title: Utility of HbA(1c) levels for diabetes case finding in hospitalized patients with hyperglycemia.
abstract: OBJECTIVE
  We evaluated the role of a single measurement of HbA(1c) in a diabetes case finding in hospitalized patients with random hyperglycemia at admission.
  
  
  METHODS
  From 20 March to 31 July 2000, 508 patients admitted through the emergency department of one hospital were tested for random hyperglycemia (plasma glucose [PG] >125 mg/dl). Consenting patients with hyperglycemia (without preexisting diabetes or on corticosteroids) underwent testing for HbA(1c) levels, two fasting PG levels, and an outpatient oral glucose tolerance test (OGTT) if necessary.
  
  
  RESULTS
  Of the patients, 50 (9.8%) met the inclusion criteria. Of these, 70% (n = 35) completed the study, and 60% (n = 21) were diagnosed with diabetes. Patients with diabetes had higher HbA(1c) levels than subjects without diabetes (6.8 +/- 0.4 vs. 5.3 +/- 0.1%, P = 0.002). An HbA(1c) level >6.0% was 100% specific (14/14) and 57% sensitive (12/21) for the diagnosis of diabetes. When a lower cutoff value of HbA(1c) at 5.2% was used, specificity was 50% (10/21) and sensitivity was 100% (7/14).
  
  
  CONCLUSIONS
  In acutely ill patients with random hyperglycemia at hospital admission, an HbA(1c) >6.0% reliably diagnoses diabetes, and an HbA(1c) level <5.2% reliably excludes it (paralleling the operating characteristics of the standard fasting glucose measurements); however, the rapidity of the HbA(1c) level can be useful for diabetes case finding and treatment initiation early in the hospital course.
authors.affiliation: Department of Preventive Medicine, Griffin Hospital, Yale University School of Medicine, Derby, Connecticut, USA. laura_greci@CHS.net
authors.forename: Laura S
authors.initials: LS
authors.lastname: Greci
authors.forename: Mala
authors.initials: M
authors.lastname: Kailasam
authors.forename: Samir
authors.initials: S
authors.lastname: Malkani
authors.forename: David L
authors.initials: DL
authors.lastname: Katz
authors.forename: Ilja
authors.initials: I
authors.lastname: Hulinsky
authors.forename: Ramin
authors.initials: R
authors.lastname: Ahmadi
authors.forename: Haq
authors.initials: H
authors.lastname: Nawaz
mesh_terms: D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose / Q000032:analysis; D003237:Connecticut; D003920:Diabetes Mellitus / Q000097:blood / Q000175:diagnosis*; D005951:Glucose Tolerance Test; D006442:Glycated Hemoglobin / Q000032:analysis*; D006764:Hospitals, Community; D006785:Hospitals, University; D006801:Humans; D006943:Hyperglycemia / Q000097:blood*; D007297:Inpatients; D008875:Middle Aged; D018579:Patient Selection; D015203:Reproducibility of Results; D018401:Sample Size; D012680:Sensitivity and Specificity
chemical_list: D015415:Biomarkers; D001786:Blood Glucose; D006442:Glycated Hemoglobin