OBJECTIVES: I. Compare growth hormone (GH) levels at baseline and after glucose suppression
measured with both a polyclonal radioimmunoassay and a highly sensitive immunoradiometric
assay (IRMA) in patients with acromegaly and normal volunteers.
II. Measure the levels of IGF-I and its binding protein, IGFBP-3, in these cohorts.
III. Determine any correlation between levels of IGF-I and IGFBP-3 and GH suppressibility
as assessed by sensitive IRMA.
IV. Determine if patients who demonstrate biochemical features of mild GH excess are at
risk for progression to active disease.
PROTOCOL OUTLINE: Blood samples are collected and assessed for growth hormone and IGF-I by
polyclonal radioimmunoassay (RIA) and immunoradiometric assay (IRMA). Growth hormone is
measured at baseline and 60, 90, and 120 minutes after a 100 g glucose drink. Serum glucose
is measured at baseline and at 2 hours post dextrose administration by the glucose
Clinical scores are determined for headache, perspiration, fatigue, joint pain, and acne.
Exams and tests may be repeated every 6 months for 2 years.
PROTOCOL ENTRY CRITERIA:
Diagnosis of acromegaly and treated with transsphenoidal surgery
Biochemically and histologically confirmed growth hormone secreting tumor
- See Disease Characteristics
- Greater than 6 months since prior surgery
Other: At least 1 month since prior bromocriptine or octreotide
Performance status: Ambulatory
Hepatic: No active hepatic disease
Renal: No active renal disease
- No diabetes mellitus
- No glucose intolerance
- Hypopituitarism allowed if on stable doses of replacement therapy