Blood levels of true insulin and immunoreactive insulin in evaluating beta-cell function with arginine stimulation test.
- Author:
Xiao-jing MA
1
;
Wei-ping JIA
;
Jian ZHOU
;
Hui-juan LU
;
Jun-qian LU
;
Song-hua WU
Author Information
- Publication Type:Journal Article
- MeSH: Adult; Aged; Arginine; pharmacology; Blood Glucose; metabolism; Diabetes Mellitus, Type 2; blood; Female; Glucose Tolerance Test; Humans; Insulin; blood; immunology; Insulin Resistance; Insulin-Secreting Cells; physiology; Male; Middle Aged; Proinsulin; blood
- From: Journal of Zhejiang University. Medical sciences 2006;35(3):255-259
- CountryChina
- Language:Chinese
-
Abstract:
OBJECTIVETo investigate the difference between serum true insulin (TI) and immunoreactive insulin (IRI) in evaluating islet beta-cell function and insulin resistance.
METHODSThe arginine stimulation test was performed in 141 individuals, including 35 with normal glucose tolerance (NGT) and 106 with type 2 diabetes (T2DM). Plasma glucose (PG), TI, IRI and proinsulin (PI) levels were measured; the incremental value of TI/PG, (TI+PI)/PG and IRI/PG (delta TI/PG, delta(TI+PI)/PG and deltaIRI/PG) and the area under curve of TI/PG, (TI+PI)/PG and IRI/PG (AUC [TI/PG], AUC[(TI+PI)/PG] and AUC [IRI/PG]) after arginine stimulation were calculated to evaluate beta-cell function.
RESULTThere were positive correlations of delta TI/PG with delta (TI+PI)/PG and delta IRI/PG in both NGT and T2DM patients (r=0.68 - 0.99, P<0.01). The similar correlations of AUC [TI/PG] with AUC [(TI+PI)/PG] and AUC [IRI/PG] were also shown (r=0.62 - 0.99, P<0.01). delta TI/PG was correlated with AUC [TI/PG] in two groups (NGT r=0.96, T2DM r=0.82, P<0.01). HOMA-IRTI, HOMA-IR(TI+PI) and HOMA-IRIRI in T2DM were higher than those in NGT (P<0.01). After arginine stimulation T2DM subjects mainly presented insulin resistance and decreased insulin secretion.
CONCLUSIONThe determination of TI may be more accurate than IRI in evaluating beta-cell function and insulin resistance.
