Rationale and Comments
The lifespan of an A1C is approximately 90 to 120 days, and the full effects of a patient’s change in behavior, diet, or newly adjusted medications will not be fully appreciated until all previous A1C in circulation are replaced (~90 days). Therefore, testing at time intervals earlier than three months may not allow enough time to pass to reach the expected target by the clinician. Testing at six-month intervals may be considered when glycemic targets are consistently achieved.
Sponsoring Organizations
- American Society for Clinical Laboratory Science
- American Society for Clinical Pathology
Sources
Disciplines
References
- American Diabetes Association. Standards of medical care in diabetes—2007. Diabetes Care. 2007;30 Suppl 1:S4-S41.
- Driskell OJ, Holland D, Waldron JL, et al. Reduced testing frequency for glycated hemoglobin, HbA1c, is associated with deteriorating diabetes control. Diabetes Care. 2014;37(10):2731-2737.
- McCarter RJ, Hempe JM, Chalew SA. Mean blood glucose and biological variation have greater influence on HbA1c levels than glucose instability: an analysis of data from the Diabetes Control and Complications Trial. Diabetes Care. 2006;29(2):352-355.