A Comparative Study of Iron Status in Subclinical Hypothyroid and Euthyroid Subjects in a Tertiary Care Hospital

The physiological equilibrium of the entire human body's metabolism is significantly influenced by thyroid hormones. Subclinical hypothyroidism, which is often concealed, is connected to iron deficiency anemia and various other hematological disorders. We in the current study tried to determine the prevalence and severity of iron deficiency anemia and investigate the correlation of subclinical hypothyroidism with iron deficiency.

A total of 100 subjects included in the study were divided into two groups. Group 1 included 50 cases with subclinical hypothyroidism, and Group 2 included 50 healthy age- and sex-matched controls. Hemoglobin (Hb) levels were measured within 24 hours of sample collection using a Sysmex automated cell counter (Kobe, Hyogo, Japan). Thyroid hormones (free triiodothyronine (fT3), free thyroxine (fT4), and thyroid-stimulating hormone (TSH)) were measured.

Out of 50 cases, 48 (96%) have iron deficiency anemia, and 52 (104%) have subclinical hypothyroidism. Among the cases with iron deficiency anemia, 43 (86%) also have subclinical hypothyroidism. There was a negative correlation between thyrotropin (TSH) and Hb levels. Pearson's correlation coefficient "r" values were -0.86408. The serum ferritin levels of cases were decreased as compared to the healthy controls, and the difference in means for cases and controls in terms of serum ferritin is also statistically significant.

The prevalence of anemia in subclinical hypothyroidism is significantly elevated, and considering the absence of significant clinical manifestations in the early stages, it is recommended to routinely conduct investigations for early detection, facilitating prompt management. Consequently, our study emphasizes that both overt and subclinical hypothyroidism should be recognized as risk factors for the development of iron deficiency anemia.