- Methods to Measure Hemoglobin A1c
- Erythrocyte Production
- Ethnicity and Hemoglobin Variants
- Chemically Modified Hemoglobin
- Altered Rate of Glycation
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Many factors exist that may affect a patient's A1c. When A1c and self monitoring blood glucose (SMBG) results do not correlate, it is especially important to consider these patient-specific factors. The 2015 American Diabetes Association (ADA) Standards of Care state that discrepancies between a patient's A1c and SMBG levels should warrant exploration of the reasons for these discrepancies. Considerations should include testing method, hemoglobinopathies, conditions affecting red blood cell turnover, chemically modified hemoglobin, altered rates of glycation, race, and age. If a healthcare provider decides A1c is unreliable in a particular patient, alternative strategies for assessment of glycemic control should include more frequent or different timing of SMBG and continued glucose monitoring, as recommended by the ADA. In addition, clinicians can consider evaluation of fructosamine, glycolated albumin, and 1,5-AG; however, there are no consensus guidelines for their use.
Limitations of A1c Interpretation (Free registration to the site is needed)