The inhibition of growth hormone secretion presented in obesity is not mediated by the high leptin levels: a study in human leptin deficiency patients.

Ozata M, Dieguez C, Casanueva FF

The Journal of clinical endocrinology and metabolism1 Jan 2003Cited by 22 (Europe PMC)

PMID12519870DOI10.1210/jc.2002-020122PepBankPUB-12519870

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 study7

No result from this study comes from a test of the peptide.

Studies that did not test the peptide alone7

In this study, GHRP-6 was a lab tool or a carrier, part of a mix, or the subject of a lab method. These results are not evidence about taking GHRP-6.

01HumanNot a test of GHRP-6 aloneObservational studyOther
After GHRH plus GHRP‑6, homozygous patients and their controls had lower GH peaks than the other groups.
In plain wordsThe combined test produced lower GH peaks in homozygous patients and their controls than the other groups.
Peptide
GHRP-6
Outcome
DecreaseGH peaks in severe obesity
Study
n = 21
Comparator
Heterozygous patients, their controls, and nonobese subjects
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Measurements
Stimulated GH peak
9.4 micrograms per liter
Homozygous patients
Stimulated GH peak
9.3 micrograms per liter
Controls for homozygous patients
Source sentences
Summary
homozygous group, 9.4 +/- 3.0; control for homozygous, 9.3 +/- 1.0 (significantly lower than the heterozygous, control for heterozygous, and nonobese groups).
2 context sentences(design, population, supporting numbers)
Summary · context
Three homozygous and 5 heterozygous patients with leptin gene mutations as well as 13 control subjects were studied.
Summary · context
In all subjects basal levels of leptin and GH values stimulated by the combined administration of GHRH plus GH-releasing peptide-6 (GHRP-6) were analyzed.
In this study, GHRP-6 was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking GHRP-6.
Report a problemFND-1251987003
02HumanNot a test of GHRP-6 aloneObservational studyOther
In controls, GH peaks after GHRH plus GHRP‑6 correlated negatively with BMI.
In plain wordsIn controls, lower GH peaks after the combined test were linked to higher BMI.
Peptide
GHRP-6
Outcome
DecreaseGH peak and BMI in controls
Study
n = 13
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Source sentences
Summary
To further analyze this observation, a correlation analysis showed that GH peaks were negatively correlated with BMI in the 13 control subjects as well as in the 8 leptin-deficient patients.
2 context sentences(design, population, supporting numbers)
Summary · context
Three homozygous and 5 heterozygous patients with leptin gene mutations as well as 13 control subjects were studied.
Summary · context
In all subjects basal levels of leptin and GH values stimulated by the combined administration of GHRH plus GH-releasing peptide-6 (GHRP-6) were analyzed.
In this study, GHRP-6 was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking GHRP-6.
Report a problemFND-1251987004
03HumanNot a test of GHRP-6 aloneObservational studyOther
In controls, GH peaks after GHRH plus GHRP‑6 correlated negatively with leptin levels.
In plain wordsIn controls, lower GH peaks after the combined test were linked to higher leptin levels.
Peptide
GHRP-6
Outcome
DecreaseGH peak and leptin in controls
Study
n = 13
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Source sentences
Summary
On the contrary, the GH peaks were negatively correlated with leptin levels in controls, but showed the opposite pattern in homo- and heterozygous patients.
2 context sentences(design, population, supporting numbers)
Summary · context
Three homozygous and 5 heterozygous patients with leptin gene mutations as well as 13 control subjects were studied.
Summary · context
In all subjects basal levels of leptin and GH values stimulated by the combined administration of GHRH plus GH-releasing peptide-6 (GHRP-6) were analyzed.
In this study, GHRP-6 was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking GHRP-6.
Report a problemFND-1251987006
04HumanNot a test of GHRP-6 aloneObservational studyOther
After GHRH plus GHRP‑6, nonobese subjects had higher GH peaks than heterozygous leptin mutation patients.
In plain wordsThe combined test produced higher GH peaks in nonobese subjects than heterozygous leptin mutation patients.
Peptide
GHRP-6
Outcome
IncreaseStimulated GH peak in nonobese versus heterozygous patients
Study
n = 10
Comparator
Heterozygous leptin mutation patients
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Measurements
Stimulated GH peak
86.8 micrograms per liter
Nonobese subjects
Stimulated GH peak
28.6 micrograms per liter
