A study of prevalence and pattern of anemia in primary hypothyroidism

Abstract

Background: Anemia is a common disorder affecting Indian population which may be further influenced by hypothyroidism. Hematopoietic system is one of the primary systems affected by hypothyroidism and anemia could be its first manifestation. Numerous mechanisms are involved in the pathogenesis of this anemia that can be microcytic, macrocytic, and normocytic. We designed this study to investigate the incidence of anemia its morphological pattern in hypothyroidism patients. Objectives: The objectives were to investigate the incidence of anemia and its morphological pattern in patients with overt and subclinical hypothyroidism. Materials and Methods: A prospective observational study was conducted in patients presenting with overt or subclinical primary hypothyroidism in King George Medical University from August 2016 to September 2017. Patients with age >18 years and newly diagnosed cases of subclinical hypothyroidism were included. Patients with secondary causes for anemia or patients under treatment with drugs that might affect blood parameters were excluded. Results: In our present study, female predominance was 82% with more common age group between 31 and 40 years. The incidence of anemia was found to be 69% in the overt hypothyroid group and 56% in the subclinical hypothyroid group. Normocytic normochromic (53%) was the most common type of anemia, followed by microcytic (30%) and macrocytic anemia (27%). Serum iron levels were significantly low in both overt and subclinical hypothyroid groups. Serum anti-thyroid peroxidase (TPO) positivity was 65.53%. Anemia was severe in cases with high thyroid-stimulating hormone (TSH). Conclusion: Normocytic normochromic anemia is the most common type of anemia in hypothyroid patients. The incidence of anemia was found to be 69% in the overt hypothyroid group and 56% in the subclinical hypothyroid group. Presence of anemia in subclinical hypothyroidism was almost as high as in patients with overt hypothyroidism. TPO antibodies were linked with higher likelihood of developing anemia in hypothyroidism. Higher TSH values were associated with more severe anemia.