Effect of zinc treatment on serum thyroid hormones in uremic patients under peritoneal dialysis

In order to evaluate the effect of zinc (Zn) deficiency on thyroid abnormalities in chronic renal failure, a Zn supplement (100 mg/day, p.o.) was given for four weeks to eight uremic patients under peritoneal dialysis. Zn supplementation increased plasma levels of TSH (5.8 +/- 0.7 to 7.4 +/- 0.7 mU/l, p < 0.02), T4 (61.6 +/- 3.9 to 93.9 +/- 6.2 nmol/l, p < 0.01), T3 (1.31 +/- 0.14 to 1.70 +/- 0.18 nmol/l, p < 0.01) and Zn (7.23 +/- 0.45 to 12.27 +/- 0.76 mumol/l, p < 0.01). A close correlation was found between changes in plasma levels of Zn and changes in TSH (r = 0.82), T4 (r = 0.55) and T3 (r = 0.64), suggesting that Zn deficiency may play a role in the biosynthesis or release of hormones of the hypothalamic-pituitary-thyroid axis in chronic renal failure.