Assessing the Health Loss from Kashin-Beck Disease and Its Relationship with Environmental Selenium in Qamdo District of Tibet, China

Effects of selenium and iodine on Kashin-Beck disease: an updated review

Kashin-Beck disease (KBD) is an endochondral osteogenesis disorder characterised by epiphysis damage and secondary deformable arthropathy induced by multiple external factors, among which selenium (Se) and iodine deficiency are important influencing factors. Iodine deficiency is usually accompanied by a low Se content in the soil in the KBD areas of China. Se can reverse oxidative damage to chondrocytes. In addition, Se is related to the bone conversion rate and bone mineral density. Low Se will hinder growth and change bone metabolism, resulting in a decrease in the bone conversion rate and bone mineral density. Thyroid hormone imbalance caused by thyroid dysfunction caused by iodine deficiency can damage bone homeostasis. Compared with Se deficiency alone, Se combined with iodine deficiency can reduce the activity of glutathione peroxidase more effectively, which increases the vulnerability of chondrocytes and other target cells to oxidative stress, resulting in chondrocyte death. Clinical studies have shown that supplementation with Se and iodine is helpful for the prevention and treatment of KBD.

Topsoil selenium (Se) under Se-rich farming in China: Current status, cropping impacts and ecological risk assessment

Selenium (Se), as an essential microelement, can be supplied through Se-biofortified food from Se-rich soils and associated farming practices for human health, while it can also cause eco-risks if overapplied. In this study, a multi-scale spatiotemporal meta-analysis was conducted to guide sustainable Se-rich farming in China by combining a long-term survey with a reviewed database. The weighted mean concentration, spatial distribution of soil Se, nationwide topsoil Se variation from cropping impacts and its bioavailability-based ecological risks were assessed and quantified. The results showed that the weighted mean content (0.3 mg kg-1) of China was slightly higher than that of previous nationwide topsoil Se surveys, as more Se-rich areas were found in recent high-density sampling surveys. Cropping has overall reduced Se content by 9.5% from farmland across China and deprived more with the increase in farming rotation driven by geo-climatic conditions. Long-term cropping removed Se from Se-rich areas but accumulated it in Se-deficient areas. Additionally, the bioavailable Se content of topsoil in China ranged from 0 to 332 μg kg-1, and the bioavailability-based eco-risks indicated that high eco-risks only existed in overfertilized and extremely high-Se soils, such as in Enshi, Ziyang and some coalfield areas. This work provides evidence for the development of sustainable Se-rich farming with proper utilization of soil Se resources, simultaneously protecting the soil eco-environment.

Dietary sources apportionment and health risk assessment for trace elements among residents of the Tethys-Himalayan tectonic domain in Tibet, China

Dietary intake of toxic elements (TEs) and essential trace elements (ETEs) can significantly impact human health. This study collected 302 samples, including 78 food, 104 drinking water, 73 cultivated topsoil, and 47 sedimentary rock from a typical area of Tethys-Himalaya tectonic domain. These samples were used to calculate the average daily dose of oral intake (ADDoral) and assess the health risks of five TEs and five ETEs. The results indicate that grain and meat are the primary dietary sources of TEs and ETEs for local residents. The intake of manganese (Mn) and copper (Cu) is mainly from local highland barley (66.90% and 60.32%, respectively), iron (Fe) is primarily from local grains (75.51%), and zinc (Zn) is mainly from local yak meat (60.03%). The ADDoral of arsenic (As), Mn, Fe and Zn were found to be higher than the maximum oral reference dose in all townships of study area, indicating non-carcinogenic health risks for local residents. Additionally, lead (Pb) and nickel (Ni) in 36.36% townships, and Cu in 81.82% townships were above the maximum oral reference dose, while As posed a carcinogenic risk throughout the study area. The concentrations of As, mercury (Hg), Pb, Mn, Cu Fe and selenium (Se) in grains were significantly correlated with those in soils. Moreover, the average concentrations of As in Proterozoic, Triassic, Jurassic and Cretaceous was 43.09, 12.41, 15.86 and 6.22 times higher than those in the South Tibet shell, respectively. The high concentrations of TEs and ETEs in the stratum can lead to their enrichment in soils, which, in turn, can result in excessive intake by local residents through the food chain and biogeochemical cycles . To avoid the occurrence of some diseases caused by dietary intake, it is necessary to consume a variety of exotic foods, such as high-selenium foods, foreign rice and flour in order to improve the dietary structure.

