Iron status and its association with HbA1c levels in Dutch children with diabetes mellitus type 1

Children with diabetes mellitus (DM) type 1 may be at risk for iron deficiency (ID) although this has been little studied. ID is either an absolute (depleted iron stores) or a functional (restricted iron stores due to chronic inflammation) deficiency each requiring a different therapeutic approach. Unfortunately, absolute ID is often not distinguished from functional ID. Furthermore, iron-deficient anemia may influence hemoglobin A1c (HbA1c) levels. We aimed to determine the prevalence and type of ID and investigate its association with HbA1c levels in pediatric DM type 1 patients. We performed a two-center prospective observational study in which the iron status of Dutch children with DM type 1 was determined during a regular check-up. Absolute ID and functional ID were found in 13/227 (5.7%) and 100/214 (47%) patients, respectively, while only 15/113 (13%) patients also had anemia. HbA1c levels in patients with and without a deprived iron status (absolute or functional) were not significantly different (65 +/- 17 vs. 65 +/- 16 mmol/mol, p = 0.815). Conclusion: Functional, but not absolute, ID was common in Dutch pediatric DM type 1 patients. HbA1c levels were not associated with ID, which can be explained by the relatively mild deprived iron status in our patients. Trial registration: NTR4642 What is Known: Iron deficiency is either an absolute (depleted iron stores) or a functional (restricted iron stores due to chronic inflammation) deficiency each requiring a different therapeutic approach. Children with diabetes mellitus type 1 may be at risk for both types of iron deficiency and this can influence their hemoglobin A1c levels although this has been little studied. What is New: In Dutch children with diabetes mellitus type 1, functional, but not absolute iron deficiency, is common and should not be treated with iron replacement therapy. Hemoglobin A1c levels were not associated with iron deficiency, probably due to the relatively mild deprived iron status in our patients.