Reliability of hormonal levels for assessing the hypothalamic-pituitary-adrenocortical system in clinical pharmacology.

What Was Tested

Researchers studied beta-Endorphin in this randomized controlled trial publication.

Two placebo controlled cross-over trials in 20 normal healthy male subjects offered the opportunity to perform three repeat samplings of adrenocortical and corticotroph hormones at 1 to 5 week intervals during the placebo periods.

Measurements of baseline levels of plasma, salivary and urinary cortisol, plasma adrenocorticotroph hormone (ACTH), lipotrophic hormone (LPH), beta-endorphin, post tetracosactrin levels of plasma and salivary cortisol, post corticotrophin releasing hormone (CRH)-lysine vasopressine (LVP) levels of plasma cortisol, ACTH and LPH; and post metyrapone levels of plasma cortisol and 11-deoxycortisol (compound S), ACTH, LPH, beta-endorphin were performed in the same laboratory.

Who Took Part

The abstract describes 20 subjects taking part.

The age groups tagged for this paper are adults, men only.

How the Study Was Run

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

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

Neither the subjects nor the staff measuring them knew who was on beta-Endorphin, so expectations could not easily colour the readings.

The comparison arm used a placebo, so changes seen with beta-Endorphin could be set against what happens without it.

Each person switched between beta-Endorphin and the comparison at some point, usually with a gap in between.

What Was Measured

Measurements of baseline levels of plasma, salivary and urinary cortisol, plasma adrenocorticotroph hormone (ACTH), lipotrophic hormone (LPH), beta-endorphin, post tetracosactrin levels of plasma and salivary cortisol, post corticotrophin releasing hormone (CRH)-lysine vasopressine (LVP) levels of plasma cortisol, ACTH and LPH; and post metyrapone levels of plasma cortisol and 11-deoxycortisol (compound S), ACTH, LPH, beta-endorphin were performed in the same laboratory.

The reliability of the measurements was estimated by computing the intraclass correlation coefficient (R) and by using Altman-Bland graphical method.

PubMed files the paper under topics including Adrenocorticotropic Hormone, Corticotropin-Releasing Hormone, Cortodoxone, Hormones, Hydrocortisone, Hypothalamo-Hypophyseal System and Immunoradiometric Assay.

What This Means in Plain Language

The paper is a randomized, double-blind and placebo-controlled study of beta-Endorphin in 20 subjects.

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 publication is from 1994 (British journal of clinical pharmacology), a journal based in England.

More context: all human trials.