV infection, or Klinefelter's Syndrome)
More than 20% over ideal body weight
Disabilities that would prevent participation in strength testing (e.g., amputation of limbs, blindness, severe arthritis, angina, or neurologic disorders such as Parkinson's disease, stroke, or myopathy)
Uncontrolled hypertension, diabetes, congestive heart failure, or chronic obstructive lung disease
Alcohol or drug dependence in the 6 months prior to study entry
Disorders that might be exacerbated by androgen treatment (e.g., benign prostatic hyperplasia or prostate cancer, erythrocytosis [hematocrit > 51% at baseline], or sleep apnea assessed by Berlin's questionnaire)
Serum PSA levels > 4 microg/L
AST, ALT, or alkaline phosphatase elevation greater than three times the upper limit of normal
Creatinine greater than 2 mg/dL
Medications that might affect muscle or bone metabolism (e.g., glucocorticoid, rhGH, androgenic steroids, oral androgen precursors such as androstenedione or DHEA) or androgen metabolism, action, or clearance (e.g., dilantin, phenobarbitol, aldactone, flutamide, finasteride)

Contacts and Locations

Please refer to this study by its ClinicalTrials.gov identifier: NCT00070733

Locations

United States, California
Charles R. Drew University	Recruiting
Los Angeles, California, United States, 90059
Contact: Shalender Bhasin, MD 323-563-9353

Sponsors and Collaborators

Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)

Investigators

Principal Investigator:

Shalender Bhasin, MD

Charles R. Drew University

More Information

No publications provided

ClinicalTrials.gov Identifier:	NCT00070733 History of Changes
Other Study ID Numbers:	R01 HD43348-01
Study First Received:	October 7, 2003
Last Updated:	November 4, 2005
Health Authority:	United States: Federal Government

Keywords provided by Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD):

Testosterone
5-alpha Reductase
Muscle Strength
Libido

Sexual Function
Muscle Mass
Testosterone 5-alpha-Reductase

Additional relevant MeSH terms:

Sexual Dysfunction, Physiological
Genital Diseases, Male
Genital Diseases, Female
Testosterone
Testosterone enanthate
Testosterone undecanoate
Testosterone 17 beta-cypionate
Methyltestosterone
Androgens

Hormones
Hormones, Hormone Substitutes, and Hormone Antagonists
Physiological Effects of Drugs
Pharmacologic Actions
Antineoplastic Agents, Hormonal
Antineoplastic Agents
Therapeutic Uses
Anabolic Agents

ClinicalTrials.gov processed this record on February 12, 2012