Renata de Oliveira Campos1,2,3, Lorena Maia de Jesus3, Déborah Araújo Morais4, Wellington Tavares de Sousa Júnior4, Vanessa Cristina de Oliveira Souza4, Clotilde Assis Oliveira1, Fernando Barbosa Júnior4, Mariana Macedo5, Laszlo Hegedüs6, Helton Estrela Ramos7,8. 1. Health and Science Center, Federal University Reconcavo of Bahia, Santo Antonio de Jesus, BA, Brazil. 2. Postgraduate Program in Interactive Processes of Organs and Systems, Health & Science Institute, Federal University of Bahia, Salvador, BA, Brazil. 3. Bioregulation Department, Health and Science Institute, Federal University of Bahia, Salvador, BA, Brazil. 4. Laboratory of Toxicology and Essentiality of Metals, School of Pharmaceutical Sciences of Ribeirao Preto, University of Sao Paulo, Ribeirao Preto, SP, Brazil. 5. Federal University of Jequitinhonha e Mucuri Valleys, Teófilo Otoni, Brazil. 6. Department of Endocrinology and Metabolism, University of Southern Denmark, Odense, 5000, Denmark. 7. Postgraduate Program in Interactive Processes of Organs and Systems, Health & Science Institute, Federal University of Bahia, Salvador, BA, Brazil. ramoshelton@gmail.com. 8. Bioregulation Department, Health and Science Institute, Federal University of Bahia, Salvador, BA, Brazil. ramoshelton@gmail.com.
Abstract
BACKGROUND: Selenium (Se) and iodine (Io) are important micronutrients for the proper functioning of the thyroid gland, as they are crucial for the synthesis and activation of the thyroid hormones (TH) triiodothyronine (T3) and thyroxine (T4). OBJECTIVE: To evaluate the Se and Io nutritional status among schoolchildren. METHODOLOGY: Cross-sectional, descriptive and analytical study conducted in 982 schoolchildren aged 6-14 years from public schools in the state of Bahia, Brazil. Sociodemographic and anthropometric variables, as well as urinary Se (USC) and Io concentrations (UIC) using the inductively coupled plasma mass spectrometry (ICP-MS) method and thyroid-stimulating hormone (TSH) from filter paper blood collection, were evaluated. RESULTS: The median USC and UIC were 38.7 and 210.0 (IQR: 26.8-52.9 and 129.3-334.1 μg/L, respectively). The prevalence of iodine deficiency and excessive UIC were observed in 17.1% and 30.9% of schoolchildren, respectively. Concomitant low USC and IoD was found in 3.9% of schoolchildren. There was a positive correlation between USC and UIC (r = 0.60; p = 0.00). The median TSH was 0.95 (IQR: 0.69-1.30 µUI/L). CONCLUSIONS: This study demonstrates that USC is a good biomarker for assessing Se status, meantime more studies are needed to establish cutoff USC in child population. Despite adequate median intake, a subgroup of schoolchildren had IoD and low USC. The correlation between UIC and USC point at the importance of two micronutrients, raising the question whether measuring Se should be included in monitoring programs that address the prevention of nutritional disturbances.
BACKGROUND:Selenium (Se) and iodine (Io) are important micronutrients for the proper functioning of the thyroid gland, as they are crucial for the synthesis and activation of the thyroid hormones (TH) triiodothyronine (T3) and thyroxine (T4). OBJECTIVE: To evaluate the Se and Io nutritional status among schoolchildren. METHODOLOGY: Cross-sectional, descriptive and analytical study conducted in 982 schoolchildren aged 6-14 years from public schools in the state of Bahia, Brazil. Sociodemographic and anthropometric variables, as well as urinary Se (USC) and Io concentrations (UIC) using the inductively coupled plasma mass spectrometry (ICP-MS) method and thyroid-stimulating hormone (TSH) from filter paper blood collection, were evaluated. RESULTS: The median USC and UIC were 38.7 and 210.0 (IQR: 26.8-52.9 and 129.3-334.1 μg/L, respectively). The prevalence of iodinedeficiency and excessive UIC were observed in 17.1% and 30.9% of schoolchildren, respectively. Concomitant low USC and IoD was found in 3.9% of schoolchildren. There was a positive correlation between USC and UIC (r = 0.60; p = 0.00). The median TSH was 0.95 (IQR: 0.69-1.30 µUI/L). CONCLUSIONS: This study demonstrates that USC is a good biomarker for assessing Se status, meantime more studies are needed to establish cutoff USC in child population. Despite adequate median intake, a subgroup of schoolchildren had IoD and low USC. The correlation between UIC and USC point at the importance of two micronutrients, raising the question whether measuring Se should be included in monitoring programs that address the prevention of nutritional disturbances.