Correlation of Iron Deficiency Anemia on HbA1C Levels: Comparison among Patients living with Diabetic and Non-diabetics

Abstract

Background: Glycated hemoglobin A1c (HbA1c) reflects average plasma glucose for the previous 3 months and is a principal parameter in the diagnosis of diabetes. Multiple non-glycemic parameters affect HbA1c such as iron deficiency anemia (IDA). However, reports on the effects of iron deficiency anemia on HbA1c levels are inconsistent. Objective: To find out the influence of iron deficiency anemia over HbA1c levels.  Methods: Study was conducted in iron-deficiency anemia and non-anemia patients who were either diabetic or non-diabetic. Basic blood parameters were evaluated long with HbA1c and fasting plasma glucose and population was classified in different grades of anaemia. Correlation of anemia and HbA1c was evaluated using statistical analysis. Results:The mean HbA1C in controlled diabetics with and without IDA were 9.53±0.93 & 5.43±0.45 respectively (P<0.05) and in non-diabetics with and without IDA were 5.84±0.71 & 5.12±0.52 respectively (P>0.05).  The difference between no, mild, moderate and severe anemia in both diabetics and non-diabetics was statistically significant (p<0.01). Mean HbA1C% was highest in groups with severe anemia (10.2%). Other blood parameters such as Hb, MCV, MCH and MCHC were also significantly different among diabetics who were IDA.  Conclusions: This study found a positive correlation between iron deficiency anemia and increased HbA1C levels, especially in the controlled diabetic. IDA should be diagnosed and corrected prior to alteration of treatment regimen based on HbA1C for diabetes. Concurrent evaluation for anemia is critical to correctly interpret glycemic status in Indian population with prevalent IDA.