Keshan Disease Areas Research Articles

A Comparative Study on Soil-Crop Selenium Characteristics in High-Incidence Areas of Keshan Disease in Chinese Loess and Black Soil

With the gradual emphasis on health by people, the research on the pathogenesis of endemic diseases has become increasingly in-depth. Through analyzing the environmental selenium characteristics and conducting a comparative study in typical areas of Chinese loess and black soil in this paper, it is concluded that the environmental selenium in the two regions has different characteristics. The soil in the loess area has the characteristics of high alkalinity, low selenium, and relatively high selenium availability, and the crops are selenium-deficient, while the soil in the black soil area has the characteristics of high organic matter, low selenium availability, and relatively high selenium in crops. The research concluded that the environmental occurrence mechanism of Keshan disease in the loess area and the black soil area is different. Keshan disease can be induced in both low-selenium and sufficient-selenium environments, and environmental selenium should be one of the inducing factors of Keshan disease. This research provides a reference for predicting the areas where Keshan disease occurs and for disease prevention, and it can also serve in the prevention and control of endemic diseases.

Prevalence of hypertension in endemic and non-endemic areas of Keshan disease: A cross-sectional study in rural areas of China.

Hypertension is a major public health concern that strongly influences the quality of life of people worldwide. Keshan disease (KD) is an endemic cardiomyopathy related to low selenium, threatening residents in rural areas of 16 provinces in China. Furthermore, the prevalence of hypertension in the KD-endemic areas has been increasing annually. However, hypertension research associated with KD has only focused on endemic regions, and no studies have compared hypertension prevalence between endemic and non-endemic areas. Therefore, this study investigated the prevalence of hypertension to provide a basis for preventing and controlling hypertension in the KD-endemic areas, even in rural areas. We extracted blood pressure information from cardiomyopathy investigation data from a cross-sectional study of the KD-endemic and non-endemic areas. The hypertension prevalence between the two groups was compared using the Chi-square test or Fisher s exact test. Additionally, Pearson's correlation coefficient was employed to evaluate the relationship between the per capita gross domestic product (GDP) and hypertension prevalence. There was a statistically significant increase of hypertension prevalence in the KD-endemic areas (22.79%, 95% confidence interval [CI]: 22.30-23.27%) over the non-endemic areas (21.55%, 95% CI: 21.09-22.02%). In the KD-endemic areas, more men had hypertension than women (23.90% vs. 21.65%, P < 0.001). Furthermore, the hypertension prevalence was higher in the north than in the south in the KD-endemic areas (27.52% vs. 18.76%, P < 0.001), non-endemic areas (24.86% vs. 18.66%, P < 0.001), and overall (26.17% vs. 18.68%, P < 0.001). Finally, the prevalence of hypertension positively correlated with per capita GDP at province level. The increasing hypertension prevalence is a public health problem in the KD-endemic areas. Healthy diets, such as high consumption of vegetables and seafoods, and foods that are rich in selenium, might help prevent and control hypertension in the KD-endemic areas and other rural areas in China.

慢型克山病与扩张型心肌病患者抗氧化能力对比研究

Objective : To compare the serum levels of selenium, selenoprotein and malondialdehyde about Keshan disease (KSD) and dilated cardiomyopathy (DCM) patients and to investigate the relationship between the antioxidant capacity and myocardial injury. Method s: 26 KSD patients, 18 DCM patients, 24 healthy people in KSD areas and 22 healthy people in non-KSD areas were selected by all-round physical examination and electrocardiography. Blood samples were collected by informing consent and volunteering. The serum selenium was determined by using 2,3 - two amino-naphthalene fluorescence method. The serum selenoprotein and malondialdehyde were measured by using biotin double-antibody sandwich method of enzyme linked immunosorbent assay (ELISA) (according to kit instructions). Result s: There were no statistical differences about the distribution of the gender and age in every subjects’ groups ( P ＞0.05). The levels of serum selenium and selenoprotein in Keshan disease group and dilated cardiomyopathy group were significantly lower than those of healthy group whether in KSD areas or in non- KSD areas , and the serum malondialdehyde were higher than those in healthy controls. There were no statistical significance about the concentrations of serum selenium, selenoprotein and malondialdehyde between Keshan disease group and dilated cardiomyopathy group, KSD areas’ control group and non- KSD areas’ control group. Conclusion : The myocardial injury of KSD patients and dilated cardiomyopathy patients may be associated with the decrease of antioxidant ability because of the lower selenium levels.

