بررسي تاثير مكمل هاي آهن ، يد و توام آنها بر وضعيت هورموني تيروييد دختران نوجوان مبتلا به فقرآهن

Effects of administration of iron, iodine and iron+iodine on thyroid hormone profile in iron deficient adolescent girls

Introduction: Iron deficiency is the most common single nutrient deficiency in the world and is a major concern for about 15% of the worldʹs population. Extensive data from animal and human studies indicate that iron deficiency impairs thyroid metabolism. Since, thyroid hormones play a vital role in growth, development and metabolism, the aim of this study, conducted in southern Iran, 2001-2002, was to ascertain the effects of administration of iron, iodine and iron+iodine on thyroid hormone profiles in iron deficient adolescent girls. Materials and Methods: This double blind clinical trial was conducted on 94 iron deficient adolescent girls; the selected subjects were randomly assigned in a double blind fashion to be placed in one of the four groups which, for 12 weeks, received a single oral dose of 190mg lipiodol plus 300mg ferrous sulfate 5 times a week, 300mg ferrous sulfate 5 times a week plus placebo, a single oral dose of 190mg lipiodol plus placebo, and the 4th group were given placebos, respectively. Fasting blood samples were collected at the beginning and at the end of the period, for analyses of indices Ferritin, TT4, FT4, TT3, FT3, TSH, RT3 and T3RU were measured via RIA, selenium using atomic absorption, and urinary iodine using the digestion method, TIBC, iron and albumin using the calorimetric method and hemoglobin using the cyanomethemoglobin method. For statistical analyses of data we used ANOVA,ANCOVA and the Paired t-test. Results: The analysis of food consumption revealed no significant change in nutrient intake during study, with the exception of energy, carbohydrate, vitamin A and vitamin C. There was a significant increase in Ferritin, hemoglobin and urinary iodine after administration of iron and iodine (p< 0.001). Indices of thyroid at the end of study revealed a significant increase in TT4, TT3, T3RU and a significant decrease in rT3 level, in comparison to the initial values (respectively in iron group: p<0.001, p<0.05, p<0.001, p<0.001 and in iron+iodine group: p<0.001, p<0.05, p<0.001, p<0.001). There were no significant differences in these indices between the iron and iron+iodine groups, but a significant difference was found when computed to the iodine and control groups. There was no significant difference in FT3 and TSH levels at the end of study in comparison to the initial levels or between groups, but FT4 value revealed a significant difference between beginning and end of study in iron and iron+iodine groups (p<0.001 and p<0.01 respectively). Conclusion: The results indicate that improvement of iron status of subjects is accompanied by an improvement in some indices of thyroid hormones. Comparison of these indices in iron and iron+iodine groups revealed that iodine supplementation had no effects on thyroid hormone changes due to iron supplementation.