Prevalence of T-2 Toxin in the Food and Beverages of Residents Living in a Kashin-Beck-Disease Area of Qamdo, Tibet.

It has been strongly suggested that selenium deficiency and T-2 toxin contamination have a strong relationship with the occurrence and development of Kashin-Beck disease (KBD). In order to provide information for understanding the high prevalence of KBD in Tibet, this study collected the responses to a cubital venous blood and dietary questionnaire of 125 subjects including 75 KBD patients and 50 healthy controls in a KBD-prevalent county (Luolong County) in Tibet, China. A total of 10 household local families were randomly selected in this area, and local diet samples of brick tea, Zanba powder, milk residue, and hulless Barley were collected from these residents. Selenium content in blood was detected by inductively coupled plasma mass spectrometry (ICP-MS). The T-2 toxin contamination level in food sample was assayed using an ELISA kit. The selenium levels of patients and controls were 42.0 ± 19.8 and 56.06 ± 22.4 µg/L, respectively. The serum selenium level in controls was higher than that in patients, but there was no significant difference, and the serum selenium level both in patients and controls in Tibet was lower than the normal range. The results of the dietary survey showed that the number of respondents who consumed butter tea was large; 46.67% of patients indicated that they drank buttered tea every day, which was significantly higher than in controls. The contents of T-2 toxin in Zanba powder, milk residue, hulless barley and drinking water samples were below the detection limit (0.05 µg/kg); this result was labeled Tr. Unexpectedly, the contents of T-2 toxin in brick tea were higher, with average levels of 424 ± 56 µg/kg in Detong village and 396 ± 24 µg/kg in Langcuo village. For the first time, we report the presence of an extremely high concentration of T-2 toxin in brick tea of Tibet.

[Blood cadmium level and the change of cadmium exposure risk in Chinese urban school-age children in 2002 and 2012].

OBJECTIVE: To investigate the blood cadmium concentrations and the related change in Chinese urban children derived from the China Nutrition and Health Survey 2002 and 2012(CNHS 2002 and CNHS 2012). METHODS: The Chinese urban children aged 6-11 years were selected according to gender, age and regional distribution using the multi-stage stratified cluster random sampling method, as well as the corresponding whole blood samples. The blood cadmium concentration was carefully determined by the quadrupole inductively coupled plasma mass spectrometry(ICP-MS) and the percentage of blood cadmium over 2 µg/L was subsequently estimated. In addition, the upper limit values of the 95%CI of the 95th percentiles of available blood cadmium data was assessed as the threshold of cadmium exposure. RESULTS: Totally, 2182 Chinese urban children were included, and of these, 1036 children were from the CNHS 2002 and 1146 children were from the CNHS 2012. From the CNHS 2002 to the CNHS 2012, the median blood cadmium concentration was increased from 0.28 µg/L to 0.95 µg/L, and the percentage of blood cadmium with over 2 µg/L was elevated from 1.45% to 10.47%. In addition, the new estimated threshold of blood cadmium was ascended from 1.24 µg/L up to 2.89 µg/L. CONCLUSION: The risk of cadmium exposure in Chinese urban children aged 6-11 years was increasingly aggravated from the CHNS 2002 to the CNHS 2012.

[Analysis of diet structure of Kashin-beck disease area in Chamdo-Lhorong of Tibet in 2021].

