Relationship between iron metabolism and thyroid hormone profile in hypothyroidism

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