In vivo insulin sensitivity and insulin binding to erythrocytes in children

Abstract

The aim of this study was to determine whether RBC insulin receptor assay represents an useful means for assessment of the clinical sensitivity of insulin. Steady State Plasma Glucose(SSPG) was established by constant infusion of somatostatin (125μg loading followed by 125μg/m2/hr), glucose(6mg/kg/min) and insulin(0.8 mU/kg/min). Insulin binding to RBC receptors was measured and compared with SSPG. Insulin binding to RBC was assayed by the modified method of Gambhir. Plasma insulin area was measured by GTT. A decreased specific insulin binding(SB) to RBC, due to reduced receptor concentrations was observed in hyperinsulinemic obese children. In 21 children with various body weights, SB was inversely related to fasting plasma insulin level (r=-0.651, p<0.01) and also with plasma insulin area (r=-0.547, p<0.01). A highly significant inversed correlation was noted between SSPG and SB(r=-0.807, p<0.005). SSPG was, also, correlated with the fasting plasma insulin level(r=0.669, p<0.05). It was concluded that RBC insulin receptor is an useful tool for clinical evaluation of tissue insulin sensitivity.