Continuous GHRH Plus GHRP-2 Infusion Restores GH and IGF-1 in Critically Ill Patients | Research

The takeaway

Continuous combined GHRH and GHRP-2 infusion in critically ill patients restored GH secretion and raised IGF-1, offering a novel approach to combat ICU muscle wasting.

GH axis restored in ICU
Combined GHRH+GHRP-2 continuous infusion restored GH pulsatility and substantially increased IGF-1 in critically ill patients

What the researchers found

Continuous GHRH plus GHRP-2 infusion partially restored GH pulsatility and substantially raised IGF-1 levels in critically ill patients with suppressed somatotropic axes.

Why it matters

ICU muscle wasting significantly impacts recovery and survival. Restoring the GH/IGF-1 axis through secretagogues rather than GH injections may be safer and more effective.

How the study worked

Clinical trial using continuous IV infusion of combined GHRH and GHRP-2 in critically ill patients, measuring GH secretion profiles and IGF-1 levels.

What this study cannot tell us

Clinical trial in heterogeneous critically ill population. Functional outcomes (muscle preservation, recovery) not assessed. Comparison to GH replacement not included.

How to read the evidence

Moderate clinical evidence demonstrating hormonal restoration in critically ill patients. Lacks functional outcome data.

When this study was published

Published in 1997, this study offered an alternative to direct GH replacement, which was later shown to increase mortality in ICU patients (1999 Finnish study).

The bigger picture

This study demonstrated a practical approach to combating ICU muscle wasting using physiological GH stimulation rather than supraphysiological GH replacement, which had shown concerning mortality in ICU studies.

Questions still open

Does GH/IGF-1 restoration through secretagogues improve ICU outcomes?
Is combined GHRH+GHRP-2 infusion safer than direct GH replacement in critical illness?

Common questions

Why not just give GH directly to ICU patients?

A landmark 1999 study showed direct GH replacement actually increased mortality in ICU patients. Using secretagogues like GHRH+GHRP-2 instead stimulates the body's own GH production, which is self-limiting and may be safer.

Why combine GHRH with GHRP-2?

In critical illness, the GH axis is suppressed at multiple levels. GHRH acts on the pituitary and GHRP-2 acts on both the hypothalamus and pituitary through a different pathway. The combination restores GH release more effectively than either alone.

Read the original research

The somatotropic axis in critical illness: effect of continuous growth hormone (GH)-releasing hormone and GH-releasing peptide-2 infusion.

The Journal of clinical endocrinology and metabolism, 82(2), 590-9

View on PubMed ↗

Citation

Van den Berghe, G; de Zegher, F; Veldhuis, J D; Wouters, P; Awouters, M; Verbruggen, W; Schetz, M; Verwaest, C; Lauwers, P; Bouillon, R; Bowers, C Y. (1997). The somatotropic axis in critical illness: effect of continuous growth hormone (GH)-releasing hormone and GH-releasing peptide-2 infusion.. The Journal of clinical endocrinology and metabolism, 82(2), 590-9.