OBJECTIVE: To investigate and compare the dietary structure between healthy people and patients in KBD area of Chamdo-Lhorong of Tibet. METHODS: A case-control study design was used, retrospectively select patients who had completed screening and registered in the national Kashin-Beck Disease surveillance system in 2021 in Luolong County, Qamdo, Tibet as the source population of the case group, and randomly selected people who had not been screened for Kashin-Beck disease in the same county as the control group. The self-made diet questionnaire was used to record the types of food consumption, frequency of food intake, basic information of the respondents, family size and other basic information in the past year by one-on-one interview. RESULTS: The staple food with the highest response among the patients(97.33%) was rice(rice/rice noodle), and the highest response among the healthy people(90%) was non-wheat products, non-fried pasta(bread/steamed bun/noodles/dumplings), except instant noodles.78.7% of patients chose not to eat local wheat(Tibetan noodles), and the number of non-patients who chose to eat non-local wheat(Tibetan noodles) 3-4 times a week was significantly higher than that of patients. The meat and meat products with the highest response in both patients(93.33%) and healthy people(90%) was yak meat(local). The control group also chose to consume beef(non-local/lamb/mutton/other non-processed meat), poultry and livestock offal, fish(all seawater and freshwater fish), shrimp and crabs or other seafood, and their consumption rate and intake frequency were significantly higher than those of the case group. The consumption rate and frequency of tomato, onion and garlic(garlic shoots/leek/onion/onion) and fresh eggs(egg/duck egg/quail egg/goose egg) in control group were significantly higher than those in case group. There was no significant difference in consumption rate and frequency of fruits, milk and dairy products between the two groups. CONCLUSION: In addition to the local highland barley(zanba), most people also chose to purchase rice and flour, which changed the situation of single staple food in the past. However, compared with the healthy population in the disease area, the consumption rate and intake frequency of fish, shrimp and crabs, poultry and livestock viscera, eggs(fresh eggs) and vegetables(tomatoes, scallions, ginger and garlic) in KBD patients were significantly lower, the selection of meat varieties is single, mainly local yak meat, and the overall dietary structure still presents the risk of single type and unbalanced diet.

Re-exploration of dietary iodine intake in Chinese adult males using a modified iodine balance study.

There is still controversy about optimal dietary iodine intake as the Universal Salt Iodization policy enforcement in China. A modified iodine balance study was thus conducted to explore the suitable iodine intake in Chinese adult males using the iodine overflow hypothesis. In this study, thirty-eight apparently healthy males (19·1 (sd 0·6) years) were recruited and provided with designed diets. After the 14-d iodine depletion, daily iodine intake gradually increased in the 30-d iodine supplementation, consisting of six stages and each of 5 d. All foods and excreta (urine, faeces) were collected to examine daily iodine intake, iodine excretion and the changes of iodine increment in relation to those values at stage 1. The dose-response associations of iodine intake increment with excretion increment were fitted by the mixed effects models, as well as with retention increment. Daily iodine intake and excretion were 16·3 and 54·3 µg/d at stage 1, and iodine intake increment increased from 11·2 µg/d at stage 2 to 118·0 µg/d at stage 6, while excretion increment elevated from 21·5 to 95·0 µg/d. A zero iodine balance was dynamically achieved as 48·0 µg/d of iodine intake. The estimated average requirement and recommended nutrient intake were severally 48·0 and 67·2 µg/d, which could be corresponded to a daily iodine intake of 0·74 and 1·04 µg/kg per d. The results of our study indicate that roughly half of current iodine intakes recommendation could be enough in Chinese adult males, which would be beneficial for the revision of dietary reference intakes.

Re-exploring the requirement of dietary iodine intake in Chinese female adults based on 'iodine overflow theory'.

PURPOSE: We re-explored the basal iodine requirement based on healthy Chinese female and a new iodine overflow theory was proposed for iodine balance study. METHODS: Thirty-six Chinese healthy female adults (age 20.7 ± 1.1) were recruited for this study, which included 40 days low iodine depletion period and six stages of 30 days supplementation period. Uniform diets with low iodine were provided and the content of iodine in the diet was regulated by dairy products. The total iodine intake from food and the total iodine excretion through 24-h urine and staged feces were completely gathered and monitored. The incremental (Δ) intake and excretion over the range were calculated. RESULTS: The iodine intake and excretion were 13.6 µg/day and 48.6 µg/day at the first stage, respectively. The incremental iodine intakes and excretions were 21.1 µg/day to 120.3 µg/day and 25.8 µg/day to 105.4 µg/day for the supplementation stages, respectively. According to the 'iodine overflow theory', the zero iodine balance (Δ iodine intake = Δ iodine excretion) derived from a mixed effect model indicated a mean iodine intake of 52.2 µg/d (1.0 µg/d kg). The RNI for iodine to healthy Chinese female adult was 73.1 µg/d (1.4 µg/d kg). CONCLUSION: A daily iodine intake of 52.2 µg/d may meet the basal iodine requirement for healthy Chinese female adults, and Chinese female may need more than 20% iodine intake than male based on the 'iodine overflow theory'. The trial was registered at the Chinese Clinical Trial Registry in May 2018 (No: ChiCTR1800016184).

