A novel kinetic model that takes into account red blood cell (RBC) turnover, cross-membrane glucose transport, and hemoglobin glycation processes to individualize the relationship between glucose levels and A1C accurately reflects laboratory A1C and provides novel concepts to explain the mechanisms for the mismatch between A1C and average glucose in some patients, according to a study published in the Journal of Diabetes Science and Technology. With evidence indicating that discrepancies commonly occur between estimated A1C from continuous glucose monitoring (CGM) and laboratory A1C, investigators sought to develop a glycemic marker that better reflects laboratory A1C using CGM data from two previous clinical studies in 120 patients with diabetes. They calculated kinetic rate constants for RBC glycation and turnover using CGM data and two laboratory A1C measurements, using these rate constants to project future A1C and creating a new individualized glycemic marker they termed calculated HbA1c (cHbA1c). Unlike with estimated A1C, cHbA1c provided an accurate estimation of laboratory A1C across participants, demonstrating a non-linear relationship between laboratory A1C and steady-state glucose and that glycation status is modulated by age.
