O câncer de mama é apontado como o tipo de câncer mais prevalente no mundo. No Brasil, as taxas de mortalidade por câncer de mama continuam elevadas, observando-se diferenças inter-regionais. Foi realizado um estudo ecológico de série temporal (1980-2002) na Região Sul, com dados anuais do Departamento de Informação e Informática do SUS (DATASUS), para avaliar o comportamento do coeficiente de mortalidade por câncer de mama, padronizado por idade. Utilizou-se regressão linear simples e múltipla para estimar as taxas de mortalidade e as diferenças entre os três Estados. O Rio Grande do Sul parte de um patamar mais elevado e apresenta maior taxa média de mortalidade (14,45), sendo significativamente diferente (p < 0,001) quando comparado com Santa Catarina (8,93) e Paraná (9,95). Observou-se um aumento anual de 0,47 óbito na taxa de mortalidade por câncer de mama, independente do Estado. Conclui-se que há uma tendência similar de aumento da mortalidade por câncer de mama nos três Estados da Região Sul, com índices significativamente maiores no Rio Grande do Sul, enfatizando-se a importância da identificação dos fatores relacionados a esse quadro alarmante e o estabelecimento de medidas efetivas a fim de reverter esses números.

Aims: We aimed to assess the extent of variability in urinary iodine (UI) within a day, to determine the period of the day when UI was better associated with the UI in 24 h, and to study the relationship between UI and urinary sodium. Methods: This cross-sectional study included 60 volunteers. Four urine samples were collected from each participant (A: from breakfast to lunch; B: from lunch to dinner; C: from dinner to bedtime, and D: from bedtime to breakfast) and were compared with the 24-hour sample (calculated from samples A–D ). UI, creatinine and Na⁺ levels were measured in the partial samples and in the 24-hour sample. Results: The content of iodine and sodium in urine varied during the day (p < 0.001). The UI concentration from lunch to dinner was closest to the 24-hour UI concentration using the method of Bland and Altman. There were correlations between the UI content in the different periods of the day and in 24 h: A (r = 0.54; p < 0.000), B (r = 0.78; p < 0.000), C (r = 0.37; p = 0.004) and D (r = 0.77; p < 0.000). UI and urinary sodium content were strongly correlated in all periods of the day (samples A and B: r = 0.69, p < 0.000; sample C: r = 0.85, p < 0.000, and sample D: r = 0.78, p < 0.000). Conclusions: There was a within-day variation in UI content, which was strongly associated with urinary sodium content. Iodine concentration in the afternoon urine sample better reflected the 24-hour UI concentration. Therefore, urine collected in the afternoon is probably the best to evaluate iodine sufficiency in subjects with similar dietary habits.

Two weeks of an LID are probably sufficient to augment thyroid uptake of ¹³¹I, with little or no benefit from longer periods of an LID. Questionnaires regarding exposure to iodine similar to those employed here should identify individuals in whom the LID has not been as effective in increasing the thyroid uptake of ¹³¹I.

The healthy pregnant women studied had adequate iodine intake. In this situation, the main thyroid size determinants are probably genetic factors.

Aims: To evaluate the variability of 24-hour urinary iodine (UI) excretion intra- and interindividually on three days of a week in healthy subjects, living in southern Brazil, and the correlation among the urinary excretion of iodine and sodium. Methods: Cross-sectional study, including 47 volunteers: 18 individuals with one, 15 individuals with two and 14 individuals with three 24-hour urine samples. Iodine, creatinine and Na⁺ excretion in urine during 24-hour were measured. Results: Mean height, weight, BMI and 24-hour urinary excretion of creatinine were higher in men. UI and urinary sodium were correlated (n = 89, r = 0.524, p = 0.000). UI excretion varied widely, both inter- and intraindividually, on the 3 days of the week, but the mean excretion of UI was similar. In single individuals, the ratio between the maximum and minimum 24-hour UI excretion (m/m) ranged from 1.03 to 2.87, and the median coefficient of variation (CV) was 21% (P₂₅ = 7.0% and P₇₅ = 36.8%), with a range of 1%-51%. 24-hour UI excretion varied greatly among individuals on Sunday (CV = 47.5% and m/m = 7.75), Monday (CV = 38.7% and m/m = 4.60) and Thursday (CV = 40.4% and m/m = 4.50). UI was adequate in the group of 14 people, however, the UI excretion of two women suggested iodine intake persistently below that recommended by WHO. Conclusion: The variability of 24-hour UI excretion on different days in the same individual is lower than that observed among individuals.