High (but Not Low) Urinary Iodine Excretion Is Predicted by Iodine Excretion Levels from Five Years Ago

Background: It has not been investigated whether there are associations between urinary iodine (UI) excretion measurements some years apart, nor whether such an association remains after adjustment for nutritional habits. The aim of the present study was to investigate the relation between iodine-creatinine ratio (ICR) at two measuring points 5 years apart. Methods: Data from 2,659 individuals from the Study of Health in Pomerania were analyzed. Analysis of covariance and Poisson regressions were used to associate baseline with follow-up ICR. Results: Baseline ICR was associated with follow-up ICR. Particularly, baseline ICR >300 mu g/g was related to an ICR >300 mu g/g at follow-up (relative risk, RR: 2.20; p < 0.001). The association was stronger in males (RR: 2.64; p < 0.001) than in females (RR: 1.64; p = 0.007). In contrast, baseline ICR <100 mu g/g was only associated with an ICR <100 mu g/g at follow-up in males when considering unadjusted ICR. Conclusions: We detected only a weak correlation with respect to low ICR. Studies assessing iodine status in a population should take into account that an individual with a low UI excretion in one measurement is not necessarily permanently iodine deficient. On the other hand, current high ICR could have been predicted by high ICR 5 years ago. Copyright (C) 2011 S. Karger AG, Base

Quantification of urinary iodine: a need for revised thresholds.

To compare different possibilities of reporting the iodine supply in the same urine samples. Indeed, in field studies, urinary iodine concentration (I/L: micro g I/L, micro mol I/L, I/creatinine: micro g I/g creatanine, micro mol I/mol creatinine) is more readily available than excretion (I/24h micro g I/24 h, micro mol I/24h). However, confusion exists regarding the comparability of iodine supply based upon I/L, I/creatinine and I/24h, which for decades have been regarded as biochemically equivalent.Journal ArticleResearch Support, Non-U.S. Gov'tSCOPUS: ar.jinfo:eu-repo/semantics/publishe

Does microbiota composition affect thyroid homeostasis?

The intestinal microbiota is essential for the host to ensure digestive and immunologic homeostasis. When microbiota homeostasis is impaired and dysbiosis occurs, the malfunction of epithelial barrier leads to intestinal and systemic disorders, chiefly immunologic and metabolic. The role of the intestinal tract is crucial in the metabolism of nutrients, drugs, and hormones, including exogenous and endogenous iodothyronines as well as micronutrients involved in thyroid homeostasis. However, the link between thyroid homeostasis and microbiota composition is not yet completely ascertained. A pathogenetic link with dysbiosis has been described in different autoimmune disorders but not yet fully elucidated in autoimmune thyroid disease which represents the most frequent of them. Anyway, it has been suggested that intestinal dysbiosis may trigger autoimmune thyroiditis. Furthermore, hypo- and hyper-thyroidism, often of autoimmune origin, were respectively associated to small intestinal bacterial overgrowth and to changes in microbiota composition. Whether some steps of this thyroid network may be affected by intestinal microbiota composition is briefly discussed below