The purpose of this study is to determine the levels of testosterone and/or estradiol at which changes in bone turnover, body composition, strength, sexual function etc. begin to occur. This information may help determine when to intervene with hormone replacement therapy in aging men.
There are 3 arms to this protocol, each with 5 or 6 groups.
In Arm 1, 240 men age 20-50 will receive goserelin acetate (Zoladex) plus Androgel (or placebo). (NOTE: ARM 1 IS CLOSED TO RECRUITMENT.
In Arm 2, 200 men age 20-50 will receive goserelin acetate (Zoladex) plus Androgel (or placebo) plus anastrazole (Arimidex). NOTE: ARM 2 IS CLOSED TO RECRUITMENT..
In Arm 3, 240 men age 60 to 75 will receive goserelin acetate (Zoladex) plus Androgel (or placebo). (Arm 3 is recruiting).
Subjects will be screened on the MGH General Clinical Research Center (GCRC). After obtaining informed consent for the screening procedures, subjects will undergo a complete history and physical examination. If no exclusionary findings are noted during the history and physical examination, blood will be drawn to measure hemoglobin, routine chemistries (including serum calcium, liver function tests, and creatinine), and serum levels of PTH, 25-OH vitamin D, TSH, T, and PSA.
For Arm 3, subjects who are successfully screened will be randomly assigned by a computer to one of 6 groups. All subjects will receive a GnRH agonist goserelin acetate (Zoladex; AstraZeneca, Wilmington, DE) 3.6 mg sc every 4 weeks for 16 weeks. Subjects in Group 1 will receive goserelin acetate and placebo for Androgel. Subjects in Groups 2-5 will receive varying doses of Androgel. Subjects in Group 6 will receive double placebo (e.g. placebo Zoladex and placebo Androgel). Subjects will be blinded with respect to group assignment. Dietary calcium intake will be assessed by a research dietitian and adjustments made through diet or supplements so that calcium intake is between 1000 and 1200 mg/day.
Subjects will be seen on the GCRC at 4 week intervals for 16 weeks (0, 4, 8, 12, and 16 weeks). At each visit, compliance with Androgel' will be assessed by reviewing a medication diary. A standardized series of questions will be posed to each subject to assess potential side effects of the study drugs. Subjects receiving Androgel' will be given a new 4 week supply of medication (except at week 16). A fasting blood and second voided urine sample will be collected. After the blood and urine samples have been obtained, subjects will be given their goserelin injection. The blood and urine tests listed below as well as anthropometric measures, and questionnaires will be performed at each visit. DXA, CT scans, and strength assessments will be performed at 0 and 16 weeks only. Subjects who discontinue participation at or after week 8 will be asked if they are willing to have an early discontinuation visit in which all procedures normally done at week 16 will be performed.
The following measures will be assessed:
- Routine chemistries and PSA (for safety assessment)
- Bone turnover using blood and urine tests
- Body composition
- Symptoms of hypogonadism
- Bone mineral density and bone microarchitecture
|Date last updated at source||2016-09-16|
|Study start date||2004-09-01|
|Estimated primary completion date||2018-07-01|