Effects of Growth Hormone on the Nitric Oxide Pathway

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00470002
Recruitment Status : Completed
First Posted : May 7, 2007
Last Update Posted : May 7, 2007
Information provided by:
Hannover Medical School

Brief Summary:
The purpose of the study is to determine whether the treatment with growth hormone has an influence on the nitric oxide pathway in healthy males.

Condition or disease Intervention/treatment Phase
Cardiovascular Disease Drug: Somatropin Phase 1

Detailed Description:

Nitric oxide (NO) is a potent endogenous vasodilator and has shown to inhibit key processes of atherosclerosis like monocyte adhesion, platelet aggregation, and vascular smooth muscle cell proliferation. Impaired endothelial NO production is a main feature of endothelial dysfunction, which by itself is an early step in the course of atherosclerotic vascular disease.

Recent studies could confirm this close association between parameters of the NO pathway and cardiovascular disease and could further enhance the knowledge on the pathophysiological mechanisms. There is a significant relationship between insulin resistance and the endogenous NO synthase inhibitor asymmetric dimethylarginine (ADMA). Moreover, evidence could be provided that plasma levels of ADMA are a strong and independent predictor of mortality and cardiovascular outcome in haemodialysis patients.

Patients with growth hormone deficiency are characterized by a 1.9 fold higher risk of death from cardiovascular disease. Again, there is good evidence, that alterations of the NO-pathway are involved in this increase of cardiovascular risk. A reduced endogenous systemic production of NO was found in patients with growth hormone deficiency, treatment with recombinant growth hormone normalized NO production. The effects of growth hormone on NO are possibly mediated by insulin-like growth factor-I (IGF-I), which stimulates NO synthesis in vitro. The onset of IGF-I increase in healthy volunteers treated with GH is evident after 12 h, the maximum effect takes place between 5 to 8 days. Also in adults with growth hormone deficiency, the major effects of growth hormone treatment on IGF-I levels are observed within 2 weeks. After discontinuation of growth hormone therapy, IGF-1 levels return to base line within 2-3 days.

The aim of the present study is to further elucidate the in vivo effects of GH on the NO pathway and NO mediated cardiovascular functions.

Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 16 participants
Allocation: Non-Randomized
Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Basic Science
Official Title: Effects of Growth Hormone (GH) on Parameters of the Nitric Oxide (NO) Pathway
Study Start Date : May 2004
Actual Study Completion Date : January 2005

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Hormones

Primary Outcome Measures :
  1. Urinary nitrate excretion [ Time Frame: 10 days ]

Secondary Outcome Measures :
  1. Insulin-like growth factor-1 in serum [ Time Frame: 10 days ]

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

Ages Eligible for Study:   50 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   Male
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Healthy male subjects without recent severe diseases
  • Age 50 yrs or older
  • Body mass index at or below 30 kg/m2
  • Insulin-like growth factor-1 level below 200 ng/ml
  • Evidence of a personally signed and dated informed consent document indicating that the subject has been informed of all pertinent aspects of the trial
  • Subjects that are willing and able to comply with scheduled visits, treatment plan, laboratory tests and other study procedures

Exclusion Criteria:

  • History of any severe hepatic, renal, cardiac, endocrine, metabolic, or malignant diseases
  • Requirement for medical drug treatment
  • Growth hormone treatment during the last 12 months
  • Drug dependence, alcohol or nicotine abuse
  • Other severe acute or chronic medical or psychiatric condition or laboratory abnormality that may increase the risk associated with study participation or may interfere with the interpretation of study results and, in the judgement of the investigator, would make the subject inappropriate for entry into this study.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00470002

Institute of Clinical Pharmacology, Hannover Medical School
Hannover, Lower Saxony, Germany, 30623
Sponsors and Collaborators
Hannover Medical School
Study Director: Dirk O Stichtenoth, MD Institute of Clinical Pharmacology, Hannover Medical School

Publications: Identifier: NCT00470002     History of Changes
Other Study ID Numbers: MES 03069
First Posted: May 7, 2007    Key Record Dates
Last Update Posted: May 7, 2007
Last Verified: May 2007

Keywords provided by Hannover Medical School:
growth hormone
nitric oxide
cyclic guanosine monophosphate
insulin-like growth factor-1
asymmetric dimethylarginine
blood pressure
endothelial progenitor cells

Additional relevant MeSH terms:
Cardiovascular Diseases
Nitric Oxide
Hormones, Hormone Substitutes, and Hormone Antagonists
Physiological Effects of Drugs
Bronchodilator Agents
Autonomic Agents
Peripheral Nervous System Agents
Anti-Asthmatic Agents
Respiratory System Agents
Free Radical Scavengers
Molecular Mechanisms of Pharmacological Action
Neurotransmitter Agents
Endothelium-Dependent Relaxing Factors
Vasodilator Agents
Protective Agents