title: Impact of diabetes and its treatment on cognitive function among adolescents who participated in the Diabetes Control and Complications Trial.
abstract: OBJECTIVE
  The purpose of this study was to evaluate whether severe hypoglycemia or intensive therapy affects cognitive performance over time in a subgroup of patients who were aged 13-19 years at entry in the Diabetes Control and Complications Trial (DCCT).
  
  
  METHODS
  This was a longitudinal study involving 249 patients with type 1 diabetes who were between 13 and 19 years old when they were randomly assigned in the DCCT. Scores on a comprehensive battery of cognitive tests obtained during the Epidemiology of Diabetes Interventions and Complications follow-up study, approximately 18 years later, were compared with baseline performance. We assessed the effects of the original DCCT treatment group assignment, mean A1C values, and frequency of severe hypoglycemic events on eight domains of cognition.
  
  
  RESULTS
  There were a total of 294 reported episodes of coma or seizure. Neither frequency of hypoglycemia nor previous treatment group was associated with decline on any cognitive domain. As in a previous analysis of the entire study cohort, higher A1C values were associated with declines in the psychomotor and mental efficiency domain (P < 0.01); however, the previous finding of improved motor speed with lower A1C values was not replicated in this subgroup analysis.
  
  
  CONCLUSIONS
  Despite relatively high rates of severe hypoglycemia, cognitive function did not decline over an extended period of time in the youngest cohort of patients with type 1 diabetes.
authors.affiliation: 1Joslin Diabetes Center/Harvard Medical School, Boston, Massachusetts, USA. gail.musen@joslin.harvard.edu
authors.forename: Gail
authors.initials: G
authors.lastname: Musen
authors.forename: Alan M
authors.initials: AM
authors.lastname: Jacobson
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Ryan
authors.forename: Patricia A
authors.initials: PA
authors.lastname: Cleary
authors.forename: Barbara H
authors.initials: BH
authors.lastname: Waberski
authors.forename: Katie
authors.initials: K
authors.lastname: Weinger
authors.forename: William
authors.initials: W
authors.lastname: Dahms
authors.forename: Meg
authors.initials: M
authors.lastname: Bayless
authors.forename: Nancy
authors.initials: N
authors.lastname: Silvers
authors.forename: Judith
authors.initials: J
authors.lastname: Harth
authors.forename: Neil
authors.initials: N
authors.lastname: White
mesh_terms: D000293:Adolescent; D000328:Adult; D002986:Clinical Trials as Topic; D003071:Cognition; D003922:Diabetes Mellitus, Type 1 / Q000188:drug therapy* / Q000523:psychology*; D004334:Drug Administration Schedule; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D007003:Hypoglycemia / Q000453:epidemiology / Q000517:prevention & control / Q000523:psychology; D007328:Insulin / Q000627:therapeutic use*; D007332:Insulin Infusion Systems; D008137:Longitudinal Studies; D008297:Male; D009483:Neuropsychological Tests
chemical_list: D006442:Glycated Hemoglobin; D007328:Insulin