An investigation of current prevalence situation of dilated cardiomyopathy in non-keshan disease areas of Yunnan Province in 2011

Objective In order to master the current prevalence situation of dilated cardiomyopathy in Yunnan Province.Methods An investigation of dilated cardiomyopathy was carried out in 17 counties from August to December in 2011 in non-Keshan disease areas.Two townships (towns) that similar to Keshan disease areas in natural environment,pattern of production and lifestyle in non-Keshan disease areas were selected in each project county,and 1 village was selected as surveillance site in each selected township(town).The number of resident in each village no less than 500 people was appropriate and deficiency was supplemented from neighboring villages.The sampling rate was no less than 80％.Clinical examination and electrocardiographic tracings were carried out.The patients with suspected dilated cardiomyopathy and latent Keshan disease were taken anteroposterior chest X-ray in accordance with the Non-Keshan Disease Area Dilated Cardiomyopathy Condition Survey Program.The surveillance was carried out based on National Investigation Scheme of Dilated Cardiomyopathy in Non-Keshan Disease Areas.Cases were diagnosed based on the diagnostic standard of dilated cardiomyopathy and suspected latent Keshan disease.Results In the 34 villages of 17 selected counties,14 545 people were investigated.Twenty-six cases of latent dilated cardiomyopathy and suspected latent Keshan disease were detected,and the total detection rate was 17.88/million.One case was dilated cardiomyopathy,and 25 cases were suspected latent Keshan disease,detection rates were 0.69/million and 17.19/million,respectively.Male and female cases were 15 and 11,respectively.The ratio of people aged 65 and older accounted for 42.31％(11/26),among them suspected latent Keshan disease accounted for 44.00％(11/25),and 1 case of dilated cardiomyopathy was in the 45 to 54 years old group.Electrocardiographic examination of 14 519 people,the abnormal rate was 8.13％(1 180/14 519).Among 112 chest X-ray films,104 cases had a cardiothoracic ratio less than or equal to 0.50,4 cases from 0.51 to 0.55,3 cases from 0.56 to 0.60,and 1 case more than or equal to 0.61.Conclusion The detection rate of dilated cardiomyopathy cases is lower in non-Keshan disease area of Yunnan Province,but suspected latent Keshan disease is detected. Key words: Dilated cardiomyopathy; Keshan disease; Investigation of situation

Suboptimal Selenium Supply—A Continuing Problem in Keshan Disease Areas in Heilongjiang Province

This study explores whether the declining prevalence of Keshan disease is associated with increasing selenium levels in Keshan disease areas in Heilongjiang province. Six counties endemic with Keshan disease and three non-endemic counties were selected as study areas. In each county, two townships and in each township one village were chosen in which to survey ten families about head hair, grain, and soil samples and to obtain demographic information. Selenium was measured with hydride generation-atomic fluorescence spectrometry. In each county endemic with Keshan disease, one of the villages was chosen to investigate the prevalence of the disease. We collected 534 head hair samples, 446 staple food samples, and 180 soil samples. The selenium levels of head hair and corn in the endemic counties were significantly lower than those in non-endemic counties. Family demographic information was homologous except for the composition of staple food. More residents in Keshan disease areas preferred flour and corn. The detection rate for latent Keshan disease had a significantly negative correlation with the corn selenium level in six counties endemic with Keshan disease. As the population in this region is still at risk for Keshan disease, selenium surveillance measures should be intensified.

