Gender, sex-steroid, and secretagogue-selective recovery from growth hormone-induced feedback in older women and men

What Was Tested

Researchers studied Exogenous HGH, sermorelin & older GHRPs (why they're passed over) and GHRH (Growth Hormone-Releasing Hormone) in this randomized controlled trial publication.

Supplementation with sex steroids and/or a peptidyl secretagogue will enhance the escape of GH from autoinhibition, thus framing a mechanism for amplifying pulsatile GH secretion.

Why It Was Studied

GH negatively regulates its own secretion.

How gender, sex steroids, and secretagogues modulate GH autofeedback is not known.

Who Took Part

According to the abstract, 10 men were involved.

PubMed indexes the participants as middle-aged adults, older adults and people over 80, both men and women.

Ten healthy postmenopausal women and 10 comparably aged men participated at the Clinical-Translational Science Unit.

Randomly ordered, double-blind, prospective crossover treatment with placebo vs. testosterone (men) or placebo vs. estradiol (women).

How the Study Was Run

The design is described as randomized, double-blind, placebo-controlled and crossover.

Random assignment meant chance, not the researchers, decided who got Exogenous HGH, sermorelin & older GHRPs (why they're passed over) and who got the comparison, which limits bias.

As a double-blind Exogenous HGH, sermorelin & older GHRPs (why they're passed over) study, the assignments were hidden from both participants and investigators until the end.

A placebo (an inactive look-alike) gave the Exogenous HGH, sermorelin & older GHRPs (why they're passed over) group a baseline to be compared against.

Each person switched between Exogenous HGH, sermorelin & older GHRPs (why they're passed over) and the comparison at some point, usually with a gap in between.

Autofeedback was imposed by an iv pulse of GH.

Recovery of feedback inhibition was quantified during constant infusion of saline, GHRH, or GH-releasing peptide-2 (three peptide categories).

What Was Measured

The subject headings attached to it are Androgens, Drug Synergism, Estradiol, Feedback, Physiological, Growth Hormone-Releasing Hormone, Homeostasis and Human Growth Hormone.

What This Means in Plain Language

The paper is a randomized, double-blind and placebo-controlled study of Exogenous HGH, sermorelin & older GHRPs (why they're passed over) and GHRH (Growth Hormone-Releasing Hormone) in 10 men.

With fewer than 40 people, it is a small study, so it is better read as an early signal for further research than as a settled answer.

The abstract goes on to report its results in about 6 sentences; this page does not restate them, so read the paper for the findings and their limits.

The publication is from 2011 (The Journal of clinical endocrinology and metabolism), a journal based in United States.

More context: the Exogenous HGH, sermorelin & older GHRPs (why they're passed over) compound page and the GHRH (Growth Hormone-Releasing Hormone) compound page, all human trials.