study of serum zinc, copper and thyroid hormones in children with chronic renal failure

ABSTRACT

The study included 21 patients [13 males and 8 females, aged from 9-17ys] with chronic renal failure [CRF] on regular hemodialysis. In addition, 10 apparently healthy age-matched children were included as a control group. Serum levels of zinc [Zn], copper [Cu], tri-iodothyronine [T[3]], thyroxin [T[4]], thyroid stimulating hormone [TSH] and creatinine were measured in all studied cases and controls. Serum levels of Zn and Cu were significantly lower among the studied cases [96.76 +/- 41.4 micro g/dl and 82.33 +/- 16.4 micro g/dl, respectively], compared with the controls [134.4 +/- 43 micro g/dl and 100.2 +/- 14.4 micro g/dl respectively], p<0. 05 and p<0.01 respectively. As regards the studied thyroid hormones and TSH, the studied cases showed significant lower serum T[3] level [61.85 +/- 9.7 nano g/dI] compared with the control group [85.80 +/- 4.26 nano g/dl], p< 0.001. While no significant statistical differences were found between the studied cases and controls regarding T[4] and TSH serum level. On the other hand, the mean value of T[3]/T[4] ratio was significantly lower among studied patients [12.91 +/- 1.87] in comparison with the controls [16.23 +/- 2.63], p<0.001. Additionally, a significant positive correlation was found between T[3] and T[4] [r=0.645, p<0.01]. Serum Zn exhibited also positive significant correlation with T[3] and T[4] [r=-0.506 and r=0 .514 respectively], p<0.05 for each. However, no significant correlation was detected between serum Cu levels and thyroid hormones. In conclusion; patients with CRF had low levels of serum Zn and Cu. They may have a state of subclinical hypothyroidism. The significant decrease in the mean value of serum T[3] level, the insignificant decrease in the mean value of serum T[4] level, the significant low T[3]/T[4] ratio as well as the significant positive correlation between serum Zn and T[3] may reflect impaired peripheral conversion of T[4] to T[3] due to Zn deficiency