Experimental study on cardiac pathological change in rats fed with corn and bean puree of Keshan disease area

Objective To investigate the myocardial damage in rats fed with corn from Keshan disease area added with bean puree. Methods Male Wistar rats were randomly divided into 3 groups according to their body weights, and fed with corn, corn from Keshan disease area added with bean puree, corn from non-endemic area. The GSH-Px activity of vena cardalis blood was examined in 1 and 3 months, rats were sacrificed after being fed for 6 months to examine the heart changes with HE stain. Results The three groups of GSH-Px activity were different in 1 and 3 months respectively(F=23.60,72.46, all P 0.05). Myocardial damage incidence of the three groups was 3/9,1/9,2/7. Difference among three groups did not have statistical significance(χ2=1.33, P> 0.05). Conclusions Only corn from Keshan disease area may induce myocardial damage pathology change. Adding bean puree into corn does not increase damage. Key words: Keshan disease; Glutathione peroxidase; Myacardium; Corn

Electrocardiography analysis of residents in Keshan disease area in Shaanxi Province

Objective To explore the Electrocardiography (ECG) changes of residents in Keshan disease area and the status of growth and decline of Keshan disease in Shaanxi Province. Methods Using stratified randomized sampling method,2 mild,2 moderate and 2 serious disease counties were selected respectively in 2005 and 2006. A total of 6 counties were sampled,2 villages,one with severe disease and one with mild,were selected from each sampled county. A total of 12 villages were selected. The clinical examination and ECG were conducted in 3-year old children of agricultural population of the selected villages. Results ECG of 5692 cases were performed in the selected 12 village in the 6 counties,in which 4917 cases showed normal electrocardiogram,up to 86.38% (4917/5692). Two hundred and fifty-two cases showed roughly normal electrocardiograms,up to 4.43%(252/5692). Five hundred and twenty-three cases had abnormal electrocardiogram,accounting for 9.19% (523/5692). Among them,the abnormal electrocardiogram rates in mild,moderate and serious disease areas were 7.07% (144/2036), 11.41%(167/1646) and 10.54%(212/2010),respectively. Atrioventricular block was the major abnormal electrocardiogram change,followed by arrhythmia,ST-T changes,and low voltage. One hundred and thirty-nine cases were confirmed as latent and chronic Keshan diseases. One hundred and thirty-one cases were latent Keshan, and detection rate was 2.30%(131/5692). Eight cases were chronic Keshan,and the detective rate was 0.14% (8/5692). Complete right bundle branch block [37.06% (63/170) ],ST-T changes [22.35% (38/170) ],multiple premature ventricular beats [12.94% (22/170)] were the major abnormal electrocardiogram change of Keshan patients. Conclusions Atrioventricular block and arrhythmia are the major abnormal electrocardiogram changes. Keshan disease incidences are controlled under a stable condition. Key words: Keshan disease; Electrocardiography; Epidemiulogy

Mechanism of hepatocellular damage in rat caused by low serum selenium

The aim of this paper is to investigate the mechanism of hepatocellular damage in rats caused by low serum selenium. Thirty six rats were randomly divided into 2 groups: group A (fed with low-selenium diet from the Keshan Disease area with the content of selenium being 0.017 mg/kg); group B [fed with selenium-supplemented diet and 0.3 mg/L selenium (Na2SeO3) was added to the drinking water]. Both were respectively fed for 12 weeks. At the end of the 12th week, the levels of serum selenium, glutathione peroxidase (GPX) and malondialdehyde (MDA) in hepatic tissue were measured; the hepatocellular ultrastructure and apoptosis were observed as well. The levels of serum selenium and GPX in group A were markedly lower than those in group B. MDA level in group A was significantly higher than that in group B. Under the electron microscope (EM), the mitochondria were remarkably changed in group A. The rate of liver cell apoptosis appeared much higher in group A as well. It indicated that the damage caused by selenium deficiency was through the process of oxidation. Selenium deficiency led to apoptosis of hepatocytes where oxidative damage to mitochondria might be the cause.

