Growth hormone-releasing hormone effects on brain γ-aminobutyric acid levels in mild cognitive impairment and healthy aging.

Friedman SD, Baker LD, Borson S, Jensen JE, Barsness SM, Craft S, Merriam GR, Otto RK, Novotny EJ, Vitiello MV

JAMA neurology1 Jul 2013Cited by 47 (Europe PMC)

PMID23689947PMCIDPMC3764915DOI10.1001/jamaneurol.2013.1425PepBankPUB-23689947

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 study9

9 results from studies that gave the peptide. 9 results from people.

01HumanRandomized controlled trialMechanism
In adults with mild cognitive impairment and healthy older adults, 20 weeks of GHRH (tesamorelin) increased brain GABA levels in all measured regions.
In plain wordsIn older adults with and without mild cognitive impairment, 20 weeks of tesamorelin raised brain GABA levels in all regions measured.
Peptide
Tesamorelin
Outcome
IncreaseBrain GABA levels
Study
n = 30
Comparator
Placebo
Outcome group
Neuroprotection · Nervous system and cognition
Studied dose
1 mg/d · subcutaneous · 20 weeksAs given in this study (human).
Source sentences
Summary
After 20 weeks of GHRH administration, GABA levels were increased in all brain regions (P < .04)
2 context sentences(design, population, supporting numbers)
Summary · context
Thirty adults (17 with mild cognitive impairment [MCI]), ranging in age from 55 to 87 years, were enrolled and successfully completed the study.
Summary · context
Participants self-administered daily subcutaneous injections of tesamorelin (Theratechnologies Inc), a stabilized analogue of human GHRH (1 mg/d), or placebo 30 minutes before bedtime for 20 weeks.
Report a problemFND-2368994701
02HumanRandomized controlled trialMechanism
In adults with mild cognitive impairment and healthy older adults, 20 weeks of GHRH (tesamorelin) increased NAAG levels in the dorsolateral frontal cortex.
In plain wordsIn older adults with and without mild cognitive impairment, 20 weeks of tesamorelin raised NAAG levels in one frontal brain region.
Peptide
Tesamorelin
Outcome
IncreaseNAAG level in dorsolateral frontal cortex
Study
n = 30
Comparator
Placebo
Outcome group
Neuroprotection · Nervous system and cognition
Studied dose
1 mg/d · subcutaneous · 20 weeksAs given in this study (human).
Source sentences
Summary
NAAG levels were increased (P = .03) in the dorsolateral frontal cortex
2 context sentences(design, population, supporting numbers)
Summary · context
Thirty adults (17 with mild cognitive impairment [MCI]), ranging in age from 55 to 87 years, were enrolled and successfully completed the study.
Summary · context
Participants self-administered daily subcutaneous injections of tesamorelin (Theratechnologies Inc), a stabilized analogue of human GHRH (1 mg/d), or placebo 30 minutes before bedtime for 20 weeks.
Report a problemFND-2368994702
03HumanRandomized controlled trialMechanism
In adults with mild cognitive impairment and healthy older adults, 20 weeks of GHRH (tesamorelin) decreased myo-inositol levels in the posterior cingulate.
In plain wordsIn older adults with and without mild cognitive impairment, 20 weeks of tesamorelin lowered myo-inositol levels in one brain region.
Peptide
Tesamorelin
Outcome
DecreaseMyo-inositol level in posterior cingulate
Study
n = 30
Comparator
Placebo
Outcome group
Neuroprotection · Nervous system and cognition
Studied dose
1 mg/d · subcutaneous · 20 weeksAs given in this study (human).
Source sentences
Summary
and MI levels were decreased in the posterior cingulate (P = .002).
2 context sentences(design, population, supporting numbers)
Summary · context
Thirty adults (17 with mild cognitive impairment [MCI]), ranging in age from 55 to 87 years, were enrolled and successfully completed the study.
Summary · context
Participants self-administered daily subcutaneous injections of tesamorelin (Theratechnologies Inc), a stabilized analogue of human GHRH (1 mg/d), or placebo 30 minutes before bedtime for 20 weeks.
Report a problemFND-2368994703
04HumanRandomized controlled trialMechanism
