[New method of estimating iodine overload in the urine from a simple urination].

Iodine research holds an increasing place in thyroid pathology, either to cover a radioisotopic investigation with paradoxal results or to find an iatrogenic cause to an unexplained hypo- or hyperthyroidism in new born children as well as in adults. To determine iodine overloads we may need a urinary iodine estimation, in addition to blood iodine determination (quickly eliminated products) or instead of it (difficult blood taking: new born children, etc.). Classically, the 24 hours urinary iodine estimation (total urinary iodine) covers this need but, in practice, as we generally deal with ambulatory patients, the risks linked to the obtention of a perfect 24 hours urine collecting make us abandon it. This article presents an original and simple way of getting round this difficulty: it demonstrates that an excellent iodine overload estimation can be obtained by measuring simultaneously from a simple miction: on one hand iodine concentration, on the other hand the urinary creatinine.