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Short-term Effects of Aromatase Inhibition in Obese Men

This study has been completed.
ClinicalTrials.gov Identifier:
First Posted: August 30, 2005
Last Update Posted: October 22, 2010
The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
Information provided by:
Rijnstate Hospital
In this study, 50 obese men with a hormonal imbalance will be treated with letrozole or placebo for six months in order to examine the effects on the hormonal balance, and on weight loss. The study will also address the side effects and psychological effects of letrozole as compared to placebo.

Condition Intervention Phase
Hypogonadotrophic Hypogonadism Obesity Drug: Letrozole (Femara) Phase 3

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double
Primary Purpose: Treatment
Official Title: Short-term Effects of Aromatase Inhibition in Obese Men

Resource links provided by NLM:

Further study details as provided by Rijnstate Hospital:

Primary Outcome Measures:
  • Body weight
  • Body mass index (BMI)
  • Waist circumference
  • Body composition
  • Exercise capacity
  • Serum levels of hormones
  • Glucose tolerance
  • Reported side effects
  • Psychological characteristics (Symptom Checklist, intelligence quotient [IQ] NPV)

Secondary Outcome Measures:
  • Lipid profile
  • Blood counts
  • Bone markers
  • Liver enzymes

Estimated Enrollment: 50
Study Start Date: August 2005
Study Completion Date: January 2010
Primary Completion Date: January 2010 (Final data collection date for primary outcome measure)
Detailed Description:

The aim of the study is to establish the short-term efficacy and safety of aromatase inhibition in restoring and maintaining eugonadism in hypogonadotrophic hypogonadal men. Secondary aim is to detect the short-term somatic and psychological effects.

Study design: Double blind randomized placebo-controlled trial.

Treatment: 26 weeks of either letrozole or placebo. All patients will start on 1 tablet per week, dose adjustments will be performed if serum testosterone or estradiol are outside the target range. All men will be prescribed a mildly hypocaloric diet.

Endpoints: BMI, body weight, waist circumference, body composition, exercise capacity, serum levels of several hormone markers, glucose tolerance, psychological characteristics.

All patients will be measured 6 times during the study.


Information from the National Library of Medicine

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Ages Eligible for Study:   20 Years to 50 Years   (Adult)
Sexes Eligible for Study:   Male
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • BMI between 35 and 50
  • Male sex
  • Ages between 20 and 50
  • Serum total testosterone under 10 nmol/l
  • Serum luteinizing hormone (LH) under 9 mU/l
  • Serum estradiol over 40 pmol/l

Exclusion Criteria:

  • Comorbidity
  • Serum prostate-specific antigen (PSA) over 4.0 U/l
  • Discontinuation of smoking less than six months ago
  • Medication known to affect hormonal parameters
  Contacts and Locations
Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00138710

Rijnstate Hospital
Arnhem, Netherlands, 6815 AM
Sponsors and Collaborators
Rijnstate Hospital
Principal Investigator: Hans de Boer, MD PhD Rijnstate Hospital, Arnhem, the Netherlands
  More Information

ClinicalTrials.gov Identifier: NCT00138710     History of Changes
Other Study ID Numbers: LTC-323-150405
First Submitted: August 29, 2005
First Posted: August 30, 2005
Last Update Posted: October 22, 2010
Last Verified: October 2010

Keywords provided by Rijnstate Hospital:
Hypogonadotrophic hypogonadism
aromatase inhibition

Additional relevant MeSH terms:
Gonadal Disorders
Endocrine System Diseases
Antineoplastic Agents
Aromatase Inhibitors
Steroid Synthesis Inhibitors
Enzyme Inhibitors
Molecular Mechanisms of Pharmacological Action
Estrogen Antagonists
Hormone Antagonists
Hormones, Hormone Substitutes, and Hormone Antagonists
Physiological Effects of Drugs