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Does the iodized salt therapy of pregnant mothers increase the children IQ? Empirical evidence of a statistical study based on permutation tests

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Abstract

The nutritional iodine deficiency disorders are still a major health problem in industrialized countries, but they are completely preventable by means of iodine prophylaxis. Iodine is essential for thyroid hormone (TH) synthesis and TH is required for normal brain development. Gestational iodine supplementation may improve infant cognitive development. In this study we aimed at evaluating the intelligence quotient of children born to mothers with different levels of iodine supplementation, with or without the administration of levothyroxine (LT4), prior to and during pregnancy. In particular we focused our attention on some mother–child pairs and we compared them according to iodized salt consumption and LT4 treatment. In this specific context, NPC test was applied to compare four groups of children, defined on the basis of maternal history related to iodized salt consumption and LT4 treatment. The results show that the deficit in functionality cognitive (in terms of intelligence quotient) is significantly higher in the children of mothers that does not make supplementation of iodized salt. This shows how a lack of iodine can hinder children in reaching their full intellectual potential. From a methodological point of view, our research showed the utility of the Non Parametric Combination test (NPC test) into analyze data concerning medical research.

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Authors and Affiliations

  1. Department of Economics and Statistics, University of Naples Federico II, Complesso Universitario di Monte Sant’Angelo, Cupa Nuova Cintia 21, 80126, Naples, Italy

    Massimiliano Giacalone

  2. Department of Economics, Section of Statistical and Mathematical Sciences, University of Messina, Via dei Verdi 75, 98122, Messina, Italy

    Agata Zirilli & Angela Alibrandi

  3. Department of Clinical and Experimental Medicine, AOU Policlinico G. Martino, University of Messina, Via Consolare Valeria 1, 98125, Messina, Italy

    Mariacarla Moleti

Authors
  1. Massimiliano Giacalone
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  2. Agata Zirilli
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  3. Mariacarla Moleti
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  4. Angela Alibrandi
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Correspondence to Angela Alibrandi.

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The study involved mother–child pairs.

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Giacalone, M., Zirilli, A., Moleti, M. et al. Does the iodized salt therapy of pregnant mothers increase the children IQ? Empirical evidence of a statistical study based on permutation tests. Qual Quant 52, 1423–1435 (2018). https://doi.org/10.1007/s11135-017-0529-0

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