Arsenic and Selenium in Human Hair: A Comparison of Five Countries With and Without Arsenicosis

The selenium (Se) content of the diet and/or selenium supplements might have an ameliorating effect on arsenic (As) toxicity as recently shown by Wang et al., Yang et al., and as reviewed by Spallholz et al.. The underlying principles of the ameliorating effect is the complexation of Se with As forming the seleno-bis (S-glutathionyl) arsinium ion excreted in bile and the complexation of Se with As in tissues forming nontoxic insoluble selenides. Additional protection afforded by Se supplementation from arsenicosis could be the elevation of glutathione peroxidase activity reducing the oxidative stress induced by As. The present study assessed the status of Se and As in hair by neutron activation analysis (NAA). Human hair samples were collected from the United States, Canada, The People's Republic of China (PRC), Bangladesh, and Nepal, the latter two countries now engaged in a struggle to find relief from human arsenicosis resulting from extensive domestic groundwater contamination by As. No statistically significant differences were observed in the samples between the Se and As content of hair from, Lubbock, Texas (USA) or Winnipeg, Canada. The concentration of As in all hair samples analyzed correlated (r = 0.960, p < 0.001) with the amount of As in the drinking water. Selenium levels in hair were highest from Nepal. The results demonstrate the viability of hair as a noninvasive biomonitor in assessing aspects of dietary Se and environmental As exposure. The hair data confirmed the known low intake of Se in the Keshan disease area of the PRC, the very high accumulation in hair of As from subjects consuming contaminated groundwaters, and an adequate Se status in subjects from North America consuming municipal water of low As content. The high As content of hair from people in Bangladesh is the result of a high As consumption from contaminated water compounded by a less than desirable intake of Se. From Nepal, the As content of hair corresponded to the known low and high intake of As from contaminated groundwater. The very high Se content found in all hair samples from Nepal might be the result of the use of henna.

Keshan disease--a review from the aspect of history and etiology

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. We made a reference survey and summarised the etiology, pathological changes, clinical manifestation, and other views of Keshan disease. 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.

Environmental Se-Mo-B deficiency and its possible effects in Jiantou Keshan disease area in Shaanxi Province, China

Keshan disease (KD) occurs in a wide geographic belt stretching from the Heilongjiang Province in northeastern China to Yunnan Province in southwestern China, including Huangling County, Shaanxi Province. In order to research relationships between eco-environmental geochemistry and KD pertaining to Se, Mo, B, Zn, Mn, and Cu, this investigation was conducted in the Jiantou KD area in Huangling County, one of the areas in China where the incidence of KD is highest. Environmental samples (rock, soil, plant and children’s hair) were collected from the area. Se in plants is low, ranging from 0.03 to 0.06 µg Se g−1 in corn, potato and soybean. Se contents in children’s hair are normal or reach the limitation of dangerous level. This study reports 0.18 µg Se g−1, B <40 µg g−1, and Mo <1.0 µg g−1 in aeolian soil, 0.14–0.38 µg Mo g−1 and 3–8 µg B g−1 in corn and potato (daily staple food for local human beings in the area). The Jiantou KD area is one where the elements Se, Mo and B are deficient. It is proposed that the deficiency of elements Se, Mo and B may be involved in the pathogenicity of KD with respect to the eco-environmental system because Se, Mo and B are essential micronutrients for plants and human beings. It seems that there is no significant relationship between the Zn–Mn–K–Pb–Ba associations and KD.

Selenium distribution in the local environment of selected villages of the Keshan Disease belt, Zhangjiakou District, Hebei Province, People's Republic of China

The distribution of Se in cultivated topsoils, grains, human hair and drinking water has been studied in 15 villages from a Keshan disease area of the People's Republic of China, villages being classified into 3 groups according to the Keshan disease incidence in the local population. In grain, hair and water the total Se follows expected trends; i.e. the highest concentrations are found in the villages where there is no incidence of Keshan disease. However, the soils from the high-incidence Keshan disease villages have the highest total Se content, an apparent contradiction, as Keshan disease is a response to a Se deficient environment. Soil analyses suggest that the organic content of the soils is a major factor in controlling the availability of Se and it is the high-incidence Keshan disease villages that have the most organic-rich soils. Although higher in total Se, the organic-rich soils have little bioavailable Se resulting in a Se deficient food chain. Soil pH is also seen to be a related factor in restricting the availability of Se and all the grain samples collected on soils with a pH <7.6 had a total Se content of less than 10% of the total soil Se. In an environment that can be classified as Se deficient small changes in the soil organic content and pH can have a critical affect on the Keshan disease status of a village.

