SODIUM SELENITE THERAPY AND THYROID-HORMONE STATUS IN CYSTIC-FIBROSIS AND CONGENITAL HYPOTHYROIDISM

The effectiveness of a peroral sodium selenite therapy (115 mu g Se/m(2) BSA/d) administered to cystic fibrosis patients (n = 32) could after three months be identified in a significant serum selenium increase (0.69 --> 0.96 mu mol/L), a significant malondialdehyde decrease (2.72 --> 1.64 mu mol/L), as well as in a significant serum vitamin E increase (4.31 --> 5.72 mu g/mL). Parallel to that, a serum T-3 increase as well as a highly Significant decrease in the serum T-4/T-3-ratio were found, too, which point to improved peripheral T-4 --> T-3 conversion during selenium medication. Type-I-iodothyronine-5'-deiodinase has recently been identified as a specific selenoenzyme. In the case of congenital hypothyroidism (n = 37) application of sodium selenite in the above specified dosage yielded a mean serum selenium increase (0.87 --> 1.12 mu mol/L), a not significant T-3 increase (2.57 --> 2.61 nmol/L) as well as a not significant TSH decrease (5.34 --> 4.49 mIU/L) without an expected T-4 decrease. With the serum lipids, however, a lowering of total cholesterol (4.85 --> 4.53 mmol/L) simultaneous with a mean increase in HDL-cholesterol (1.52 --> 1.66 mmol/L) as well as a decrease in LDL-cholesterol (2.93 --> 2.52) could be observed. We view the reduction of the atherogenic serum lipid constellation in the course of selenium medication as an expression of increased thyroid-hormone efficacy. Apart from an improvement of the antioxidant status a stimulation of thyroid-hormone efficacy owing to increased T-4 --> T-3 conversion is also noteworthy in sodium selenite medication.