Correlação entre níveis de iodo na urina e alterações anatomopatológicas em tireoide / Correlation between iodine urinary levels and pathological changes in thyroid glands

OBJETIVOS: Determinar o aporte nutricional de iodo na população estudada e correlacionar os níveis de iodo encontrados em amostras casuais de urina (iodúria) com alterações anatomopatológicas observadas nas tireoides dessa população. MATERIAIS E MÉTODOS: Determinou-se a iodúria em 30 amostras casuais de urina e realizou-se o estudo anatomopatológico de 55 tireoides colhidas de cadáveres que deram entrada no Departamento Médico Legal de Vitória, Espírito Santo, Brasil, no período de maio a agosto de 2011. RESULTADOS: Em 29 amostras de urina (96,7%) encontrou-se iodúria acima do limite máximo preconizado pela Organização Mundial da Saúde (OMS) de 300 µg/L. Em 14 tireoides (25,5%) foi identificada a presença de quadros histológicos compatíveis com tireoidite. Níveis mais elevados de iodo na urina foram observados no sexo feminino e nos casos de tireoides com presença de achados inflamatórios (tireoidites). CONCLUSÕES: Podemos concluir que na população estudada houve um excesso de iodo em seu aporte nutricional e uma maior incidência de quadros inflamatórios tireoidianos.

OBJECTIVES: To determine iodine nutrition in the population and to correlate levels of iodine found in random samples of urine with pathological changes observed in thyroids collected in this population. MATERIALS AND METHODS: Urinary iodine was determined in 30 random samples of urine and the pathological study was carried out in 55 thyroid glands from corpses received by the Department of Forensic Medicine of Vitória, Espírito Santo, Brazil from May to August 2011. RESULTS: In 29 urine samples (96.7%) urinary iodine was above the maximum limit recommended by the World Health Organization (WHO), of 300 mg/L. Fourteen thyroids (25.5%) showed the presence of histological changes compatible with thyroiditis. Higher levels of iodine in urine were observed in females and in of thyroid that showed inflammation (thyroiditis). CONCLUSIONS: We conclude that, in this population, there is excess iodine intake, and greater incidence of inflammatory thyroid disease.

Alta frecuencia de patología tiroidea funcional y autoinmune en mujeres embarazadas chilenas catalogadas como sanas / High frequency of functional and autoimmune thyroid disease in women classified as healthy Chilean pregnant

Background: Untreated functional thyroid diseases are a risk factor for maternal and fetal complications during pregnancy. Aim: To determine the frequency of functional or autoimmune thyroid disease in healthy women during the first trimester of pregnancy. Subjets and Methods: healthy pregnant women attending a routine consult during their first trimester of pregnancy were studied. Thyroid stimulating hormone (TSH), total and free thyroxin (T4) anti-thyroid peroxidase (TPO) antibodies and spot urine iodine levels were measured. The reference ranges provided by the Atlanta Georgia Consensus in 2004 were used as normal values. A urine iodine concentration < 150 ug/L was considered low. Results: One hundred women age 30 +/- 5 years with a mean gestational age of 8,8 +/- 1,9 weeks, were studied. The frequencies of subclinical hypothyroidism, clinical hypothyroidism, isolated low thyroxin lecels, high antiTPO antibodies and low urine iodine levels were 19, 2, 3, 13 and 15 percent, respectively. Women with high TSH levels had lower total and free T4 levels. Conclusions: Twenty one percent of this sample of apparently healthy pregnant women had a clinical or subclinical hypothyroidism.

Dietary iodine intake and urinary iodine excretion in patients with thyroid diseases

This study was conducted to examine the usual iodine intake in patients with thyroid diseases and to compare iodine status with normal subjects. The dietary iodine intake was assessed using a semi-quantitative food frequency questionnaire, and urinary iodine excretion was measured in 184 patients diagnosed with thyroid diseases and 207 normal subjects. The average usual iodine intake of patients with thyroid diseases was 673.8 +/- 794.9 ug/day and that of normal subjects was 468.9 +/- 481.9 ug/day. Among the patients with thyroid diseases, higher values were found in the patients with thyroid cancer (1460.6 +/- 1044.8 ug/day) and lower values were found in patients with simple goiter (443.5 +/- 470.4 ug/day). The urinary iodine excretions of patients and normal subjects were 4.33 +/- 5.70 mg/L and 2.11 +/- 0.69 mg/L, respectively. The iodine intake and urinary iodine excretion of patients with thyroid diseases were significantly higher than those of normal subjects (p < 0.05). The dietary iodine intake and urinary excretion of patients with thyroid cancer were significantly higher than other patients with thyroid diseases and normal subjects because of the use of seaweed or seaweed-containing dietary supplements (p < 0.01). This study suggests that the habitual ingestion of seaweed-containing dietary supplements in addition to dietary iodine intake will have adverse effects due to its excessive iodine intake.