Studies on the relations of selenium and Keshan disease

Keshan disease is an endemic cardiomyopathy of unknown cause in The People's Republic of China that occurs most frequently in children under 15 years of age and women of child-bearing age. Studies of children 1-9 years old in Mianing County of Sichuan Province have indicated that Keshan disease is a selenium responsive condition. Incidence rates of 9.5-13.5/1000 in 1974-1975 were reduced to 1-2/1000 in children treated with a tablet weekly of 0.5-1 mg sodium selenite. During 1974-1977, only 21 cases of the disease occurred in 36,603 treated children, compared with 106 cases in 9430 untreated children, of whom 53 died and 5 still have insufficient heart function. Occurrence of the disease was invariably associated with a lower selenium content of cereals, and of hair (less than 0.12 ppm Se) in residents from affected, compared with non-affected, areas. The dose relationship between selenium and regional characteristics of Keshan disease suggests that it is probably a biogeochemical disease; other etiological factors have also been considered.