Stunting, selenium deficiency and anemia are associated with poor cognitive performance in preschool children from rural Ethiopia

Background: Anthropometric characteristics and iron status affect cognitive performance in children. In addition, selenium can influence cognitive outcomes; protection of the brain from oxidative stress and its role in thyroid hormone metabolism are putative mechanisms. Methods: To investigate their association with cognitive performance, anthropometric indicators, iron biomarkers, and serum selenium of children (n = 541) of 54-60mo of age from rural Ethiopia were assessed. Cognitive assessment was conducted with the administration of two reasoning subtests of the Wechsler Preschool and Primary Scale of Intelligence and the school readiness test. Results: Stunting was found in 41.4 % of children, 28.7 % were underweight, and 6.3 % were wasted. The mean score of stunted children was lower than that of non-stunted children on non-verbal reasoning (7.0 +/- 3.2vs7.9 +/- 3.1; p = 0.01) and the school readiness tests (4.3 +/- 2.2 vs 3.3 +/- 2.1; p < 0.001). Compared to non-anemic children, anemic children had lower score for the verbal reasoning test (9.5 +/- 1.7 vs 8.9 +/- 2.2; p = 0.02). However, except for hemoglobin, none of the iron biomarkers had significant associations with the cognitive score of the study children (p > 0.05). Selenium deficient children had lower scores on all cognitive tests than normal children (p < 0.05). Conclusion: The present study finding linking chronic undernutrition and micronutrient deficiency to cognitive deficits suggests the need for designing effective intervention programmes to control for protein energy malnutrition and micronutrient deficiency and address cognitive development in children.