non-KBD Areas Research Articles

The Role of Selenium-Mediated Notch/Hes1 Signaling Pathway in Kashin-Beck Disease Patients and Cartilage Injury Models.

Kashin-Beck disease (KBD) is a nutrition-related osteoarthropathy, and selenium (Se) deficiency is an environmental risk factor for KBD. Notch/Hes1 signaling pathway plays a vital role in regulating cartilage, but its exact mechanisms in KBD remain unknown. The Se contents were determined using the hydride atomic fluorescence spectrometry assay technique, and the mRNA levels were detected via quantitative real-time PCR. The chondrocyte injury models were established by Se deficiency and tert-butyl hydroperoxide (tBHP), respectively; apoptosis and necrosis rates were detected using Hoechst 33,342/PI and Annexin V-FITC/PI. The results showed that the Se levels in the flour of KBD areas were lower than that of the non-KBD areas, and the Se levels in the plasma of KBD patients were lower than that of the controls. The expressions of Notch1, Jagged1, and Hes1 were higher in the whole blood of KBD patients than those of the controls, and Notch1 was negatively correlated with the expression of BCL2, while was positively correlated with BAX. In injury, chondrocytes induced by low Se and tBHP, the expression of Notch1, Jagged1, and Hes1 increased, apoptosis and necrosis rates increased in Se deficiency and tBHP groups, while Se supplementation reversed it. Decreased plasma Se in KBD patients may be related to low dietary Se. Se deficiency might be involved in the pathological process of KBD by activating the Notch/Hes1 signaling pathway to induce excessive apoptosis of chondrocytes, the activation of Notch/Hes1 promotes oxidative injury, and Se supplementation could reverse it. The importance of Notch/Hes1 signaling pathway in KBD development will provide a new potential target for KBD.

Thermodynamic control on chemical weathering of river bedrock at the Aba and Qamdo in Kaschin-beck disease region, eastern Tibet Plateau

Groundwater is the main source of water for living and agriculture in an area. To investigate the relationship between water environment and Kaschin-beck disease (KBD), we collected published data on water samples (data from the KBD areas of Aba Prefecture, Qamdo area, the Yellow River Basin region and the non-KBD area of the Yangtze River Basin region) for thermodynamic simulations to further analyze the hydrogeochemical properties. The analysis results show that: (1) The groundwater in Aba Prefecture and Qamdo area is weakly alkaline. (2) The groundwater type in Aba Prefecture and Qamdo area is Ca-HCO3− type. (3) The average concentration of cations Mg2+and Ca2+ can be expressed as Yellow River Basin > Yangtze River Basin > Aba Prefecture > Qamdo area. The average concentration of cation Na+and anion Cl− can be expressed as Yellow River Basin > Qamdo area > Yangtze River Basin>Aba Prefecture. The value of TDS can be expressed as Yellow River Basin > Qamdo area > Yangtze River Basin > Aba Prefecture. This may indicate that there is no direct relationship between KBD and water environment. (4) The dissolution of calcite and dolomite in quartzite controls the change of element content of water. (5) Analysis of the Gibbs distribution shows that most of the elements in the groundwater of the KBD areas (Aba Prefecture, Qamdo area and the Yelllow River Basin region) and non-KBD area (the Yangtze River Basin region) majorly come from rock weathering. (6) The overall quality of groundwater is good, the salinity is low, and it is suitable for agricultural irrigation.

Differences of selenium and other trace elements abundances between the Kaschin-Beck disease area and nearby non-Kaschin-Beck disease area, Shaanxi Province, China

In order to find out the environmental geochemical characteristics of KBD affected area, KBD and non-KBD villages in KBD Counties, Weibei KBD area, Shaanxi Province, China were studied. Contents of Se and other elements in soil, wheat, maize and drinking water were analyzed. The results show that soil of Weibei KBD area is deficient in trace elements comparing with BSC and non-KBD area. Wheat of Weibei KBD area is deficient both in major elements and trace elements comparing with REC. Wheat of KBD village is especially deficient in Cr, Co, Se, Mo and Mg. Contents of Sr, Li and Mo in wheat of KBD village are significantly lower than nearby non-KBD village, but the average Se content is slightly higher. The deficiency of trace elements, especially Se, Sr, Li and Mo in staple food and trace elements in soil, is the main characteristic for the environment of KBD area.

