Plasma Glucose, Free Fatty Acids, and Immunoreactive Insulin in Sixty-six Obese Children: Studies in Reference to a Family History of Diabetes Mellitus

Abstract

Oral glucose tolerance tests (1.75 gm/kg ideal body weight) were performed on 66 obese children and adolescents, 4-16 years of age. Ten subjects of normal height and weight of the same age range and without a family history of diabetes served as controls. Plasma glucose, IRI and FFA levels were determined. Twenty-seven (45%) of the subjects had normal tolerance, fifteen (23%) had distinctly abnormal tolerance. Hyperinsulinemia was observed in nearly all the obese subjects, but it was significantly greater in those with abnormal tolerance than in those with normal tolerance. FFA fell rapidly after the ingestion of glucose in the majority of subjects. In some there was a delay in return to fasting levels. Thirty-four of the obese subjects had close diabetic relatives (diabetic family history [DHF +]) and 32 did not (DFH [long dash]). The incidence of moderately abnormal tolerance in the 2 groups, was the same but markedly abnormal tolerance was found only in the DFH + group. DFH + children had significantly greater elevations in insulin levels than DFH [long dash]children at both levels of tolerance. The DFH + subjects with severe hyperglycemia had somewhat increased levels of insulin occurring only after the 1st hour of the test. The hyperinsulinemia observed in the obese children in this study cannot be completely explained by compensatory overproduction due to peripheral resistance to insulin, and an alternate hypothesis is suggested.