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Considering the influence of body's growth and development on thyroid volume (TVOL), whether five existed corrected methods could be applied to correct TVOL remains unclear, in terms of Chinese children's increased growth and development trends. This study aimed to compare the applicability of five correction methods: Body Surface Area corrected Volume (BSAV), Body Mass Indicator corrected Volume (BMIV), Weight and Height corrected Volume Indicator (WHVI), Height corrected Volume Indicator 1 (HVI1) and Height corrected Volume Indicator 2 (HVI2) and to establish the reference values for correction methods. The data of Iodine Nutrition and Thyroid Function Survey were used to analyse the differences in TVOL between normal and abnormal thyroid function children. Data of National Iodine Deficiency Disorders Survey were used to compare five correction methods and to establish their reference values. The median urinary iodine concentrations of children surveyed were 256·1 μg/l in 2009 and 192·6 μg/l in 2019. No significant difference was found in TVOL and thyroid goitre rate between children with normal and abnormal thyroid function. In the determination of goitre, HVI1, HVI2, BSAV and BMIV all showed high agreement with TVOL, while the area under the receiver operating characteristic curve (AUC) of WHVI was relatively low for children aged 8 (AUC = 0·8993) and 9 (AUC = 0·8866) years. Most differences of TVOL between light and heavy weight, short and tall height children can be eliminated by BSAV. BSAV was the best corrected method in this research. Reference values were established for corrected TVOL in Chinese children aged 8–10 years by sex. [ABSTRACT FROM AUTHOR]

Reference values of cardiopulmonary exercise testing (CPX) vary with race/ethnicity. Chinese Americans are the fastest-growing racial/ethnic group in the United States. However, there is limited information about the reference values of cardiopulmonary exercise testing (CPX) variables in the Chinese population. As part of the Xiangya Hospital Exercise Testing project (the X-ET project), this cross-sectional study screened 20,696 consecutive CPXs performed by 17,802 unique individuals at Xiangya Hospital of Central South University, China, from January 1, 2002, to December 31, 2019. A total of 964 unique healthy adults/tests (42% female) aged 49 ± 12 who completed a maximal ramp incremental CPX with cycle ergometry were included in this study. The reference values of primary CPX variables were expressed as the lower limit or upper limit of normal. Stepwise linear regression was used to fit the equations of key CPX variables. Predictive accuracy analysis for the equations with a comparison between present and previous studies were performed. Peak oxygen consumption (V ̇ O 2), carbon dioxide production, ventilation/min, work rate, and V ̇ O 2 at the anaerobic threshold were regressed on age, height, weight, and sex. These predictive equations showed good in- and out-sample predictive accuracy. Comparison with prior research revealed that prediction equations of peak V ̇ O 2 resultant from studies in which populations were entirely or primarily Caucasian had overestimated our subjects' actual values. The reference values and predicted equations of CPX variables in this study may provide a more appropriate framework to interpret the response to maximal ramp incremental cycle ergometry in the Chinese adult population. • The reference values of key CPX variables in Chinese population are described. • Comparisons were made between present and past predictive CPX variable equations. • Our equations of key CPX variables fitted well to the Chinese population. • Results may provide an appropriate frame to interpret CPX in Chinese population. [ABSTRACT FROM AUTHOR]

MOOC has been the main application platform of online education, and the higher education in our country has been greatly promoted with the popularization of MOOC in colleges and universities and with the sharing of the high quality teaching resources. The outbreak of COVID-19 in China makes online teaching be the focus of attention again, which has boosted the development of MOOC in China. The author of this essay has conducted a survey of the present situation of MOOC in academically average colleges in China, among which Jining Medical college was set as an example. The present situation of MOOC has been analyzed in this essay, while data has been collected through questionnaires and has been analyzed with scientific methods, the result of which will be of some reference value to the network resources construction of teaching platform like MOOC in China. [ABSTRACT FROM AUTHOR]

