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Title Iodine and selenium deficiency associated with cretinism in northern Zaire [see comments] Author Vanderpas JB; Contempr´e B; Duale NL; Goossens W; Bebe N; Thorpe R; Ntambue K; Dumont J; Thilly CH; Diplock AT Address Public Health School, Free University of Brussels, Belgium. Source Am J Clin Nutr, 52(6):1087-93 1990 Dec Abstract Selenium status was determined in an endemic-goiter area and in a control area of Zaire. Compared with the reference values of a noniodine-deficient area, serum selenium in subjects living in the core of the northern Zaire endemic-goiter belt (Karawa villages) was seven times lower in 52 school-children and similarly low in 23 cretins; erythrocyte glutathione peroxidase (RBC-GPX) was five times lower in schoolchildren and still two times lower in cretins (P = 0.004). In a less severely iodine-deficient city of the same endemia (Businga), selenium status was moderately altered. RBC-GPX activity was linearly associated with serum selenium concentration up to a value of 1140 nmol/L and leveled off at approximately 15 U/g Hb at greater selenium concentration. At Karawa villages, selenium supplementation normalized both the serum selenium and the RBC-GPX. This combined iodine and selenium deficiency could be associated with the elevated frequency of endemic myxedematous cretinism in Central Africa.Title Kashin-Beck osteoarthropathy in rural Tibet in relation to selenium and iodine status [see comments] Author Moreno-Reyes R; Suetens C; Mathieu F; Begaux F; Zhu D; Rivera MT; Boelaert M; N`eve J; Perlmutter N; Vanderpas J Address Department of Nuclear Medicine, Erasme Hospital, Brussels, Belgium. Source N Engl J Med, 339(16):1112-20 1998 Oct 15 Abstract BACKGROUND AND METHODS: Kashin-Beck disease is a degenerative osteoarticular disorder that is endemic to certain areas of Tibet, where selenium deficiency is also endemic. Because selenium is involved in thyroid hormone metabolism, we studied the relation among the serum selenium concentration, thyroid function, and Kashin-Beck disease in 575 subjects 5 to 15 years of age in 12 villages around Lhasa, Tibet, including 1 control village in which no subject had Kashin-Beck disease. Clinical, radiologic, and biochemical data were collected. RESULTS: Among the 575 subjects, 280 (49 percent) had Kashin-Beck disease, 267 (46 percent) had goiter, and 7 (1 percent) had cretinism. Of the 557 subjects in whom urinary iodine was measured, 66 percent had a urinary iodine concentration of less than 2 microg per deciliter (157 nmol per liter; normal, 5 to 25 microg per deciliter [394 to 1968 nmol per liter]). The mean urinary iodine concentration was lower in subjects with Kashin-Beck disease than in control subjects (1.2 vs. 1.8 microg per deciliter [94 vs. 142 nmol per liter], P<0.001) and hypothyroidism was more frequent (23 percent vs. 4 percent, P=0.01). Severe selenium deficiency was documented in all villages; 38 percent of subjects had serum concentrations of less than 5 ng per milliliter (64 nmol per liter; normal, 60 to 105 ng per milliliter [762 to 1334 nmol per liter]). When age and sex were controlled for in a multivariate analysis, low urinary iodine, high serum thyrotropin, and low serum thyroxine-binding globulin values were associated with an increased risk of Kashin-Beck disease, but a low serum selenium concentration was not. CONCLUSIONS: In areas where severe selenium deficiency is endemic, iodine deficiency is a risk factor for Kashin-Beck disease.Title Effect of selenium supplementation in hypothyroid subjects of an iodine and selenium deficient area: the possible danger of indiscriminate supplementation of iodine-deficient subjects with selenium. Author Contempre B; Dumont JE; Ngo B; Thilly CH; Diplock AT; Vanderpas J Address Institute of Interdisciplinary Research, School of Medicine, Free University of Brussels, Belgium. Source J Clin Endocrinol Metab, 73(1):213-5 1991 Jul Abstract Selenium and seleno dependent glutathione peroxidase (GPX) deficiency has been described in endemias of myxedematous cretinism. In northern Zaire, a selenium supplementation trial has been conducted. Beside correcting the GPX