Kashin-Beck disease selenium deficiency

Pure selenium deficiency, without concurrent vitamin E deficiency, is not generally seen except in animals on experimental diets (113). In China, selenium deficiency in humans has been associated with Keshan disease, a cardiomyopathy seen in children and in women of child-bearing ages, and Kashin-Beck disease, an endemic osteoarthritis in adolescents (113). 

Selenium deficiency has been identified iu humans iu a broad area of China, stretching from the northeast to the southwest. Two syndromes are evident Keshan disease, an endemic cardiomyopathy which affects children, and Kashin-Beck disease, an edemic osteoarthropathy (big-joiat), also mainly involving children, which occurs iu eastern Siberia and parts of China. As a result of these observations, a protective effect for selenium has been proposed, and various selenium-containing preparations have been appHed to preserve animal and human health. 

In contrast, selenium deficiency has been implicated in several human diseases, most notably Keshan disease (KD) and Kashin-Beck disease (KBD). KD is an endemic selenium-responsive cardiomyopathy that mainly affects children and women of child-bearing age and is named after... 

Biomarkers of Deficiency. Two endemic diseases, Keshan disease and Kashin-Beck disease, have been reported in selenium-deficient populations in China in which mean hair, blood, and urine selenium levels are low (Yang et al. 1988). Keshan disease, manifested as nausea, vomiting of yellowish fluid, and necrosis of the myocardium, has been found in a population with an average whole blood selenium concentration of 0.018 mg selenium/L, an average urinary concentration of 0.007 mg selenium/L, and an... 

Peng X, Lingxia Z, Scheauzee GN and Xiong G (2000) Selenium, boron, and germanium deficiency in the etiology of Kashin-Beck disease. Biol Trace Elem Res 77 193-197. 

Kashin-Beck Disease (KBD), a condition characterized by collagen breakdown and joint deterioration, was the second human disease to be associated with selenium deficiency (Dongxu 1990). Seasonal incidence variations suggest the involvement of infectious agents and of mycotoxins, as well as deficiencies of certain other trace elements (iodine, boron, germanium) (Dongxu 1990, Peng et al. 2000). 

Iodine, Selenium Deficiency and Kashin-Beck Disease... 

Selenium deficiency has been associated with specific diseases in China and Africa Keshan and Kashin-Beck disease (KBD) in Tibet and China and myxedematous cretinism in Central Africa. Interestingly, in all these selenium-deficient areas iodine deficiency is also endemic. The specific impact of iodine deficiency on human health is described elsewhere in this book and will not be repeated here, with the exception of health conditions where the interaction of iodine and selenium may contribute to the pathogenesis of a specific disease. This chapter will deal with diseases where both iodine and selenium deficiency play a role in disease causation and particularly with KBD. 

Figure 71.4 Neurological cretinism. Three-year-old boy from a severely selenium-deficient area of Tibet with neurological cretinism. He is severely mentally impaired, deaf-mute and suffered from spastic diplegia, but without clinical signs of Kashin-Beck disease.

The realization that selenium (Se) may be an essential micronutrient for human diets has arisen only recently, in the second half of the twentieth century. Selenium deficiency, attributable to low soil selenium levels in farm animals, especially sheep that are afflicted by selenium-responsive white muscle disease, has been recognized for at least half a century. However, the more recent identification of Keshan and Kashin-Beck diseases as endemic selenium-responsive conditions, occurring in a central 4000-1— km-wide belt of central China and in areas of Russia, demonstrated conclusively that not only is selenium an essential element for man but also deficiencies occur naturally and require public health measures to alleviate them. Selenium incorporation into plants is affected by the acidity of the soil and by the concentrations of iron and aluminum present so that selenium content of human diets is modulated by these components of the environment. The very recent discovery that these diseases probably arise through the interaction of selenium deficiency with enhanced viral virulence has added a further layer of complexity, but it does not alter the fact that selenium is an essential dietary component that cannot be substituted by any other element. Another complicating factor is that moderately increased soil selenium concentrations result in the opposite condition of seleno-sis, or selenium overload, with equally debilitating consequences. Of all elements, selenium has a very narrow safe intake range, and unlike some other potentially toxic elements, it is absorbed efficiently by the intestine over a wide range of concentrations and across a variety of different molecular forms. 

As noted previously, neither Keshan disease nor Kashin-Beck disease are now thought to be simple dietary deficiency diseases. They probably also involve viral components and may be exacerbated by environmental toxins, including mycotoxins. Thus, they are probably multifactorial, but importantly, public health selenium supplementation interventions have had a dramatically beneficial effect on the prevalence of these diseases. The main clinical features of Keshan disease are cardiac insufficiency and enlargement, electrocardiographic changes, and fibrosis. Those of Kashin-Beck disease are osteoarthropathy and necrosis of the joints and epiphysial plate cartilage. Both diseases occur in school-age... 

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