Aim: The aim of this study was to determine reference values for oxygen saturation (SpO2 ) in neonates at mild and moderate altitudes.Methods: Our study included 41 097 consecutively born, asymptomatic neonates from 35 hospitals, located in Yunnan, China, with altitudes ranging from 267 to 2202 m. Pre-and post-ductal SpO2 of each neonate was measured at 24 hours of age and before hospital discharge. All study participants, according to the altitude of birth, were categorised into three groups: low (0-500 m), mild (500-1500 m) and moderate altitude (1500-2500 m).Results: Every 1000-m increase in altitude was associated with a 1.54 per cent decrease in mean SpO2 . The means of pre-ductal SpO2 at low, mild and moderate groups were 97.9%, 96.4% and 95.5%, respectively. We used the 2.5th percentile of SpO2 distribution as the cut-off for neonatal SpO2 screening and defined new cut-off values of ≤93% for mild altitudes, ≤92% for moderate altitudes and no adjustment for low altitudes.Conclusion: We recommend revised cut-off values for neonatal SpO2 at mild and moderate altitudes and provide new values for paediatricians to refer to when screening neonates for severe congenital heart or lung diseases. [ABSTRACT FROM AUTHOR]

The current perception threshold (CPT) is a device which can evaluate different sensory fibers quantitatively through different frequencies of the electrical stimulus and has been applied in clinical practice. Previous studies have implied that CPT valuesmay be affected by age, gender, and other factors, yet not conclusively. The objective of our study is to clarify the influencing factors of CPT values and establish a reference value range. Twenty healthy volunteers recruited publicly and 146 subjects who took CPT tests in the census of the national project cardiovascular and cerebrovascular diseases in rural areas of China from 2013 to 2015 were analyzed. Past medical history and demographic characteristics such as age, gender, and occupation were collected. Each subject was tested on the left index finger (or back of the left hand) and the right hallux. CPT values of 2000, 250, and 5Hz on both sites were recorded for statistical analysis. Gender differences were shown at 2000Hz CPT on the back of the hand and hallux (p < 0.01), and male subjects had a higher CPT. Age had a positive correlation with 250Hz CPT on the index finger (p < 0.05, r = 1.5), 2000Hz CPT on the back of the hand (p < 0.001, r = 1.2) and index finger (p < 0.05, r = 2.5). Manual workers had a higher 250Hz CPT on the hallux than mental workers (p < 0.01). After investigating the impact of different factors on CPT testing, we established the reference value for subjects with different characteristics. [ABSTRACT FROM AUTHOR]

The article discusses the study that aimed to establish normal reference ranges of fetal cardiac dimensions between 20 and 34 weeks from fetal echocardiograms noted at one center in China, as global racial variability in human development can result to fetal cardiac structure size differences. Topics discussed include increase in measurements of fetal cardiac structures with advancing gestational age (GA), and study data to provide reference values of fetal echocardiography in China.

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 (RV 95 s: 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 RV 95 s 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., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Summary: We pooled bone mineral density (BMD) data published in 91 articles including 139,912 Chinese adults and then established a national-wide BMD reference database at the lumbar spine and femur neck for Chinese adults. The prevalence of osteoporosis in the middle-aged and elderly Chinese population was also estimated. Introduction: Well-accepted reference value of BMD is lacking in Chinese. We established the reference database and assessed osteoporosis prevalence based on published literature conducted in the Mainland China, Taiwan, and Hong Kong Chinese. Methods: We searched for all published articles indexed in MEDLINE, PubMed, CNKI, and SinoMed up to January 2013. We included cross-sectional studies that examined BMD using a dual-energy X-ray absorptiometry at the femur neck (FN) and/or lumbar spine (LS) in healthy adults. Overall age-specific mean (SD) BMD were pooled after standardization. Results: Ninety-one studies including 51,906 males and 88,006 females (≥20 years) in 38 cities in China were included in this pooling study. Gender- and age-specific reference curves of standardized BMD (sBMD) at the LS and FN were constructed. The sBMD cutoffs for osteoporosis classification were 0.746 and 0.549 in women, and 0.680 and 0.568 g/cm in men; age-standardized prevalence of osteoporosis was 23.9 % and 12.5 % in women and 3.2 % and 5.3 % in men aged ≥50 years at the LS and FN, respectively. Meta-regression analysis showed that greater age and altitude, lower latitude, smaller city size, earlier detection time, and random sample were correlated to lower sBMD in at least one gender-specific bone sites; the Hologic DXA produced a higher value of FN sBMD than the other two devices (Lunar and Norland). Conclusion: We have established a national-wide BMD reference database at the LS and FN for Chinese adults and estimated the prevalence of osteoporosis in the middle-aged and elderly Chinese population. [ABSTRACT FROM AUTHOR]

