Relationship between serum zinc levels, thyroid hormones and thyroid volume following successful iodine supplementation

Abstract

ObJEcTIVE: Zinc is essential for many biochemical processes and also for cell proliferation. Thyroid hormones influence zinc metabolism by affecting zinc absorption and excretion. Additionally, zinc deficiency affects thyroid function. The aim of the present study was to evaluate a possible association of zinc levels with thyroid volume, thyroid hormones and thyroid autoantibody levels in healthy subjects, patients with autoimmune thyroid disease (AITD) and patients with nodular goitre following successful iodine supplementation. This is a cross-sectional study in which 201 subjects who were not under medical treatment and did not have previous thyroid surgery or radio-iodine treatment were evaluated. seventy patients had nodular goitre, 67 AITD and 64 had normal thyroid. Thyroid volume was calculated by ultrasonographic measurements. serum free T4, T3, TsH, anti-thyroglobulin and anti-thyroid peroxidase levels were determined by appropriate methodology.REsULTs: In patients with normal thyroid, zinc levels were significantly positively correlated with free T3 levels (p<0.001). In the nodular goitre group, thyroid volume was negatively correlated with TsH and circulating zinc levels (p=0.014 and p=0.045, respectively). In the AITD group, thyroid autoantibodies and zinc were significantly positively correlated. Multiple regression analysis revealed a significant relationship between thyroid volume and zinc only in the patients with nodular goitre (p=0.043). cONcLUsION: There was significant correlation of serum zinc levels with thyroid volume in nodular goitre patients, with thyroid autoantibodies in AITD and with free T3 in patients with normal thyroid.

Factors Associated with the Prevalence of Thyroid Nodules and Goiter in Middle-Aged Euthyroid Subjects

“…Conflicting data exists concerning the effects of TSH on thyroid growth. Some studies observed significant association between serum TSH and thyroid volume [37, 38], although others did not confirm any TSH-related associations [39], suggesting that TSH alone is not a mitogenic factor [40]. Some authors reported that iodine may modulate the thyroid cell response to TSH [41].…”

The effect of aspartame on the pituitary thyroid axis of adult male albino rat and the possible protective effect of Pimpinella anisum oil

“…These findings were confirmed ultrastructurally as most thyrotrophs showed signs of hyperactivity such as irregular nuclei and few secretory granules that mostly exocytosed. Zinc levels were significantly positively correlated with free T3 levels; thus, its deficiency could decrease the production of thyroid hormone [31]. These changes might occur in chronically stimulated thyrotrophs secondary to the decrease in thyroid hormone production by the affected thyroid, which led to cellular exhaustion.…”

Effects of Zinc and Selenium Supplementation on Thyroid Function in Overweight and Obese Hypothyroid Female Patients: A Randomized Double-Blind Controlled Trial

“…Serum Zn and Se were reported to be lower in patients with hypothyroidism or nodular goitre [18,39,40] compared to healthy control subjects, and Nishi et al [41] found no significant difference in serum Zn concentrations between patients with hypothyroidism and healthy subjects. In our study, serum Zn and Se concentrations did not change significantly after 12 weeks' supplementation.…”