KASHIN-BECK OSTEOARTHROPATHY IN RURAL TIBET IN RELATION TO SELENIUM AND IODINE STATUS

Background and Methods Kashin-Beck disease is a degenerative osteoarti cular disorder that is endemic to certain areas of Tibet, where seleni um 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 subjec ts 5 to 15 years of age in 12 villages around Lhasa, Tibet, including 1 control village in which no subject had Kashin-Beck disease. Clinica l, radiologic, and biochemical data were collected. Results Among the 575 subjects, 280 (49 percent) had Kashin-Beck disease, 267 (46 percen t) had goiter, and 7 (1 percent) had cretinism. Of the 557 subjects in whom urinary iodine was measured, 66 per cent had a urinary iodine co ncentration of less than 2 mu g per deciliter (157 nmol per liter; nor mal, 5 to 25 mu g per deciliter [394 to 1968 nmol per liter]). The mea n urinary iodine concentration was lower in subjects with Kashin-Beck disease than in control subjects (1.2 vs. 1.8 mu g per deciliter [94 v s. 142 nmol per liter], P<0.001) and hypothyroidism was more frequent (23 percent vs. 4 percent, P=0.01). Severe selenium deficiency was doc umented in all villages; 38 percent of subjects had serum concentratio ns 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, hi gh serum thyrotrophin, 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 s evere selenium deficiency is endemic, iodine deficiency is a risk fact or for Kashin-Beck disease. (N Engl J Med 1998;339: 1112-20.) (C) 1998 , Massachusetts Medical Society.