Effect of Oral Iron on Markers of Oxidative Stress and Antioxidant Status in Children with Iron Deficiency Anaemia.

INTRODUCTION: Conflicting reports are available on the relationship of Iron Deficiency Anaemia (IDA) and iron therapy with oxidative stress.

AIM: To study the levels of markers of oxidative stress and anti-oxidant status in children with IDA and to assess the effect of iron therapy on the same.

MATERIALS AND METHODS: This prospective, single centre, hospital based study was a sub-study of a randomized controlled trial conducted in the Department of Paediatrics, Jawaharlal Nehru Medical College, Aligarh Muslim University, Aligarh, Uttar Pradesh in collaboration with the Department of Biochemistry (of the same institution) between October 2009 to February 2011. The sub-study was conducted in two parts: in the first part, levels of a biomarker of oxidative stress {Malondialdehyde (MDA)} and anti-oxidant enzymes {Superoxide Dismutase (SOD), Catalase (CAT), Glutathione Peroxidase (GPx)} were assessed and compared between 67 children with IDA and 31 non-anaemic controls; in the second part, the effect of oral iron (6mg/kg/day) for eight weeks on these markers was studied in a subset of 35 children with IDA. The Bivariate correlations procedure was used to compute pair wise associations for a set of variables. T-tests (Independent samples t-test/Paired sample t-test) and Non-parametric tests (Mann-Whitney test/Wilcoxon signed-rank test) were applied as applicable for normally and non-normally distributed data, respectively.

RESULTS: Levels of anti-oxidant enzymes were significantly lower (p<0.001) in children with IDA as compared to controls, viz., SOD {median, 8.63 (IQR, 8.60-8.66) vs. 9.46 (IQR, 9.14-9.62) units/mg protein}, CAT {median, 8.49 (IQR, 8.46-8.50) vs. 9.10 (IQR, 9.04-9.14) μmol H2O2/min/mg protein} and GPx {median, 49.19 (IQR, 48.99-49.60) vs. 56.94(IQR, 56.80-57.14) mol NADPH oxidized /min/ mg protein}. Whereas, levels of MDA were significantly higher (p<0.001) in IDA group {median, 1.50 (IQR, 1.48-1.52) vs. 1.24 (IQR, 1.20-1.27) moles/ml of serum}. Levels of Haemoglobin (Hb) and markers of iron status (serum iron, transferrin saturation and ferritin) had a very strong, highly significant positive correlation (p<0.001) with levels of anti-oxidant enzymes (SOD, CAT, and GPx) but a very strong, highly significant negative correlation (p<0.001) with MDA. Total Iron Binding Capacity (TIBC) on the other hand, had a strong, highly significant (p<0.001) negative correlation with SOD, CAT, and GPx but a strong, highly significant positive correlation (p<0.001) with MDA. After eight weeks of daily iron therapy, a highly significant rise (p<0.001) from baseline was observed in levels of SOD, CAT, and GPx in subjects with IDA. On the other hand, MDA levels declined significantly (p<0.001).

CONCLUSION: Lipid peroxidation is increased and anti-oxidant defenses lowered in IDA. These changes, however, may be mitigated effectively with oral iron therapy.