Yale New Haven Hospital

Department of Laboratory Medicine
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Hemoglobin A1c

Lab Section: 



Lab Location: 

Main Lab

Test ID: 




Glycosylated Hgb Level


Quantitative High Performance Liquid Chromatography/Boronate Affinity




1 day

Specimen Requirements: 

Collection: 3.0 mL Blood in a Lavender Top Tube.
Pediatric volume: 1 mL.
Stability: Ambient: 24 hours; Refrigerated: 1 week



Clinical Indications: HbA1c level reflects the mean glucose concentration over the previous period (approximately 8-12 weeks, depending on the individual) and provides a much better indication of long-term glycemic control than blood and urinary glucose determinations. Diabetic patients with very high blood concentrations of glucose have from 2 to 3 times more HbA1c than normal individuals.

Estimated Average Glucose (eAG) is also reported. This boronate affinity Hb A1c method provides accurate analytical results in the presence of nearly all Hb variants. Hb F higher than 10% of total Hb may yield falsely low results. Conditions that shorten red cell survival, such as the presence of unstable hemoglobins like Hb SS, Hb CC, and Hb SC, or other causes of hemolytic anemia may yield falsely low results. Iron deficiency anemia may yield falsely high results.

Reference Interval: 

4.0-6.0 %

CPT Code(s): 


Last Changed: 

12/28/2016 14:38:46

Last Reviewed: 

9/22/2017 12:11:43 PM