Overview
- Plasma concentrations of glucose
and insulin are usually tightly linked. - Alterations in [glucose] result in rapid alteration of [insulin] to bring [glucose] back to normal range.
Uses
Alone
- A diagnosis of insulinoma is supported by demonstration of abnormally high insulin levels in the presence of hypoglycemia.
Result data
Normal (reference) values
- A direct insulin:glucose ration is calculated by dividing the [insulin] by [glucose].
- Insulin:glucose ratio (IGR) = insulin (uU/ml) x 100/glucose (mg/dl).
Glucose in mg/dl = mmol/l at 0.0555 - Amended insulin:glucose ratios have been recommended since they allow for the fact that serum insulin is undetectable in animals with normal blood glucose concentrations.
- Other studies have suggested that amended ratios are less accurate than direct ratios.
- Amended I:G ratio = (serum insulin uU/ml x 100)/(serum glucose mg/dl -30).
Abnormal values
- IGR >30 → Insulinoma .
Sources
Publications
Refereed papers
- Dunn J K, Heath M F, Herrtage M E, Jackson K F & Walker M J (1992) Clinical diagnosis of insulinoma in the dog; a study of 11 cases. JSAP 33 , 514-520.
- Edwards D F (1986) Is it time to unamend the insulin glucose ratio? JAVMA, 951-953.
- Knowlen G C & Schall W D (1984) The amended insulin glucose ration is it really better? JAVMA 185 , 397-399.
