The impact of dietary iodine intake on lipid metabolism in mice.

The present study has been designed to investigate the impact of dietary iodine intake on lipid metabolism in mice, including iodine deficiency and iodine excess. Different amounts of iodine mixed in the drinking water were continuously administered to mice. The body weights and the levels of urinary iodine were measured 8 months after the treatment. Thyroid hormones in the serum were detected by chemiluminescence immunoassay. Serum total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol and low-density lipoprotein cholesterol (LDL-C) were determined enzymatically by automatic analyzer. Results showed that the urine iodine concentrations paralleled the amounts of iodine intakes. No statistical differences of body weights among different groups were found. The levels of thyroid hormones were dramatically decreased in iodine deficiency while no significant differences were found between iodine excess groups and normal iodine group. In iodine deficiency groups, the levels of TG, TC, and LDL were increased at varying degrees. In iodine excess groups, the levels of TG in the male mice and the levels of TC in the female mice were much lower than normal iodine group. In conclusion, dietary iodine intake may affect the metabolism of serum lipids. Hypothyroid function induced by iodine deficiency may be responsible for the changes of lipids. Higher iodine intake might benefit lipid metabolism.