Untargeted Metabolomics Approach Correlated Enniatin B Mycotoxin Presence in Cereals with Kashin-Beck Disease Endemic Regions of China

Kashin-Beck disease (KBD) is a multifactorial endemic disease that only occurs in specific Asian areas. Mycotoxin contamination, especially from the Fusarium spp., has been considered as one of the environmental risk factors that could provoke chondrocyte and cartilage damage. This study aimed to investigate whether new mycotoxins could be identified in KBD-endemic regions as a potential KBD risk factor. This was investigated on 292 barley samples collected in Tibet during 2009-2016 and 19 wheat samples collected in Inner Mongolia in 2006, as control, from KBD-endemic and non-endemic areas. The LC-HRMS(/MS) data, obtained by a general mycotoxin extraction technic, were interpreted by both untargeted metabolomics and molecular networks, allowing us to identify a discriminating compound, enniatin B, a mycotoxin produced by some Fusarium spp. The presence of Fusarium spp. DNA was detected in KBD-endemic area barley samples. Further studies are required to investigate the role of this mycotoxin in KBD development in vivo.

A study on atypical Kashin-Beck disease: an endemic ankle arthritis

BACKGROUND

To study the epidemiological characteristics of atypical Kashin-Beck disease cases without characteristic hand lesions such as interphalangeal joint enlargement and brachydactyly and the characteristics of ankle joint lesions.

METHODS

We investigated Kashin-Beck in the endemic villages in Heilongjiang Province. The patients were judged according to the "Diagnosis of Kashin-Beck Disease" (WS/T 207-2010). The severity of foot lesions was judged based on the changes of X-ray images. Residents of non-Kashin-Beck disease area were selected as normal controls in Jilin Province.

RESULTS

A total of 119 residents over 40 years old were surveyed in a natural village in the non-endemic area. A total of 1190 residents over 40 years old were surveyed in 38 endemic areas of Kashin-Beck disease. A total of 710 patients with Kashin-Beck disease were detected, including 245 patients with grade I, 175 patients with grade II, 25 patients with grade III, and 265 atypical patients. Among all investigated patients, 92.0% (653/710) had ankle joint changes, and it was 80.0% (196/245) in grade I patients and 95.4% (167/175) in grade II. Varying degrees of ankle joint changes were found in both grade III and atypical patients. The grade of Kashin-Beck disease was correlated with the degree of ankle joint change (P < 0.001), and the correlation coefficient r_s = 0.376. Atypical Kashin-Beck disease patients in mild and severe endemic area of Kashin-Beck disease were younger than those with typical Kashin-Beck disease.

CONCLUSIONS

We found a correlation between the degree of ankle joint change and the grade of Kashin-Beck disease. The higher the grade of Kashin-Beck disease, the more serious the change of the ankle joint.

Use of Microbial Consortia in Bioremediation of Metalloid Polluted Environments

Metalloids are released into the environment due to the erosion of the rocks or anthropogenic activities, causing problems for human health in different world regions. Meanwhile, microorganisms with different mechanisms to tolerate and detoxify metalloid contaminants have an essential role in reducing risks. In this review, we first define metalloids and bioremediation methods and examine the ecology and biodiversity of microorganisms in areas contaminated with these metalloids. Then we studied the genes and proteins involved in the tolerance, transport, uptake, and reduction of these metalloids. Most of these studies focused on a single metalloid and co-contamination of multiple pollutants were poorly discussed in the literature. Furthermore, microbial communication within consortia was rarely explored. Finally, we summarized the microbial relationships between microorganisms in consortia and biofilms to remove one or more contaminants. Therefore, this review article contains valuable information about microbial consortia and their mechanisms in the bioremediation of metalloids.

