Last updated on July 2019

Growth Hormone Feedback to Insulin-like Growth Factor-I (IGF-1) and Oral Glucose Tolerance Test (OGTT)


Are you eligible to participate in this study?

You may be eligible for this study if you meet the following criteria:

  • Conditions: Acromegaly | Type 2 Diabetes Mellitus
  • Age: Between 18 - 100 Years
  • Gender: Male or Female
  • Other:
    Active acromegaly due to excess GH produced by a pituitary adenoma.
    Patients must have an elevated IGF-I compared to age and gender matched controls (as
    upplied by the laboratory) and fail to suppress GH to below 1 ng/ml after a standard
    75g oral glucose tolerance test.
    Type 2 diabetes mellitus, defined by elevated fasting glucose ≥ 126 mg/dl (verified
    by two historical measurements), or plasma glucose ≥ 200 mg/dl two hours after a 75 g
    oral glucose load, or a random glucose ≥ 200 mg/dl.

You may not be eligible for this study if the following are true:

  • Acromegaly Group
    Current medical therapy for acromegaly including dopamine agonists, somatostatin
    analogues, or growth hormone antagonists.
    For subjects on current therapy the following washout periods may be used:
    Cabergoline: 4 weeks
    Bromocriptine: 1 week
    Sandostatin LAR: 3 months
    Short-acting octreotide: 1 week
    Lanreotide: 3 months
    Pegvisomant: 4 weeks
    Subjects with a history of surgical therapy for treatment of acromegaly must
    have verification of active disease with verified elevated IGF-I for the
    ubjects' age and gender compared to healthy controls (as supplied by the
    laboratory) (two measures) as well as a failure to suppress GH to below 1 ng/ml
    after OGTT.
    Current treatment for insulin resistance or type 2 DM including oral or
    injection medications.
    Fasting glucose ≥ 126 mg/dl at screening evaluation.
    Evidence of hepatic or renal disease defined as elevated transaminases, elevated
    erum creatinine.
    Pregnancy or breast feeding.
    Type 2 diabetes mellitus group
    Patients taking non-insulin medications for diabetes treatment will be excluded.
    Diagnosis of acromegaly.
    Evidence of hepatic or renal disease defined as elevated transaminases, elevated
    erum creatinine.
    Pregnancy or breast feeding.
    Healthy Control Group
    History of diabetes mellitus or impaired glucose tolerance, history of
    acromegaly.
    Fasting glucose ≥ 126 mg/dl at screening evaluation.
    Evidence of hepatic or renal disease defined as elevated transaminases, elevated
    erum creatinine.
    Pregnancy or breast feeding.

Recruitment Status: Closed


Brief Description Eligibility Contact Research Team


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