Overview
- Serial blood glucose measurement gives much better assessment of pattern of glycemic control than a 'spot' sample.
- Allows confirmation of time of peak insulin activity and duration of insulin effect.
- Ideally sample at 1-2 hourly intervals.
Uses
Alone
- Diabetic cases: assess insulin
responsiveness, peak activity, duration and extent of glycemic control over 12-24 hour period. - Stabilization of diabetic cases.
- Best used early in therapy to allow optimization of feeding and insulin administration.
- Very helpful where glycemic control deteriorating.
- Diagnosis of insulinoma .
Other points
- Test of choice for identification of the 'Somogyi phenomenon' (insulin-induced hypoglycemia inducing a rebound hyperglycemia).
Result data
Abnormal values
- Diabetes mellitus :
- Persistent hyperglycemia → inadequate insulin dose/insulin antagonism.
- Initial rapid hypoglycemia followed by compensatory hyperglycemia (Somogyi overswing) → insulin overdose.
- Initial stabilization of glucose levels then evening hyperglycemia → inadequate duration of insulin action.
- Islet cell tumor: persistent hypoglycemia .
