Evaluation of error levels in hemoglobin A1c and glycated albumin in type 2 diabetic patients due to inter-individual variability.
OBJECTIVE
To evaluate error levels in hemoglobin A1c (A1C) and glycated albumin (GA) in type 2 diabetic patients due to inter-individual variability.


METHODS
Type 2 diabetic patients with stable glycemic control and without complications affecting either A1C or GA were enrolled (n=154; age 68.4+/-9.9 years). Blood examination was performed 1-4h after breakfast or lunch every 2-3 months on > or =3 occasions. A1C data were changed to IFCC values for analysis.


RESULTS
A1C and GA correlated significantly with postprandial plasma glucose. The correlation coefficient between A1C and GA was 0.728 (p<0.001) when calculated using raw data and 0.747 (p<0.001) when calculated using averaged data for each patient. The ratio R of GA to A1C was 3.88+/-0.50 for raw data and 3.88+/-0.47 for averaged data, indicating coefficients of variation of R (CV(R)) of 12.9% and 12.1%, respectively. Multiple regression analysis reduced CV(R) to 11.2%. After dividing CV(R)(2) into CV(A1C)(2) and CV(GA)(2), CV(A1C) and CV(GA) were calculated as 9.1% for raw data and 8.6% for averaged data, and were reduced to 7.9% after multiple regression analysis.


CONCLUSIONS
Error levels in A1C and GA reach 7.9-9.1%, suggesting the existence of maximal 18% errors in A1C and GA levels.
Tahara
Yasuhiro
Y
Diabetes Division, Department of Internal Medicine, Meimai Central Hospital, Matsugaoka 4-1-32, Akashi, Hyogo 678-0862, Japan. ystahara.dmdr@zeus.eonet.ne.jp
Shima
Kenji
K
D000368:Aged; D001786:Blood Glucose / Q000378:metabolism; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism*; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism*; D017127:Glycation End Products, Advanced; D006801:Humans; D008297:Male; D008875:Middle Aged; D019518:Postprandial Period; D012044:Regression Analysis; D012709:Serum Albumin / Q000378:metabolism*; D000093423:Glycated Serum Albumin
D001786:Blood Glucose; D006442:Glycated Hemoglobin; D017127:Glycation End Products, Advanced; D012709:Serum Albumin; D000093423:Glycated Serum Albumin