Possible Role of Inadequate Quantities of Intra-Thyroidal Cobalt, Rubidium and Zinc in the Etiology of Female Subclinical Hypothyroidism

Background: Subclinical hypothyroidism does affect fertility. The prevalence of subclinical hypothyroidism is 10-15 times more common in women than in men. Trace elements play important roles in thyroid function and fertility. Objective: The aim of this exploratory study was to evaluate whether significant differences of trace element contents exists between female and male thyroids and how they can be related to the etiology of subclinical hypothyroidism. Methods: Thyroid tissue levels of ten trace elements: silver, cobalt, chromium, iron, mercury, rubidium, antimony, scandium, selenium, and zinc were prospectively evaluated in 105 healthy persons (33 females and 72 males). Measurements were performed using instrumental neutron activation analysis with high resolution spectrometry of long-lived radionuclides. Tissue samples were divided into two portions. One was used for morphological study while the other was intended for trace element analysis. Results: It was found that content of cobaltin thyroid of females was significantly higher than that of males, while contents of rubidiumand zinc were lower. Conclusions: Inappropriate content of intra-thyroidal cobalt, rubidiumand zinc can be associated with the etiology of female subclinical hypothyroidism.