Background: As a noninvasive tool, myocardial deformation imaging may facilitate the early detection of cardiac dysfunction. However, normal reference ranges of myocardial strain and strain rate (SR) based on large-scale East Asian populations are still lacking. This study aimed to provide reference values of left ventricular (LV) and right ventricular (RV) strain and SR based on a large cohort of healthy Chinese adults using cardiovascular magnetic resonance (CMR) feature tracking (FT)., Methods: Five hundred and sixty-six healthy Chinese adults (55.1% men) free of hypertension, diabetes, and obesity were included. On cine CMR, biventricular global radial, circumferential, and longitudinal strain (GRS, GCS, and GLS), and the peak radial, circumferential, and longitudinal systolic, and diastolic SRs (PSSRR, PSSRC, PSSRL, PDSRR, PDSRC, and PDSRL), and regional radial and circumferential strain at the basal, mid-cavity, and apical levels were measured. Associations of global and regional biventricular deformation indices with age and sex were investigated., Results: Women demonstrated greater magnitudes of LV GRS (37.6 ± 6.1% vs. 32.1 ± 5.3%), GCS (- 20.7 ± 1.9% vs. - 18.8 ± 1.9%), GLS (- 17.8 ± 1.8% vs. - 15.6 ± 1.8%), RV GRS (25.1 ± 7.8% vs. 22.1 ± 6.7%), GCS (- 14.4 ± 3.6% vs. - 13.2 ± 3.2%), GLS (- 22.4 ± 5.2% vs. - 20.2 ± 4.6%), and biventricular peak systolic and diastolic SR in all three coordinate directions (all P < 0.05). For the LV, aging was associated with increasing amplitudes of GRS, GCS, and decreasing amplitudes of PDSRR, PDSRC, PDSRL (all P < 0.05). For the RV, aging was associated with an increase in the magnitudes of GRS, GCS, GLS, PSSRR, PSSRC, PSSRL, and a decrease in the magnitude of PDSRR, PDSRC (all P < 0.05). Biventricular radial and circumferential strain measurements at the basal, mid-cavity, and apical levels were all significantly related to age and sex in both sexes (all P < 0.05)., Conclusions: We provide age- and sex-specific normal values of biventricular strain and SR based on a large sample of healthy Chinese adults with a broad age range. These results may be served as a reference standard for cardiac function assessment, especially for the Chinese population., (© 2022. The Author(s).)

Objective: To investigate the dietary selenium (Se) intake of Jinan residents; to study the selenium concentrations and the relationships between serum selenium level and sex and age, and discuss the serum reference values of selenium of healthy people in Jinan, China. Methods: Investigation of the dietary Se intake and subjects' individual behavior was performed by filling in 7 days dietary intake questionnaire and individual behavior questionnaire. Blood samples were collected from our subjects in 3 different towns of Jinan Shandong province. Then the hydrogenation atomic absorption spectrometry (HGAAS) was applied to detect the concentrations of serum Se after the samples were digested by microwave.SPSS11.5 was used to analyze the data. Results: The Se dietary intake of Jinan residents was 55.93 µg/d and the selenium intake of males (66.98 µg/d) was higher than that of females (49.57 µg/d). Selenium intake level was not influenced by age. The serum reference Se value of an adult was 31.72 - 82.26 µg/l. The serum selenium level of males was higher than that of females, and the serum selenium level was increased a bit with age. Selenium level was increased a bit along with the sleep hours. Conclusion: The reference value of serum Se of healthy people in Jinan was 31.72 - 82.26 µg/l, and the dietary intake of Se and serum Se level of Jinan residents were lower than other internal or abroad regions. This suggests that Jinan residents should take more Se-enriched foods or foods rich in Se. [ABSTRACT FROM AUTHOR]

