Endocrine Abstracts

Selenoproteins play a major role in the redox-systems of the body. Gluthathionperoxidase is important for the enzymatic reduction of hydro-peroxidases in the thyroid gland. Selenium (Se) is able to capture radicals, one of which is oxygen originating from thyroxin-peroxidase (TPO) activity. It has been shown that Se supplementation is associated with a decrease of anti-TPO-titers. Women with Hashimoto’s were shown to have lowered serum Se concentrations.

We estimated Se concentrations in pregnant women upon detection of the pregnancy. If Se was decreased (<1 μmol/l), a daily dose of 100 μg sodium selenite was substituted. Serum Se was re-evaluated between weeks 32 and 40 of pregnancy and it was also measured in the cord blood of the new – born.

In the first trimester of pregnancy serum Se levels were significantly (P<0.05) decreased in Hashimoto’s (0.65±0.08, n=7 vs controls 0.97±0.11, n=13). At term serum Se concentrations were 0.72±0.1 (n=15) without and 1.13±0.2 following Se Supplementation (P<0.05, n=20). Serum cord levels were 0.55±0.07 (n=15) and 0.78±0.09 (P<0.05, n=20) respectively.

The results indicate that serum Se decreases during pregnancy for about 25%, most probably due to the requirement of the fetus. To prevent a lack of this trace element, a daily supplementation dose of 100 μg appears adequate. It is well established that a detoriation of Hashimoto’s occurs in women post partum with known immunthyreoiditis in up to 60% (Lazarus 2000). There is also a fair number of women where manifestation of Hashimoto’s is occurring for the first time during the post partum period. Whether a deficiency of Se is responsible for this disease, cannot profoundly be proven, but it seems to be a logical hypothesis.