activity, two months of selenium supplementation was shown to modify the serum thyroid hormones parameters in clinically euthyroid subjects and to induce a dramatic fall of the already impaired thyroid function in clinically hypothyroid subjects. These results further support a role of selenium in thyroid hormone metabolism. In an iodine deficient area, this selenium deficiency could lead to opposite clinical consequences: protect the general population and the fetus against iodine deficiency and brain damage; and in turn, favour the degenerative process of the thyroid gland leading to myxoedematous cretinism.Title Selenium deficiency mitigates hypothyroxinemia in iodine-deficient subjects. Author Vanderpas JB; Contempr´e B; Duale NL; Deckx H; Bebe N; Longomb´e AO; Thilly CH; Diplock AT; Dumont JE Address Cemubac Medical Team, Public Health School, Free University of Brussels, Belgium. Source Am J Clin Nutr, 57(2 Suppl):271S-275S 1993 Feb Abstract Studies were performed to assess the role of combined selenium and iodine deficiency in the etiology of endemic myxedematous cretinism in a population in Zaire. One effect of selenium deficiency may be to lower glutathione peroxidase activity in the thyroid gland, thus allowing hydrogen peroxide produced during thyroid hormone synthesis to be cytotoxic. In selenium-and-iodine-deficient humans, selenium supplementation may aggravate hypothyroidism by stimulating thyroxin metabolism by the selenoenzyme type I iodothyronine 5'-deiodinase. Selenium supplementation is thus not indicated without iodine or thyroid hormone supplementation in cases of combined selenium and iodine deficiencies.Title Selenium-induced thyroid dysfunction. Author Hofbauer LC; Spitzweg C; Magerst¨adt RA; Heufelder AE Address Division of Endocrinology, Klinikum Innenstadt, Ludwig-Maximilians-Universit¨at, Germany. Source Postgrad Med J, 73(856):103-4 1997 Feb Abstract Administration of the anti-oxidative trace element selenium is currently being evaluated for its benefits in patients with inflammatory diseases. However, little is known about the risks of selenium. We report on a patient in whom, along with standard therapy, administration of large intravenous doses of selenite for sepsis secondary to pneumonia resulted in development of marked hypothyroidism. In addition, severe iodine deficiency was noted, and supplementation with iodine led to normalisation of thyroid function.Title Changes in myocardial thyroid hormone metabolism and alpha-glycerophosphate dehydrogenase activity in rats deficient in iodine and selenium. Author Wu HY; Xia YM; Ha PC; Chen XS Address Department of Trace Element Research, Chinese Academy of Preventive Medicine, Beijing, People's Republic of China. Source Br J Nutr, 78(4):671-6 1997 Oct Abstract Weanling Wistar rats were fed on diets prepared from grain from areas deficient in I and Se where Keshan disease in endemic. Rats were divided into four groups, each of twelve rats, and received a diet supplemented with: I, Se, I + Se or nothing. At 8 weeks after weaning, myocardial alpha-glycerophosphate dehydrogenase (EC 1.1.1.8; alpha-GPD) activity and indices of Se and thyroid hormone status were determined. The group supplemented with iodine had increased plasma thyroxine levels. There was no difference in plasma triiodothyronine concentration between the groups but triiodothyronine levels in heart were reduced in the Se-supplemented group. Se supplementation increased myocardial glutathione peroxidase activity (EC 1.11.1.9) and the type I 5'-deiodinase (EC 3.8.1.4) activity in rat liver, but no type I 5'-deiodinase activity was detected in heart. alpha-GDP activity in heart was increased in group supplemented with Se, I or both. There was a significant relationship (P < 0.05) between myocardial alpha-GDP activity and plasma thyroxine levels but not between alpha-GDP and myocardial glutathione peroxidase activity. The results indicate that iodine may be more important than Se in energy metabolism in the myocardium, which may give a new insight for the study of the aetiology of Keshan disease in areas where foodstuffs are deficient in both Se and I.
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