ARUP's Laboratory Test Directory

Proinsulin/Insulin Ratio : 0070256

Mnemonic: PRO INS

Ordering Recommendation: Aids in the detection of insulinoma. Do not use to diagnose diabetes mellitus.
Methodology: Quantitative Chemiluminescent Immunoassay/Quantitative Enzyme-Linked Immunosorbent Assay
Performed: Refer to individual components
Reported: 1-6 days
Specimen Required: Patient Prep: Patient must be fast for 12-15 hours prior to collection.

Collect: Serum separator tube. Also acceptable: Lavender (EDTA) or pink (K2EDTA).

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

Storage/Transport Temperature: Frozen.

Unacceptable Conditions: Heparinized plasma. Vitreous or I.V. fluids.

Stability (collection to initiation of testing): After separation from cells: Ambient: Unacceptable; Refrigerated: 1 week; Frozen: 3 months (avoid repeated freeze/thaw cycles)
Reference Interval:
 
Test Number Components Reference Interval
0070063Insulin, Fasting 3-19 µIU/mL
0070112Proinsulin Effective August 15, 2011
 
0-1 year Not established
2 years and older Less than or equal to 26.8 pmol/L
 Proinsulin/Insulin Ratio CalculationProinsulin/Insulin Ratio as %:
  Normal fasting adults: 3.4-21
  Normal fasting children: 6.4-16

Interpretive Data: 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 (< 3 percent). To convert to pmol/L, multiply µIU/mL by 6.0.
CPT Code(s): 84206; 83525