The characteristics of positive and confusing hand X-ray signs in diagnosing Kashin\u2013Beck Disease in children in China

When screening for Kashin–Beck disease (KBD) in children, hand X-ray examination is the most important measure. However, there is high rate of misdiagnosis because of confusing X-ray signs. We studied the characteristics of positive and confusing hand X-ray signs. Clinical and radiological examinations were conducted in all 7- to 12-year-olds in selected villages from some KBD and non-KBD areas. We analysed the radiological and epidemiological characteristics of the X-ray signs of KBD and the confusing signs. Images from 3,193 children were valid. No cases of KBD were found. Seventeen children (0.53%) had X-ray signs positive for KBD. The confusing X-ray signs included closure reaction of metaphysis-epiphysis (CRME, 14.28%), thumb variation (0.22%), little finger variation (8.89%), the second metacarpal-phalangeal variation (0.13%) and cystic change (3.85%). The onset of CRME in children occurred earlier in girls (9) than in boys (10). The onset occurred earlier in KBD areas (9) than in non-KBD areas (10). The onset occurred earlier in Han children (9) than in Tibetan children (11). In summary, KBD was effectively controlled in all investigated KBD endemic villages, and the age range should be adjusted to 7- to 11-year-olds in Han children to reduce the misdiagnosis rates in KBD surveillance.

Selenium status of children in Kashin-Beck disease endemic areas in Shaanxi, China: assessment with mercury.

The causes of Kashin-Beck disease (KBD) in children are multifactorial, and particular consideration has been given to childhood selenium (Se) deficiency. In this study, dietary intake of Se and mercury (Hg) was determined at KBD areas to investigate the Se status and risks. Therefore, total Hg and Se levels were investigated in scalp hair samples and in daily intake food samples of 150 schoolchildren in Yongshou County of Shaanxi, China. The results showed that the average concentration of Se in children's hair has risen to 302ngg-1 and significantly increased compared to the data reported decades ago. Children at KBD endemic areas likely have improved Se status due to the Se supplementation in food at recent decades. However, all the children in the study areas still showed lower Se status compared to those in other non-KBD areas of China. The probable daily intake of Se in the study areas was still lower after stopping Se supplementation in food at KBD areas, which is 17.96μgday-1. Food produced locally cannot satisfy the lowest demand for Se nutrition for local residents. If the interactions of Se-Hg detoxification are considered, Hg intake from food exacerbates Se deficiency at the KBD areas.

Trace Element Levels in Scalp Hair of School Children in Shigatse, Tibet, an Endemic Area for Kaschin-Beck Disease (KBD).

Kaschin-Beck disease (KBD) is an endemic osteoarthritis, and the etiology is closely related with levels of trace elements in the human body. Currently, it is clear that the selenium (Se) status of children in KBD areas is lower than that in non-KBD areas in the Tibetan Plateau, whereas role of other elements are yet unknown. This study aimed to assess some essential trace elements (Se, Mo, Mn, Zn, Fe, Cu, Co, and Sr) in children using scalp hair as a biomarker, and 157 samples from school children aged 8-14years old were collected from both KBD and non-KBD areas in Shigatse, Tibet. Se and Mo were measured by inductive coupled plasma mass spectrometry, and the other elements were determined by inductive coupled plasma optical emission spectrometry. Compared with the non-KBD areas, Se, Mo, Mn, Fe, Zn, Co, and Sr levels of children in KBD areas were found to be significantly different (P<0.05); while in linear discriminant analysis, only Se and Zn were found to contribute to the KBD prevalence in the study area. The hair Se level of children in KBD areas ranged from 0.115 to 0.299mg/kg, while in non-KBD areas it ranged from 0.135 to 0.519mg/kg. The Zn content of children's hair was between 83 and 207mg/kg in KBD areas, while it was 37 and 219mg/kg in non-KBD areas. Lower Se and higher Zn levels in children in KBD areas was found when compared with non-KBD groups. In addition, Mo levels were found to be different between KBD areas and non-KBD areas on the opposite side of the Yarlung Zangbo River, but no close relationship was shown because there was no difference compared with the non-KBD area on the same side of the river. Our observations suggest that Se deficiency is still an important factor for the occurrence and prevalence of KBD, while the relationship between Zn and KBD needs to be further explored in the Tibetan Plateau.