Selenium and viral virulence.

A mouse model of coxsackievirus-induced myocarditis is being used to investigate nutritional determinants of viral virulence. This approach was suggested by research carried out in China which showed that mice fed diets composed of low selenium ingredients from a Keshan disease area suffered more extensive heart damage when infected with a coxsackie B4 virus than infected mice fed the same diet but supplemented with selenium by esophageal intubation. Selenium deficiency in our mice increased the virulence of an already virulent strain of coxsackievirus B3 (CVB3/20) and also allowed conversion of a non-virulent strain (CVB3/0) to virulence. Such conversion of CVB3/0 was accompanied by a change in the viral genome to more closely match that of the virulent virus, CVB3/20. As far as the authors are aware, this is the first report of host nutrition influencing the genetic make-up of an invading pathogen. Nutritionists may need to consider this mechanism of increased viral virulence in order to gain a better understanding of diet/infection relationships.

Effects of selenium and alpha-tocopherol on liver damage induced by feeding grains from an endemic area of Keshan disease in rats.

Previous studies have shown the pathogenic effects of grains cultivated in the endemic areas of Keshan disease and selenium is effective in the prevention of this disease. In this study, liver damages induced by feeding grains from an endemic area (endemic diet), and the effects of selenium and alpha-tocopherol supplement were examined. After 3 months on the endemic diet, the amounts of serum enzymes were significantly increased when compared to controls (animals receiving diet from a non-endemic area). Liver enzymes (alkaline phosphatase and choline esterase) were also found to be altered in the serum, further suggesting liver damages in animals on an endemic diet. Supplement of the endemic diet with selenium or alpha-tocopherol reversed the changes in serum enzymes. Increase in lipid peroxidation in the liver of animals on the endemic diet was observed when compared to that in control animals. Selenium and alpha-tocopherol supplements prevented the increase in lipid peroxidation in the liver by the endemic diet. Semi-quantitative histochemical analysis of glutamate dehydrogenase and succinate dehydrogenase in liver tissue showed that the livers of animals on an endemic diet were more sensitive to ischemic damages in vitro. Supplementation of the endemic diet with either selenium or alpha-tocopherol reduced the sensitivity to ischemic damages. The results suggest that increased lipid peroxidation in the liver of rats on an endemic diet may be responsible for liver damages and elevation of serum enzymes.(ABSTRACT TRUNCATED AT 250 WORDS)

Activity of 45Ca uptake by myocardial mitochodria from rats fed on grains from Keshan disease areas

Activity of 45Ca uptake by myocardial mitochodria from rats fed on grains from Keshan disease areas

The effect of organic selenium on the metabolism of free-radicals in rats fed on grains from Keshan disease areas

The effect of organic selenium on the metabolism of free-radicals in rats fed on grains from Keshan disease areas

Study on the superprecipitation of cardiac actomyosin of the rat fed on grains from Keshan disease areas

Study on the superprecipitation of cardiac actomyosin of the rat fed on grains from Keshan disease areas

Superoxide dismutase activities in erythrocytes from population in Keshan disease area

Superoxide dismutase activities in erythrocytes from population in Keshan disease area

Serum biochemical assay in population in Keshan disease area

Serum biochemical assay in population in Keshan disease area

STUDY ON RUBIDIUM CONCENTRATION OF DIFFERENT SAMPLES FROM KESHAN DISEASE AREA OF SICHUAN PROVINCE

Rubidium (Rb) concentration in different samples collected from Keshan disease (KD) area of Sichuan Province has been determined with PIXE and NAA (Neutron Activity Analysis), and compared with that in three non-KD areas. About 200 erythrocyte samples of healthy children aged from 6 to 11 were collected from four different areas with various selenium status. 20 rice samples and 6 soil samples were taken from two of above four areas. The results showed that Rb content of erythrocyte of children in KD area (Dechang county) was three times that in the other three non-KD areas. The Rb contents of rice and soil in KD area were higher than that in non-KD areas, too. The abnormal high Rb concentration in erythrocyte of children depended on the Rb intake and the Rb level of the living environment.