Laboratory A1C does not precisely reflect glycemic control in those with altered RBC lifespan and our aim was to evaluate an adjusted A1C, a glycemic measure that adjusts A1C to a reference RBC lifespan. By removing the individual RBC lifespan variation, adjusted A1C better reflects intracellular glucose exposure in RBCs and perhaps other organs susceptible to complications. Iron-deficiency anemia and treatment is known to affect RBC lifespan and therefore provides opportunity to evaluate the model.
The patient was a 53-year-old woman with iron-deficiency anemia and type 1 diabetes utilizing sensor-augmented pump therapy. Longitudinal A1C and CGM were evaluated with a novel kinetic model to estimate RBC lifespan and glucose uptake rate. During the six months before iron therapy, the RBC lifespan was estimated at 151 days and 93% of a reference glucose uptake. During six months of iron therapy, the RBC lifespan decreased to 122 days, while the RBC glucose uptake increased slightly to 101% of reference value. The RBC lifespan change explains the observed laboratory A1C change (Figure) and can be attribute to the iron therapy and supported by Hb, RDW and Ferritin data. The adjusted A1C based on these two different RBC lifespans agree with the stable CGM mean glucose of this patient. In this case study, we confirmed the clinical relevance of adjusted A1C to account for variations in RBC lifespan.
Y.Hirota: Speaker's Bureau; Abbott Japan Co., Ltd., Astellas Pharma Inc., AstraZeneca, Boehringer Ingelheim International GmbH, Daiichi Sankyo, Kissei Pharmaceutical Co., Ltd., Kowa Company, Ltd., Kyowa Kirin Co., Ltd., Lilly, Medtronic, Mochida Pharmaceutical Co., Ltd., Novo Nordisk, Ono Pharmaceutical Co., Ltd., Pfizer Japan Inc., Sanofi, Sanwa Kagaku Kenkyusho, Sumitomo Dainippon Pharma Co., Ltd., Takeda Pharmaceutical Company Limited, Teijin Pharma Limited, Terumo Corporation. Y.Xu: Employee; Abbott Diabetes. A.Yamamoto: None. A.Matsuoka: None. T.Dunn: Employee; Abbott. W.Ogawa: Advisory Panel; Abbott Japan Co., Ltd., Nippon Boehringer Ingelheim Co. Ltd., Novo Nordisk, Other Relationship; Abbott Japan Co., Ltd., Mitsubishi Tanabe Pharma Corporation, Nippon Boehringer Ingelheim Co. Ltd., Sumitomo Dainippon Pharma Co., Ltd., Takeda Pharmaceutical Company Limited, Research Support; Abbott, Astellas Pharma Inc., Eli Lilly and Company, Kowa Company, Ltd., Nippon Boehringer Ingelheim Co. Ltd., Novo Nordisk, Ono Pharmaceutical Co., Ltd., Sumitomo Dainippon Pharma Co., Ltd.
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