Association between iron status and thyroid function in Nepalese children

Abstract

BackgroundDeficiencies of iodine and iron may have adverse effect on thyroid function. This study was undertaken to investigate the association between iron status and thyroid function in Nepalese children living in hilly regions.MethodsA cross-sectional study was conducted among 227 school children aged 6–12 years living in hilly regions of eastern Nepal. Urine and blood samples were analyzed for urinary iodine concentration, free thyroxine, free triiodothyronine, thyroid stimulating hormone, hemoglobin, serum iron and total iron binding capacity, and percentage transferrin saturation was calculated.ResultsThe cohort comprised euthyroid (80.6 %, n = 183), overt hypothyroid (1.3 %, n = 3), subclinical hypothyroid (16.3 %, n = 37) and subclinical hyperthyroid (1.8 %, n = 4) children respectively. About 35.2 % (n = 80) children were anemic, 43.6 % (n = 99) were iron deficient and 19.8 % (n = 45) had urinary iodine excretion < 100 μg/L. Hypothyroidism (overt and subclinical) was common in anemic and iron deficient children. The relative risk of having hypothyroidism (overt and subclinical) in anemic and iron deficient children was 5.513 (95 % CI: 2.844−10.685, p < 0.001) and 1.939 (95 % CI: 1.091-3.449, p = 0.023) respectively as compared to non-anemic and iron sufficient children. Thyroid stimulating hormone had significant negative correlation with hemoglobin (r = −0.337, p < 0.001) and transferrin saturation (r = −0.204, p = 0.002).ConclusionsThyroid dysfunction, iron deficiency and anemia are common among Nepalese children. In this cohort, anemic and iron deficient children had poor thyroid function.

Prevalence of thyroid autoimmunity and dysfunction in women with iron deficiency during early pregnancy: is it altered?

“…This association remained significant after correction for confounders such as age and BMI and even for TPO-abs. Our findings were concordant with those in literature (9,10,11). Potential mechanisms have already been discussed above in relation to a lower TPO activity.…”

“…A recent study showed that women with both ID and anemia were at higher risk to develop increased serum TSH levels as compared with ID alone (10). In the study by Zimmerman et al, the prevalence of anemia in case of ID was low and it did not influence the prevalence of SCH (11).…”

“…Data on the association between ferritin and thyroid disorders as outcome are limited to a few well-designed studies, of which one showed that ID was doubling the risk of developing hypothyroidism (9,10). None of these studies investigated the impact of ID on thyroid autoimmunity (TAI).…”

Correlation Between Hypothyroidism and Iron Deficiency Anemia in Female Patients

“…[24,25,10] In reproductive age, female with hypothyroidism is highly percentage of female thyroid disease population because of increase estrogen which has an anti-thyroid action. [26] Indeed, the patients with hypothyroid there are decreased in the number and proliferative activity of erythroid cells in the marrow [27] by reduce in plasma erythropoietin levels and then the decrease oxygen supplement of the tissues [28] leading to slowly metabolic rate in hypothyroidism due to reduce the diffusion of oxygen to tissues in deficiency of thyroid hormones leads to anemia. so that a significant negative correlation between TSH and Hb was observed leading to occur iron deficiency may both be a cause and an effect of hypothyroidism.…”

Iodine and Thyroid Function Status, and Anti-thyroid Peroxidase Antibody among Pregnant Women in Eastern Nepal

“…[20][21][22] Recently, a study in school children of eastern Nepal reported thyroid dysfunction in 19.4% of school age children, and 16.3% had subclinical hypothyroidism. 23 When focused with thyroid disorders among pregnant women in other countries, varied rate were reported. Study by Singh et al, found subclinical hypothyroidism and overt hypothyroidism in 18% and 4.5% among pregnant women in first and second trimester respectively.…”