title: The prevalence of undiagnosed diabetes mellitus and the association of baseline glycemic control on mortality in the intensive care unit: a prospective observational study.
abstract: OBJECTIVE
  Hyperglycemia is common during critical illness and can adversely affect clinical outcomes. We sought to determine the prevalence of undiagnosed diabetes among medical intensive care unit (MICU) patients with stress hyperglycemia and the association between baseline glycemic control and mortality.
  
  
  METHODS
  A prospective, observational cohort study was performed at a tertiary care MICU. Hemoglobin A1c (HbA1c) levels were obtained from any patient who developed hyperglycemia and all known diabetic patients. We assessed the prevalence of undiagnosed diabetes (defined by HbA1c) among patients with stress hyperglycemia, and the association between baseline glycemic control and mortality.
  
  
  RESULTS
  We enrolled 299 patients. One hundred two (34.1%) had no history and 197 (65.9%) had a history of diabetes. Of the nondiabetic patients, 14 (13.7%) had an HbA1c of at least 6.5%. There was a significant difference in mortality between patients with HbA1c less than 6.5% and those with HbA1c of at least 6.5% (19.3% vs 11.7%, P=.038), despite similar Acute Physiology and Chronic Health Evaluation II scores. There was no significant difference in demographic characteristics between these groups. Multivariable logistic regression revealed lower HbA1c levels to be significantly associated with increased hospital mortality (odds ratio, 1.92; 95% confidence interval, 1.30-2.85; P=.001).
  
  
  CONCLUSIONS
  A significant number of MICU patients with stress hyperglycemia have undiagnosed diabetes. Hyperglycemia with lower baseline HbA1c was associated with increased mortality.
authors.affiliation: Yale School of Medicine Department of Internal Medicine, New Haven, CT, US. Electronic address: Hoang.Quynh25@gmail.com.
authors.forename: Quynh N
authors.initials: QN
authors.lastname: Hoang
authors.affiliation: Yale School of Medicine Department of Pulmonary Critical Care, New Haven, CT, US. Electronic address: Margaret.Pisani@yale.edu.
authors.forename: Margaret A
authors.initials: MA
authors.lastname: Pisani
authors.affiliation: Yale School of Medicine Department of Endocrinology, New Haven, CT, US. Electronic address: Silvio.Inzucchi@yale.edu.
authors.forename: Silvio
authors.initials: S
authors.lastname: Inzucchi
authors.affiliation: Yale School of Medicine Department of Pulmonary Critical Care, New Haven, CT, US. Electronic address: Buqu.Hu@yale.edu.
authors.forename: Buqu
authors.initials: B
authors.lastname: Hu
authors.affiliation: Yale School of Medicine Department of Pulmonary Critical Care, New Haven, CT, US. Electronic address: Shyoko.Honiden@yale.edu.
authors.forename: Shyoko
authors.initials: S
authors.lastname: Honiden
mesh_terms: D018806:APACHE; D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000032:analysis; D015331:Cohort Studies; D016001:Confidence Intervals; D016638:Critical Illness / Q000401:mortality; D003920:Diabetes Mellitus / Q000097:blood / Q000453:epidemiology* / Q000401:mortality; D005260:Female; D006442:Glycated Hemoglobin / Q000032:analysis; D017052:Hospital Mortality; D006801:Humans; D006943:Hyperglycemia / Q000097:blood / Q000453:epidemiology* / Q000401:mortality; D007362:Intensive Care Units / Q000706:statistics & numerical data; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D015995:Prevalence; D011446:Prospective Studies
chemical_list: D001786:Blood Glucose; D006442:Glycated Hemoglobin
keywords: Diabetic status; Hemoglobin A1c (HbA1c); Intensive care unit outcomes; Mortality; Stress hyperglycemia