Impact of Endogenous E2 on SSI and GH Rebound

What Was Tested

In this phase 1 trial, researchers set out to test Somatostatin.

Endogenous estrogens maintain growth hormone (GH) secretion in postmenopausal women by potentiating endogenous GH-releasing hormone (GHRH) drive and restraining somatostatin inhibition of GH release.

It had four arms (groups): IM Placebo/Oral Placebo (experimental), IM Placebo/PO Anastrozole (experimental), IM Fulvestrant/PO Placebo (experimental) and IM Fulvestrant/IM Anastrozole (experimental).

The registry classes the interventions as drug.

More on the Plan

Systemic concentrations of testosterone (Te), estradiol (E2), GH, IGF-I and IGFBP-3 decline in healthy aging individuals (1-3).

Sex-steroid deprivation accentuates GH and IGF-I depletion, since Te and E2 stimulate GH and IGF-I production in older adults, hypogonadal patients of all ages, and patients undergoing gender reassignment (1,2,4).

E2 also stimulates GH secretion in women, putatively via the nuclear estrogen receptor (ER-alpha) (1,2,6,7).

Because Te, E2 and GH fall with menopause, and Te is converted to E2 by aromatization in the body (8-10), the researchers postulate that diminished Te concentrations, Te→E2 concentrations and low E2 mediate low GH output in older women.

Who Took Part

Enrollment: 62 actual participants took part.

It was open to women only aged from 55 years up to 80 years.

Healthy volunteers could join, not only people with the condition.

Examples of who could join: 60 healthy post-menopausal women (ages 55 to 80 y);. BMI 18-30 kg/m2. Community dwelling; and voluntarily consenting. Recent use of psychotropic or neuroactive drugs (within five biological half-lives);. Obesity (outside weight range above);.

The full record lists 19 inclusion and 0 exclusion criteria.

How the Study Was Run

The set-up was randomized, crossover and triple-blind.

Because people in this Somatostatin study were split into groups at random, differences between the groups are less likely to reflect who happened to join each one.

In the crossover set-up each of the participants took both Somatostatin and the comparison in turn, acting as their own control.

As a double-blind Somatostatin study, the assignments were hidden from both participants and investigators until the end.

Those kept unaware of assignments: participant, care provider and investigator.

It started in 2014-03 with completion listed for 2015-11.

It ran at 1 site in United States.

Its stated primary purpose is basic science.

What Was Measured

The main thing measured (primary outcome): The summed mass of GH over 10 hours (time frame: 14-18 days: From date of randomization to overnight visit).

It also tracked 1 secondary outcome, for example The summed mass of GH over a 2h Somatostatin infusion and 3h rebound window.

What This Means in Plain Language

Put simply, this is a phase 1, randomized trial of Somatostatin in 62 people.

The trial is marked completed; no results are posted to the registry yet, so nothing here describes outcomes.

More context: the Somatostatin compound page, all human trials.