Introduction: Black individuals with diabetes have greater hypoglycemic hospitalizations, perhaps due to overtreatment of elevated laboratory A1C compared to average glucose (AG), related to altered red blood cell (RBC) biology. Our aim was to evaluate the size of the problem and improve A1C accuracy using a new glycemic marker.
Methods: Continuous glucose monitoring (CGM) and bi-monthly A1C were collected in a 26-week study of adults with type 1 or type 2 diabetes across different race groups. RBC personal glycation ratio (PGR) was determined at 12 weeks and used to calculate personalized A1C (pA1C) with this new glycemic marker assessed against paired 56-day AG-derived A1C.
Results: Of 811 A1C and AG-derived A1C comparisons in 245 individuals, 34% displayed greater than 0.5% disagreement. This was reduced to 13% using pA1C, with the largest improvement detected in 56 Black individuals (reducing from 42% deviation rate for A1C to 17% for pA1C, Figure). For A1C values <7%, more than 0.5% discrepancy between A1C and AG-derived A1C for the whole group and Black individuals was lowered from 27% and 34%, respectively, to 5% and 9% with pA1C.
Conclusion: Clinically significant A1C and AG-derived A1C discordance is common, particularly in Black individuals. Personalized A1C addresses this discrepancy potentially improving clinical management in diabetes and reducing health disparities.
R. Ajjan: Research Support; Abbott. Speaker's Bureau; Abbott. Advisory Panel; Abbott, AstraZeneca, Novo Nordisk. Speaker's Bureau; Boehringer-Ingelheim. Research Support; Diabetes UK. Advisory Panel; Eli Lilly and Company, Sanofi. T. Dunn: Employee; Abbott. Y. Xu: None. P. Choudhary: Advisory Panel; Abbott, Biolinq. Speaker's Bureau; Dexcom, Inc., Eli Lilly and Company, Novo Nordisk, Sanofi. Advisory Panel; Ypsomed AG, Vertex Pharmaceuticals Incorporated.