In adults with mild cognitive impairment and healthy older adults, GHRH (tesamorelin) did not change brain glutamate levels.
In plain wordsIn older adults with and without mild cognitive impairment, tesamorelin did not change brain glutamate levels.
Peptide
Tesamorelin
Outcome
No significant changeBrain glutamate levels
Study
n = 30
Comparator
Placebo
Outcome group
Neuroprotection · Nervous system and cognition
Studied dose
1 mg/d · subcutaneous · 20 weeksAs given in this study (human).
Source sentences
Summary
No changes in the brain levels of glutamate were observed.
2 context sentences(design, population, supporting numbers)
Summary · context
Thirty adults (17 with mild cognitive impairment [MCI]), ranging in age from 55 to 87 years, were enrolled and successfully completed the study.
Summary · context
Participants self-administered daily subcutaneous injections of tesamorelin (Theratechnologies Inc), a stabilized analogue of human GHRH (1 mg/d), or placebo 30 minutes before bedtime for 20 weeks.
Report a problemFND-2368994704
05HumanRandomized controlled trialMechanism
In the posterior cingulate of adults with and without mild cognitive impairment given tesamorelin, treatment-related changes in serum IGF-1 correlated positively with changes in GABA.
In plain wordsIn older adults given tesamorelin, changes in IGF-1 were linked to changes in GABA in one brain region.
Peptide
Tesamorelin
Outcome
Not applicableCorrelation of IGF-1 change with GABA change in posterior cingulate
Study
n = 30
Outcome group
Neuroprotection · Nervous system and cognition
Studied dose
1 mg/d · subcutaneous · 20 weeksAs given in this study (human).
Measurements
Correlation r
0.47
IGF-1 vs GABA, posterior cingulate
Source sentences
Summary
In the posterior cingulate, treatment-related changes in serum insulin-like growth factor 1 were positively correlated with changes in GABA (r = 0.47; P = .001)
2 context sentences(design, population, supporting numbers)
Summary · context
Thirty adults (17 with mild cognitive impairment [MCI]), ranging in age from 55 to 87 years, were enrolled and successfully completed the study.
Summary · context
Participants self-administered daily subcutaneous injections of tesamorelin (Theratechnologies Inc), a stabilized analogue of human GHRH (1 mg/d), or placebo 30 minutes before bedtime for 20 weeks.
Report a problemFND-2368994705
06HumanRandomized controlled trialMechanism
In the posterior cingulate, treatment-related changes in serum IGF-1 tended to correlate negatively with myo-inositol, without reaching significance.
In plain wordsIn older adults given tesamorelin, IGF-1 rises tended to be linked to lower myo-inositol in one brain region, but this was not significant.
Peptide
Tesamorelin
Outcome
Not applicableCorrelation of IGF-1 change with myo-inositol change in posterior cingulate
Study
n = 30
Outcome group
Neuroprotection · Nervous system and cognition
Studied dose
1 mg/d · subcutaneous · 20 weeksAs given in this study (human).
Measurements
Correlation r
−0.34
IGF-1 vs MI, posterior cingulate
Source sentences
Summary
In the posterior cingulate, treatment-related changes in serum insulin-like growth factor 1 were positively correlated with changes in GABA (r = 0.47; P = .001) and tended to be negatively correlated with MI (r = -0.34; P = .06)
2 context sentences(design, population, supporting numbers)
Summary · context
Thirty adults (17 with mild cognitive impairment [MCI]), ranging in age from 55 to 87 years, were enrolled and successfully completed the study.
Summary · context
Participants self-administered daily subcutaneous injections of tesamorelin (Theratechnologies Inc), a stabilized analogue of human GHRH (1 mg/d), or placebo 30 minutes before bedtime for 20 weeks.
Report a problemFND-2368994706
07HumanRandomized controlled trialEfficacy outcome
In substudy participants, GHRH (tesamorelin) had a favorable effect on cognition compared with placebo.
In plain wordsIn older adults with and without mild cognitive impairment, tesamorelin had a favorable effect on thinking tests compared with placebo.
Peptide
