The relationship between estimated average glucose and fasting plasma glucose.
BACKGROUND
Estimated average glucose (eAG) is a value calculated from hemoglobin A1c (HbA1c) that reflects average glycemic status over the preceding few months. A linear relationship between HbA1c and eAG was demonstrated by the International HbA1c-Derived Average Glucose (ADAG) Trial in 2008. We investigated the relationship between fasting plasma glucose (FPG) and eAG.


METHODS
This retrospective study was conducted by reviewing the medical records of 6443 subjects, including 5567 diabetic patients and 876 non-diabetic subjects. The levels of HbA1c and FPG were reviewed and eAG was calculated using the regression equation published by the ADAG trial: eAGmmol/L=1.59×HbA1c(NGSP, %)-2.59[eAGmg/dL= 28.7×HbA1c(NGSP, %)-46.7].


RESULTS
In all subjects, FPG showed a moderate correlation with eAG (r=0.672, p<0.001). When diabetic and non-diabetic subjects were divided into subgroups according to FPG level, the correlation between eAG and FPG decreased in both diabetic [FPG ≥10.0 mmol/L (180 mg/dL), r=0.425; FPG 7.2-9.9 mmol/L (130-179 mg/dL), r=0.373; FPG <7.2 mmol/L (130 mg/dL), r=0.202] and non-diabetic [FPG 5.6-6.9 mmol/L (100-125 mg/dL), r=0.363; FPG <5.6 mmol/L (100 mg/dL), r=0.186] subgroups as the FPG level decreased. The differences between eAG and FPG were statistically significant (p<0.001). Only 81% (4487/5567) of diabetic patients had a lower FPG level than eAG level.


CONCLUSIONS
Our results suggest that the relationship between eAG and FPG may depend on glycemic control, thereby enhancing our understanding of eAG.
Hyun-Young
HY
Kim
Soo-Youn
SY
Lee
Sunghwan
S
Suh
Jae Hyeon
JH
Kim
Moon Kyu
MK
Lee
Hyung-Doo
HD
Park
D001774:Blood Chemical Analysis / Q000379:methods*; D001786:Blood Glucose / Q000032:analysis*; D003920:Diabetes Mellitus / Q000097:blood; D005215:Fasting / Q000097:blood*; D005260:Female; D006442:Glycated Hemoglobin / Q000032:analysis*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies
D001786:Blood Glucose; D006442:Glycated Hemoglobin; C517652:hemoglobin A1c protein, human