title: Prevalence and Impact of Unknown Diabetes in the ICU.
abstract: OBJECTIVE
  Many patients with diabetes and their care providers are unaware of the presence of the disease. Dysglycemia encompassing hyperglycemia, hypoglycemia, and glucose variability is common in the ICU in patients with and without diabetes. The purpose of this study was to determine the impact of unknown diabetes on glycemic control in the ICU.
  
  
  METHODS
  Prospective observational study.
  
  
  METHODS
  Nine ICUs in an academic, tertiary hospital and a hybrid academic/community hospital.
  
  
  METHODS
  Hemoglobin A1c levels were ordered at all ICU admissions from March 1, 2011 to September 30, 2013. Electronic medical records were examined for a history of antihyperglycemic medications or International Classification of Diseases, 9th Edition diagnosis of diabetes. Patients were categorized as having unknown diabetes (hemoglobin A1c > 6.5%, without history of diabetes), no diabetes (hemoglobin A1c < 6.5%, without history of diabetes), controlled known diabetes (hemoglobin A1c < 6.5%, with documented history of diabetes), and uncontrolled known diabetes (hemoglobin A1c > 6.5%, with documented history of diabetes).
  
  
  METHODS
  None.
  
  
  RESULTS
  A total of 15,737 patients had an hemoglobin A1c and medical record evaluable for the history of diabetes, and 5,635 patients had diabetes diagnosed by either medical history or an elevated hemoglobin A1c in the ICU. Of these, 1,460 patients had unknown diabetes, accounting for 26.0% of all patients with diabetes. This represented 41.0% of patients with an hemoglobin A1c > 6.5% and 9.3% of all ICU patients. Compared with patients without diabetes, patients with unknown diabetes had a higher likelihood of requiring an insulin infusion (44.3% vs 29.3%; p < 0.0001), a higher average blood glucose (172 vs 126 mg/dL; p < 0.0001), an increased percentage of hyperglycemia (19.7% vs 7.0%; blood glucose > 180 mg/dL; p < 0.0001) and hypoglycemia (8.9% vs 2.5%; blood glucose < 70 mg/dL; p < 0.0001), higher glycemic variability (55.6 vs 28.8, average of patient SD of glucose; p < 0.0001), and increased mortality (13.8% vs 11.4%; p = 0.01).
  
  
  CONCLUSIONS
  Patients with unknown diabetes represent a significant percentage of ICU admissions. Measurement of hemoglobin A1c at admission can prospectively identify a population that are not known to have diabetes but have significant challenges in glycemic control in the ICU.
authors.affiliation: 1Emory Critical Care Center, Emory University School of Medicine, Atlanta, GA. 2Department of Surgery and Emory Critical Care Center, Emory University School of Medicine, Atlanta, GA.
authors.forename: David L
authors.initials: DL
authors.lastname: Carpenter
authors.forename: Sara R
authors.initials: SR
authors.lastname: Gregg
authors.forename: Kejun
authors.initials: K
authors.lastname: Xu
authors.forename: Timothy G
authors.initials: TG
authors.lastname: Buchman
authors.forename: Craig M
authors.initials: CM
authors.lastname: Coopersmith
mesh_terms: D000046:Academic Medical Centers / Q000706:statistics & numerical data*; D001786:Blood Glucose; D015992:Body Mass Index; D003920:Diabetes Mellitus / Q000175:diagnosis* / Q000453:epidemiology*; D057286:Electronic Health Records; D005260:Female; D006442:Glycated Hemoglobin; D006801:Humans; D006943:Hyperglycemia / Q000188:drug therapy / Q000453:epidemiology; D007003:Hypoglycemia / Q000453:epidemiology / Q000628:therapy; D007004:Hypoglycemic Agents / Q000008:administration & dosage; D007328:Insulin / Q000008:administration & dosage; D007362:Intensive Care Units / Q000706:statistics & numerical data*; D019359:Knowledge; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011446:Prospective Studies
chemical_list: D001786:Blood Glucose; D006442:Glycated Hemoglobin; D007004:Hypoglycemic Agents; D007328:Insulin