Impact of Iron Deficiency Anemia on Glycated Hemoglobin (HbA1c) Levels in Diabetics with Controlled Plasma Glucose Levels

Abstract

Background: Glycated hemoglobin (HbA 1 C) is used as a gold standard for monitoring glycemic control. American Diabetes Association (ADA) has certified HbA 1 C ≥ 6.5% as a diagnostic criterion for diabetes mellitus (DM). Recent studies suggest that conditions affecting erythrocyte turnover like Iron deficiency anemia (IDA) alters HbA 1 C levels but their results are conflicting. However the effect of IDA on HbA 1 C is rarely reported.To determine the impact of IDA on HbA 1 C levels among controlled diabetics [Fasting plasma glucose (FPG) <126mg/dl since last 6 months] independent of blood glucose concentration and its variation according to the degree of anemia. Methods:This cross-sectional study carried out in SRM Medical College Hospital and Research Centre, Chennai includes totally 300 controlled diabetic patients -Type 2 DM (150 with IDA and 150 without IDA). Medical history recorded. HbA1C, complete hemogram and FPG were tested. Result:The mean HbA 1 C among controlled diabetics with IDA (7.86 ± 0.11%) was significantly higher than those without IDA (5.45 ± 0.038%) (P<0.05). HbA 1 C results were higher with the reduction of total hemoglobin (p< 0.05) Conclusion: IDA spuriously elevates HbA 1 C levels independent of blood glucose concentration in controlled-diabetics.HbA 1 C increases significantly as severity of anemia worsens. Thereby this study insists on the utter importance to exclude IDA and to correct it before any diagnostic or therapeutic decision is made based solely on HbA 1 C level.

RSSDI-ESI clinical practice recommendations for the management of type 2 diabetes mellitus 2020

“…In a cross-sectional study, the mean HbA1c in patients with controlled diabetes with iron deficiency anaemia (IDA) was significantly higher than those without IDA (7.86 ± 0.11% vs 5.45 ± 0.038% [p<0.05]) and the HbA1c values were inversely proportional to total haemoglobin (p<0.05). [ 714 ] Further, significantly higher HbA1c levels are observed in patients with IDA than healthy individuals (5.51 ± 0.696 v/s 4.85 ± 0.461%, p<0.001) and the HbA1c levels significantly decline following iron supplementation (p<0.001). [ 35 ] Therefore, HbA1c results in diabetes patients with IDA should be interpreted carefully.…”

“…In a cross-sectional study, the mean HbA1c in patients with controlled diabetes with iron deficiency anaemia (IDA) was significantly higher than those without IDA (7.86 ± 0.11% vs 5.45 ± 0.038% [p<0.05]) and the HbA1c values were inversely proportional to total haemoglobin (p<0.05). [ 714 ]…”

Exploring the Impact of Iron Deficiency Anaemia on Glycated Haemoglobin A1c Levels in Pregnant and Non-Pregnant Women: A Systematic Review

“…Many relationship between IDA and HbA1c is a subject of research, with several studies suggesting that IDA is associated with higher HbA1c levels in diabetic and nondiabetic males and non-pregnant women, [31][32][33][34][35][36][37][38][39][40] while others propose a contrary association. [41][42][43][44][45] The literature contains different systematic reviews and meta-analyses that discuss the correlation between IDA and HbA1c levels in this group.…”

Exploring the Interrelationship Between Electrolytes, Anemia, and Glycosylated Hemoglobin (Hba1c) Levels in Type 2 Diabetics

“…Diabetic patients have a greater risk of developing a number of major health problems [11]. The incidence of diabetes is sharply increasing worldwide with many long-term macro-and micro-vascular complications [12,13]. The International Diabetes Federation reported that total number of diabetic subjects in India is 41 million in 2006 and that this would increase to 70 million by the year 2025 [14].…”