Ordering Recommendation

Aids in the detection of insulinoma. Do not use to diagnose diabetes mellitus.

Mnemonic

PRO INS

Methodology

Quantitative Chemiluminescent Immunoassay/Quantitative Chemiluminescent Immunoassay

Performed

Refer to individual components

Reported

1-6 days

New York DOH Approval Status

This test is New York DOH approved.

Specimen Required

Patient Preparation

Patient must be fasting for 12-15 hours prior to collection.

Collect

Serum Separator Tube (SST).

Specimen Preparation

Separate from cells ASAP or within 2 hours of collection. Transfer 1 mL serum to an ARUP Standard Transport Tube and freeze immediately. (Min: 0.8 mL)

Storage/Transport Temperature

CRITICAL FROZEN. Separate specimens must be submitted when multiple tests are ordered.

Unacceptable Conditions

Heparinized plasma. Vitreous or I.V. fluids. Hemolyzed specimens.

Remarks
Stability

After separation from cells: Ambient: Unacceptable; Refrigerated: 48 hours; Frozen: 2 months (avoid repeated freeze/thaw cycles)

Reference Interval

Test Number
Components
Reference Interval
  Insulin, Fasting 3-25 µIU/mL
  Proinsulin, Intact
Age
pmol/L
0-17 year Not established
18 years and older Less than or equal to 8.0

  Proinsulin, Intact/Insulin Ratio Calc
Age
Ratio (%)
0-17 years Not established
18 years and older 0.8-21.7

Interpretive Data

Insulin, Fasting: This test reacts on a nearly equimolar basis with the analogs insulin aspart, insulin glargine, and insulin lispro. Insulin detemir exhibits approximately 50 percent cross-reactivity. Test reactivity with insulin glulisine is negligible (less than 3 percent). To convert to pmol/L, multiply µIU/mL by 6.0.

Proinsulin, Intact: Fasting intact proinsulin values above the reference interval indicate a possible insulin secreting pancreatic tumor (insulinoma) in patients with hypoglycemia. Fasting intact proinsulin values range from 3 to 50 pmol/L in patients with untreated type 2 diabetes.

Compliance Category

FDA

Note

Hotline History

N/A

CPT Codes

84206; 83525

Components

Component Test Code* Component Chart Name LOINC
0070063 Insulin, Fasting 27873-9
0070112 Proinsulin, Intact 10451-3
0070257 Proinsulin, Intact/Insulin Ratio Calc 45338-1
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.

Aliases

Proinsulin, Intact/Insulin Ratio