As part of the diagnostic workup of suspected insulinoma; as part of the diagnostic workup of patients with suspected prohormone convertases1/3 deficiency; as part of the diagnostic workup of patients with suspected proinsulin mutations.
3.6 - 22 pmol/L
To avoid misdiagnoses, all proinsulin measurements used in the diagnostic workup of patients with hypoglycemia must be interpreted in the context of coexisting illnesses, blood glucose concentration at the time of sampling, and other tests, namely, insulin, c-peptide, beta-hydroxybutyrate measurements, and a sulfonylurea drug screen. Patients with chronic renal failure and type II diabetes mellitus can have increased proinsulin, c-peptide, and insulin values, but usually without suppressed (<45 mg/dL) blood glucose.
2 - 7 days
- PROINSULIN, PLASMA
Collect specimen in a chilled lavender top tube from a fasting patient. Chill the whole blood on ice for at least 10 minutes, spin down in a refrigerated centrifuge, aliquot plasma into a plastic vial and freeze. If specimen processing equipment is not available, the patient should have the specimen collected at a UM Medical Center Center Blood Drawing station.
If refrigerated centrifuge is not available, the patient should have the specimen collected at a UM Medical Center Center Blood Drawing station.
Fasting specimen. Collect in prechilled tube and place on ice immediately. Must arrive in lab or spin down in refrigerated centrifuge, aliquot, and freeze within 10 minutes of collection.
Test sent to Mayo Medical Laboratories.