Topographic constraints on the distribution of selenium in the supergene environment: A case study at Yutangba, China

The local topography and leaching conditions significantly affect the spatial distribution of selenium (Se) in the local environment. However, the driving factors controlling Se distribution have not been well addressed. In this paper, taking Yutangba, a village known for human selenosis in China, as an example, we demonstrate how topographic factors influence the spatial distribution of Se in soils and plants. In the scenarios of slope ≤25°, the correlations among slope and soil/extractable/plant Se are significantly negative (P < 0.05), whereas they become weak or unclear when the slope is > 25°, suggesting that 25° of slope is a critical transition boundary. Similar observations were further verified by the soil erosion modulus (SEM) and the surface runoff intensity index (SRI), indicating that Se transport via soil erosion is limited and accounts for 11.2-17% of the soil Se, while surface runoff plays a dominant role in the Se distribution, accounting for 83-88.1%. Soil extractable Se is negatively correlated with SRI (Pearson r = -0.87 at slope < 25°), showing that the migration capacity of Se is higher at steep terrain and controlled by topography through soil erosion and surface runoff. The positive relationship between plant Se and soil/extractable Se demonstrates that topography indirectly influences plant Se through soil Se bioavailability. Abnormally local Se enrichment observed at the elevated steep hillside (>25°) in northwestern Yutangba primarily was resulted from the weathering of Se-rich rocks. These observations confirm that the topographic slope gradient influences the transport and spatial distribution of soil Se, implying that topography should be considered when studying the spatial distribution of soil Se at a regional scale, especially for the Se-poor belt in China.

Highland barley grain and soil surveys reveal the widespread deficiency of dietary selenium intake of Tibetan adults living along Yalung Zangpo River

Objective

In order to assess selenium (Se) flux through the soil-plant-human chain in Tibet plateau and explore the reason why local Tibetan adult residents from large scale agricultural production areas in Tibet lacked daily Se intake.

Methods

A total of 210 intact highland barley plants and their corresponding cultivated topsoil samples were collected in fields of 14 agricultural counties along Yalung Zangpo River and quantitative dietary data were collected from a cross-sectional survey using a cultural-specific food frequency questionnaire that contained all local Tibetan foods in 2020.

Results

The mean value of The estimated daily Se dietary intake by each participant was 17.1 ± 1.9 μg/day/adult, the Se concentration in topsoil and highland barley grain were 0.128 ± 0.015 mg/kg and 0.017 ± 0.003 mg/kg, respectively. Although highland barley was the first contributor of dietary Se in local adult residents (34.2%), the dietary Se intake provided by highland barley only about 10% of the EAR value (50 μg/day/adult) currently. A significantly positive relationship was determined between soil total Se content (STSe), available Se content (SASe) and highland barley grain Se content (GSe). The amount of Se in food system depends on a number of soil properties (TOC, pH, clay content, Fe/Mn/Al oxides), climate variables (MAP, MAT) and terrain factor (altitude).

Conclusion

To sum up, it can be inferred that the insufficient dietary Se intake of Tibetan adult population living along Yalung Zangbo River is mainly caused by the low Se content in highland barley grain, which was result from the low Se content in cultivated soil. In order to enable adult participants in the present study to achieve recommended dietary Se-intake levels, agronomic fortification with selenised fertilizers applied to highland barley could be a great solution. It is necessary to combine the influencing factors, and comprehensively consider the spatial variation of local soil properties, climatic and topographic conditions, and planting systems.

Dietary and drinking water intake of essential trace elements in a typical Kashin-Beck disease endemic area of Tibet, China

BACKGROUND

Essential trace elements (ETEs), such as copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), selenium (Se), zinc (Zn), are very important elements for human health.

METHODS

In this study, 89 drinking water samples and 85 highland barleys were collected from 48 villages in 11 townships, and the average daily dose (ADD) of ETEs were calculated, in addition, health effects of ETEs to rural residents in Luolong County, a typical Kashin-Beck disease (KBD) endemic area in Tibet, were assessed.

