Diagnosis of acromegaly in a patient with type 1 diabetes mellitus.

Abstract

OBJECTIVE:

To describe a case of acromegaly in a young patient with poorly controlled diabetes mellitus and suggest guidelines to distinguish acromegaly and high growth hormone (GH) levels previously reported in poorly controlled type 1 diabetes.

METHODS:

We present a detailed case report, including clinical findings and serial laboratory results in a patient with type 1 diabetes and a GH-secreting pituitary tumor.

RESULTS:

A 28-year-old woman with type 1 diabetes underwent assessment for secondary amenorrhea and worsening glycemic control. A low estradiol level and an inappropriately low level of follicle-stimulating hormone prompted magnetic resonance imaging of the head, which demonstrated a pituitary adenoma. Subsequent endocrine investigation revealed a high insulin-like growth factor I (IGF-I) level (849 mg/L; normal range, 122 to 400). The concentration of insulin-like growth factor-binding protein-3 (IGFBP-3) was also elevated (5.5 mg/L; normal range, 2.0 to 4.2). GH levels measured during episodes of spontaneous hyperglycemia (>180 mg/dL) were in the range of 3 to 5 ng/mL and failed to suppress to below 2 ng/mL after a bromocriptine suppression test. The patient underwent transsphenoidal resection of a pituitary tumor, which stained positively for GH by immunohistochemistry. Postoperatively, glycemic control improved, with decreased fluctuations of hypoglycemia and hyperglycemia, despite a decrease in insulin requirements.

CONCLUSION:

This report highlights the difficulty in interpreting GH and IGF-I levels in patients with type 1 diabetes. In addition, a detailed review of the literature suggests that IGFBP-3 measurements may be helpful in confirming the diagnosis of concurrent acromegaly and distinguishing it from high GH levels attributable to poor control of diabetes.

• Authors: Elisa A Hofmann, Kenneth S Polonsky, Roy E Weiss
• Journal: Endocrine practice : official journal of the American College of Endocrinology and the American Association of Clinical Endocrinologists (Endocr Pract) 2002 Mar-Apr Vol. 8 Issue 2 Pg. 113-8 ISSN: 1530-891X [Print] United States
• PMID: 11942776 (Publication Type: Case Reports, Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Insulin-Like Growth Factor Binding Protein 3
• Human Growth Hormone
• Estradiol
• Insulin-Like Growth Factor I
• Follicle Stimulating Hormone

Topics

• Acromegaly (complications, diagnosis)
• Adenoma (diagnosis, metabolism, surgery)
• Adult
• Diabetes Mellitus, Type 1 (complications)
• Estradiol (blood)
• Female
• Follicle Stimulating Hormone (blood)
• Glucose Tolerance Test
• Human Growth Hormone (metabolism)
• Humans
• Immunohistochemistry
• Insulin-Like Growth Factor Binding Protein 3 (blood)
• Insulin-Like Growth Factor I (analysis)
• Magnetic Resonance Imaging
• Pituitary Neoplasms (diagnosis, metabolism, surgery)