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Study · Randomized controlled trial · n = 22 · 2009

4 results

Factors other than sex steroids modulate GHRH and GHRP-2 efficacies in men: evaluation using a GnRH agonist/testosterone clamp.

Veldhuis JD, Bowers CY

The Journal of clinical endocrinology and metabolism7 Apr 2009Cited by 2 (Europe PMC)

PMID19351731 (opens in a new tab)PMCIDPMC2708950 (opens in a new tab)DOI10.1210/jc.2008-2767 (opens in a new tab)PepBankPUB-19351731
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Summary

The text of this summary is not shown here, because the article license does not allow reuse. Read it at the source (opens in a new tab)

Text rights: Publisher copyright. Results still quote short attributed sentences.

Results from this study4

4 results from studies that gave the peptide. 4 results from people.

  1. 01HumanRandomized controlled trialEfficacy outcome

    Under a leuprolide/testosterone clamp, L-arginine/GHRP‑2 stimulated 1.3-fold more GH release in young than in older men (P = 0.045).

    In plain wordsWith sex hormones held steady, young men released 1.3 times more GH than older men after GHRP‑2.

    Peptide
    GHRP-2
    Outcome
    DecreaseGH release after L-arginine/GHRP-2 in young versus older men
    Study

    n = 22

    Comparator
    Young men
    Outcome group
    Growth hormone and IGF-1 · Endocrine and hormones
    Studied dose
    Dose not stated · infusionAs given in this study (human).

    Source sentences

    Summary
    In this controlled milieu, sequential l-arginine/GHRH infusion stimulated 1.4-fold more (P = 0.021) and l-arginine/GHRP-2 1.3-fold more (P = 0.045) GH release in young than older men.
    2 context sentences
    Summary · context
    Eleven young (age, 24 +/- 0.99 yr) and 11 older (64 +/- 2.4 yr) men participated in the study.
    Summary · context
    The study consisted of GnRH-agonist down-regulation of the gonadal axis followed by fixed-dose testosterone (T) replacement (leuprolide/T clamp) and consecutive infusion of l-arginine and GHRH or GH-releasing peptide-2 (GHRP-2) to quantify peptide-secretagogue efficacies.
  2. 02HumanRandomized controlled trialMechanism

    Abdominal visceral fat correlated negatively with GHRP‑2 efficacy (R2 = 0.29).

    In plain wordsIn men with controlled sex hormones, more belly fat was linked to a weaker GH response to GHRP‑2.

    Peptide
    GHRP-2
    Outcome
    DecreaseAbdominal visceral fat correlation with GHRP-2 efficacy
    Study

    n = 22

    Outcome group
    Growth hormone and IGF-1 · Endocrine and hormones
    Studied dose
    Dose not stated · infusionAs given in this study (human).

    Source sentences

    Summary
    Abdominal visceral fat (AVF) correlated negatively with both GHRH (P = 0.0006; R(2) = 0.39) and GHRP-2 (R(2) = 0.29)
    2 context sentences
    Summary · context
    Eleven young (age, 24 +/- 0.99 yr) and 11 older (64 +/- 2.4 yr) men participated in the study.
    Summary · context
    The study consisted of GnRH-agonist down-regulation of the gonadal axis followed by fixed-dose testosterone (T) replacement (leuprolide/T clamp) and consecutive infusion of l-arginine and GHRH or GH-releasing peptide-2 (GHRP-2) to quantify peptide-secretagogue efficacies.
  3. 03HumanRandomized controlled trialMechanism

    IGF-I positively predicted both GHRH and GHRP‑2 efficacy (R2 = 0.25 to 0.30 across the two endpoints).

    In plain wordsIn men with controlled sex hormones, higher IGF-I was linked to stronger GH responses to both GHRH and GHRP‑2.

    Peptide
    GHRP-2
    Outcome
    IncreaseIGF-I correlation with GHRP-2 efficacy
    Study

    n = 22

    Outcome group
    Growth hormone and IGF-1 · Endocrine and hormones
    Studied dose
    Dose not stated · infusionAs given in this study (human).

    Source sentences

    Summary
    whereas IGF-I positively predicted the same endpoints (R(2) = 0.25 to 0.30)
    2 context sentences
    Summary · context
    Eleven young (age, 24 +/- 0.99 yr) and 11 older (64 +/- 2.4 yr) men participated in the study.
    Summary · context
    The study consisted of GnRH-agonist down-regulation of the gonadal axis followed by fixed-dose testosterone (T) replacement (leuprolide/T clamp) and consecutive infusion of l-arginine and GHRH or GH-releasing peptide-2 (GHRP-2) to quantify peptide-secretagogue efficacies.
  4. 04HumanRandomized controlled trialMechanism

    In multivariate analysis, IGF-I was a primary positive determinant of GHRP‑2 efficacy (P = 0.007; R2 = 0.31).

    In plain wordsIn men with controlled sex hormones, IGF-I remained the main factor linked to a stronger GH response to GHRP‑2.

    Peptide
    GHRP-2
    Outcome
    IncreaseIGF-I as determinant of GHRP-2 efficacy in multivariate analysis
    Study

    n = 22

    Outcome group
    Growth hormone and IGF-1 · Endocrine and hormones
    Studied dose
    Dose not stated · infusionAs given in this study (human).

    Source sentences

    Summary
    IGF-I as a primary positive determinant of GHRP-2 efficacy (P = 0.007; R(2) = 0.31)
    2 context sentences
    Summary · context
    Eleven young (age, 24 +/- 0.99 yr) and 11 older (64 +/- 2.4 yr) men participated in the study.
    Summary · context
    The study consisted of GnRH-agonist down-regulation of the gonadal axis followed by fixed-dose testosterone (T) replacement (leuprolide/T clamp) and consecutive infusion of l-arginine and GHRH or GH-releasing peptide-2 (GHRP-2) to quantify peptide-secretagogue efficacies.

AI wrote and checked these results. AI can make mistakes, so check important results against the source.

Version history

PepBank keeps every version of the data on this study. Status changes from Retraction Watch, Europe PMC and Crossref are listed with their source.

  1. Version 2Current

    13 Oct 2026, 21:44 UTC

    Study results updated

  2. Version 1

    13 Oct 2026, 16:31 UTC

    First added · source update from Europe PMC

Subjects

Terms as the source lists them.

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