The Time Trend of Blood Lead and Cadmium Levels in Rural Chinese Children: China Nutrition and Health Survey 2002 and 2012.

This study was to investigate blood lead (Pb) and cadmium (Cd) levels and time trend in rural Chinese children derived from the China Nutrition and Health Survey 2002 and 2012 (CNHS 2002, CNHS 2012). In total, 1698 and 1581 of rural Chinese children were selected from the CNHS 2002 and the CNHS 2012 databases, respectively. The blood Pb and Cd levels were determined by inductively coupled plasma mass spectrometer (ICP-MS), whilst the prevalence of blood Pb levels >5 µg/dL and blood Cd levels >0.5 µg/L and the corresponding reference values (RV95s: the upper limit of 95% confidence interval of 95th percentile) were together calculated. From the CNHS 2002 to the CNHS 2012, median concentrations in blood were severally decreased from 6.3 to 3.1 µg/dL for Pb and from 0.64 to 0.39 µg/L for Cd. The prevalence of blood Pb levels >5 µg/dL had decreased from 63.6 to 14.2%, together with blood Cd levels >0.5 µg/L prevalence from 62.7 to 33.5%, respectively. The RV95s of blood Pb and Cd levels were 15.2 µg/dL and 1.54 µg/L in the CNHS 2002, as well as 6.3 µg/dL and 1.12 µg/L in the CNHS 2012. In conclusion, blood Pb and Cd levels had been obviously improved in rural Chinese children during the past 10 years. However, the risks of Pb and Cd exposure are still serious and required to have continuous health monitoring and evaluation, even call for greater collaboration of the government and society.

Urine trace element disorder along with renal function injury in vitamin D deficient diabetic rats and intervention effect of 1α,25-dihydroxyvitamin D3.

Introduction: Trace element metabolism disorders are often secondary to disorders of glucose metabolism in diabetes. Although 1α,25-dihydroxyvitamin D3 [1,25(OH)2D3] could ameliorate abnormal glucose metabolism in the development of diabetes, the effect on trace element metabolism is unclear. The objective of this study was to evaluate the influence of 1,25(OH)2D3 on urinary excretions of trace elements in Zucker diabetic fatty (ZDF) rats. Methods: At 6 weeks of age, male ZDF (n = 40) rats were subdivided into four groups: diabetic model (ZDF), low-dose (ZDF + VL, 2 µg/kg⋅bw), middle-dose (ZDF + VM, 8 µg/kg⋅bw) and high-dose (ZDF + VH, 16 µg/kg⋅bw) 1,25(OH)2D3 groups. Another 10 Zucker lean (ZL) rats served as a control group. All rats were given vitamin D deficient Purina #5008 chow and the intervention groups were given the corresponding dose of 1,25(OH)2D3 by gavage on alternate days for 7 weeks. Microalbuminuria (MALB) and urinary creatinine concentration were detected by a biochemical autoanalyzer. Urine trace element concentrations were measured using inductively coupled plasma mass spectrometry (ICP-MS) and were corrected by urinary creatinine. Results: Throughout the intervention phase, MALB, UACR and urinary creatinine levels in the ZDF group were significantly higher than those in the ZL group, and showed a gradual increase with the prolongation of the intervention time. These changes were reversed in a dose-dependent manner after 1,25(OH)2D3 intervention (P < 0.05). Correspondingly, most of the urinary trace element excretions in the ZDF rats were significantly increased compared with the ZL group, and 1,25(OH)2D3 intervention significantly reduced the urinary copper (Cu), zinc (Zn), selenium (Se) and molybdenum (Mo) levels in the ZDF rats (P < 0.05), especially in the medium and high dose groups. Conclusion: 1,25(OH)2D3 had improvement effects on urinary Cu, Zn, Se, and Mo excretions in ZDF rats, suggesting that it may be related to the reduction of diabetic renal impairment and renal oxidative damage.

