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Updated: Jul 14, 2026
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Improving IV Insulin Administration in a Community Hospital
Published on: June 11, 2012
Glycated hemoglobin in insulinoma.
A A Hassoun1, F J Service, A P O'Brien
1Division of Endocrinology, Metabolism, Nutrition, and Internal Medicine, Mayo Clinic and Mayo Foundation, Rochester, Minnesota 55905, USA.
Summary
Preoperative glycated hemoglobin (GHb) levels were significantly lower in patients with functioning insulinoma compared to controls. While not diagnostic, GHb values below 4.1% strongly suggest insulinoma in patients with suspected hypoglycemia.
Area of Science:
- Endocrinology
- Clinical Chemistry
Background:
- Functioning insulinoma is a rare tumor causing hypoglycemia.
- Glycated hemoglobin (GHb) reflects average blood glucose over weeks.
- Assessing preoperative GHb may aid in insulinoma diagnosis.
Purpose of the Study:
- To investigate if preoperative glycated hemoglobin (GHb) levels are lower in functioning insulinoma patients.
- To determine if GHb levels can differentiate insulinoma patients from controls.
Main Methods:
- Retrospective analysis of preoperative GHb (Hemoglobin A1, HbA1) in 64 insulinoma patients and 38 controls.
- HbA1 measured using the Isolab Glyc-Affin Test System.
- Control subjects underwent a 72-hour supervised fast to exclude hypoglycemia.
Main Results:
- Insulinoma patients had significantly lower median HbA1 (4.7%) than controls (5.3%) (P<0.001).
- 25% of insulinoma patients had HbA1 below the lowest control value (4.1%).
- Diazoxide treatment did not significantly alter HbA1 levels in insulinoma patients.
Conclusions:
- No single GHb value is diagnostic for insulinoma due to overlapping ranges.
- Preoperative HbA1 values below 4.1% are highly suggestive of insulinoma.
- Lowered GHb may serve as a supportive indicator for insulinoma diagnosis.
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