Islet Cell Dysfunction Group 1 (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 I.V. 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.

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. PubMed 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. PubMed 9467581

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