RESULTS

The mean concentrations of Cu, Fe, Mn, Mo, Se, Zn in drinking water were 0.278 ± 0.264 μg·kg^-1, 0.766 ± 0.312 μg·kg^-1, 0.411 ± 0.526 μg·kg^-1, 0.119 ± 0.223 μg·kg^-1, 0.155 ± 0.180 μg·kg^-1, and 0.804 ± 1.112 μg·kg^-1, respectively; and mean concentrations of Cu, Fe, Mn, Mo, Se and Zn in highland barley were 3.550 ± 0.680 mg·kg^-1, 81.17 ± 38.14 mg·kg^-1, 14.03 ± 1.42 mg·kg^-1, 0.350 ± 0.200 mg·kg^-1, 0.0028 ± 0.0056 mg·kg^-1, and 23.58 ± 3.10 mg·kg^-1, respectively. The ADD of Cu in the study area was appropriate; the ADD of Fe and Mn in each township were higher than the maximum oral reference dose recommended by the National Health Commission of China, indicating that Fe and Mn had non-carcinogenic health risks; the ADD of Mo and Zn in 36.36% and 54.55% of the townships exceeded the maximum oral reference dose; and 72.73% of the townships had insufficient ADD of Se. The ADD of Mo, Cu and Se in different townships was significantly correlated with the prevalence of KBD.

CONCLUSIONS

Therefore, in order to prevent and control the prevalence of KBD and ensure the health of local residents, it is necessary to reduce the intake of high concentrations of Fe, Mn and Zn in diet, as well as increase the intake of Mo, Cu, especially Se.

Increased Incidence of Hashimoto Thyroiditis in Selenium Deficiency: A Prospective 6-Year Cohort Study

CONTEXT

In 2015, we reported an increased prevalence of thyroid disease in a county of low habitual selenium (Se) intake in comparison to a neighboring county with higher intake in a cross-sectional survey in Shaanxi Province, China.

OBJECTIVE

To explore longitudinal effects of low Se status, a prospective cohort study was conducted in the same area from 2013 to 2019, and thyroid peroxidase autoantibodies (TPO-Abs) and disease incidence were compared.

METHODS

A total 1254 individuals from 1500 reinvited participants were successfully enrolled. Venous blood, fingernails, and urine samples were collected and analyzed to evaluate thyroid status, TPO-Abs, serum Se, and urinary iodine. Diagnosis of Hashimoto thyroiditis (HT) was based on elevated thyrotropin, presence of TPO-Abs, and ultrasound characteristics. Se deficiency was categorized using a serum concentration of 80 µg/L as a threshold, and tested by logistic regression for a relationship to TPO-Abs and HT.

RESULTS

Se deficiency was observed in 46.2% of participants from the adequate-Se county (Ziyang) and in 89.7% from the low-Se county (Ningshan). Se concentrations in fingernails differed strongly by residency (Ziyang vs Ningshan; 678.7 vs 364.3 μg/kg; Z = -9.552; P < .001). Newly diagnosed HT in Ziyang was less frequent than in Ningshan (0.09% vs 0.31%; χ 2 = 4.350; P = .037). The conversion rate to seropositive TPO-Abs was 10.2% in Ningshan vs 5.6% in Ziyang. Excluding iodine as confounding factor, low-Se was confirmed as a risk factor for HT (relative risk [95% CI]; 3.65 [1.03-12.90]; P < .05).

CONCLUSION

The data indicate an increased incidence of TPO-Ab seroconversion with low Se supply and support the hypothesis that Se deficiency contributes to HT as a modifiable risk factor.

