Insulin levels can be useful predicting susceptibility to the development of type II diabetes, although C-peptide has largely supplanted insulin measurement for this role.1 The American Diabetes Association recommendations for the diagnosis of diabetes do not include the measurement of insulin levels.

Circulating antibodies to insulin, both autoantibodies and antibodies to therapeutic insulin, can interfere with the immunoassays for insulin.1,3 In the work-up of insulinoma, factitious hypoglycemia must be considered.1 C-peptide measurement is useful in this context. Since C-peptide is produced as the result of the cleavage of proinsulin in the β-cell, it is not found in pharmaceutical insulin. Thus, C-peptide levels are low with the surreptitious injection of insulin. C-peptide levels are increased when endogenous levels of insulin are elevated.

After placing an order, you will receive a doctor approved lab order by email usually within 20-30 minutes. The emailed Lab Requisition will allow you to go to a local patient collection site to get tested. You will not have to pay any additional lab, collection or doctor's fees.  Most test will normally report within 48-72 hours by secure email. List of collections site can be found using our Lab Locator Tool. If you have any questions please call our offices at 1-844-455-6355 or chat online with a member of our Care Team.