Heterozygous leptin mutation patients
Source sentences
Summary
In these matched groups, the GHRH- and GHRP-6-stimulated GH secretion (mean peak +/- SE; micrograms per liter) was: nonobese, 86.8 +/- 8.9 [significantly higher than heterozygous (28.6 +/- 4.9) and control for heterozygous (39.9 +/- 10.4)]
2 context sentences(design, population, supporting numbers)
Summary · context
Three homozygous and 5 heterozygous patients with leptin gene mutations as well as 13 control subjects were studied.
Summary · context
In all subjects basal levels of leptin and GH values stimulated by the combined administration of GHRH plus GH-releasing peptide-6 (GHRP-6) were analyzed.
In this study, GHRP-6 was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking GHRP-6.
Report a problemFND-1251987001
05HumanNot a test of GHRP-6 aloneObservational studyOther
After GHRH plus GHRP‑6, nonobese subjects had higher GH peaks than controls for heterozygous patients.
In plain wordsThe combined test produced higher GH peaks in nonobese subjects than controls for heterozygous patients.
Peptide
GHRP-6
Outcome
IncreaseStimulated GH peak in nonobese versus heterozygous controls
Study
n = 10
Comparator
Controls for heterozygous patients
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Measurements
Stimulated GH peak
86.8 micrograms per liter
Nonobese subjects
Stimulated GH peak
39.9 micrograms per liter
Controls for heterozygous patients
Source sentences
Summary
In these matched groups, the GHRH- and GHRP-6-stimulated GH secretion (mean peak +/- SE; micrograms per liter) was: nonobese, 86.8 +/- 8.9 [significantly higher than heterozygous (28.6 +/- 4.9) and control for heterozygous (39.9 +/- 10.4)]
2 context sentences(design, population, supporting numbers)
Summary · context
Three homozygous and 5 heterozygous patients with leptin gene mutations as well as 13 control subjects were studied.
Summary · context
In all subjects basal levels of leptin and GH values stimulated by the combined administration of GHRH plus GH-releasing peptide-6 (GHRP-6) were analyzed.
In this study, GHRP-6 was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking GHRP-6.
Report a problemFND-1251987002
06HumanNot a test of GHRP-6 aloneObservational studyOther
In leptin-deficient patients, GH peaks after GHRH plus GHRP‑6 correlated negatively with BMI.
In plain wordsIn leptin-deficient patients, lower GH peaks after the combined test were linked to higher BMI.
Peptide
GHRP-6
Outcome
DecreaseGH peak and BMI in leptin deficiency
Study
n = 8
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Source sentences
Summary
To further analyze this observation, a correlation analysis showed that GH peaks were negatively correlated with BMI in the 13 control subjects as well as in the 8 leptin-deficient patients.
2 context sentences(design, population, supporting numbers)
Summary · context
Three homozygous and 5 heterozygous patients with leptin gene mutations as well as 13 control subjects were studied.
Summary · context
In all subjects basal levels of leptin and GH values stimulated by the combined administration of GHRH plus GH-releasing peptide-6 (GHRP-6) were analyzed.
In this study, GHRP-6 was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking GHRP-6.
Report a problemFND-1251987005
07HumanNot a test of GHRP-6 aloneObservational studyOther
In homozygous and heterozygous leptin-mutation patients, the relation between GH peaks after GHRH plus GHRP‑6 and leptin levels showed the opposite pattern to that in controls.
In plain wordsIn leptin mutation patients, GH peaks and leptin levels showed the opposite pattern from controls.
Peptide
GHRP-6
Outcome
IncreaseGH peak and leptin in mutation patients
Study
n = 8
Outcome group
Growth hormone and IGF-1 · Endocrine and hormones
Source sentences
Summary
On the contrary, the GH peaks were negatively correlated with leptin levels in controls, but showed the opposite pattern in homo- and heterozygous patients.
2 context sentences(design, population, supporting numbers)
Summary · context
Three homozygous and 5 heterozygous patients with leptin gene mutations as well as 13 control subjects were studied.
Summary · context
In all subjects basal levels of leptin and GH values stimulated by the combined administration of GHRH plus GH-releasing peptide-6 (GHRP-6) were analyzed.
In this study, GHRP-6 was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking GHRP-6.
Report a problemFND-1251987007

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.

Version 2Current
21 Oct 2026, 15:58 UTC
Study results updated
Version 1
9 Oct 2026, 03:13 UTC
First added · source update from Europe PMC

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