Distribution and translocation of selenium from soil to highland barley in the Tibetan Plateau Kashin-Beck disease area.

Kashin-Beck disease (KBD), which is still active and severe in the Tibetan Plateau, is considered to be a kind of selenium (Se)-deficient disease. Highland barley as the most popular staple food in the Tibetan Plateau is one of the dominant Se sources for local people. To improve Se levels in crops in the Tibetan Plateau KBD area, the distribution and translocation of Se from soil to highland barley in both non-KBD and KBD endemic areas were investigated. The results showed that Se levels in highland barley were too low to meet the minimum requirements of human for daily intake of Se. The total Se concentrations of highland barley fractions in KBD areas were lower than that in non-KBD areas (grain P=0.238; straw P=0.087; root P=0.008). However, no significant difference was observed in corresponding cultivated soil Se between the two areas (P=0.993). The calculation of Se transfer factors indicated that the restricting step for Se translocation was from soil to root. Water-soluble, exchangeable and fulvic acid-bound Se fractions in the soil are key species dominating in this transfer process, according to their significant correlations with root Se. Se transfer from soil to root significantly increases as the pH value of soil increases (P=0.007), and soil organic matter content decreases (P=0.019). The information obtained may have considerable significance for proposing effective agricultural measures to increase grain Se in KBD endemic areas.

The effects of T-2 toxin on the prevalence and development of Kashin-Beck disease in China: a meta-analysis and systematic review.

To reveal the influence of T-2 toxin detection rate and detection amount in food samples on Kashin-Beck disease (KBD), and define a linking mechanism between T-2 toxin induced chondrocytes or cartilage damage and KBD pathological changes, seven electronic databases were searched to obtain epidemiological and experimental studies. For epidemiological studies, subgroup analyses of the positive detection rate (PDR) of the T-2 toxin and PDR of the T-2 toxin with concentrations (PDRC of T-2) >100 ng g-1 were carried out, together with a histogram of the T-2 toxin concentrations in different food types in KBD and non-KBD areas. For experimental studies, a systematic review of a variety of chondrocyte and cartilage changes and damage induced by the T-2 toxin was performed. As a result, in epidemiological studies, meta-analysis demonstrated that the T-2 toxin PDR and the overall PDRC of T-2 toxin >100 ng g-1 showed a slightly significant increase in KBD areas than that in non-KBD areas separately. From the histogram, T-2 toxin accumulation was more serious in endemic areas, especially in wheat flour samples. In experimental studies, the T-2 toxin could induce damage of chondrocytes and cartilage, and inhibit cell proliferation by promoting apoptosis and catabolism as well as intracellular injuries, which is similar to the characteristics of KBD. In conclusion, the amount of T-2 toxin detected has a more significant influence on KBD prevalence and development as compared to the T-2 toxin detection rate. Besides, the T-2 toxin induces chondrocyte and cartilage damage through apoptosis, catabolism promotion and intracellular impairment, which is similar to the KBD change.

Is It the Appropriate Time to Stop Applying Selenium Enriched Salt in Kashin-Beck Disease Areas in China?

We aimed to identify significant factors of selenium (Se) nutrition of children in Kashin-Beck disease (KBD) endemic areas and non-KBD area in Shaanxi Province for providing evidence of whether it is the time to stop applying Se-enriched salt in KBD areas. A cross-sectional study contained 368 stratified randomly selected children aged 4–14 years was conducted with 24-h retrospective questionnaire based on a pre-investigation. Food and hair samples were collected and had Se contents determined with hydride generation atomic fluorescence spectrometry. Average hair Se content of 349.0 ± 60.2 ng/g in KBD-endemic counties was significantly lower than 374.1 ± 47.0 ng/g in non-KBD counties. It was significantly higher in the male children (365.2 ± 52.3 ng/g) than in the female (345.0 ± 62.2 ng/g, p = 0.002) and significantly higher in the 4.0–6.9 years group (375.2 ± 58.9 ng/g) than the 7.0–14.0 years group (347.0 ± 56.1 ng/g, p < 0.01). Gender, living area, Se intake without supplements, Se-enriched salt, oil source and protein intake were identified as significant factors of hair Se contents. Cereals, meat and milk were commonly included as significant food categories that mainly contributed to Se intake without supplement of the whole population. Balanced dietary structure without Se supplement could effectively enhance and maintain children’s Se nutrition. It may be the time to stop applying Se-enriched salt in KBD areas in Shaanxi Province.

