Measurement of HbA1c in Gingival Crevicular Blood Using a High-Pressure Liquid Chromatography Procedure.
OBJECTIVE
To validate an ion exchange high-pressure liquid chromatography (HPLC) method for measuring glycated hemoglobin (HbA1c) in gingival crevicular blood (GCB) spotted on filter paper, for use in screening dental patients for diabetes.


METHODS
We collected the GCB specimens for this study from the oral cavities of patients during dental visits, using rigorous strategies to obtain GCB that was as free of debris as possible. The analytical performance of the HPLC method was determined by measuring the precision, linearity, carryover, stability of HbA1c in GCB, and correlation of HbA1c results in GCB specimens with finger-stick blood (FSB) specimens spotted on filter paper.


RESULTS
The coefficients of variation (CVs) for the inter- and intrarun precision of the method were less than 2.0%. Linearity ranged between 4.2% and 12.4%; carryover was less than 2.0%, and the stability of the specimen was 6 days at 4°C and as many as 14 days at -70°C. Linear regression analysis comparing the HbA1c results in GCB with FSB yielded a correlation coefficient of 0.993, a slope of 0.981, and an intercept of 0.13. The Bland-Altman plot showed no difference in the HbA1c results from the GCB and FSB specimens at normal, prediabetes, and diabetes HbA1c levels.


CONCLUSIONS
We validated an HPLC method for measuring HbA1c in GCB; this method can be used to screen dental patients for diabetes.
Department of Pathology, Columbia University Medical Center, New York Presbyterian Hospital, New York University, New York, NY map8@cumc.columbia.edu.
Michael A
MA
Pesce
College of Nursing, New York University, New York, NY.
Shiela M
SM
Strauss
College of Nursing, New York University, New York, NY.
Mary
M
Rosedale
Department of Pathology, Columbia University Medical Center, New York Presbyterian Hospital, New York University, New York, NY.
Jane
J
Netterwald
Department of Pathology, Columbia University Medical Center, New York Presbyterian Hospital, New York University, New York, NY.
Hangli
H
Wang
D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D005883:Gingival Crevicular Fluid / Q000737:chemistry*; D006442:Glycated Hemoglobin / Q000032:analysis*; D006801:Humans; D016014:Linear Models; D013048:Specimen Handling
D006442:Glycated Hemoglobin
HPLC assay; HbA1c; HbA1c stability; dried blood spot; gingival crevicular blood; screening for diabetes