Status nutricional de selênio em crianças e adolescentes da Bahia

Abstract

Selenium is an essential micronutrient for human health, since it constitutes the selenoproteins that play an antioxidant role and participate in the biosynthesis and activation of thyroid hormones. This study present as methodology a descriptive approach and cross-sectional design, developed from two distinct strategies. In article 1, a systematic review with meta-analysis was performed on the nutritional status of selenium in children in Brazil and worldwide. In article 2, data from 982 schoolchildren aged 6 to 14 years from public schools in Bahia, Brazil. In this study, urinary selenium and iodine were measured by the ICP-MS method, along with thyroid stimulating hormone (TSH) in filter paper blood samples. As results, article 1 revealed high prevalence of selenium deficiency (SD) in previously conducted studies in Brazil and worldwide (63% and 41%, 95% IC, respectively); however, high heterogeneity was found (I2= 100%). Article 2 showed adequacy in selenium and iodine nutrition. The median CSU and CIU 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 CIU were observed in 17.1% and 30.9% of schoolchildren, respectively. There was a positive correlation between CSU and UIC (r = 0.60; p = 0.00). The mean TSH was 0.95 (IQR: 0.69–1.30 μUI/L). It is concluded that the article 1 verified the overall prevalence of SD among children, noting the complexity and methodological differences between studies. In article 2, an important correlation between urinary selenium and iodine concentration points to the fact that selenium nutrition may interact with other nutrients and/or dietary components. Thus, the inclusion of selenium measurement in micronutrient monitoring actions can contribute to a greater effectiveness of programs to prevent disorders in the child population.