Indexes of insulin resistance using the oral glucose tolerance test (O-GTT) in Japanese children and adolescents

An oral glucose tolerance test (O-GTT) was conducted in 96 non-obese healthy children (7 to approximately 11 years old) and adolescents (12 to approximately 16 years old) to obtain the index of insulin resistance from the insulin (IRI) and C-peptide (CPR) values of fasting. 2-hour postload conditions and the sigma values, and the homeostasis model assessment ratio (HOMA-R) by assuming the value of the mean + 2SD to be the upper limit of the normal value for each clinical variable. The results show that the adolescents, whose insulin resistance is thought to increase, showed higher IRI and CPR values of the 2-hour postload condition and sigma values compared to those of the children, but there were no differences between the 2 age groups in the values of the fasting condition, as well as in the HOMA-R values which were calculated from the fasting values. These findings indicate that there is a limitation in using fasting values to judge insulin resistance. Instead, using the 2-hour postload values and/or the sigma values is more appropriate.

Criteria for medical intervention in obese children: a new definition of 'obesity disease' in Japanese children

The Committee of the Japan Society for the Study of Obesity reported the new criteria for 'obesity disease' for Japanese adults in 2000. We defined the criteria for the diagnosis of obesity in children with medical problems, corresponding to the 'obesity disease' criteria in adults. Obesity in childhood was defined as follows: percentage of overweight (POW) and body fat exceeded the criteria. 'Obesity disease in childhood' was defined as obesity associated with health or medical problems, and with indications for medical intervention. Medical problems with indications for immediate intervention were grouped as A problems, which consisted of (i). hypertension; (ii). sleep apnea or hypoventilation; (iii). Type 2 diabetes mellitus or impaired glucose tolerance; and (iv). increased waist circumference or accumulation of visceral adipose tissue. Metabolic derangements or equivalent associated with obesity were grouped as B problems: (i). liver dysfunction; (ii). hyperinsulinemia; (iii). hypercholesterolemia; (iv). hypertriglyceridemia; (v). low serum high-density lipoprotein cholesterol; (vi). acanthosis nigricans, and (vii). hyperuricemia. Obese children over 5 years of age with following conditions were diagnosed as 'obesity disease in childhood': (i). any 'A problem', (ii) POW >or= 50% and any 'B problem', or (3) POW < 50% and more than one 'B problem' or equivalent. We decided to take physicosocial problems related to obesity into consideration as the criteria. The resultant criteria are proposed by the Committee for Research of Appropriate Body Build in Children*.