The relation between glucose tolerance and insulin binding to circulating monocytes in obese children.

The quantitative relation between insulin binding to circulating monocytes in vitro and glucose tolerance in obese children in vivo is reported. Sixty-one obese children and 11 healthy control children participated in this study. The oral glucose tolerance test (OGTT) was performed by giving them glucose (1.75 gm/kg of body weight), orally in the morning, and the binding of 125I-labeled insulin to circulating monocytes in vitro was measured prior to OGTT. The glucose tolerance expressed by sigma BS (milligrams/100 ml), the sum of the plasma glucose (blood sugar [BS]) values at OGTT, was significantly correlated with the degree of overweight (r = .316, P less than .01) and more highly with sigma IRI (microunits per milliliter), the sum of immunoreactive insulin (IRI) values at OGTT (r = .512, P less than .001). Insulin binding to monocytes in vitro (picograms/10(6) cells) was inversely correlated with the degree of overweight (r = -.687, P less than .001). Furthermore, sigma BS was inversely correlated significantly with insulin binding to monocytes in vitro (r = -.435, P less than .002). These data suggest that the decrease of insulin receptors might be one cause for the impairment of the glucose tolerance associated with obesity in children.