Acta Paediatrica 23. (1982)
2. szám - D. Molnár-M. Kardos-G. Soltész-S. Baranyai: Intravenous glucose tolerance test in childhood obesity
Acta Paediatrica Academiae Scientiarum Hungaricae, Vol. 23 (2), pp. 127 — 135 ( 1982) Intravenous glucose tolerance test in childhood obesity: Metabolite levels and their relation to glucose utilization rate (Kg)* D. Molnár, Maria Kardos, G. Soltész, Susan Baranyai Department of Paediatrics, University Medical School, Pécs Intravenous glucose tolerance tests were performed in 33 obese and 12 nonobese children. In addition to the glucose disappearance rate the changes in response to the glucose load in plasma insulin, FFA, glycerol, cholesterol, triglyceride, lactate and pyruvate were examined. The relationship between biochemical parameters and the glucose disappearance rate was also studied. 1. Reduced glucose tolerance, basal and glucose-induced hyperinsulinaemia were frequent in the obese children. 2. Normal or reduced glucose tolerance in spite of the apparent hyperinsulinaemia and the negative correlation between fasting insulin level and KQ in the nonhypertriglyceridaemic obese group was the marker of insulin resistance in overweight children. 3. The reduced elevation of FFA in the 2nd hour of the intravenous glucose tolerance test might be the sign of an impaired lipolysis in obesity. 4. The significant negative correlation found between KG, fasting FFA and triglyceride levels in certain obese subgroups suggested the importance of FFA and triglyceride in the regulation of peripheral glucose utilization. Obesity is characterized by basal and reactive hyperinsulinaemia (3, 8-10, 26, 27). In spite of the increased insulin secretion, abnormalities in glucose metabolism and increased frequency of impaired glucose tolerance have been observed in obese children (3, 13, 20, 24, 36) and adults (29, 34), but normal results have also been found (6, 15, 35). In the present study the changes of plasma glucose, insulin, FFA, glycerol, cholesterol, triglyceride, lactate and pyruvate were measured during a standard intravenous glucose tolerance test (IVGTT). The rate of disappearance of glucose (Kq) was calculated and the relationship between biochemical parameters and Kq was also studied. The correlation between anthropometric parameters and Kq has been described previously (23). Materials and Methods Investigations were carried out in 12 non-obese and 33 obese children weighing more than 20% in excess of their ideal body weight as given in the tables of Maaser (21). In cases with height exceeding 100 cm the ideal body weight was calculated according to the formula: (height — 100)x0.9. The anthropometric * Supported by the Scientific Research Council, Hungarian Ministry of Health. Acta Paediatrica Academiae Scientiarum Hungaricae 23, 1082