Primary objective: The study evaluated the accuracy of body mass index (BMI) in detecting hyperinsulinaemia during oral glucose tolerance testing (OGTT) in severely obese children. Research design: A cross-sectional study was carried out. Materials and methods: A total of 118 obese children and adolescents (49 females and 69 males) aged 6-19 years were consecutively studied at an outpatient paediatric clinic. Hyperinsulinaemia was defined as a value of log-transformed fasting insulin greater than or equal to80th percentile and OGTT hyperinsulinaemia as a value of the log-transformed area under the curve (AUC) of insulin greater than or equal to80th percentile. The study hypothesis was tested using a logistic regression model with hyperinsulinaemia as the outcome variable and the z-score of BMI corrected for age (z-BMIage) as the predictor variable. Receiver-operator characteristic (ROC) curves were used to evaluate accuracy. Results: The mean (SD) BMI for age of the children was 28.6 (4.0) kg m(-2), corresponding to 2.2 (0.5) standard deviation scores. The odds ratio (OR) of OGTT hyperinsulinaemia was 2.0 (95% CI 1.2-3.3; p = 0.007) for each unit increase of z-BMIage and the corresponding ROC-AUC was 0.74 (95% CI 0.61-0.86; p = 0.0001). In comparison, the OR of fasting hyperinsulinaemia was 1.1 (95% CI 0.7-1.7; p = 0.716) for each unit increase of z-BMIage and the corresponding ROC-AUC was 0.49 (95% CI 0.35-0.62; p = 0.863). Conclusion: BMI is reasonably accurate in detecting OGTT hyperinsulinaemia in severely obese children.
Relationship between body mass index and insulin measured during oral glucose tolerance testing in severely obese children and adolescents / Iughetti, Lorenzo; De Simone, M; Bernasconi, Sergio; Predieri, Barbara; Battistini, Nino Carlo; Bedogni, G.. - In: ANNALS OF HUMAN BIOLOGY. - ISSN 0301-4460. - STAMPA. - 31:(2004), pp. 196-201. [10.1080/03014460310001652266]