Abnormally Decreased HbA1c Can Be Assessed With Erythrocyte Creatine in Patients With a Shortened Erythrocyte Age

Yufei Jiao; Toshika Okumiya; Toshiji Saibara; Keunsik Park; Masahide Sasaki

doi:10.2337/diacare.21.10.1732

Original Articles

Abnormally Decreased HbA_1c Can Be Assessed With Erythrocyte Creatine in Patients With a Shortened Erythrocyte Age

Yufei Jiao, MD, MSC,
Toshika Okumiya, PHD,
Toshiji Saibara, MD, PHD,
Keunsik Park, MD, PHD and
Masahide Sasaki, MD, PHD

Department of Laboratory Medicine, Department of Internal Medicine, Kochi Medical School Nankoku
Department of Medical Informatics, Osaka City University Osaka, Japan
Faculty of Medicine, Osaka City University Osaka, Japan

Address correspondence and reprint requests to Toshika Okumiya, PhD, Department of Laboratory Medicine, Kochi Medical School, Oko-cho, Nankoku 783-8505, Japan. E-mail: okumiyat/kms{at}kochi-ms.ac.jp

Diabetes Care 1998 Oct; 21(10): 1732-1735. https://doi.org/10.2337/diacare.21.10.1732

Abstract

OBJECTIVE To investigate whether erythrocyte creatine can serve as a corrective index for HbA_1c in patients with a shortened mean age of erythrocytes.

RESEARCH DESIGN AND METHODS HbA_1c and creatine in density-fractionated erythrocytes from 18 normal subjects were measured. HbA_1c and erythrocyte creatine in the whole blood of 43 patients with liver cirrhosis (LC), 14 patients with hemolytic anemia (HA), 38 other patients with high reticulocyte counts (HRC) (>2.2%), and 59 normal subjects were also measured. The patients in this study all had normal blood glucose levels. A correction formula derived from the linear regression equation for the correlation between HbA_1c and erythrocyte creatine was used to correct the patients' HbA_1c values.

RESULTS Among density-fractionated erythrocytes, the young cells exhibited low HbA_1c and high creatine values. With progressively increasing density, HbA_1c gradually increased and creatine gradually decreased. In the whole blood samples, the HbA_1c values were significantly lower (P < 0.001) in LC, HA, and HRC patients than in normal subjects. By contrast, the erythrocyte creatine values were significantly higher (P < 0.001) in LC, HA, and HRC patients than in normal subjects. A linear correlation between HbA_1c Cy) and erythrocyte creatine (x) was observed (y = −0.224x + 5.00; n = 154; r = −0.70; P < 0.001). Based on the regression equation, a correction formula was obtained. Low HbA_1c values (<4.3%) were found in 24 of the 43 LC patients, 12 of the 14 HA patients, and 20 of the 38 HRC patients. After correction of the HbA_1c values, 15 of the 24 LC patients, 9 of the 12 HA patients, and 16 of the 20 HRC patients had HbAlc values within the normal range.

CONCLUSIONS HbA_1c decreased in inverse proportion to the increase in erythrocyte creatine because of a shortened mean age of erythrocytes. The abnormally decreased HbA_1c value could be assessed with erythrocyte creatine.