Evolution of urinary iodine excretion over eleven years in an adult population

Iodine Status, Thyroid Function, and Birthweight: A Complex Relationship in High-Risk Pregnancies

(1) Background: The consequences of iodine deficiency and/or thyroid dysfunction during pregnancy have been extensively studied, emphasizing on infant neurodevelopment. However, the available information about the relationship between iodine, thyroid hormones, and fetal growth in high-risk pregnancies is limited. We aim to investigate if iodine metabolism and/or thyroid parameters can be affected by adverse antenatal/perinatal conditions. (2) Methods: A cross-sectional study examined differences in iodine status, thyroid function, and birthweight between high-risk (HR group; n = 108)) and low-risk pregnancies (LR group; n = 233) at the time of birth. Urinary iodine concentration (UIC), iodine levels in amniotic fluid, and thyroid parameters [thyroid-stimulating hormone (TSH), free thyroxine (FT4)] were measured in mother–baby pairs. (3) Results: There were significant differences between HR and LR groups, free thyroxine (FT4) concentration in cord blood was significantly higher in the LR group compared with HR pregnancies (17.06 pmol/L vs. 15.30 pmol/L, respectively; p < 0.001), meanwhile iodine concentration in amniotic fluid was significantly lower (13.11 µg/L vs. 19.65 µg/L, respectively; p < 0.001). (4) Conclusions: Our findings support the hypothesis that an adverse intrauterine environment can compromise the availability of FT4 in cord blood as well as the iodine metabolism in the fetus. These differences are more noticeable in preterm and/or small fetuses.

Iodine nutrition status in Spain Needs for the future

Although iodine nutrition in Spain has improved in recent years, the problem is not completely resolved. It is necessary that health institutions establish measures to ensure an adequate iodine nutrition of the population, especially among the highest risk groups (children and adolescents, women of childbearing age, pregnant women and nursing mothers). A low salt intake should be advised, but it should be iodized. It is also imperative that food control agencies establish effective control over adequate iodization of salt. Indicators on iodine nutrition should be included in future health surveys. The EUthyroid study and the Krakow Declaration on iodine nutrition provide an opportunity to set up a pan-European plan for the prevention of iodine deficiency that should be considered and used by health authorities.

Hyperthyroidism secondary to hysterosalpingography: an extremely rare complication: A case report

RATIONALE

Hysterosalpingography (HSG), a standard procedure for the evaluation of women with infertility and repetitive pregnancy loss, is associated with complications such as uterine perforation, infection, allergic reactions, syncope, hemorrhage and shock, and pulmonary or retinal embolus. However, hyperthyroidism has not been reported as one of its complications.

PATIENT CONCERNS AND DIAGNOSES

We report the case of a 33-year-old euthyroid woman who presented to our hospital with palpitation, hand tremor, fatigue, and excessive sweating after HSG. Thyroid function tests revealed a thyroid stimulating hormone (TSH) level of 0.012 μIU/mL (range 0.38-4.34 μIU/mL), free T4 of 2.886 ng/dL (range 0.81-1.89 ng/dL), and free T3 levels of 9.4 pg/mL (range 1.80-4.10 pg/mL), and antithyroglobulin antibody of 31.78 IU/mL (range <115 IU/mL). The triiodothyronine uptake was 3.057 ng/mL (range 0.66-1.92 ng/mL). Serum iodine (SI) and urinary iodine (UI) levels: SI of 4717.748 μg/L (range 45-90 μg/L) and UI of 18069.336 μg/L (range 26-705 μg/L).

INTERVENTIONS AND OUTCOMES

The patient was diagnosed with iodine-induced hyperthyroidism (IIH), but was not treated with antithyroid drugs. She has spontaneously recovered and is pregnant currently.

LESSONS

This is the first reported case of overt IIH caused by HSG in a euthyroid patient without risk factors. It suggests that HSG also leads to excessive iodine absorption, which induces secondary hyperthyroidism.

Amiodarone-induced thyrotoxic thyroiditis: a diagnostic and therapeutic challenge

Amiodarone is an iodine-based, potent antiarrhythmic drug bearing a structural resemblance to thyroxine (T4). It is known to produce thyroid abnormalities ranging from abnormal thyroid function testing to overt hypothyroidism or hyperthyroidism. These adverse effects may occur in patients with or without preexisting thyroid disease. Amiodarone-induced thyrotoxicosis (AIT) is a clinically recognized condition commonly due to iodine-induced excessive synthesis of thyroid, also known as type 1 AIT. In rare instances, AIT is caused by amiodarone-induced inflammation of thyroid tissue, resulting in release of preformed thyroid hormones and a hyperthyroid state, known as type 2 AIT. Distinguishing between the two states is important, as both conditions have different treatment implications; however, a mixed presentation is not uncommon, posing diagnostic and treatment challenges. We describe a case of a patient with amiodarone-induced type 2 hyperthyroidism and review the current literature on the best practices for diagnostic and treatment approaches.