title: Reduced prevalence of impaired awareness of hypoglycemia in a population-based clinic sample of youth with type 1 diabetes.
abstract: BACKGROUND
  Impaired awareness of hypoglycemia (IAH) is associated with an increased risk for severe hypoglycemia (SH). However, reduced rates of SH raise the question as to whether there has been a reduction in IAH. The aim of this study was to determine the change in prevalence of IAH in a population-based cohort of adolescents with Type 1 diabetes (T1D).
  
  
  METHODS
  Children older than 12 years with T1D documented their responses to hypoglycemia based on the modified Clarke questionnaire. The prevalence of IAH was also analyzed in a similar population-based cohort using the same questionnaire in 2002. The clinical details of the participants and the number of SH events in the preceding year were determined from the Western Australian diabetes database.
  
  
  RESULTS
  The questionnaire was administered to 413 children in 2002 and to 444 children in 2015 with similar baseline characteristics. The prevalence of IAH was 33% in 2002 and 21% in 2015 (P < .001). A lower HbA1c, younger age at diagnosis and longer duration of diabetes correlated with IAH in 2002 but not in 2015. There was a significant decline in the rates of SH in 2015 compared with 2002 (P < .001) despite a reduced HbA1c in 2015. IAH increased the risk of SH in both cohorts (52 vs 16 events/100 patient years in 2002 and 8 vs 2 events/100 patient years in 2015).
  
  
  CONCLUSIONS
  Although IAH has reduced, IAH is still prevalent in a substantial minority of adolescents and continues to be associated with an increased risk of SH.
authors.affiliation: Department of Endocrinology and Diabetes, Princess Margaret Hospital, Perth, Australia.|School of Paediatrics and Child Health, The University of Western Australia, Perth, Australia.
authors.forename: Mary B
authors.initials: MB
authors.lastname: Abraham
authors.affiliation: Department of Endocrinology and Diabetes, Princess Margaret Hospital, Perth, Australia.|Lawson Health Research Institute, University of Western Ontario, London, Canada.|Children's Hospital, London Health Sciences Centre, London, Canada.
authors.forename: Patricia H
authors.initials: PH
authors.lastname: Gallego
authors.affiliation: Telethon Kids Institute, The University of Western Australia, Perth, Australia.
authors.forename: Wade M
authors.initials: WM
authors.lastname: Brownlee
authors.affiliation: Telethon Kids Institute, The University of Western Australia, Perth, Australia.
authors.forename: Grant J
authors.initials: GJ
authors.lastname: Smith
authors.affiliation: Department of Endocrinology and Diabetes, Princess Margaret Hospital, Perth, Australia.|School of Paediatrics and Child Health, The University of Western Australia, Perth, Australia.|Telethon Kids Institute, The University of Western Australia, Perth, Australia.
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Davis
authors.affiliation: Department of Endocrinology and Diabetes, Princess Margaret Hospital, Perth, Australia.|School of Paediatrics and Child Health, The University of Western Australia, Perth, Australia.|Telethon Kids Institute, The University of Western Australia, Perth, Australia.
authors.forename: Timothy W
authors.initials: TW
authors.lastname: Jones
mesh_terms: D000293:Adolescent; D001364:Awareness; D015331:Cohort Studies; D003922:Diabetes Mellitus, Type 1 / Q000150:complications / Q000523:psychology*; D005260:Female; D007722:Health Knowledge, Attitudes, Practice; D006801:Humans; D007003:Hypoglycemia / Q000453:epidemiology / Q000209:etiology / Q000523:psychology*; D008297:Male; D015995:Prevalence; D014904:Western Australia / Q000453:epidemiology
keywords: impaired awareness of hypoglycemia; severe hypoglycemia; type 1 diabetes