Abstract
A 65-year-old male visited our hospital for the first time in 2002 after complaining of polyposia and polyuria. His fasting blood glucose (FPG) was 169 mg/dl, indicating diabetes, but his HbA1c (HPLC method) was 5.4 % (NGSP level), which was at the reference interval. Thereafter, he underwent follow-up diet therapy and exercise therapy; however, in 2008, his average FPG and glycoalbumin (GA) levels were high, while his HbA1c was 6.1±0.1 %, transitioning at the reference interval. His average glucose level under continuous glucose monitoring was 186 mg/dl and while the HbA1c speculated based on this value was 8.4 %, the measured HbA1c was 5.9 %. No abnormalities were observed upon globin gene analysis, and the HIV antigen/antibody titer was negative. Although mild anemia and a slightly high level of indirect bilirubin were seen, no other findings indicating hemolytic anemia were observed. However, the red cell survival in this case was significantly lower than that of the control. It was therefore believed that the cause of the low level of HbA1c in this case was the decreased red cell survival, however, the cause of this decrease was unknown.
