title: Glycated Hemoglobin A1c Levels Are Not Affected by Critical Illness.
abstract: OBJECTIVE
  Glycated hemoglobin A1c is used to estimate glycemic control. However, its value upon ICU admission may be altered by critical illness and not reflect true glycemic status. We assessed the relationship between ICU admission glycated hemoglobin A1c and premorbid glycated hemoglobin A1c levels.
  
  
  METHODS
  Retrospective observational cohort study.
  
  
  METHODS
  Two tertiary ICUs in Australia.
  
  
  METHODS
  Cohort of 69 critically ill patients with diabetes and glycated hemoglobin A1c levels measured upon ICU admission and during the month prior to admission.
  
  
  METHODS
  Measurement of glycated hemoglobin A1c.
  
  
  RESULTS
  Mean (SD) glycated hemoglobin A1c level was 7.5% (1.8%) upon ICU admission and 7.8% (2.0%) in previous measurements from the preceding 30 days. The change in glycated hemoglobin A1c did not correlate with time elapsed between the two measurements (r = 0.00005; p = 0.95), but there was a strong correlation between admission glycated hemoglobin A1c levels and premorbid glycated hemoglobin A1c levels (r = 0.89; p < 0.001).
  
  
  CONCLUSIONS
  Glycated hemoglobin A1c levels are not altered by the onset of critical illness. Glycated hemoglobin A1c quantified at ICU admission can, therefore, be used to reliably estimate chronic glycemic control and guide acute glycemic therapy.
authors.affiliation: 1Department of Intensive Care, Austin Hospital, The University of Melbourne, Melbourne, VIC, Australia.2Department of Anesthesiology and Intensive Care, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.3Discipline of Acute Care Medicine, Department of Intensive Care, University of Adelaide, Adelaide, SA, Australia.4Section of Anaesthesia and Intensive Care Medicine, Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.5Australian and New Zealand Intensive Care Research Centre, Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, VIC, Australia.
authors.forename: Nora
authors.initials: N
authors.lastname: Luethi
authors.forename: Luca
authors.initials: L
authors.lastname: Cioccari
authors.forename: Aiko
authors.initials: A
authors.lastname: Tanaka
authors.forename: Palash
authors.initials: P
authors.lastname: Kar
authors.forename: Emma
authors.initials: E
authors.lastname: Giersch
authors.forename: Adam M
authors.initials: AM
authors.lastname: Deane
authors.forename: Johan
authors.initials: J
authors.lastname: Mårtensson
authors.forename: Rinaldo
authors.initials: R
authors.lastname: Bellomo
mesh_terms: D000368:Aged; D001315:Australia; D003422:Critical Care; D016638:Critical Illness; D048909:Diabetes Complications / Q000097:blood* / Q000150:complications* / Q000628:therapy; D003955:Diagnostic Tests, Routine; D017707:Erythrocyte Transfusion; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism*; D006760:Hospitalization; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012189:Retrospective Studies; D013997:Time Factors
chemical_list: D006442:Glycated Hemoglobin