Anemia

An A1c value represents the percent of the total hemoglobin in the A1c form. Both an increase of A1c hemoglobin -- due to the presence of high blood sugar -- or a decrease in total hemoglobin can make the A1c percentage higher. Certain types of anemia associated with low total hemoglobin production can elevate the proportion of hemoglobin present in the A1c form. People with anemia due to lack of iron, folate or vitamin B12 may have an elevated A1c without having diabetes. Anemia caused by certain types of untreated kidney disease may also cause an elevated A1c in the absence of diabetes.

 

Genetic Conditions

People with genetic conditions that affect the composition of their hemoglobin proteins may have high A1c values without diabetes. Examples of genetic conditions that may cause a falsely elevated A1c value include sickle cell trait and S-beta-thalassemia. However, several genetic blood disorders that cause premature red blood cell breakdown commonly cause low A1c values.
 

Medications

Certain medications may cause high blood sugar values in people who do not have diabetes. If taken for a prolonged period, these drugs may lead to an elevated A1c in the absence of underlying diabetes. Examples include corticosteroids, such as prednisone, and the antiseizure medication phenytoin (Dilantin). Some antiviral medications used to treat human immunodeficiency virus can also elevate blood sugar, including fosamprenavir (Lexiva) and saquinavir (Invirase). Drugs used after organ transplantation may suppress hemoglobin production and cause an increase in A1c without diabetes.
 

Other Reasons

Different laboratory methods are used to measure A1c and calculate the A1c value. Some test methods give a higher A1c value than others. Certain chemicals in the blood formed naturally or from the use of medicines may also interfere with the test. Discuss factors that may influence A1c with your doctor.

http://www.livestrong.com/article/153932-reasons-for-elevated-a1cs-without-diabetes/