Avaliação do estado nutricional de iodo em escolares adolescentes de 10 a 19 anos de escolas públicas do município de Vespasiano, MG

Abstract

Objective: To evaluate the urinary iodine excretion and this halogen concentration in schoolchildren´s household salt samples in the city of Vespasian (MG) and to study variables possible association. Method: Cross-sectional study carried out in students aged between 10 and 19 years, in the period from May to September 2009, regularly enrolled in four public schools in Vespasiano. Data related to age, sex, weight, height, body mass rate and arterial pressure were collected. Questionnaire was applied for students´ identification, observation of possible presence of thyroid disease or use of iodine-based medication. To calculate the sample it was determined 95% confidence level and 5% precision from 50% estimate frequency. Urine samples were collected from the participants, as well as the culinary salt consumed in their homes, for determination of the iodine concentration, and analyzed in the Ouro Preto Federal University Laboratory of Bromatology (Laboratório de Bromatologia da Universidade Federal de Ouro Preto (MG). The association between the iodine in the urine and study variables was verified by the exact and asymptotic Pearson Chi-square tests. The stratified analysis was performed by the Mantel Haenszel method for verifying the continuing association between the variables under study . The study was previously approved by the UFMG Ethics in Research Committee (Comitê de Ética em Pesquisa da UFMG). Results: the study was composed by 428 students from public schools, 63,3% female and e 36,7% male; 62,9% aged between 10 and 14 years old and 37,1% between 14 and 19 years old. From the nutrition point of view, 58,9% were normal, 0,5% with thinness and 46,7% with overweight or obesity. The results of iodine concentration in the urine showed 4,4% samples with com deficiency, 28,7% with appropriate rate , 46,7% more than adequate and 20,1% excessive. Among the study variables, only age showed significant association with the iodine concentration in the urine. After stratified analysis, it was found that the association was continuing for female adolescents, with overweight or obesity who had adequate iodine concentration in the household salt. Conclusion: Correlating results of iodine data in urine and in salt, with the age, sex and body mass rate variables, the findings were that the excessive concentrations of iodine in the urine were associated to female adolescents, over 14 years old, with adequate iodine levels in the salt and with overweight or obesity