title: Relationship between body mass index and insulin measured during oral glucose tolerance testing in severely obese children and adolescents.
abstract: OBJECTIVE
  The study evaluated the accuracy of body mass index (BMI) in detecting hyperinsulinaemia during oral glucose tolerance testing (OGTT) in severely obese children.
  
  
  METHODS
  A cross-sectional study was carried out.
  
  
  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 >/= 80th percentile and OGTT hyperinsulinaemia as a value of the log-transformed area under the curve (AUC) of insulin >/= 80th 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-BMI(age)) 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-BMI(age) 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-BMI(age) and the corresponding ROC-AUC was 0.49 (95% CI 0.35-0.62; p = 0.863).
  
  
  CONCLUSIONS
  BMI is reasonably accurate in detecting OGTT hyperinsulinaemia in severely obese children.
authors.affiliation: Paediatrics Clinic, University of Modena and Reggio Emilia, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Iughetti
authors.forename: M
authors.initials: M
authors.lastname: De Simone
authors.forename: S
authors.initials: S
authors.lastname: Bernasconi
authors.forename: B
authors.initials: B
authors.lastname: Predieri
authors.forename: N
authors.initials: N
authors.lastname: Battistini
authors.forename: G
authors.initials: G
authors.lastname: Bedogni
mesh_terms: D000293:Adolescent; D000328:Adult; D001786:Blood Glucose / Q000032:analysis; D015992:Body Mass Index; D002648:Child; D005260:Female; D005951:Glucose Tolerance Test; D006801:Humans; D006946:Hyperinsulinism / Q000097:blood*; D008297:Male; D009765:Obesity / Q000097:blood*
chemical_list: D001786:Blood Glucose