Background: The present study was designed to explore the reference values of serum lipids in children in Beijing. Methods: A total of 1071 healthy children from Beijing between 3 and 18 years of age were enrolled and divided into four groups: A, 3–5-year-old group; B, 6–9-year-old group; C, 10–14-year-old group; and D, 15–18-year-old group. Blood samples were obtained from the cubital veins of the participants under a fasting condition. A Hitachi 7600 Automatic Biochemistry Analyzer was used to determine the serum levels. The cut-off points of reference values were the 75th and 95th percentiles for total cholesterol (TC), triglyceride (TG), and low-density lipoprotein cholesterol (LDL-C) while the 25th and 5th percentiles were used for high-density lipoprotein cholesterol (HDL-C) concentrations. Results: The highest 95th percentiles of TC among the four groups were 5.34 mmol/L for boys and 5.11 mmol/L for girls. Compared with those of boys, female TG levels were obviously higher in the 10–14-year-old group ( P < 0.05) and HDL-C levels were significantly higher in the 15–18-year-old group ( P < 0.05). The serum TC, HDL-C, and LDL-C all peaked during the 6–9-year-old period and then declined during the adolescent stage. Also, the serum TG continuously increased with a relative plateau during the 6–14-year-old period. Obese and overweight children had higher TG and LDL-C levels but lower HDL-C levels. Conclusion: This study showed a picture of the serum lipids distribution in Chinese children and found that their TC levels were lower than those of children in Japan, Iran, and France, but were higher than those of Italian children. [ABSTRACT FROM AUTHOR]

Background and objective: Two sets of local reference values are available for spirometry in Hong Kong, but it is uncertain how well they work in the assessment of occupational lung diseases. This study examined their relative performance in the compensational assessment of silicosis. Methods: Local reference values published in 1982 and 2006 were compared in two different populations comprising normal construction/quarry workers and silicosis patients. Only men aged 20–74 years were included. Results: The FVC results of 93 normal workers were significantly higher than those predicted by either the 1982 or the 2006 reference values. Compared with the 1982 reference values, the mean FEV1% or FVC% was age-dependent and 5.2% higher in the normal workers. Smoking decreased the forced expiratory ratio, but did not show a major effect on FEV1 or FVC among asymptomatic subjects. Despite their derivation largely from never-smokers, the 2006 reference values better predicted FEV1 and FVC among all smoking categories. Among the 357 silicosis patients, the 1982 reference values also gave 8.8% higher FEV1% and 7.4% higher FVC%. These spirometric values differed by more than 10% in patients aged 60 years or more. Despite the presence of disease, the mean FVC% was still significantly above 100%. Conclusions: Both the 1982 and 2006 local reference values underestimated the FVC of normal construction and quarry workers, reflecting possible occupational selection factors. The 2006 reference values outperformed the 1982 ones, especially among older subjects. Careful calibration with similar occupational groups in the same laboratory is highly desirable in the choice of spirometric reference values for compensation assessment. Smoking does not appear to affect this choice. [ABSTRACT FROM AUTHOR]