Hair Selenium Levels of School Children in Kashin-Beck Disease Endemic Areas in Tibet, China.

Previous studies have shown that the selenium (Se) deficiency is an important factor for the etiology of Kashin-Beck disease (KBD). Although KBD is presently controlled in most regions of China, it is still active in the Tibetan Plateau. The present study aimed to assess the nutritional status of selenium in school children by using the Se level in hair as a biomarker in KBD endemic areas of Lhasa in Tibet, China. Hair samples of 155 school children aged 6-15years were collected in both KBD areas and non-KBD areas of Lhasa in 2013. The Se level in the hair samples was determined by inductive coupled plasma mass spectrometry (ICP-MS). The average concentration of Se in children's hair was 0.232μg/g in KBD areas of Lhasa, which was significantly higher than the data reported decades ago. A significant difference in hair Se was observed between the boys (0.255μg/g) and the girls (0.222μg/g) in the studied KBD areas (P < 0.01, Mann-Whitney U test), but hair Se did not vary by age or region. School children in KBD endemic areas in Lhasa likely have improved Se status as a result of high Se content staple food substitution with the enforcement of Free Education Policy and Nutrition Improvement Plan in Tibet. Nevertheless, there were still 20.3% of students with low Se status (hair Se <0.20μg/g), which showed that Se status of school children was also partly affected by low Se environment in KBD endemic areas of Lhasa.

Effects of the consumption of rice from non-KBD areas and selenium supplementation on the prevention and treatment of paediatric Kaschin–Beck disease: an epidemiological intervention trial in the Qinghai Province

Based on the aetiological hypothesis of Kaschin-Beck disease (KBD), different interventions were adopted, and the preventive and therapeutic effects of interventions was observed and evaluated in this trial. A total of 358 children from seven villages of Qinghai Province in China were examined, and 280 children aged 6-11 years old were eligible for the trial. The children were divided into three groups that received either no intervention (n = 64), 150 kg/person of rice from non-KBD areas (n = 103) or 7 kg/family of selenium-iodine salt (n = 113) for 12 months. Data were collected and used to calculate the proportion of patients with X-ray lesions, the proportion of new patients and the metaphyseal repair rate. All indicators were analysed with Pearson chi-square or Fisher's exact tests. The registration number of this trial is ChiCTR-PNRC-12002309 (http://www.chictr.org). After interventions, the proportion of patients with X-ray lesions increased dramatically in the control group and decreased significantly in two intervention groups; significant differences were seen between the control group and two intervention groups (P < 0.05). Moreover, significant differences were observed in the proportions of new patients and the metaphyseal repair rates between the control group and two intervention groups (P < 0.05). Additionally, the proportion of new patients was lowest and the metaphyseal repair rate was highest in group B. The effects of eating rice from non-KBD areas and selenium supplementation on the prevention and treatment of paediatric KBD were notable, the consumption of rice might be the most effective and safest intervention and should be encouraged.

Evaluation of the therapeutic effect of treatment with intra-articular hyaluronic acid in knees for Kashin-Beck disease: A meta-analysis

To assess the efficacy and safety of intra-articular hyaluronic acid (IAHA) injection in knee joints of patients with Kashin-Beck disease (KBD). We searched nine electronic databases as well as unpublished data from inception until November 30th 2013 using a combination of search terms for KBD and hyaluronic acid (HA). For dichotomous data, odds ratios (OR) and 95% confidence intervals (CI) were estimated. For continuous data, standard mean difference (SMD) was used for outcomes pooled on the difference scale using a "random-effects" or "fixed-effects" model. We also compared the mean and standard deviation of cytokine levels in post-treatment. The seven eligible trials included 954 IAHA and 495 control patients. The methodological quality of included trials was low. The overall effectiveness of the IAHA group and control group were 93.7% and 62.9%, respectively. IAHA group resulted in very large treatment effects compared to pre-treatment values in 12 months, with SMD values ranging from 1.19-2.64 (all P<0.05). Compared to controls, SMDs in IAHA group ranged from 0.19-0.64 at 1 week to 1 month (all P>0.05) and 0.68-1.47 at 2 months to 12 months (all P<0.05). There was significant improved of HA, cluster of differentiation44 (CD44), keratan sulfate (KS), interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α) and nitric oxide (NO) contents in serum compared with that in the post-treatment and healthy control in non-KBD area (all P<0.05). IAHA for the treatment of KBD was safe and efficacious at 12 months with low and transient adverse reactions. However, more high-quality randomized controlled trials (RCTs) are needed to confirm its therapeutic effect.

