Relationship between glycosylated hemoglobin and iron deficiency anemia: A common but overlooked problem

Integrity loss of glycosylated hemoglobin with deepening anemia

“…Following the observation that HbA1c decreases with treatment of IDA, the first question is: how much HbA1c decrease is caused by the rise in Hgb. There is only one study on this subject in diabetic patients without a control group, and it was found that 2.2 mg/dL increase in Hgb value caused a 0.4% decrease in HBA1c level (10). In our study, it was determined that 1 mg/dL increase in Hgb value caused a 0.113% decrease in HBA1c value.…”

“…If the HBA1c level decreases after iron treatment in a patient with IDA, it is necessary to demonstrate how much increase in Hgb causes a decrease in HBA1c in order for the decrease in HBA1c to be useful in the diagnosis and follow-up of diabetic patients. There is only one study on this subject in the diabetic patient population without a control group (10), and further studies are needed. Our study was carried out in the nondiabetic patient group in comparison with the control group.…”

Relationship Between Glycosylated Hemoglobin and Vitamin B12 Deficiency Anemia

“…No study has examined this subject in patients with vitamin B12 deficiency anemia. In a single study conducted with patients with IDA, one of the nutritional anemias, it was reported that an increase of 2.2 mg/dL in Hgb leads to a 0.4% decrease in the HbA1c level [ 16 ]. As shown in this study, HbA1c level significantly decreases in vitamin B12 deficiency anemia, just like in IDA, after vitamin B12 replacement and a 0.94 mg/dL increase in Hgb level corresponds to a 0.24% decrease in HbA1c level, possibly indicating that the more severe the anemia, the more HbA1c loses its reliability in the diagnosis and follow-up of DM.…”

“…However, there is no study examining how much of the increase in Hgb level after treatment leads to a decrease in HbA1c. While there is only one study on the patient population with iron deficiency anemia (IDA) [ 16 ], there is no study on the patient population with vitamin B12 deficiency anemia. This study aimed to demonstrate whether there is a decrease in HbA1c after the treatment of vitamin B12 deficiency anemia and if there is how much Hgb increase causes a decrease in HbA1c.…”

Causal association between type 2 diabetes mellitus, inflammatory bowel disease and iron deficiency anemia: A multivariable Mendelian randomization Study

“…IDA poses a signi cant burden among patients hospitalized for Crohn's disease, as shown by a large cohort study conducted in the United States 5 ; another observational study focusing on patients with in ammatory bowel disease (IBD) revealed that approximately one-fth of the cohort experienced anemia primarily due to ID 6 ; recent guidelines from the European Crohn's Disease and Colitis Organization underline the importance of regular screening and prompt treatment for IDA in individuals with IBD 7 ; a recent study reported varying prevalence rates of ID in hospitalized IBD patients, ranging from 13-90%, with an average of 23% 8 . In the context of type 2 diabetes mellitus (T2DM), a retrospective study involving 1,137 patients found that 39.3% had ID, with ID being most prevalent (61.7%) among those with a duration of diabetes less than 5 years 9 ; another study demonstrated an association between IDA and elevated glycosylated hemoglobin concentrations, which signi cantly declined following iron treatment 10 .…”