Islet Cell Dysfunction Group 1

CPT: 83525; 84206
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Test Details


  • Proinsulin:Insulin Ratio


The proinsulin:insulin ratio may be useful in managing type 2 diabetic patients. High basal proinsulin:insulin ratio in noninsulin-dependent diabetic patients may predict acute beta-cell dysfunction.


Prolonged IV glucose challenges in normal and obese subjects can produce significant increases in proinsulin:insulin ratios. Plasma/serum must be frozen due to the lability of insulin.


Immunochemiluminometric assay (ICMA)

Specimen Requirements


Serum (preferred) or plasma, frozen


1 mL

Minimum Volume

0.6 mL (Note: This volume does not allow for repeat testing.)


Red-top tube, gel-barrier tube, lavender-top (EDTA) tube, or green-top (heparin) tube

Patient Preparation

Under various protocols, the patient may be fasting and drawn, or fasting and drawn after a glucose load.


Separate serum or plasma from cells within 45 minute of collection. Send serum or plasma in a plastic transport tube. To avoid delays in turnaround time when requesting multiple tests on frozen samples, please submit separate frozen specimens for each test requested.

Storage Instructions

Freeze; stable for 200 days. Stable at room temperature for six hours or refrigerated for 24 hours.

Causes for Rejection

Quantity not sufficient for analysis

Clinical Information


Davis SN, Piatti PM, Monti L, et al. Proinsulin and insulin concentrations following intravenous glucose challenges in normal, obese, and noninsulin-dependent diabetic subjects. Metabolism. 1993 Jan; 42(1):30-35. 8446045
Roder ME, Porte D Jr, Schwartz RS, Kahn SE. Disproportionately elevated proinsulin levels reflect the degree of impaired B cell secretory capacity in patients with noninsulin-dependent diabetes mellitus. J Clin Endocrinol Metab. 1998 Feb; 83(2):604-608. 9467581


Order Code Order Code Name Order Loinc Result Code Result Code Name UofM Result LOINC
500757 Islet Cell Dysfunction Group 1 500755 Proinsulin ICMA, Endo Sci pmol/L 27882-0
500757 Islet Cell Dysfunction Group 1 503065 Insulin uIU/mL 20448-7
500757 Islet Cell Dysfunction Group 1 500753 Proinsulin as Percent % 45338-1

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