Estimation of the hemoglobin glycation rate constant

Abstract

In a previous study, a method of obtaining mean erythrocyte age ($M_{\mathit{RBC}}$) from HbA1c and average plasma glucose (AG) was proposed. However, the true value of the hemoglobin glycation constant ($k_g$ dL/mg/day), required for this model has yet to be well characterized. Another study also proposed a method of deriving $M_{\mathit{RBC}}$ from erythrocyte creatine (EC). Utilizing these formulae, this study aimed to determine a more accurate estimate of $k_g$. One hundred and seven subjects including 31 patients with hemolytic anemia and 76 subjects without anemia were included in this study. EC and HbA1c data were analyzed, and $M_{\mathit{RBC}}$ using HbA1c, AG and the newly-derived constant, $k_g$ were compared to $M_{\mathit{RBC}}$ using traditional ${}^{51}\text{Cr}$ in three patients whose data were taken from previous case studies. A value of $7.0\times {10}^{-6}$ dL/mg/day was determined for $k_g$. $M_{\mathit{RBC}}$ using HbA1c, AG and $k_g$ were found to no be significantly different (paired t-test, $p=0.45$) to $M_{\mathit{RBC}}$ using traditional ${}^{51}\text{Cr}$. $k_g$ enables the estimation of $M_{\mathit{RBC}}$ from HbA1c and AG.