Expressions of interleukin-1β,interleukin-6 and tumor necrosis factor alpha in articular cartilage of children with Kashin-Beck disease

Objective: To investigate the expressions of interleukin-1β(IL-1β), interleukin-6 (IL-6) and tumor necrosis factor alpha(TNF-α) in cartilage of children with Kashin-Beck disease(KBD) in order to provide a possible mechanism of the disease. Methods: Articular cartilage tissues of 5 KBD children(KBD group) were selected from KBD children autopsy samples keeping in Institute of Endemic Diseases, Medical School of Xi'an Jiaotong University; articular cartilage tissues of 5 normal children(control group) were selected from non-KBD areas of Shaanxi Province, three cases were from accident death children, two cases were the samples of congential malformation of six finger. Expressions of IL-1β, IL-6 and TNF-α in the cartilage were detected using immunohistochemistry; the cells of articular cartilage were divided into three areas (superficial zone, middle zone and deep zone) to analyze the expressions of IL-1β, IL-6 and TNF-α. Results: The expressions of IL-1β in superficial zone, middle zone and deep zone of articular cartilage of KBD group(63.50 ± 7.19, 54.75 ± 5.50, 66.20 ± 9.91) were significandy higher than those of control group (5.75 ±1.26, 0.00 ± 0.00, 0.00 ± 0.00, all P < 0.05). The expression of IL-6 in superficial zone of articular cartilage in KBD group(55.25 ± 6.24) was significandy higher than that of control group (0.00 ± 0.00, P < 0.05). The expressions of TNF-a in all zone of articular cartilage of KBD group(33.25 ± 6.50, 3.75 ± 0.96, 29.80 ± 1.92) were significantly higher than those of control group (3.74 ± 0.82, 0.00 ± 0.00, 0.00 ± 0.00, all P < 0.05), Conclusion: The levels of IL-1β, IL-6 and TNF-α are up-regulated in articular cartilage of KBD children, suggesting that cytokines may play an important role in matrix degradation in KBD children cartilage.

Speciation, Distribution, and Bioavailability of Soil Selenium in the Tibetan Plateau Kashin–Beck Disease Area—A Case Study in Songpan County, Sichuan Province, China

To clarify the relationship between the soil selenium distribution and its bioavailability with the distribution of Kashin-Beck disease (KBD) endemic areas on the eastern edge of the Tibetan Plateau, samples of natural soil (0-20 cm), cultivated topsoil, and main crops of the region (highland barley) were collected at different altitudes according to topographical and geomorphological features in both KBD and non-KBD areas of Songpan County. These samples were used for determination and analysis of total selenium content in soil and highland barley and available selenium that can be absorbed and utilized by plants. The results showed that the average total selenium content of natural and cultivated topsoil in KBD areas was lower than that in non-KBD areas (natural soil, P = 0.061; cultivated soil, P = 0.002), which is in agreement with the geographical distributions of selenium in other KBD-affected areas. However, the total soil selenium content exhibits certain micro-spatial distribution features, namely, the total selenium content in some endemic areas was significantly higher than that of non-KBD areas. This result was contrary to the general distribution that total selenium content in a KBD-affected area is lower than that in a non-KBD area. We further studied the extraction rate and content of soil selenium in six different fractions. The results indicated that the content and extraction rate of available selenium in KBD-affected areas were significantly lower than those in non-KBD areas. There is a distinct positive correlation between plant-available selenium and highland barley selenium (r = 0.875, P = 0.001) and a distinct negative correlation with altitude (r = -0.801, P = 0.010). Therefore, in KBD endemic areas, the selenium content in crops decreases as the available selenium content in soil decreases and is closely related to the geographical environment features (such as altitude and precipitation). These results suggest that the soil available selenium and ecological features are important factors that restrict the dietary selenium flux for residents in KBD endemic areas of the Tibetan Plateau, providing a theoretical and experimental basis for implementing agricultural measures to regulate the ecological cycle of the selenium flux in the KBD endemic area.