Exploration of the lower threshold of iodine intake in Southern Chinese young adults based on 'overflow theory' in an iodine balance study.

BACKGROUND: Appropriate iodine intake for adults is essential to reduce the prevalence of thyroid diseases, but there is little research data on iodine requirement of Chinese population. This study aimed to explore the iodine requirement of young adults to maintain a healthy status based on 'overflow theory'. METHODS: Iodine-balance experiment has been performed in this project. We conducted an 18-day study consisted of a 6-day acclimation period and 3 consecutive experimental stages in 37 Chinese healthy young adults (23 female and 14 male). Each stage was consumed for 4 days. Strictly-controlled low-iodine intake diets were provided for adults in the first period, an egg or 125mL milk was added in the second and third period, respectively. The dietary samples, 24-h urine specimens and faeces of volunteers were collected daily for assessment of iodine intake and excretion in volunteers. RESULTS: Mean values of iodine intake (22.7±3.6, 35.1±3.7, and 52.2±3.8µg/d), excretion (64.7±13.9, 62.3±12.6, and 94.3±14.5µg/d) and iodine balance (-35.2±19.5, -21.0±19.8, and -33.5±26.9µg/d) were significantly different among three periods for male (P<0.001 for all); mean values of iodine intake (16.6±3.1, 29.7±2.7, and 48.0±2.7µg/d), and excretion (47.0±9.9, 55.5±8.1, and 75.7±12.4µg/d) were significantly different among three periods for female (P < 0.001 for all). No significant difference was observed among the 3 periods for female in the iodine balance (-30.5±9.3, -25.9±7.3, and -27.6±12.1µg/d). The linear regression equation of iodine excretion on iodine intake was Y=0.979X+37.04 (male) and Y=0.895X+31.48 (female). Compared with stage 2, iodine excretion increments in stage 3 had exceeded the iodine intake increment for men. The ratio of increment was 1.675 for male when the average iodine intake was 52.2µg/d in stage 3. When the iodine excretion increment equaled to the iodine intake increment, the daily iodine intake of men was 47.0µg. CONCLUSION: We have evaluated the iodine requirement of young adults in southern China based on overflow theory. Our results indicate the lower limit of iodine requirement for Chinese young men is 47.0µg/d. The trial was registered at www.chictr.org.cn as ChiCTR1800014877.

[Establishment and application of high performance liquid chromatography-inductively coupled plasma mass spectrometry method for the determination of iodine species in serum].

OBJECTIVE: To establish a method for the determination of iodine species in human serum by inductively coupled plasma mass spectrometry(ICP-MS). METHODS: Total iodine was determined by ICP-MS in helium mode after dilution of serum with tetramethylammonium hydroxide solution. The serum was added to methanol solution to precipitate the protein, and the supernatant was separated by liquid chromatography(LC) followed by ICP-MS for the determination of inorganic iodine. RESULTS: The limit of detection(LOD) of serum I~- by ICP-MS was 0.17 µg/L, the limit of quantification(LOQ) was 0.57 µg/L, and the linear correlation coefficient R~2=0.9998; the LOD of serum IO_3~- was 0.16 µg/L, the LOQ was 0.55 µg/L, and the linear correlation coefficient R~2=0.9998.The I~- recoveries were 96.2%-104.5% for the total serum iodine assay and 93.7%-98.6% for the inorganic iodine assay. Analysis of the iodine species of the actual serum samples showed that the I~- content was 2.6-12.2 µg/L, the organic iodine content was 45.3-66.0 µg/L, and the serum samples were essentially free of IO_3~-. CONCLUSION: A convenient, efficient and accurate method for the determination of serum iodine species was established using high performance liquid chromatography tandem with inductively coupled plasma mass spectrometry.

An iodine balance study to explore the recommended nutrient intake of iodine in Chinese young adults.

