Relationship between iron metabolism and thyroid hormone profile in hypothyroidism

Abstract

Background: Iron and thyroid hormone metabolism are closely related with each other. Iron plays an important role for both the synthesis as well as metabolism of thyroid hormones acting as a component of many enzymes including thyroid peroxidase (TPO). So, iron deficiency can lead to abnormal functioning of thyroid gland. Ferritin is storage form of iron in our body. Several studies in showed that nutritional iron deficiency can significantly decrease the circulating levels of both T4 and T3 and it can also reduce peripheral conversion of T4 to T3. So, the aim of the study is to find out whether there is any relationship between hypothyroidism and iron metabolism.Methods: This cross-sectional descriptive study was conducted at Deben Mahata Government Medical College and Hospital, Purulia on 50 hypothyroid patients and 50 age and sex matched controls after imposing inclusion and exclusion criterias. Blood samples were collected and estimation of Serum TSH, fT4 and fT3, iron, ferritin and TIBC levels were done. Then the data obtained were analysed by proper statistical methods.Results: Out of 100 subjects 68 were male and rest were female. The mean serum TSH level in study population was significantly higher than that of comparison group. While serum fT3 and fT4 level in study group were lower than the control group and both were statistically significant. In the other hand, the mean serum ferritin and iron levels in cases were lower than that in controls and the mean TIBS was higher in study group and all the differences were statistically significant. There were significant correlation between Serum ferritin and serum iron (positive correlation), Serum ferritin and TSH (negative correlation), Serum TSH and fT4 (negative correlation) but there was no significant relationship between serum TSH and iron.Conclusions: The iron metabolism is disturbed in hypothyroidism reflected by low serum ferritin and iron.

Relationship between Serum Ferritin and Thyroid Hormones: A Hospital Based Cross Sectional Study

“…In this study, we found that there was statistically significant relationship between iron deficiency anemia and hypothyroidism. The findings of our study were similar to that of study conducted by Chatterjee et al 1 Similarly, in a randomized double blind controlled study done by Ravanbod M et al 12 demonstrated that treatment of patients with subclinical hypothyroidism and iron-deficiency anemia with a combination of iron levothyroxine resulted in a favorable outcome compared with treatment of patients with monotherapy of iron or levothyroxine alone. The study conducted by Binita et al showed, there was no statistically significant relations of thyroid dysfunction in patient with IDA in Lalitpur Nepal.…”

“…So, deficiencies of these elements can impair thyroid functions. 1 Iron is one of the essential elements for the thyroid gland to function properly and it is stored in the form of ferritin. 2 First two initial steps of thyroid hormone biosynthesis require an iron containing enzyme known as thyroperoxidase (TPO), which is a membrane bound glycosylated protein.…”

Serum Copper, Iron, and Total Iron Binding Capacity in Hypothyroidism: A Case Control Study

“…8 Many studies suggest that iron deficiency impairs thyroid hormone metabolism in both animals and humans. 9,10,11 Iron deficiency has also been shown to decrease plasma T3 and T4 concentrations while increasing in vitro hepatic reverse T3 (rT3) deiodination, implying that iron deficiency affects thyroid hormone metabolism via a deactivating pathway. T4 is transformed to T3, however a large part is converted to rT3, a physiologically inactive metabolite.…”