[Glucose tolerance test in morbidly obese children and adolescents]

Oral glucose tolerance tests (50 g/m2 body surface) were performed in fifty-two children and adolescents (28 girls and 24 boys) aged 3.1 to 16.8 (mean +/- SD 11.4 +/- 3.28) years. Mean overweight of the patients was calculated to be 69.7 +/- 28.5%. Plasma glucose and immunoreactive insulin were determined before, and 15, 30, 60, 90, 120 and 180 minutes after the oral glucose load. According to the criteria of the National Diabetes Data Group six (11.5%) of the subjects had abnormal glucose test profiles (fasting glucose concentrations over 140 mg/dl or after 120 minutes above 140 mg/dl), and in four of the six probands we could detect elevated fasting insulin levels (above 17 E/ml) as well. In twenty-three out of forty-eight serum samples (47.9%) basal insulin levels were elevated. No correlation between age, sex, duration of overweight with glucose or insulin levels could be found. Our results are in accordance with findings in obese adults reflecting a high prevalence of impaired glucose tolerance and hyperinsulinemia in obese children and adolescents. On the other hand pathophysiologic relevance and clinical importance of these findings in obese children of an impaired glucose tolerance and hyperinsulinemia is questionable in view of the rapid normalization after weight loss.