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Glucagon test in insulinoma: Is it useful?
J S Felício1, C L L P Martins, K B Mileo
1Endocrinology Division, Brigadeiro Hospital, São Paulo, Brazil.
Journal of Endocrinological Investigation
|July 28, 2011
Summary
Diagnosing insulinoma involves confirming hypoglycemia with elevated insulin. A glucagon test showing glucose below 55 mg/dl at 120 minutes strongly supports an insulinoma diagnosis.
Area of Science:
- Endocrinology
- Metabolic Disorders
Background:
- Endogenous hyperinsulinism is diagnosed by correlating hypoglycemia symptoms with elevated insulin levels.
- Insulinoma patients often exhibit an exaggerated insulin response and subsequent hypoglycemia post-glucagon injection.
Purpose of the Study:
- To evaluate the diagnostic utility of the glucagon test in identifying insulinoma.
- To determine specific glucose level thresholds indicative of insulinoma during the glucagon test.
Main Methods:
- The glucagon test (1 mg IV) was administered to 11 patients with insulinoma pre-therapy and 4 post-therapy.
- Plasma glucose levels were monitored at timed intervals post-injection.
Main Results:
- A plasma glucose level below 55 mg/dl at the 120-minute mark of the glucagon test was observed.
- This specific glucose nadir strongly correlated with the presence of insulinoma.
Conclusions:
- The glucagon test is a valuable tool for diagnosing insulinoma.
- A post-glucagon glucose level <55 mg/dl at 120 minutes significantly enhances insulinoma diagnosis.
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