Abstract
This study reports the serum concentrations of trace elements Cu and Zn as well as the thyroid hormones triiodothyronine (T3), thyroxine (T4) and thyroid-stimulating hormone (TSH) in 30 hypothyroidisms, 30 hyperthyroidisms, and 30 healthy Sudanese objects. The study aims to reveal possible relationships between the levels of trace elements and thyroid hormones. Atomic absorption spectrometry was employed for the measurements of trace elements, while a radioimmunoassay method was employed for the measurements of thyroid hormones. For the hypothyroidism group, the mean values were as follows: Cu 1.01 mg/L, Zn 0.50 mg/L, T3 0.76 nmol/L, T4 32.72 nmol/L, and TSH 30.85 mU/L. For the hyperthyroidism group, the mean values were as follows: Cu 1.27 mg/L, Zn 0.73 mg/L, T3 2.72 nmol/L, T4 224.40 nmol/L, and TSH 0.58 mU/L. For both Cu and Zn, the difference between the three groups was statistically significant (p = 0.001). Cu was found proportionally correlated with T3 and T4 (the correlation coefficients (R) = 0.31 for each combination), while disproportionally correlated with TSH (R = -0.08). Similar trend of correlations were also observed for Zn with T3 (R = 0.22), T4 (R = 0.34) and TSH (R = -0.33). The correlations between serum Cu and Zn concentrations and thyroid hormones were all significant (p < 0.05), with the exception of Cu-TSH (p = 0.49). Hierarchical cluster analysis (HCA) was carried out for the analytes in each group. The HCA categorized Cu, Zn, and T3 of the hypothyroidisms in one cluster, while categorized Cu, Zn, T3, and TSH of both the hyperthyroidisms and the healthy group in one cluster.