title: Severe hypoglycemia rates are not associated with HbA1c: a cross-sectional analysis of 3 contemporary pediatric diabetes registry databases.
abstract: OBJECTIVE
  To examine the association between glycated hemoglobin (HbA1c) and severe hypoglycemia rates in patients with type 1 diabetes receiving usual care, by analysing data from the US Type 1 Diabetes Exchange (T1DX), German/Austrian Diabetes Patienten Verlaufsdokumenation (DPV), and Western Australian Children Diabetes Database (WACDD) diabetes registries.
  
  
  METHODS
  Data for patients with type 1 diabetes, aged <18 years with a minimum duration of diabetes of 2 years, were extracted from each registry for a 12-month observation period between 2011 and 2012 (7,102 T1DX, 18,887 DPV, and 865 WACDD). Rates of severe hypoglycemia (self-reported loss of consciousness/convulsion) were estimated per 100 patient-years and analyzed by HbA1c, source registry, treatment regimen, and age group.
  
  
  RESULTS
  Overall, the severe hypoglycemia rate per 100 patient years was 7.1, 3.3, and 6.7 in T1DX, DPV, and WACDD patients, respectively. Lower HbA1c was not associated with an increased rate of severe hypoglycemia when examined by source registry, treatment regimen, or age group.
  
  
  CONCLUSIONS
  An inverse relationship between mean HbA1c and risk of severe hypoglycemia was not observed in this study of 3, independent cohorts of children and adolescents with type 1 diabetes. Investigation in other large, longitudinal cohorts is recommended to further characterize the contemporary relationship between glycemic control and risk of severe hypoglycemia rates in pediatric patients with type 1 diabetes.
authors.affiliation: Telethon Kids Institute, The University of Western Australia, Perth, Australia.
authors.forename: Aveni
authors.initials: A
authors.lastname: Haynes
authors.affiliation: University of Ulm, ZIBMT, Institute of Epidemiology and Medical Biometry, Ulm, Germany.|German Center for Diabetes Research (DZD), München-Neuherberg, Germany.
authors.forename: Julia M
authors.initials: JM
authors.lastname: Hermann
authors.affiliation: Jaeb Center for Health Research, Tampa, Florida.
authors.forename: Kellee M
authors.initials: KM
authors.lastname: Miller
authors.affiliation: Department of Pediatrics, Medical University of Innsbruck, Innsbruck, Austria.
authors.forename: Sabine E
authors.initials: SE
authors.lastname: Hofer
authors.affiliation: Telethon Kids Institute, The University of Western Australia, Perth, Australia.|Department of Diabetes & Endocrinology, Princess Margaret Hospital, Perth, Australia.
authors.forename: Timothy W
authors.initials: TW
authors.lastname: Jones
authors.affiliation: Jaeb Center for Health Research, Tampa, Florida.
authors.forename: Roy W
authors.initials: RW
authors.lastname: Beck
authors.affiliation: Department of Pediatrics, Stanford University, Stanford, California.
authors.forename: David M
authors.initials: DM
authors.lastname: Maahs
authors.affiliation: Telethon Kids Institute, The University of Western Australia, Perth, Australia.|Department of Diabetes & Endocrinology, Princess Margaret Hospital, Perth, Australia.
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Davis
authors.affiliation: University of Ulm, ZIBMT, Institute of Epidemiology and Medical Biometry, Ulm, Germany.|German Center for Diabetes Research (DZD), München-Neuherberg, Germany.
authors.forename: Reinhard W
authors.initials: RW
authors.lastname: Holl
mesh_terms: D000293:Adolescent; D001317:Austria / Q000453:epidemiology; D002648:Child; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D003922:Diabetes Mellitus, Type 1 / Q000097:blood* / Q000628:therapy; D057286:Electronic Health Records; D005260:Female; D005858:Germany / Q000453:epidemiology; D006442:Glycated Hemoglobin / Q000032:analysis*; D006801:Humans; D007003:Hypoglycemia / Q000453:epidemiology / Q000503:physiopathology* / Q000517:prevention & control; D015994:Incidence; D008137:Longitudinal Studies; D008297:Male; D011446:Prospective Studies; D012042:Registries; D012306:Risk; D012640:Seizures / Q000209:etiology; D012720:Severity of Illness Index; D014474:Unconsciousness / Q000209:etiology; D014481:United States / Q000453:epidemiology; D014904:Western Australia / Q000453:epidemiology
chemical_list: D006442:Glycated Hemoglobin; C517652:hemoglobin A1c protein, human
keywords: adolescent; child; diabetes mellitus; hypoglycemia; registries; type 1