Keshan disease is an endemic
cardiomyopathy found in Keshan, north-east China. The first patient was identified in 1935. This disease is characterized by a blood circulation disorder, endocardium abnormality and myocardium
necrosis.
Selenium (Se) deficiency is thought to be a major factor by Chinese scientists. However, the exact etiology has not been clarified up to now. The government decided to apply
sodium selenite to growing crops, and the incidence of the disease decreased dramatically. However, a few cases still occur as chronic or latent types. This paper reviews
Keshan disease from a historical aspect and also the present situation.
METHODS: So far, epidemiological surveys have shown that
Keshan disease occurs in large areas in 14 provinces in China, mainly in the countryside. It has been confirmed by clinical and pathological studies that
Keshan disease is an independent endemic
myocardial disease caused by
biological and geological factors. The largest prevalence age rates are boys under 15 years old and women of childbearing age. There are several hypotheses; acute
carbon monoxide poisoning,
virus infection,
malnutrition, or
selenium deficiency. The first is not currently believed to be the cause. The following was pointed out; studies on the relationship between diet and the endemic areas of
Keshan disease in 1961, where the food custom of the local residents was relatively simple and a so-called "one-sided diet" (eating a limited variety of food) might be related to the incidence of
Keshan disease. In 1973, large-scale investigations on the natural environments were performed in the endemic areas of
Keshan disease in the whole country. As a result, it was reported that there was a relationship between the incidence of
Keshan disease and the special natural environment in the endemic areas and the cause of
Keshan disease was strongly supported by nutritional,
biological, geological and chemical (
selenium deficiency) factors. In 1981, on the other hand, it was found that the levels of
antibodies against Coxsackie virus were higher in the serum of
Keshan disease patients than of normal subjects. This fact supposed that the cause of
Keshan disease was related to a
virus infection. However, it is difficult to explain why the clinical and pathological manifestations of
Keshan disease are similar to those of other diseases, e.g. idiopathic dilatational
myocardial disease. Further research should be performed on
Keshan disease to clarify the etiology.