Mechanisms of Testosterone-Driven Growth-Hormone (GH) Secretion in Aging Men: Modulation of GHRH, GHRP and Somatostatin Action by Estrogenic Versus Androgenic Steroids
试验速览
- 阶段
- 1 期
- 状态
- 已完成
- 发起方
- Mayo Clinic
- 入组人数
- 80
- 试验地点
- 1
- 主要终点
- Growth Hormone concentration after injections
研究概览
简要总结
This study is being done to understand how testosterone, the major male sex hormone, controls the pituitary gland's secretion of growth hormone (GH). GH is an important metabolic hormone, which controls sugar; fat and protein use in the body and maintains muscle strength and bone calcium content. Both testosterone and GH decline in older men. The age-related fall in these hormones probably contributes to relative frailty, reduced quality of life, bone loss, muscle wasting and impaired sexual function.
详细描述
Repletion of testosterone in older men drives pulsatile GH secretion via conjoint facilitation of feedforward by the primary secretagogues GHRH and GHRP and repression of feedback by the dominant inhibitor, somatostatin; and, in corollary, testosterone acts via aromatization to estradiol and/or reduction to 5 alpha-dihydrotestosterone
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Basic Science
- 盲法
- Double (Participant, Investigator)
入排标准
- 年龄范围
- 50 Years 至 80 Years（Adult, Older Adult）
- 性别
- Male
- 接受健康志愿者
- 是
入选标准
- •healthy men between the ages of 50 and 80;
- •normal weight (within 30% of ideal body weight defined by New York Metropolitan Life tables); and
- •normal hematocrit (greater than 38%);
- •community dwelling; and
- •voluntarily consenting
排除标准
- •recent use of psychotropic or neuroactive drugs (within five biological half-live);
- •obesity (outside weight range above);
- •anemia (hematocrit < 38%);
- •drug or alcohol abuse, psychosis, depression, mania or severe anxiety;
- •acute or chronic organ-system disease;
- •endocrinopathy, other than primary thyroidal failure receiving replacement;
- •nightshift work or recent transmeridian travel (exceeding 3 time zones within 7 days of admission);
- •acute weight change (loss or gain of > 2 kg in 6 weeks);
- •allergy to administered compounds; and
- •unwillingness to provide written informed consent.
研究组 & 干预措施
Double Placebo
(i.m. vehicle 0.5 mL weekly x three injections and oral placebo once daily x 21 days)
干预措施: Placebo (Drug)
Testosterone IM and oral placebo
IM injections weekly x three injections and oral placebo once daily x 21 days
干预措施: Testosterone (Drug)
Testosterone and Oral Anastrozole
IM injections weekly x 3 injections and oral daily x 21 days
干预措施: Testosterone (Drug)
Testosterone and Oral Anastrozole
IM injections weekly x 3 injections and oral daily x 21 days
干预措施: Anastrazole (Drug)
Testosterone and Dutasteride
IM injections weekly x 3 injections and oral once daily x 21 days
干预措施: Testosterone (Drug)
Testosterone and Dutasteride
IM injections weekly x 3 injections and oral once daily x 21 days
干预措施: Dutasteride (Drug)
结局指标
主要结局
Growth Hormone concentration after injections
时间窗: 24 days
GH will be measured 4 different times mornings within 16-21 days following the first testosterone injection (day 1).
次要结局
未报告次要终点