• Ecosystem services were employed to develop an integrated ecosystem health assessment of coastal bays. • An approach based on historical condition was applied to establish reference benchmark. • Health condition in Daya Bay was better than that in Jiaozhou Bay. • Ecosystem health is closely associated with natural characteristics and human interventions. Coastal bays, situated within Earth's critical zone, play important ecological and socioeconomic roles. This study developed an integrated ecosystem health assessment framework based on ecosystem services specific to coastal bays, particularly exploring approaches to determine critical indicators and establish a reference benchmark. The framework was applied to two typical coastal bays (Jiaozhou Bay and Daya Bay) to ascertain significant health differences, subsequent challenges and prospective management. Comparatively, Daya Bay was healthier. Daya Bay received an overall comprehensive index ecosystem health score of 69.42 (good); however, its ecosystem services scores differed significantly (supporting services = 71.34, regulating services = 87.29, provisioning services = 3.59, cultural services = 74.30), indicating severe degradation in its ecosystem food provisioning function. Jiaozhou Bay received corresponding score of 55.79 (moderate), and its ecosystem services scores were relatively lower (supporting services = 63.31, regulating service = 54.30, provisioning services = 6.18, and cultural services = 54.74), indicating widespread ecosystem degradation. The health status of coastal bays is closely associated with both natural characteristics and human interventions. The narrow bay mouth of Jiaozhou Bay, its limited enclosed seawater area, and the intensive land reclamation that has taken place since the 1950s have directly or indirectly led to the low score of most of its indicators, particularly regarding the significant reductions in its water area and shoreline. The geological advantages of Daya Bay is its large area of water and that it is open to the outer sea, which have contributed to its comparatively healthier status, wherein scores of only a few indicators were bad (i.e., biological indicators of sensitive organisms in the upper food chain). Results from this study provide important information for prospective bay management. For Jiaozhou Bay, more effort should be paid to improving ecosystem health in a comprehensive way, particularly fishing control, land reclamation control and habitat restoration. For Daya Bay, overfishing should be better controlled, while more emphasis should be paid to protecting and restoring certain moderately specific habitats and species. For effective management, we highlight that ecosystem management strategies needs to be differentiated among different bays based on their significant natural and social features. Our approach provides a practical ecosystem health assessment tool that can be applied to other coastal bays to better inform sustainable management and conservation initiatives. [ABSTRACT FROM AUTHOR]

Background and objective: This study was conducted to define normal reference values and lower limits of normal (LLN) for single-breath carbon monoxide diffusing capacity (DLco) and DLco per unit of alveolar volume (Kco) for Chinese adults in Hong Kong. Methods: Healthy non-smoking men and women aged 18–80 years were recruited by random digit dialling. DLco and Kco were measured according to American Thoracic Society standards. Reference equations were obtained by multiple linear regression; LLN were derived by distribution-free method for estimation of age-related centiles. Results: Tests from 568 subjects (259 men, 309 women) were analysed. DLco declined with age in both genders, and increased with height and the interaction term of height and age in men and women, respectively. Considering Hb values did not improve the reference equations. Kco declined with age and increased with weight in both genders, while height and its interaction term with age were additional determinants in women. The reference DLco was lower than some Caucasian values, and was only explained partially by a smaller body size and alveolar volume in Chinese. The distribution-free method yielded better overall approximation to the fifth percentile compared with the traditional method of determining LLN. Conclusions: The equations for reference values and LLN of diffusing capacity derived in this study are of clinical relevance to Chinese subjects. [ABSTRACT FROM AUTHOR]

The aim of the study was to supply a scientific basis for standard reference values of haemoglobin in Chinese adolescent boys. We carried out a randomised blind analysis of 12,640 haemoglobin measurements in adolescent boys and of five geographical factors in 78 areas of China. There was a significant correlation between geographical factors and the normal reference value of haemoglobin in adolescent boys ( F=26.00). Multiple linear regression analysis showed one regression equation to be constant. Geographical effects should be factored into the normal reference values of haemoglobin in adolescent boys by the use of a regression equation. Furthermore, the geographical effects on haemoglobin in adolescent boys define China by six districts: Qingzang, Southwest, Northwest, Southeast, North and Northeast district. [ABSTRACT FROM AUTHOR]

: BackgroundThe aim of this study was to supply a scientific basis for uniting the normal reference value standard of hemoglobin of Chinese infant girls.: MethodsA research study was carried out concerning the relationship between the normal reference value of 3,771 examples of hemoglobin of infant girls and altitude in 40 areas of China. Normal reference values of hemoglobin of infant girls were determined by hemoglobincyanide method.: ResultsIt was found that correlation of normal reference value of hemoglobin of infant girls and altitude was quite significant (r = 0.545). By using method of univariate linear regression analysis, the following regression equation is inferred:Yˆ=112.9+0.008978X±20.8.: ConclusionsIf altitude values are obtained in certain areas, normal reference value of hemoglobin of infant girls of this area can be reckoned by using the regression equation. Furthermore, depending on altitude, China can be divided into three districts as follows: Qingzang District, Central District, and Eastern District. [Copyright &y& Elsevier]

