Age-Related Changes of Some Trace Element Contents in Intact Thyroid of Males Investigated by Energy Dispersive X-ray Fluorescent Analysis

Abstract

A prevalence of thyroid dysfunction is higher in the elderly as compared to the younger population. An excess or deficiency of trace element contents in thyroid play important role in goitro- and carcinogenesis of gland. The variation with age of the mass fraction of six trace elements (Br, Cu, Fe, Rb, Sr, and Zn) in intact (normal) thyroid of 71 males (mean age 37.3 years, range 2.0-80) was investigated by 109Cd radionuclide-induced energy dispersive X-ray fluorescent analysis. Mean values ± standard error of mean for mass fractions (mg/kg, on dry-mass basis) of the trace elements studied were: Br 10.8±1.3, Cu 4.25±0.20, Fe 221±13, Rb 10.1±0.89, Sr 4.52±0.43, and Zn 122±5. This work revealed that there is a significant tendency for an increase in Zn mass fraction in normal male thyroid from age 36 years to the eight decade. Moreover, a great disturbance of intrathyroidal trace element relationships with increasing age was found. Therefore, a goitrogenic and carcinogenic effect of excessive Zn level in the thyroid of old males and of disturbance in intrathyroidal trace element relationships with increasing age may be assumed.