Association of iodine status with IQ level and academic achievement of rural primary school children in West Bengal, India

Abstract

Background: Iodine being an integral component of the thyroid hormones is crucial for physical and mental development. Iodine status & intake is often measured by a surrogate measure, namely urine iodine excretion, as almost all ingested iodine is excreted in the urine. Aims &Objectives: To investigate the body Iodine status of rural primary school children and its association with their intelligence level (IQ) & academic achievement. Materials & Methods: A cross-sectional analytical study was carried out in three Government schools in the district of 24 Parganas, West Bengal, India among  300 children (150 boys & 150 girls) aged 6 to 8 years  studying in class II to IV. Urinary iodine was estimated by the 'Wet Digestion Method (Sandell-Kolthoff reaction). IQ level was evaluated using Ravens Progressive Matrices test. Academic achievement was evaluated on the marks obtained in the term end examinations.  Result: 12.34%, 15.6% & 24.3% of the children were in the severe, moderate & mild range of iodine deficiency in terms of urinary iodine excretion. It was found that 85.67% & 14.33% of the children were consumed iodated salt ?15 ppm &< 15 ppm of iodine level. 0.67%, 5% & 27.34 % of them achieved A, B & C of IQ grades, respectively.62.34 % of the students achieved first three academic grades. Body Iodine status of the children has significant positive correlation (P<0.01) with IQ grades and academic achievement. Academic achievement of the children has significant positive correlation (P<0.05) with their intelligence level. Conclusions: Poor body Iodine status of the rural primary school children may be one of the causes for their poor intelligence level and academic achievement.