Microcytic Anemia Elevates Hemoglobin A1c Levels in the Subjects with Normal Fasting Plasma Glucose

Microcytic Anemia Elevates Hemoglobin A1c Levels in the Subjects with Normal Fasting Plasma Glucose [bold]Background and Aims:[/bo [bold]Background and Aims:[/bold] HbA1c is used world-wide as a control marker of diabetes mellitus. HbA1c is known to be affected not only by plasma glucose level but also by life span of red blood cell. However whether microcytic anemia has an influence on HbA1c in subjects with normal fasting plasma glucose is unclear. The purpose of this study is to elucidate how hemoglobin A1c (HbA1c) is affected by microcytic anemia.[br][bold]Material and Methods:[/bold] The study subjects consisted of 1874 men and 1529 women who underwent health checkups including fasting plasma glucose, HbA1c, CBC. All subjects had FPG levels bellow 100mg/dl and took therapy neither for diabetes nor anemia. We investigated whether microcytic anemia has an influence on HbA1c and the attribute of discrepant cases between FPG and HbA1c.[br][bold]Results:[/bold] The subjects were divided into three groups by tertiles of hemoglobin concentration(Hb) and MCV :,the micocytic group(MC) with low MCV, the microcytic anemia(MCA) with low MCV and low Hb and the control . [br]The HbA1c levels in MCA were 2.0% higher than those in the control in men and 4.7% higher in women.[br]We defined discrepant cases between FPG and HbA1c as those with HbA1c more than 5.5%. More discrepancies between FPG and HbA1c were found in MC and MCA than in the control group. In men, the proportions of discrepant cases were 5.4%, 9.9%, 16.5% in the control group, MC and MCA, respectively. In women, the proportions were 6.2%, 24.5% and 31.5%, respectively.[br]Multiple regression analysis revealed that FPG and age were the positive independent factors for HbA1c, and Hb and MCV were the negative independent factors.[br]In the subjects who were more than 50 years old, the proportion of discrepant cases in MCA reached 36.4% in men and 45.5% in women. [br][bold]Conclusion:[/bold] It is plausible that microcytic anemia elevates HbA1c in the subjects with normal fasting plasma glucose. We should carefully evaluate HbA1c in the case with microcytic anemia, especially in elder person. RYO MAEDA, NORIKO INOUE, HIDEO SASAKI. 938-P Hiroshima, Hiroshima Prefecture, Japan. Epidemiology