Hematological Profile in Primary Hypothyroidism

Abstract

Introduction: Thyroid function disorders are among the most common endocrine diseases. Females are affected more than males, especially during the reproductive age. Hypothyroidism is the most prevalent type with a reported frequency of 2–5% worldwide. Thyroid hormones are essential for virtually all body tissues. So deficiency may affect hematopoiesis in bone marrow and eventually hematopoietic cells. Hematological abnormalities have frequently been reported in thyroid disorders. Anemia is frequently observed in patients with primary hypothyroidism.
 Objectives: To study the hematological changes and pattern of anemia in primary hypothyroid patients.
 Materials & Methods: This is a cross sectional study conducted on newly diagnosed 100 patients with primary hypothyroidism, between 18 –60 years. They were categorized as 35 patients of subclinical and 65 patients of overt hypothyroidism based on TSH level. Patients’ who fulfills the inclusion exclusion criteria were evaluated for thyroid function tests (T3, T4 and TSH) and hematological parameters (CBC and PBF).
 Results: Our analysis revealed an overall prevalence rate of anemia was 56% in patients with hypothyroidism which is higher than the WHO reported data of prevalence of anemia throughout the world. Our results showed that prevalence of normocytic normochromic anemia was significantly higher, microcytic anemia had the second rank, while macrocytic anemia had the lowest prevalence rate. On subgroup analysis, there was no statistical difference between subclinical hypothyroid and overt hypothyroid, in term of hematological parameters and type of anemia.
 Conclusion: Without proper diagnosis and effective treatment of the underlying thyroid disease, it is often difficult to achieve a complete correction of the anemia. The high prevalence of anemia in patients with hypothyroidism suggests screening for hypothyroidism during the differential diagnosis of cases presenting with anemia.
 Keywords: Hypothyroidism, subclinical, overt, anemia, hematological, thyroid, blood.

Prevalence and Characteristics of Thyroid Abnormalities and Its Association with Anemia in ASIR Region of Saudi Arabia: A Cross-Sectional Study

“…We found that females have more prevalence of thyroid disorder than males under the circumstances of thyroid dysfunction at a young age (<20 and 20-30 years), as shown in Table 3. Many researchers have reported the correlation between anemia and thyroid dysfunction, and they estimated that more than 50% of patients have blood abnormalities with thyroid dysfunction, particularly with subclinical hypothyroidism [12,13,[15][16][17]40,41].…”

“…Study subjects with thyroid dysfunction were divided into four categories [5,[24][25][26] as follows: (a) primary hypothyroidism: serum TSH > 4.94 µIU/mL and FT4 < 0.7 ng/dL; (b) primary hyperthyroidism: serum TSH < 0.35 µIU/mL and FT4 > 1.48 ng/dL; (c) subclinical hyperthyroidism: normal FT4 (0.7-1.48 ng/dL) and serum TSH below the lower limit of the reference range (<0.35 µIU/mL); (d) subclinical hypothyroidism: normal FT4 (0.85-1.4 ng/dL) and serum TSH higher than the upper limit of reference range >4.94 µIU/mL. Generally, anemia is defined by low Hb (<12 g/dL in females and <13.5 g/dL in the male), where the subdivision of anemia includes a microcytic hypochromic, which comes with low MCV and low MCH and normocytic normochromic with normal MCV and normal MCH, respectively [12][13][14][15].…”

“…Thyroid disorder can lead to a wide range of symptoms, including hypoplasia of erythroid cells in the bone marrow or proliferation of immature erythroid progenitor cells (due to hypothyroidism), or hyperplasia (due to hyperthyroidism) [10,11]. In general, thyroid dysfunction can lead to different effects on blood cells and anemia of multifarious severity and types [9,10,[12][13][14][15]. The prevalence of thyroid dysfunction and hematological abnormalities is well known [16,17].…”

Effects of thyroid dysfunction on hematological parameters: Case controlled study

“…Anemia and other blood abnormalities are common in thyroid function abnormalities mainly hypothyroidism, and most patients are improved after thyroid hormone replacement and normalization of the thyroid function [ 4 , 14 ].…”

“…Most authors recommend treatment with iron supplementation in those patients, patients who were treated with iron supplement alone without treatment with thyroxin showed lower response rates than combination therapy. Some population based studies confirmed that there is no significant association between anemia and thyroid dysfunction, this suggest that the results showed variation and this association is not constant [ 4 , 14 , [17] , [18] , [19] , [20] ].…”