Metabolic Effects of Androgenicity in Aging Men and Women

The goal of this research study is to study the effect of testosterone or estrogen on blood sugar control and fat metabolism. Changes in hormone levels with age may affect risk factors for heart disease such as diabetes. Diabetes is a glandular condition associated with lack of the hormone insulin or an insensitivity to it resulting in problems with blood sugar control and fat metabolism. The effect of commonly used hormonal supplements such as testosterone by older adults on insulin and body composition is not well understood. In this study, the role of testosterone and estrogen on your ability to control blood sugar and your body composition will be assessed.

The investigators plan to study 60 subjects. All of these subjects will be healthy older men between the ages of 60-85 years old who are not on testosterone therapy. Subjects that are screened who have any clinically significant abnormalities detected on their screening physical exam or laboratory testing (e.g. Prostate Specific Antigen > 4), who have a history of prostate cancer, polycythemia, or who cannot take testosterone will not be included.

If a subject is eligible to participate after initial screening, that subject will take medications to adjust their hormone levels and have tests performed that measure insulin sensitivity and adiposity before and after these hormone medications. The outcomes that will be measured are: 1) insulin sensitivity, 2) hormone levels (total and free testosterone levels, sex hormone-binding globulin levels) and 3) body composition and abdominal adiposity.

Study Overview

• Status: Completed
• Conditions: Insulin Resistance; Aging
• Intervention / Treatment: Drug: Testosterone; Drug: Estrogen

• Study Type: Interventional
• Enrollment (Actual): 33
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • California
    • West Los Angeles, California, United States, 90073
      • VA Greater Los Angeles Healthcare System, West Los Angeles, CA

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 60 years to 85 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: Male

Description

Inclusion Criteria:

• males age 60-85 years
• non-diabetic fasting glucose and 2-hour oral glucose tolerance test (OGTT)
• overall good general medical health and signed informed consent
• willing to travel to West Los Angeles VA and University of California, Los Angeles in Los Angeles, California

Exclusion Criteria:

• any clinically significant abnormalities detected on screening physical exam or laboratory testing (e.g. prostate specific antigen > 4)
• or other symptom or history of a significant underlying medical or psychiatric illness
• BMI < 20 or > 40
• subjects already on testosterone therapy or medications that might influence glucose regulation or hormone levels
• subjects with a history of deep venous thromboses, pulmonary embolism, breast cancer, prostate cancer, polycythemia or other contraindications to estrogen or testosterone

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: +T +E; +Testosterone, +Estrogen	Drug: Testosterone; Testosterone gel; Drug: Estrogen; Estrogen patch
Experimental: +T -E; +Testosterone, -Estrogen	Drug: Testosterone; Testosterone gel
Experimental: -T +E; -Testosterone, +Estrogen	Drug: Estrogen; Estrogen patch
No Intervention: -T -E; -Testosterone, -Estrogen

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Insulin Sensitivity	As measured by change in insulin levels pre- and post-hormone changes	6 weeks

Collaborators and Investigators

• Sponsor: VA Office of Research and Development
• Investigators: Principal Investigator: Cathy C Lee, PhD, VA Greater Los Angeles Healthcare System, West Los Angeles, CA

Study record dates

Study Major Dates

• Study Start (Actual): January 1, 2005
• Primary Completion (Actual): December 31, 2013
• Study Completion (Actual): December 31, 2016

Study Registration Dates

• First Submitted: May 8, 2008
• First Submitted That Met QC Criteria: May 16, 2008
• First Posted (Estimate): May 20, 2008

Study Record Updates

• Last Update Posted (Actual): June 15, 2017
• Last Update Submitted That Met QC Criteria: May 22, 2017
• Last Verified: May 1, 2017

More Information

Terms related to this study

• Keywords: Insulin resistance; Aging; Hormones
• Additional Relevant MeSH Terms: Glucose Metabolism Disorders; Metabolic Diseases; Hyperinsulinism; Insulin Resistance; Physiological Effects of Drugs; Hormones; Hormones, Hormone Substitutes, and Hormone Antagonists; Androgens; Testosterone; Estrogens
• Other Study ID Numbers: ARCD-034-04F

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No