Data on average iodine requirements for the Chinese population are limited following implementation of long-term universal salt iodisation. We explored the minimum iodine requirements of young adults in China using a balance experiment and the 'iodine overflow' hypothesis proposed by our team. Sixty healthy young adults were enrolled to consume a sequential experimental diet containing low, medium and high levels of iodine (about 20, 40 and 60 µg/d, respectively). Each dose was consumed for 4 d, and daily iodine intake, excretion and retention were assessed. All participants were in negative iodine balance throughout the study. Iodine intake, excretion and retention differed among the three iodine levels (P < 0·01 for all groups). The zero-iodine balance derived from a random effect model indicated a mean iodine intake of 102 µg/d, but poor correlation coefficients between observed and predicted iodine excretion (r 0·538 for µg/d data) and retention (r 0·304 for µg/d data). As iodine intake increased from medium to high, all of the increased iodine was excreted ('overflow') through urine and faeces by males, and 89·5 % was excreted by females. Although the high iodine level (63·4 µg/d) might be adequate in males, the corresponding level of 61·6 µg/d in females did not meet optimal requirements. Our findings indicate that a daily iodine intake of approximately half the current recommended nutrient intake (120 µg/d) may satisfy the minimum iodine requirements of young male adults in China, while a similar level is insufficient for females based on the 'iodine overflow' hypothesis.

[Detection and correlation between the content of sodium and iodine in pre-packaged foods].

OBJECTIVE: To evaluate the present situation of sodium and iodine content and the correlation in pre-packaged foods in the market. METHODS: After collecting samples from physical and online supermarkets, the contents of sodium and iodine of samples were detected by inductively coupled plasma mass spectrometry, SPSS 26. 0 was applied to analyze the correlation between sodium and iodine and the utilization rate of iodized salt was calculated in pre-packaged foods. RESULTS: Among various types of pre-packaged foods, fish, poultry, meat and egg products sodium(M=884 mg/100 g), iodine(M=40. 5 µg/100 g), preserved foods sodium(M=940 mg/100 g), iodine(M=40. 5 µg/100 g), animal foods sodium(M=786 mg/100 g), iodine(M=34. 9 µg/100 g) were all high in sodium and iodine content. The correlation coefficient of sodium and iodine content in staple and instant foods of animal foods was 0. 730(P<0. 01) and vegetable foods was 0. 777(P<0. 01), the preserved foods of animal foods was 0. 518(P<0. 01) and vegetable foods was 0. 973(P<0. 01). The utilization rate of iodized salt in pre-packaged foods was 88. 46% after removing those samples that could cause the iodine loss, such as baked foods. CONCLUSION: The sodium and iodine content in pre-packaged foods vary with different categories.

[Quantification and comparison of fatty acid between white peanuts and red peanuts].

OBJECTIVE: To investigate the difference of fatty acid content and types between red peanuts and white peanuts. METHODS: After being hydrolyzed, extracted, and methyl-esterificated, fatty acid in the sample were separated with the chromatographic column HP-88( 100 m × 0. 25 mm × 0. 20 µm) and analyzed by gas chromatography-mass spectrometry( GC-MS) method. Meanwhile, t-test and rank sum test will be carried on to analyze the determination results of fatty acid in both red and white peanuts growing in Shenzhen, Qingyuan and other four areas. RESULTS: The standard curves of fatty acid methyl ester hold good linearity( R~2> 0. 9980) in 0. 2- 10 mg / L, with the recovery between 92. 3% and 118. 8% and relative standard deviation( RSD) between 1. 64% and 7. 70%. Those two peanuts contained 21 fatty acids, such as oleic acid, linoleic acid, palmitic acid, stearic acid and behenic acid. The total fat content in peanuts were between 42. 5% and 50. 6%. After statistical analysis, the differences were not statistically significant. CONCLUSION: The method can quickly and sensitively detect fatty acids inpeanuts. Same species and similar content of the fatty acids are in these two peanuts particularly.

[The distribution of 24 elements in urine from Shenzhen residents].

