Soluble Transferrin Receptor and SFI Index– A new biomarker to identify Iron Deficiency in Drug Naïve Children with ADHD – A Case-Control Study

  • Johnson Pradeep R
  • Sarthak Sahu
  • Vijaya Raman
  • Sumithra Selvam
  • Ashok Mysore


Background: Children with Attention Deficit Hyperactivity Disorder (ADHD) have been associated with iron deficiency. Among several markers, serum ferritin and serum iron have been used frequently to identify iron deficiency; however, the results are inconclusive.

Aims: To compare soluble transferrin receptor levels (sTfR), sTfR/log ferritin index (SFI), and conventional markers of iron deficiency among drug naïve children with ADHD and healthy controls.

Methods: We conducted this study in a tertiary care setting with a case-control study design. Thirty-five children with ADHD compared with age-matched 35 controls. Children were assessed on clinical aspects, hematology profile, iron biomarkers, inflammatory markers, sTfR, and SFI.

Results: We found significantly reduced mean levels of serum iron and percentage transferrin saturation and an increase in the median levels of Erythrocyte sedimentation rate (ESR) in children with ADHD compared to healthy children. However, in a clinically meaningful categorical analysis, we found that socioeconomic strata, ESR, percentage transferrin saturation, and SFI were significantly different between the groups. Finally, we found that Children with SFI ≥1.5 were approximately four times more likely to be associated with ADHD as compared to the control group. However, the percentage transferrin saturation was not associated with ADHD, after controlling for socioeconomic strata and ESR

Conclusions: SFI is a new marker, which is feasible and a better marker than serum ferritin in the identification of latent iron deficiency in children with ADHD. Serum iron and percentage transferrin saturation were also found to indicate an iron deficiency in children with ADHD. These findings must be explored in large community samples.

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