The objective of this study was to determine the concentration of trace element chromium(III) and thyroid peroxidase activity in human serum , and to find a relationship between the concentration of chromium(III) and thyroid peroxidase activity in serum of patients with hypothyroidism, hyperthyroidism and healthy subjects. Serum thyroid peroxidase was measured by enzyme linked radioimmunoassay(ELISA) method and chromium determination was by atomic absorption spectrophotometer .Comparing the values of chromium concentration and thyroid peroxidase activity in both samples showed that there were significant positive correlations between chromium levels and thyroid peroxidase activity(P<0.01, r=0.11). The results showed that Serum thyroid peroxidase activity and chromium levels were significantly higher in hyperthyroidism patients (152.0±4.6 IU/L) (2.159±0.15 ppb) respectively than normal (51.0±1.8 IU/L) (0.378±0.024 ppb) respectively and lower than normal in hypothyroidism patients (35.0±0.31 IU/L)(0.099±0.011 ppb) respectively.