OBJECTIVE: This study aims to describe the distribution of 24 elements in urine of Shenzhen residents. METHODS: According to the principle of equal probability of selection method, in March 2011 to July, total 11 communities were chosen as the basic sampling unit in Shenzhen, with 1 to 2 communities in each of the municipal district. Then 75 families from each sampling unit were selected using systematic sampling method. In total, 2 200 subjects were chosen. 10-20 ml morning middle stream urine was collected, and then detected the concentration of Li, Be, Sr, Cd, Cs, Ta, Pb, V, Cr, Mn, Fe, Ni, Co, Cu, Zn, Sn, Sb, Te, As, Se, Ru, Na, Mg, K, and analysed the discrepancies between gender and among age groups. RESULTS: In those 24 elements, the concentration of Na was highest, the medians( 5th percentile (P 5), 95th percentile (P 95)) were 2 845.78 (920.29, 5 974.53) mg/L; Be was lowest, the result was 0.10(0.01, 0.58) µg/L. Except macroelements of Na (2 921.97 (985.14, 6 201.51) mg/L), Mg (48.20(8.23, 132.41) mg/L), K (2 323.20(683.98, 5 657.47) mg/L), the content of Rb was highest, 3.31(9.82, 7.83) mg/L, followed by Zn, 454.54(113.90, 1 320.00) µg/L, the content of V, Cr, Mn, Se, Tl was pretty low, the median of those elements all less than 1.00 µg/L. Statistically significant differences were found between genders and among age groups in Pb, Fe, Se (gender: Z values were 4.51, 2.53, 4.00, all P values were <0.05; age groups: H values were 55.67, 129.42, 18.46, all P values were <0.05). The medians(P5, P95) were 2.04 (0.57, 5.31), 202.88 (48.66, 564.90), 49.68 (14.34, 150.91) µg/L. The values of male were 2.22 (0.71, 5.33), 212 (47.50, 567.29), 53.42 (16.20, 160.63) µg/L. And the results of female were 1.95 (0.51, 5.24), 193.69 (49.52, 562.31), 46.62 (12.65, 142.80) µg/L; the values of less than 17 years old subjects were 1.66 (0.38, 3.77), 106.13 (26.69, 459.81), 51.86 (15.86, 169.71) µg/L; the results were 1.96 (0.52, 5.08), 209.83(52.87, 577.81), 54.14 (15.14, 144.11) µg/L in the group of 18 to 40 years old; in the 41 to 65 years old group, the values were 2.29 (0.78, 5.85), 228.15 (67.74, 615.16), 46.62 (13.95, 143.57) µg/L, the results were 2.19 (0.65, 5.69), 195.92(55.17, 490.24), 43.16 (12.42, 155.36) µg/L in 66 years old and more group. CONCLUSION: Among these 24 elements in urine of Shenzhen residents, the Na concentration was highest, while Be was lowest. Elements (Pb, Fe, Se) differed with the condition of gender and age groups. So we should take all these factors into account to establish their reference values.

[Rapid determination of 19 elements in human urine by inductively coupled plasma-mass spectrometry with dynamic reaction cell].

OBJECTIVE: A simple method is proposed for determination of Be, Rb, Sr, Cd, Pb, Cs, Tl, V, Cr, Mn, Ni, Co, Cu,Zn, Sn, Sb, Te, As and Se in urine by using inductively coupled plasma mass spectrometry with dynamic reaction cell. METHODS: Prior to analysis, samples were diluted (1: 20) in a solution of nitric acid (3%, V/V). The DRC mode was applied to determine the content of V51, Cr52, Mn55, Ni58, Co59, Cu63, Zn64 Sn120, Sb121, Te130, As75 and Se80. For the other elements, the instrument was operated in standard mode. RESULTS: The method detection limits were 2.7ng/L for Be9, 2.0ng/L for V51, 2.7ng/L for Cr52, 1.5ng/L for Mn55, 3.9ng/L for Ni58, 0.8ng/L for Co59, 5.8ng/L for Cu63, 35.3ng/L for Zn64, 32.4ng/L for As75, 21.1ng/L for Se80,1.4ng/L for Rb85, 4.2ng/ L for Sr88, 1.1 ng/L for Cd 9.1 ng/L for Sn120, 1.1ng/L for Sb121, 8.6ng/L for Te130, 0.1 ng/L for Cs133, 0.2ng/L for Tl205 and 1.0 ng/L for Pb208. The precisions of the method were in the range of 0.3% - 2.6%. CONCLUSION: The proposed method was rapid, accurate and can be used for measurement with simple pre-treatment, less sample and lower cost. The method was also suitable for massive samples in screening and monitoring.