Aromatase Inhibitors in the Treatment of Male Infertility

This study has been terminated.
(Not able meet target enrollment.)
Information provided by (Responsible Party):
Ahmad Hammoud, University of Utah Identifier:
First received: February 22, 2007
Last updated: May 20, 2014
Last verified: May 2014

February 22, 2007
May 20, 2014
March 2007
June 2014   (final data collection date for primary outcome measure)
Sperm concentration [ Time Frame: 4 months ] [ Designated as safety issue: No ]
Sperm concentration
Complete list of historical versions of study NCT00440180 on Archive Site
Other sperm parameters, hormonal measures and pregnancy rates [ Time Frame: 4 months ] [ Designated as safety issue: No ]
Other sperm parameters, hormonal measures and pregnancy rates
Not Provided
Not Provided
Aromatase Inhibitors in the Treatment of Male Infertility
The Role of Aromatase Inhibitors in the Treatment of Infertility in Obese Male

Obesity is associated with an increase in blood levels of estrogen. Estrogen or "female hormone" is believed to have a negative effect on sperm production. Aromatase inhibitors such as anastrozole work to decrease the production of estrogen and increase testosterone in the body. By decreasing the level of estrogen, sperm production should improve. In this study, the investigators will try to determine the benefit of anastrozole in obese men with low sperm counts.

Patients participating in this study will be randomly assigned (by chance) to treatment in one of two study arms: Group A: Anastrozole 1mg per day for 4 months and Group B: Placebo for 4 months. Neither patients nor doctors will know in which treatment group they are.

Screening assessments will take place prior to the start of treatment. During this time, demographic data and medical history will be reviewed and recorded. Also, testicular exam, sperm count and laboratory blood analysis will be performed. Over the course of study, semen and blood analysis including hormonal profile (testosterone, estrogen, follicle stimulating hormone and luteinizing hormone) will be recollected.

At the conclusion of the trial, the investigators expect the group that received anastrozole to have an improved sperm count, increased testosterone and decreased estrogen levels.

The role of aromatase inhibitors in the treatment of infertility (due to hypogonadism) in obese Male


The incidence of male infertility is increasing in the western world in parallel with an increase in obesity. It is estimated that in the United States sperm counts may be decreasing by as much as 1.5% each year (Swan et al, 2000). It is proposed that increased estrogen levels associated with obesity cause hypogonadism and male infertility via inappropriate suppression of gonadotropins and direct adverse effects on spermatogenesis. The link between obesity and its likely effects on the endocrine function of the male reproductive axis underlie the mechanistic justification for this novel trial of a medical therapy for hypogonadism and male infertility associated with obesity.

Study design:

The investigaotrs designed a double blind, randomized, placebo control trial of the aromatase inhibitor Anastrozole to treat men that are overweight (BMI ≥ 30 kg/m2) and oligospermic (sperm count ≤ 20 × 106/mL and ≥ than 3 × 106/mL). After enrollment, patients will be randomized to receive Anastrozole 1mg/d or placebo for 4 months. Semen analysis and hormonal profile (FSH, LH, Estradiol, total and free Testosterone will be measured at the start and the conclusion of the study. The primary outcome will be sperm density. Secondary outcomes will be other sperm parameters including: total count per ejaculate, total motile sperm per ejaculate, and sperm morphology. The investigators will also follow the change in FSH and LH, testosterone and estrogen levels, and will seek correlation between endocrine change and semen parameters. Based on a power analysis, a total of 50 patients will be included in the study. Study design and reporting will comply with the CONSORT (Consolidated Standards of Reporting Trials) guidelines.

Anticipated results:

The study will evaluate the research hypothesis that inhibition of aromatase will result in improvements in sperm density, as well as secondary semen analysis parameters (e.g. morphology and motility). Supporting endocrine data will be obtained as part of this clinical protocol that the investigators expect will show an increase in testosterone, LH and FSH levels and a decrease in estrogen levels associated with active treatment.

Phase 3
Allocation: Randomized
Endpoint Classification: Safety/Efficacy Study
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
  • Obesity
  • Oligospermia
  • Drug: Anastrozole
    1 mg qd for 4 months
    Other Name: Arimidex
  • Drug: Placebo
    Placebo Comparator
  • Placebo Comparator: Group B
    Intervention: Drug: Placebo
  • Experimental: Group A
    Intervention: Drug: Anastrozole
Not Provided

*   Includes publications given by the data provider as well as publications identified by Identifier (NCT Number) in Medline.
June 2014
June 2014   (final data collection date for primary outcome measure)

Inclusion Criteria:

  1. Male partner of a couple presenting for infertility work up after one year of unprotected intercourse
  2. Moderate oligozoospermia (defined as mean sperm count ≤ 20 × 106/mL and ≥ than 3 × 106/mL) of at least two separate occasions spanning a minimum of two weeks
  3. Obese men BMI ≥ 30
  4. FSH and LH levels < 10 mIU/mL

Exclusion Criteria:

  1. Severe Oligozoospermia: Sperm count < than 3 × 106/mL, including azoospermia
  2. Age less than 18 or greater than 65 years
  3. Pyospermia or leukospermia: defined by white blood cells ≥ 1 million leukocytes per milliliter of semen
  4. Cryptorchidism
  5. Vasectomy reversal
  6. Regular use of tobacco products
  7. BMI < 30
  8. Use of anabolic steroids or testosterone replacement
  9. All patients with abnormal initial liver function tests "AST or ALT" will be excluded form the study
16 Years to 80 Years
Contact information is only displayed when the study is recruiting subjects
United States
Not Provided
Not Provided
Ahmad Hammoud, University of Utah
University of Utah
Not Provided
Principal Investigator: Ahmad O Hammoud, MD University of Utah
University of Utah
May 2014

ICMJE     Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP