Comparative study of serum ferritin in hypothyroid and euthyroid subjects

Abstract

Background:- Thyroid harmones triiodothyronin (T3) and thyroxin (T4) are 
secreted by thyroid glands and secretion of these harmone is under feedback control of Thyroid 
Stimulating Harmone (TSH). Primary hypothyroidism is a state in which thyroid harmone T4 and T3 are reduced and TSH level increased in serum. Hypothyroidism affects haematopoietic system and causes anaemia. Iron is required for thyroid peroxidase enzyme which catalyses thyroid harmone biosynthesis. Ferritin is storage form of iron and its serum level reflects iron stores of body. Altered level of serum ferritin have been reported in patients with thyroid disease. So the present study was done to observe serum ferritin level in primary hypothyroidism and to compare it with euthyroid subjects and to determine correlation between serum ferritin and thyroid harmone level. 
Material and Methods:- This cross sectional study was done in January 2019. On the basis of TSH 
values 40 hypothyroid subjects as case and 40 euthyroid subjects as matched controls were included. Informed consent was taken from all study participants. Subjects with TSH value >5.5 
µIU/ml were taken as hypothyroid and TSH value <5.5 µIU/ml were taken as euthyroid. Serum was 
analyzed for freeT3, freeT4, Thyroid-Stimulating Hormone (TSH) and ferritin by chemiluminescent 
immunoassay autoanalyser. 
Results:- In our study we found that mean value of serum ferritin concentration in hypothyroid 
subjects was lower (13.51±6.13 ng/ml) as compared to the mean value of serum ferritin 
among euthyroid subjects (41±11.41 ng/ml) and it was found to be statistically significant. We 
observed a negative correlation between serum TSH and serum ferritin among study subjects (r= -0.89). 
Conclusion:- Serum ferritin level decreases in hypothyroid patients and it further aggravates hypothyroidism, so ferritin level should be assessed in hypothyroid subjects.