Peripheral iron levels in children with attention-deficit hyperactivity disorder: a systematic review and meta-analysis

Abstract

There is growing recognition that the risk of attention-deficit hyperactivity disorder (ADHD) in children may be influenced by micronutrient deficiencies, including iron. We conducted this meta-analysis to examine the association between ADHD and iron levels/iron deficiency (ID). We searched for the databases of the PubMed, ScienceDirect, Cochrane CENTRAL, and ClinicalTrials.gov up to August 9th, 2017. Primary outcomes were differences in peripheral iron levels in children with ADHD versus healthy controls (HCs) and the severity of ADHD symptoms in children with/without ID (Hedges’ g) and the pooled adjusted odds ratio (OR) of the association between ADHD and ID. Overall, seventeen articles met the inclusion criteria. Peripheral serum ferritin levels were significantly lower in ADHD children (children with ADHD = 1560, HCs = 4691, Hedges’ g = −0.246, p = 0.013), but no significant difference in serum iron or transferrin levels. In addition, the severity of ADHD was significantly higher in the children with ID than those without ID (with ID = 79, without ID = 76, Hedges’ g = 0.888, p = 0.002), and there was a significant association between ADHD and ID (OR = 1.636, p = 0.031). Our results suggest that ADHD is associated with lower serum ferritin levels and ID. Future longitudinal studies are required to confirm these associations and to elucidate potential mechanisms.

Maternal Ferritin Levels during Pregnancy and ADHD Symptoms in 4-Year-Old Children: Results from the INMA–INfancia y Medio Ambiente (Environment and Childhood) Prospective Birth Cohort Study

“…There is a large body of evidence about iron deficiency during pregnancy and maternal and fetal outcomes [32]. Two recent systematic reviews and meta-analyses suggest that ADHD is related to lower serum ferritin levels in children [33,34]. Nonetheless, few studies have been published so far analyzing the association between maternal ferritin levels during pregnancy and long-term effects on child neurodevelopment.…”

Prevalence and causes of anaemia in children aged 6–23 months in rural Qinghai, China: findings from a cross-sectional study

“…Anaemia has irreversible adverse effects on childhood growth and development, even their working abilities in adulthood 7. Many studies suggested an association between anaemia and impaired psychomotor development; impaired cognitive functions such as concentration, intellectual status, memory and scholastic skills; psychological and behavioural disorders such as attention-deficit/hyperactivity disorder8 and autism spectrum disorder9 and decreased physical activity 10. Meanwhile, anaemia has been confirmed to be associated with impaired renal function, increased absorption of lead and impaired immunity 11.…”

Magnesium, Iron, Zinc, Copper and Selenium Status in Attention-Deficit/Hyperactivity Disorder (ADHD)

“…Nevertheless, most of the studies indicate lower serum ferritin levels in ADHD patients [ 32 , 33 , 69 , 70 , 71 , 74 , 75 , 76 , 77 , 78 , 79 , 80 , 81 , 82 , 83 , 84 , 85 , 86 , 87 , 88 , 89 , 90 , 91 , 92 , 93 , 94 ]. Other reports found no significant relationship [ 89 , 95 , 96 , 97 , 98 , 99 , 100 ]. Only one (older) publication claimed to find higher levels [ 28 ].…”