Tesamorelin
Outcome
IncreaseCognition in substudy participants
Study
n = 30
Comparator
Placebo
Outcome group
Cognition and memory · Nervous system and cognition
Studied dose
1 mg/d · subcutaneous · 20 weeksAs given in this study (human).
Source sentences
Summary
Consistent with the results of the parent trial, a favorable treatment effect on cognition was observed in substudy participants (P = .03).
2 context sentences(design, population, supporting numbers)
Summary · context
Thirty adults (17 with mild cognitive impairment [MCI]), ranging in age from 55 to 87 years, were enrolled and successfully completed the study.
Summary · context
Participants self-administered daily subcutaneous injections of tesamorelin (Theratechnologies Inc), a stabilized analogue of human GHRH (1 mg/d), or placebo 30 minutes before bedtime for 20 weeks.
Report a problemFND-2368994707
08HumanRandomized controlled trialMechanism
No significant associations were found between treatment-related neurochemical changes and cognitive outcomes.
In plain wordsIn older adults given tesamorelin, brain chemical changes were not significantly linked to changes in thinking test results.
Peptide
Tesamorelin
Outcome
No significant changeAssociation of neurochemical changes with cognitive changes
Study
n = 30
Outcome group
Cognition and memory · Nervous system and cognition
Studied dose
1 mg/d · subcutaneous · 20 weeksAs given in this study (human).
Source sentences
Summary
No significant associations were observed between treatment-related changes in neurochemical and cognitive outcomes.
2 context sentences(design, population, supporting numbers)
Summary · context
Thirty adults (17 with mild cognitive impairment [MCI]), ranging in age from 55 to 87 years, were enrolled and successfully completed the study.
Summary · context
Participants self-administered daily subcutaneous injections of tesamorelin (Theratechnologies Inc), a stabilized analogue of human GHRH (1 mg/d), or placebo 30 minutes before bedtime for 20 weeks.
Report a problemFND-2368994708
09HumanRandomized controlled trialEfficacy outcome
Glucose homeostasis in the periphery was not reliably affected by GHRH (tesamorelin) administration.
In plain wordsIn older adults, tesamorelin did not reliably affect blood sugar control compared with placebo.
Peptide
Tesamorelin
Outcome
No significant changePeripheral glucose homeostasis
Study
n = 30
Comparator
Placebo
Outcome group
Glycemic control · Metabolic and weight
Studied dose
1 mg/d · subcutaneous · 20 weeksAs given in this study (human).
Source sentences
Summary
Glucose homeostasis in the periphery was not reliably affected by GHRH administration and did not account for treatment neurochemical effects.
3 context sentences(design, population, supporting numbers)
Summary · context
Participants also underwent glucose tolerance tests before and after intervention.
Summary · context
Thirty adults (17 with mild cognitive impairment [MCI]), ranging in age from 55 to 87 years, were enrolled and successfully completed the study.
Summary · context
Participants self-administered daily subcutaneous injections of tesamorelin (Theratechnologies Inc), a stabilized analogue of human GHRH (1 mg/d), or placebo 30 minutes before bedtime for 20 weeks.
Report a problemFND-2368994709

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

Registered trials1

Trials this study reports on, or that list this study as a reference. Registry data from ClinicalTrials.gov.

1 trial · 1 completed · source ClinicalTrials.gov (opens in a new tab)

CompletedPhase 2NCT00257712

SMART: Somatotrophics, Memory, and Aging Research Trial

University of Washingtonn = 151Feb 2006 to Dec 2011

Aging · Mild Cognitive Impairment

Trial page ClinicalTrials.govUpdated 19 Dec 2013

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
9 Oct 2026, 19:08 UTC
Study results updated
Version 1
9 Oct 2026, 03:13 UTC
First added · source update from Europe PMC

Subjects

Terms as the source lists them.

PepBank is a research reference. Talk to a doctor before you use any peptide.