Question about Insulinoma and Interpretation of Fasting Test Results

[Oregano]

Hi, I am not a diabetic and I'm unlikely to become one, but I have a question for the team that is probably relevant to those with knowledge of the pancreas and managing blood-glucose.

I have a genetic predisposition for insulinoma through MEN Type 1, which can result in hypoglycemia.  I have had hyperparathyroidism but my Calcium levels are now stable (post surgery).  I am asymptomatic but I get regular tests for a number of endocrine conditions.  Recently, I have begun getting raised proinsulin levels after a 12 hour fast.  How should I interpret that?  I can't find a lot of information on this.  My recent results are as follows:

May 2005
Glucose 5.5
Insulin 68
Proinsulin 50.9

August 2005
Glucose 4.4
Insulin 24
Proinsulin 43.1

I will have another 12 hour test in a month's time.  My understanding is that proinsulin levels should be well below that of insulin.  My Glucose and Insulin levels fit in the normal range.  What is the normal range for Proinsulin?  I have no C-peptide results to report as that doesn't seem to be measured by the lab.

thanks,

[JDRF-Team-ES]

Sorry, I have no clue.  If anyone else out there knows something about this, please respond. This does sound like a question for a medical expert, not a mere diabetes veteran like me.  I would think that the doctor who administered this test could give you a lot more information. Good luck to you!
ES