beta-carotene and Goiter

To investigate the relationship between selenium status, thyroid Volume and gland echostructure.. Cross-sectional.. In 792 men (45-60 Years) and 1108 women (35-60 Years) from the SU.VI.MAX study, thyroid Volume and gland echostructure were determined ultrasonographically. At baseline, thyrotropin, free thyroxine, selenium, zinc, alpha-tocopherol, beta-carotene, retinol, urinary iodine and thiocyanate concentrations were measured. Alcohol consumption, smoking, and menopausal status were assessed by a questionnaire. A stepwise linear and a logistic regression model were used, adjusting for antioxidant vitamins, trace elements status and age.. In women, there was an inverse association between selenium status and thyroid Volume (P=0.003). A protective effect of selenium against goiter (odds ratio (OR)=0.07, 95% confidence interval (CI)=0.008-0.6) and thyroid tIssue damage (OR=0.2, 95% CI=0.06-0.7) was observed. There was no evidence of an association between menopausal status and other antioxidant elements, thyroid Volume or thyroid hypoechogenicity. Smoking, but not alcohol consumption, was associated with an increased risk of thyroid enlargement in women (OR=3.94, 95% CI=1.64-9.48). No association between thyroid Volume, thyroid structure or selenium was found in men.. Our findings suggest that selenium may protect against goiter. Selenium was related to thyroid echostructure, suggesting it may also protect against autoimmune thyroid disease.

Topics: Adult; Aging; Antioxidants; Ascorbic Acid; beta Carotene; Cohort Studies; Cross-Sectional Studies; Double-Blind Method; Female; France; Goiter; Humans; Middle Aged; Nutritional Status; Regression Analysis; Selenium; Thyroid Gland; Ultrasonography; Vitamin E

The effects of the vitamins dl-alpha-tocopherol, ascorbic acid and beta-carotene, free radical scavengers and lipid peroxidation inhibitors, were analyzed in male Wistar rats made goitrous by feeding a low iodine diet (< 20 micrograms iodine/kg) and perchlorate (1% in drinking water) for 4, 8, 16, and 32 days. Groups of control or goitrous rats received for at least 16 days before killing a diet containing 0.6% vitamin E (as dl-alpha-tocopherol acetate), 1.2% vitamin C (ascorbic acid) and 0.48% beta-carotene, either simultaneously (vitamin cocktail) or separately. This treatment led to a 5-fold increase of vitamin E in the thyroid gland, a 24-fold increase in the liver and a 3-fold increase in the plasma. In control rats, vitamin cocktail administration increased slightly the thyroid weight with little changes in thyroid function parameters. During iodine deficiency, administration of the vitamin cocktail or vitamin E alone reduced significantly the rate of increase in thyroid weight, and DNA and protein contents, as well as the proportion of [3H]thymidine labeled thyroid follicular cells, but not that of labeled endothelial cells. Plasma tri-iodothyronine, thyroxine, TSH levels, thyroid iodine content and concentration as well as relative volumes of glandular compartments were not modified. The proportion of necrotic cells rose from 0.5% in normal animals to about 2% after 16 days of goiter development. No significant protective effect of the vitamins was observed. These results suggest that these vitamins, particularly vitamin E, modulate one of the regulatory cascades involved in the control of thyroid follicular cell growth, without interfering with the proliferation of endothelial cells.

Topics: Animals; Ascorbic Acid; beta Carotene; Drug Therapy, Combination; Goiter; Iodine; Liver; Male; Rats; Rats, Wistar; Thyroid Gland; Vitamin E