Hemoglobin A1c (HbA1c)

Hemoglobin A1c (HbA1c) measures average blood sugar (glucose) levels over the previous 90 days by assessing the amount of glucose attached to red blood cells. Unlike point-in-time measurements subject to acute fluctuations, HbA1c provides a stable assessment of glycemic control, making it the preferred biomarker for diabetes diagnosis and monitoring per the American Diabetes Association guidelines. HbA1c levels are associated with metabolic syndrome, prediabetes, and diabetes progression. Beyond metabolic applications, our model demonstrates HbA1c’s high predictive value for cardiovascular health, kidney health, and brain health, reflecting the systemic impact of chronic hyperglycemia (high blood sugar).

Note that conditions affecting red blood cell function or blood volume, such as anemia, blood disorders, or altered red blood cell lifespan, can impact HbA1c accuracy and require clinical interpretation. [57] [58] [59] [60] [61]

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[59]Sandler CN, McDonnell ME. The role of hemoglobin A1c in the assessment of diabetes and cardiovascular risk. Cleve Clin J Med. 2016;83(5 suppl 1):S4-S10. doi:10.3949/ccjm.83.s1.02

[60]Cho S, Kim CO, Cha B soo, et al. The effects of long-term cumulative HbA1c exposure on the development and onset time of dementia in the patients with type 2 diabetes mellitus: Hospital based retrospective study (2005–2021). Diabetes Res Clin Pract. 2023;201. doi:10.1016/j.diabres.2023.110721

[61]Miyake T, Furukawa S, Matsuura B, et al. Glycemic Control Is Associated with Histological Findings of Nonalcoholic Fatty Liver Disease. Diabetes Metab J. 2024;48(3):440-448. doi:10.4093/dmj.2023.0200