Spatial-Temporal Variation and Health Risk Assessment of Fluoride in Surface Water in the Tibetan Plateau

The Tibetan Plateau (TP) is known as the "Asian Water Tower" and provides vital drinking water for residents of China and Southeast Asian countries. However, large-scale regional research on water quality in this climate-sensitive and ecologically-fragile area is still lacking. Considering that drinking from fluoride-contaminated water poses serious health concerns worldwide, especially in Asian counties, it is urgent to clarify the spatial-temporal distribution characteristics, influencing factors, and health risk of fluoride in surface water in the TP. In this study, a total of 2697 surface water samples from major rivers and typical lakes in the TP were systematically analysed. Overall, fluoride concentrations ranged from 0.003 to 6.240 mg L^-1 and varied among water periods, water basins and even water types. Pearson's correlation analysis showed that the distribution of fluoride concentration was closely related to the regional climate and positively correlated with anthropogenic activities. Probabilistic health risk assessment revealed that potential hazards in the Inner Basin were the highest for all age groups (HR > 1), especially for infants and adults (HR > 3), while the risks in most other water basins were acceptable (HR < 1). Our findings can provide scientific support for fluorosis prevention, and guide water resource utilization in the TP and adjacent regions.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12403-022-00490-4.

Investigation of selenium nutritional status and dietary pattern among children in Kashin-Beck disease endemic areas in Shaanxi Province, China using duplicate portion sampling method

BACKGROUND AND OBJECTIVES

Selenium deficiency is a primary risk factor of Kashin-Beck disease (KBD). This study aimed to investigate whether children in endemic areas could maintain sufficient selenium intake after termination of selenium supplement administration, and evaluate their comprehensive nutritional status and dietary structure.

METHODS

Duplicate portion sampling combined with a questionnaire was adopted to collect data on categories and quantity of all food ingested in three consecutive days. Occipital hair was also collected to detect selenium content by hydride generation atomic fluorescence spectrometry (HGAFS). CDGSS3.0 software and factor analysis were integrated to assess the children's comprehensive nutritional status and dietary structure.

RESULTS

This study included 240 sex-matched (1:1) children aged 7-12 years from KBD endemic (n = 120) and non-endemic (n = 120) areas. Overall, 720 solid food, 720 liquid, and 240 hair samples were collected for selenium determination. The mean selenium level in hair of children in endemic areas (0.38 ± 0.16 mg/kg) was significantly lower than that in children in non-endemic areas (0.56 ± 0.28 mg/kg, Z = -5.249, p < 0.001). The dietary selenium intake of children in endemic areas was 40.0% lower than that in children in non-endemic areas (Z = -9.374, p < 0.001). Children in endemic areas consumed significantly less diverse dietary items leading to significantly less intake of multiple nutrients compared to children in non-endemic areas.

CONCLUSIONS

The dietary selenium intake of most children in endemic areas was less than the recommended amount. The dietary structure of children was undiversified, which limited the intake of multiple nutrients. Therefore, comprehensive nutrition rather than sole selenium intake should be the primary concern in the future.

Dietary and Food Consumption Patterns and Their Associated Factors in the Tibetan Plateau Population: Results from 73 Counties with Agriculture and Animal Husbandry in Tibet, China

Dietary imbalances are an important cause of morbidity and mortality, both in China and globally. Abnormal element content in the natural environment and the unbalanced dietary structure of populations coexist in the Tibetan Plateau. This study analyzed the dietary and food consumption patterns of 617 Tibetan residents and their associated factors. Cluster analysis revealed three modes of dietary pattern; the food consumption scores (FCSs) of subjects in modes with relatively high consumption frequency of staple food and relatively singular dietary structure were the lowest. Although the FCSs of most subjects were acceptable (FCS > 35), subjects with relatively low FCSs were more dependent on locally cultivated highland barley that is probably low in selenium. Hierarchical linear models revealed both individual−family and regional factors were significantly related (p values < 0.05) with the food consumption of subjects as follows: age, travel time from township to county, and cultivation area of highland barley were negatively related; numbers of individuals aged 40−60 years and pork, beef, and mutton production were positively related. Individuals with secondary or higher education had higher FCSs. A single indicator may be incomprehensive in dietary and food consumption studies. For people with a relatively unbalanced diet, an analysis of the main foods they consume is critical. Dietary and food consumption patterns might have relatively large inter-regional and intra-regional variations; therefore, factors that influence it might be multi-level and multi-scale.