title: Prevalence of impaired glucose tolerance among children and adolescents with marked obesity.
abstract: BACKGROUND
  Childhood obesity, epidemic in the United States, has been accompanied by an increase in the prevalence of type 2 diabetes among children and adolescents. We determined the prevalence of impaired glucose tolerance in a multiethnic cohort of 167 obese children and adolescents.
  
  
  METHODS
  All subjects underwent a two-hour oral glucose-tolerance test (1.75 g [DOSAGE ERROR CORRECTED] of glucose per kilogram of body weight), and glucose, insulin, and C-peptide levels were measured. Fasting levels of proinsulin were obtained, and the ratio of proinsulin to insulin was calculated. Insulin resistance was estimated by homeostatic model assessment, and beta-cell function was estimated by calculating the ratio between the changes in the insulin level and the glucose level during the first 30 minutes after the ingestion of glucose.
  
  
  RESULTS
  Impaired glucose tolerance was detected in 25 percent of the 55 obese children (4 to 10 years of age) and 21 percent of the 112 obese adolescents (11 to 18 years of age); silent type 2 diabetes was identified in 4 percent of the obese adolescents. Insulin and C-peptide levels were markedly elevated after the glucose-tolerance test in subjects with impaired glucose tolerance but not in adolescents with diabetes, who had a reduced ratio of the 30-minute change in the insulin level to the 30-minute change in the glucose level. After the body-mass index had been controlled for, insulin resistance was greater in the affected cohort and was the best predictor of impaired glucose tolerance.
  
  
  CONCLUSIONS
  Impaired glucose tolerance is highly prevalent among children and adolescents with severe obesity, irrespective of ethnic group. Impaired oral glucose tolerance was associated with insulin resistance while beta-cell function was still relatively preserved. Overt type 2 diabetes was linked to beta-cell failure.
authors.affiliation: Department of Pediatrics, Yale University School of Medicine, New Haven, Conn 06520, USA.
authors.forename: Ranjana
authors.initials: R
authors.lastname: Sinha
authors.forename: Gene
authors.initials: G
authors.lastname: Fisch
authors.forename: Barbara
authors.initials: B
authors.lastname: Teague
authors.forename: William V
authors.initials: WV
authors.lastname: Tamborlane
authors.forename: Bruna
authors.initials: B
authors.lastname: Banyas
authors.forename: Karin
authors.initials: K
authors.lastname: Allen
authors.forename: Mary
authors.initials: M
authors.lastname: Savoye
authors.forename: Vera
authors.initials: V
authors.lastname: Rieger
authors.forename: Sara
authors.initials: S
authors.lastname: Taksali
authors.forename: Gina
authors.initials: G
authors.lastname: Barbetta
authors.forename: Robert S
authors.initials: RS
authors.lastname: Sherwin
authors.forename: Sonia
authors.initials: S
authors.lastname: Caprio
mesh_terms: D000293:Adolescent; D044383:Black People; D001786:Blood Glucose / Q000378:metabolism; D002096:C-Peptide / Q000097:blood; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D003920:Diabetes Mellitus / Q000453:epidemiology* / Q000378:metabolism; D005260:Female; D005947:Glucose / Q000378:metabolism*; D005951:Glucose Tolerance Test; D006630:Hispanic or Latino; D006801:Humans; D007328:Insulin / Q000097:blood / Q000378:metabolism; D000078790:Insulin Secretion; D008297:Male; D009765:Obesity / Q000097:blood / Q000208:ethnology / Q000378:metabolism*; D015995:Prevalence; D011384:Proinsulin / Q000097:blood; D012307:Risk Factors; D044465:White People
chemical_list: D001786:Blood Glucose; D002096:C-Peptide; D007328:Insulin; D011384:Proinsulin; D005947:Glucose