Growth Hormone Administration and the Human Immune System
Condition: Healthy Volunteers
Study type: Interventional
Phase: Phase 1

Summary: 
      Background:

      - In elderly individuals, an age-associated decline in the immune system s ability to
      function is believed to contribute to increased incidence of infection, autoimmune disorders,
      and cancer. This decline in immune system function may be related to the decline in the body
      s production of growth hormone, which helps regulate human development and may contribute to
      the health of the immune system. Researchers are interested in studying whether growth
      hormone, given as an infusion over time, can improve the function of the immune system and
      other body systems associated with good health.

      Objectives:

      - To study the effects of growth hormone administration on the immune systems of healthy men.

      Eligibility:

      - Healthy men between 25 and 50 years of age.

      Design:

        -  This protocol will involve three separate studies: Study I, Study IB, and Study II.
           Participants in Study I and Study IB may participate in Study II as directed by the
           researchers.

        -  Participants will be screened with a full medical history and physical examination, and
           will provide blood, urine, and stool samples; have a glucose tolerance test; and have
           other tests as required by the researchers.

        -  Participants will have an infusion pump with a small catheter inserted beneath the skin
           to administer the study chemicals (either growth hormone or placebo).

        -  Study I and Study IB participants will receive pulses of growth hormone through the
           infusion pump at regular intervals to monitor the body s response to the hormone. Study
           IB participants will receive a higher dose of growth hormone than Study I participants.

        -  Throughout the study period, all participants will have frequent blood and urine tests,
           as well as tests of glucose tolerance and metabolism, imaging studies, and other tests
           as required by the researchers.

        -  Study II participants will be divided into two groups. The first group will receive
           pulses of either growth hormone or placebo infusion at intervals throughout the day for
           4 weeks, followed by an 8-week period without infusions. The second group will receive
           conventional once-a-day infusion of growth hormone or placebo for 4 weeks, followed by
           an 8-week period without infusions.

        -  Throughout the study period, all participants will have frequent blood and urine tests,
           as well as tests of glucose tolerance and metabolism, imaging studies, and other tests
           as required by the researchers.
    

Detailed description: 
      Objectives and Specific Aims:

      We plan to investigate whether growth hormone, administered in a physiological or pulsatile
      fashion, can elicit relevant changes in the human immune system while at the same time
      associated with no change or even an improvement in the metabolic profiles such as insulin
      sensitivity.

      Experimental Design and Methods:

      Thirty-eight healthy men, age 25-50, will be recruited for this study. There are three parts
      to this study: Study I, Study IB and Study II. Study I and IB each involve six subjects and
      are designed to test the hypothesis that pulsatile subcutaneous infusion of GH via a
      subcutaneous infusion pump will yield a reasonable pulsatile GH pattern. The dose of GH used
      in Study IB will be three-fold higher that that in Study I. Study I and IB will be done first
      before proceeding to Study II.

      Study II is a randomized, double-blinded, placebo-controlled 12-week study involving 26
      subjects divided into 2 groups: Group A and Group B. Group A will involve 13 subjects
      receiving pulsatile GH or placebo infusion for 4 weeks with 8-week washout after
      intervention. Group B will involve 13 subjects receiving conventional once a day subcutaneous
      infusion of GH or placebo for 4 weeks with 8-week washout after intervention.

      Medical Relevance and Expected Outcome:

      This study will ascertain the significance of the effect of pulsatile growth hormone
      administration on the human immune system and metabolic profile.
    

Intervention name(s): Norditropin; Placebo
Intervention type(s): Drug; Drug
Intervention description(s): Norditropin (somatropin, rDNA origin) is a polypeptide hormone of recombinant DNA origin. The amino acid sequence of the product is identical to that of the human growth hormone of pituitary origin.; 0.9% normal saline
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Investigator)
Primary purpose: Treatment
Keywords: Immune Function; Metabolism; Pulsatile Growth Hormone