Serum levels of TNF-α, IL-1β, COMP, and CTX-II in patients with Kashin-Beck disease in Sichuan, China

The aim of the study was to detect differences in serum levels of interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), cartilage oligomeric matrix protein (COMP), type II collagen (CTX-II) between patients with Kashin-Beck disease (KBD) or osteoarthritis (OA) and to assess the correlation between these differences with the clinical grade of KBD. A total of one hundred fifty adult serum samples were collected; these samples belonged to the KBD group (n = 64), the OA group in KBD-prevalent areas (n = 47) and a healthy control group in non-KBD area (n = 39). Serum levels of TNF-α, IL-1β, COMP, and CTX-II were determined by a sandwich enzyme-linked immunosorbent assay, and the results were compared among the 3 groups (KBD/OA/normal) and between the different grades of KBD as well. The serum levels of IL-1β, TNF-α, COMP, and CTX-II were significantly higher in the KBD and OA group than the healthy adult group (P < 0.001), and TNF-α and IL-1β levels in the KBD group were similar to the OA group (for TNF-α, 14.38 ± 7.42 pg/ml vs. 12.61 ± 4.00 pg/ml, respectively, [P = 0.29]; for IL-1β, 141.53 ± 71.35 pg/ml vs. 135.61 ± 68.60 pg/ml, respectively, [P = 0.63]). However, the COMP level was significantly lower and the CTX-II level was higher in the KBD group than in the OA group (for COMP, 7.03 ± 3.11 ng/ml vs. 9.20 ± 3.51 ng/ml, respectively, [P = 0.003]; for CTX-II, 2.23 ± 0.79 ng/ml vs. 1.80 ± 0.87 ng/ml, respectively, [P = 0.026]). Moreover, no significant correlations were found between clinical grade and serum levels of TNF-α, IL-1β, COMP, and CTX-II for the 3 grades of KBD patients (P = 0.645, 0.481, 0.832, and 0.270, respectively). This study showed that serum levels of COMP in KBD patients decreased and CTX-II levels increased compared with the levels in OA patients, but TNF-α and IL-1β levels in KBD and OA group were similar. In addition, increased serum levels of TNF-α, IL-1β, COMP, and CTX-II were not associated with the KBD grade.

Detection of serum proteomic changes and discovery of serum biomarkers for Kashin-Beck disease using surface-enhanced laser desorption ionization mass spectrometry (SELDI-TOF MS)

The purpose of the current study was to investigate the changes of serum proteome and discover potential biomarkers for Kashin-Beck disease (KBD) using surface-enhanced laser desorption ionization mass spectrometry (SELDI-TOF MS). The serum protein profiles from 102 cases (36 KBD patients, 16 controls in KBD areas, 33 controls in non-KBD areas, and 17 osteoarthritis controls) were detected by SELDI-TOF MS and weak cation-exchange protein chip. Differently expressed peaks in KBD were identified by comparing the data among the four groups using the nonparametric Mann-Whitney test with Bonferroni correction at a significance level of 0.05. Then, those 102 cases were used to generate a classification tree as the training set, and an additional 34 cases were collected as the test set. A classification tree was generated by Biomarker Patterns Software (Ciphergen). Multiple protein changes were detected in the KBD group, including three potential biomarkers (15 886, 5336, 6113 m/z). A classification tree with three distinct proteins was generated. The classification tree was able to distinguish the KBD patients from the controls with 88.89% specificity and 86.36% sensitivity. The study demonstrates that marked serum proteomic changes exist in KBD. The proteins represented by the differently expressed peaks are candidate biomarkers for KBD.

Selenium, boron, and germanium deficiency in the etiology of Kashin-Beck disease.

Concentrations of selenium (Se), boron (B), and germanium (Ge) were determined in scalp hair of children with Kashin-Beck disease (KBD), in healthy children in KBD-disease endemic areas, and in healthy children in non-KBD areas. Mean Se, B, and Ge concentrations were low in children with KBD; in hair of healthy children in KBD areas, Se levels were normal but B and Ge levels were lower than in KBD-free areas. The hair levels of B and Ge were unaffected by selenium supplementation. It is suggested that B and Ge deficiency may be contributing factors in the etiology of KBD.