Restoring Suppressed Hormones in ICU Patients With Growth Hormone and Thyroid Peptides | Research

The takeaway

Continuous GHRP-2 and TRH infusions reactivated suppressed growth hormone and thyroid hormone secretion in 20 critically ill patients, restoring more normal pulsatile hormone patterns.

20 ICU patients
Combined GHRP-2 + TRH restored both pulsatile GH and thyroid hormone secretion more effectively than either agent alone

What the researchers found

Combined GHRP-2 and TRH infusion most effectively reactivated both pulsatile GH secretion and the thyrotropic axis in 20 prolonged critically ill patients, with effects exceeding either agent alone.

Why it matters

The hormonal suppression in critical illness is not just a consequence of being sick — it actively worsens outcomes by driving muscle loss and metabolic dysfunction. Correcting it with peptide therapy could improve survival.

How the study worked

Randomized trial in 20 adult critically ill patients. Continuous IV infusions of TRH, GHRP-2, GHRH alone and in combinations were administered. Pulsatile GH, TSH, thyroid hormones, and IGF-1 were measured over treatment periods.

What this study cannot tell us

20 patients — small sample. Hormonal endpoints, not clinical outcomes. Heterogeneous ICU population. Continuous IV infusion is resource-intensive for routine clinical use.

How to read the evidence

Moderate evidence from a randomized trial with clear hormonal endpoints in a clinically relevant population, limited by small size and surrogate outcomes.

When this study was published

Published in 1998 by the Leuven critical illness endocrinology group. Their research has continued with landmark studies on hormonal management in the ICU.

The bigger picture

Critical illness endocrinology represents a major frontier in ICU medicine. Rather than just supporting organs and fighting infections, correcting hormonal dysfunction could fundamentally change ICU outcomes by maintaining the body's ability to heal itself.

Questions still open

Do the restored hormone levels translate to better clinical outcomes?
Can simpler dosing regimens (subcutaneous GHRP-2) achieve similar results?
Should hormonal therapy begin early in critical illness to prevent endocrine suppression?

Common questions

Why are hormones suppressed in critical illness?

The body's neuroendocrine system partially shuts down during prolonged illness, possibly as a survival mechanism. But this suppression also drives muscle wasting and impairs healing, creating a vicious cycle.

Could these peptides become standard ICU treatment?

This study provides proof-of-concept that the hormonal suppression can be corrected. Whether doing so improves survival and recovery requires larger clinical trials, which have been conducted subsequently.

Read the original research

Neuroendocrinology of prolonged critical illness: effects of exogenous thyrotropin-releasing hormone and its combination with growth hormone secretagogues.

The Journal of clinical endocrinology and metabolism, 83(2), 309-19

View on PubMed ↗

Citation

Van den Berghe, G; de Zegher, F; Baxter, R C; Veldhuis, J D; Wouters, P; Schetz, M; Verwaest, C; Van der Vorst, E; Lauwers, P; Bouillon, R; Bowers, C Y. (1998). Neuroendocrinology of prolonged critical illness: effects of exogenous thyrotropin-releasing hormone and its combination with growth hormone secretagogues.. The Journal of clinical endocrinology and metabolism, 83(2), 309-19.