Study of Thyrotropin-Releasing Hormone in Normal Volunteers and in Patients With Thyroid or Pituitary Abnormalities
Condition: Healthy; Pituitary Disease; Thyroid Disease
MeSH terms: Pituitary Diseases; Thyroid Diseases
Intervention: TRH (Thyrotropin Releasing Hormone)
Intervention MeSH terms: Hormones; Thyrotropin-Releasing Hormone
Phase: Phase 2
Study type: Interventional
Primary purpose: Diagnostic
Intervention model: Single Group Assignment
Masking: None (Open Label)
Enrollment: 96.0
Sex: All
Minimum age: 2 Years
Healthy volunteers: No
Keywords: Hypothalamic Releasing Factor; Neuropeptide; Diagnostic Testing; Pituitary Tumors; Central Hypothyroidism; Pituitary Disorder; Thyroid Disorder; Healthy Volunteer

Summary:

      This study will determine the safety and activity of a new formulation of
      thyrotropin-releasing hormone (TRH), a drug used for diagnosing and evaluating patients with
      certain thyroid gland abnormalities. Normal thyroid gland function depends on proper chemical
      signaling between the thyroid gland, the hypothalamus (the part of the brain where TRH is
      made), and the pituitary (another part of the brain). The TRH test helps assess this
      interaction. Production of the only FDA-approved preparation of TRH was stopped in July 2002.
      As a result, to have a continuous source of TRH available for NIH clinical and research
      purposes, the NIH Clinical Center (CC) Pharmacy Department produced a pharmaceutical grade
      formulation of TRH for patient use. This study will test the CC formulation in healthy
      volunteers to show that its activity and side effects are similar to those of the previously
      available commercial test preparation. It will then be studied in CC patients for whom the
      diagnostic test is recommended.

      Healthy volunteers between 18 and 65 years of age and all patients requiring TRH evaluation
      of hypothalamic-pituitary-thyroid gland interaction may be eligible for this study. Patients
      include those with pituitary reserve, inconsistent thyroid function test, inappropriate TSH
      secretion, or pre- and post-operative evaluation of pituitary tumors. Normal volunteers will
      be screened with a medical history, physical examination, and blood tests. Women of
      child-bearing potential will be given a pregnancy test; pregnant and breast-feeding women may
      not participate.

      The TRH test procedure will be the same for healthy volunteers and patients. All participants
      fast from midnight before the morning of the test. In the morning, a catheter (flexible
      plastic tube) is inserted into an arm vein for easy injection of the TRH and collection of
      blood samples. Blood pressure is monitored before and during the test. A blood sample is
      drawn, and then TRH is given through the catheter over a 1-minute period. Another nine blood
      samples are collected over a 3-hour period from the time of the TRH injection for measuring
      levels of various hormones. A total of less than 4 tablespoons of blood is taken for the
      test.
    

Eligibility criteria:

        -  DIAGNOSTIC STUDY PROTOCOL

        Inclusion Criteria:

        -All adults and children requiring dynamic testing of the hypothalamic-pituitary axis for
        the evaluation of pituitary reserve, inconsistent thyroid function test, inappropriate TSH
        secretion, or pre-and post-operative evaluation of pituitary adenomas (glycoprotein hormone
        secreting tumors, growth hormone secreting tumors and TSH secreting tumors).

        Exclusion Criteria:

          -  Uncontrolled hypertension;

          -  Uncontrolled seizure disorder;

          -  Unstable coronary disease;

          -  Known allergy to TRH.

        RESEARCH PROTOCOLS

        -TRH is available for use in other IRB approved research protocols either using the
        standard diagnostic testing protocol or the modified TRH test.

        Exclusion Criteria:

          -  Untreated hypertension;

          -  Coronary artery disease;

          -  History of asthma;

          -  History of seizures;

          -  Pregnancy;

          -  Known allergy to TRH.