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Hemoglobin A1c (HbA1c) (cont.)


When should HbA1c levels be tested?

In addition to random fasting blood glucose levels, HbA1c levels are routinely measured (tested) in the monitoring of people with type 1 and type 2 diabetes. HbA1c levels depend on the blood glucose concentration. That is, the higher the glucose concentration in blood, the higher the level of HbA1c. Levels of HbA1c are not influenced by daily fluctuations in the blood glucose concentration, but reflect the average glucose levels over the prior six to eight weeks. Therefore, HbA1c is a useful indicator of how well the blood glucose level has been controlled in the recent past (over two to three months), and may be used to monitor the effects of diet, exercise, and drug therapy on blood glucose in people with diabetes.

How can a person lower their hemoglobin A1c levels?

Following your type 1 or type 2 diabetes management plan can help lower your HbA1c level. This may consist of

  • dietary modifications,
  • physical activity,
  • medications, or
  • a combination of these.

A normal or only slightly elevated HbA1c level is an indication that your diabetes is under good control. If your HbA1c level remains high despite following your treatment plan, your doctor may suggest changing your treatment plan.

What are the limitations to measuring HbA1c?

Since HbA1c is not influenced by daily fluctuations in blood glucose concentration, it cannot be used to monitor day-to-day blood glucose concentrations, and to adjust insulin doses; nor can it detect the day-to-day presence or absence of hyperglycemia or hypoglycemia. HbA1c may be increased falsely in certain medical conditions. These conditions include

Medical conditions that may falsely decrease HbA1c include

REFERENCE: Horowitz, G. MD. et al. Hemoglobin A1c Testing. Medscape. Updated Jan 05, 2012

Medically Reviewed by a Doctor on 7/30/2015

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