Evaluation of urinary iodine concentrations in pregnant women in Tehran

Background And Objective: Congenital hypothyroidism due to iodine deficiency is the most common cause of preventable mental retardation in the world. The lowest level of iodine deficiency during pregnancy could result in disorders such as miscarriage, premature delivery, intrauterine fetal death low birth IQ, mental retardation, hearing difficulty and speech impediments. This study aimed to evaluate urinary iodine concentrations during the first, second and third trimesters of pregnancy. Methods: This cross-sectional study was conducted on 354 pregnant women referring to prenatal care clinic of Akbar Abadi Hospital in Tehran. Demographic questionnaires were completed by an expert, and random urine samples were obtained to measure urinary iodine concentrations. In addition, venous blood samples were provided to determine the levels of thyroxine (T4) and thyroid stimulating hormone (TSH) during the first, second and third trimesters. Analysis of iodine status was based on the urinary iodine excretion in the patients. Urinary iodine deficiency was defined as concentrations of �100 micrograms/liter. FINDINGS: In this study, 285 patients (80.5) had urinary iodine levels of �100 µg/l with a mean of 62.35±67.7 µg/l. The mean urinary iodine concentrations during the first, second and third trimesters were 65.83±72.4, 50.34±41.5 and 62.67±68.3 µg/l, respectively. No significant difference was observed in the mean of urinary iodine between the first and second trimesters, second and third trimesters, and first and third trimesters. Moreover, no significant differences were observed between patients with urinary iodine levels of <100 µg/l and �100 µg/l in terms of the mean of maternal age, age at pregnancy and TSH level. CONCLUSION: According to the results of this study, despite the consumption of iodized salt, urinary iodine concentrations were below the standard limits in the studied pregnant women. It could be inferred that use of iodized salt may not be a proper solution for iodine deficiency in pregnant women. Therefore, it is recommended that iodine supplements be used before and during pregnancy, and iodine content of salt be increased as well. © 2015, Babol University of Medical Sciences. All rights reserved

Effects of Zinc and Selenium Supplementation on Thyroid Function in Overweight and Obese Hypothyroid Female Patients: A Randomized Double-Blind Controlled Trial

Objective: Zinc (Zn) and selenium (Se) are essential trace elements involved in thyroid hormone metabolism. This study was conducted to investigate the effects of Zn and Se supplementation on thyroid function of overweight or obese female hypothyroid patients in a double-blind, randomized controlled trial. Methods: Sixty-eight female hypothyroid patients were randomly allocated to one of the 4 supplementation groups receiving Zn + Se (ZS; 30 mg Zn as zinc-gluconate and 200 μg Se as high-selenium yeast), Zn + placebo (ZP), Se + placebo (SP), or placebo + placebo (PP) for 12 weeks. Serum Zn, Se, free and total triiodothyronine (FT3 and FT4), free and total thyroxine (FT4 and TT4), thyroid-stimulating hormone (TSH), and anthropometric parameters were measured. Dietary intake was recorded using 24-hour food recall. Physical activity questionnaire was completed. Results: No significant alterations were found in serum Zn or Se concentrations. Mean serum FT3 increased significantly in the ZS and ZP groups (p < 0.05) but this effect was significant in the ZP group compared to those in SP or PP groups (p < 0.05). Mean serum FT4 increased and TSH decreased significantly (p < 0.05) in the ZS group. TT3 and TT4 decreased significantly in the SP group (p < 0.05). Mean FT3:FT4 ratio was augmented significantly in the ZP group (p < 0.05). No significant treatment effects were found for TT3, FT4, TT4, or TSH between groups. Conclusion: This study showed some evidence of an effect of Zn alone or in combination with Se on thyroid function of overweight or obese female hypothyroid patients. © 2015, © American College of Nutrition