Study of impact of subclinical hypothyroidism on iron status and hematological profile


  • Arvind K. Mishra Department of Medicine, King George Medical University, Lucknow, Uttar Pradesh, India
  • Rohit Anand Department of Medicine, King George Medical University, Lucknow, Uttar Pradesh, India
  • Shailendra P. Verma Department of Hematology, King George Medical University, Lucknow, Uttar Pradesh, India
  • Kamlesh K. Gupta Department of Medicine, King George Medical University, Lucknow, Uttar Pradesh, India



Anemia, Hypothyroidism, Iron, Subclinical


Background: Thyroid hormones play an important physiological role to maintain balance of metabolism of entire human body. Erythrocyte abnormalities are frequently associated with thyroid disorder. Subclinical hypothyroidism, often a hidden entity, is associated with iron-deficiency anemia along with other hematological disorders.  Thyroid hormones have a crucial role in metabolism and proliferation of blood cells. Thyroid dysfunction has profound effects on blood cells such as anemia, alters RBC indices including MCV, MCHC as well as iron stores. Present study was carried out to investigate and explore subclinical hypothyroid patients, to know the effect of subclinical hypothyroidism on hematological parameters and body iron store.

Methods: This retrospective study included 200 newly diagnosed, untreated subclinical hypothyroid, and 200 healthy euthyroid individuals. The hematological parameters and thyroid profile of the subjects were assessed by the mean, standard deviation (SD). Student’s t-test was used to report our results, with p-value <0.05 considered as statistically significant.

Results: In this study we have compared hemoglobin level, red cell indices, serum Ferritin among study group and euthyroid healthy group and found that mean hemoglobin, serum ferritin and RBC indices were significantly depleted in subclinical hypothyroid patient in comparison to euthyroid group. 37 of total 200 [18.22%] newly diagnosed subclinical hypothyroid patients was suffering from Iron deficiency anemia with significant number of patients having hemoglobin level less than 10 gm%.

Conclusions: Iron deficiency anemia is quite common in Subclinical hypothyroidism and is often associated with depleted body iron store and complication of getting converted into primary hypothyroidism. As there is no significant clinical manifestation of SCH at earlier stages with anemia it is advisable to routinely investigate it for early detection allowing its early management.


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