Ultrasonographic determination of goiter prevalence in southern Brazilian schoolchildren.
The aim of the present study was to estimate the prevalence of goiter in schoolchildren in a formerly iodine-deficient region in southern Brazil by assessing the relationship between body surface area (m2 ) and thyroid volume (ml) measured by ultrasonography. A population-based sample of 1,094 randomly selected schoolchildren (6 to 14 years; 556 boys and 538 girls) underwent clinical evaluation. A total of 119 (10.9%) children were diagnosed with goiter upon clinical examination according to WHO criteria (grade Ia: 65, grade Ib: 24, grade II: 29, grade III: 1). Of these, 85 underwent ultrasonography. In order to ascertain the absence of goiter in the 975 schoolchildren with a negative result upon clinical examination, one of ten children was randomly selected for ultrasonography. Sixty-two children agreed to be submitted to the exam. Thus, 147 schoolchildren were evaluated by ultrasonography (7.5-MHz transducer). Goiter was considered to be present when the thyroid volume:body surface area index was >6.2 ml/m . The estimated prevalence of goiter if all schoolchildren had been submitted to thyroid volume measurement by ultrasound was 7.2%; it was higher in the lower socioeconomic class (8.2%) than in the upper (7.8%) and middle classes (6.5%). In conclusion, the prevalence of goiter in schoolchildren of this region was higher than in other iodine-sufficient areas, especially in lower socioeconomic classes. Goiter in this region may be associated with naturally occurring goitrogens that operate more intensively among less privileged individuals.
Lisbõa
H R K
HR
Departamento de Medicina, Faculdade de Medicina, Universidade de Passo Fundo, Passo Fundo, RS, Brasil.
Gross
J L
JL
D000293:Adolescent; D001830:Body Surface Area; D001938:Brazil / Q000453:epidemiology; D016009:Chi-Square Distribution; D002648:Child; D005260:Female; D006042:Goiter / Q000000981:diagnostic imaging / Q000453:epidemiology*; D006801:Humans; D008297:Male; D015995:Prevalence; D012959:Socioeconomic Factors; D013961:Thyroid Gland / Q000000981:diagnostic imaging*; D014463:Ultrasonography