The purpose of this paper is to provide a scientific basis for a unified standard of the reference value of old people's hematocrit in China. The reference values of healthy old people's hematocrit have been collected according to the Wintrobe methods; the relationship between the reference values of old people's hematocrit and altitude has been tested in this paper. It has been found that the reference value of old people's hematocrit increases when the altitude gradually increases, and such relationship is quite significant. The method of mathematical univariate regression analysis is used to deduce two regression equations: $\widehat{Y}$[sub 1] =44.1+0.00351x±4.5, $\widehat{Y}$ [sub 2] =39.5+0.00298x±4.1. If the altitude value of a particular area of China is known, the reference value of old people's hematocrit there can be calculated by means of the regression equations. Furthermore, depending on the altitude, China can be divided into three districts: Qingzang District, Central District and Eastern District. [ABSTRACT FROM AUTHOR]

This research aimed to determine the background and precautionary values of Cd, Cr, Cu, Ni, Pb, Zn, Co, As, and Hg and provide the spatial distribution of these metals in Albania's soils using statistical and geostatistical methods. Since the distribution of the data was commonly not Gaussian, they were transformed into their natural logarithm for deriving background concentrations and precautionary values. Background concentrations were defined as antilog of the median. Precautionary concentration values for soil protection were defined as antilog of 90th percentile of the ln-transformed data. Background concentrations in forest soils were larger compared to those in soils under other land use types. The largest background concentrations for Cd, Cr, Ni, Cu, Co, and Zn were found in forest soils formed on magmatic rocks, while largest concentrations of Pb and Hg were found in soils formed on flysch and molasse. The background values and precautionary concentration values (in brackets) (mg kg -1 ) for agricultural soils across flysch/molasses and quaternary deposits were as follows: Cd 0.24 (0.82), Cr 131.63 (527.42), Cu 41.26 (72.75), Ni 287.15 (632.70), Pb 19.11 (284.86), Zn 81.80 (113.90). The largest background values for Cd and Zn were found in Phaeozems, for Cr, Pb, and Co in Luvisols and Cambisols, and for Cu, Hg, and Ni in Fluvisols. The proposed background concentrations and precautionary values complete the picture of metal contents in European soils, can be used as reference concentrations for the Albanian environmental legislation, and allow the identification of potential contamination hot spots., (© 2022. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Background: The urine protein/creatinine ratio (UPCR) is commonly used in current clinical practice. However, there are only few published clinical data on UPCR from large cohorts of Chinese adults. This study aimed to determine the overall and age- and sex-specific UPCR reference values for healthy Dalian adults., Methods: According to the Clinical & Laboratory Standards Institute EP28-A3c guidelines, 1321 healthy Dalian adults (646 men and 675 women) aged 20-69 years were enrolled. Urine protein and creatinine levels were analyzed in the random morning spot urine samples, and UPCR was calculated. The 95th percentile of the UPCR was used as the normal upper limit. The Mann-Whitney U test was used to test differences among groups., Results: The UPCR reference value was 141.7 mg/g for the entire cohort, 128.7 mg/g for men, and 150.8 mg/g for women. In addition, women had relatively higher UPCR values than men in the same age group. We also compared the UPCR reference values between different estimated glomerular filtration rate (eGFR) groups and found that women had significantly higher UPCR values than men in the normal eGFR groups., Conclusions: This study provides the overall and age- and sex-specific UPCR reference values for healthy Dalian adults., (© 2021 The Authors. Journal of Clinical Laboratory Analysis published by Wiley Periodicals LLC.)

In China, the first and also the latest version of national childhood lead exposure control guidelines was issued by the National Health Commission in 2006, when the reference value of high blood lead exposure was set at 100 μg/L and lead poisoning was set at 200 μg/L. Lead exposure levels have been decreasing in China over the last few decades, with almost all blood lead concentrations in children under 7 years of age being under 100 μg/L in non-industrial areas. However, lead concentrations lower than 100 μg/L in blood in children are associated with neurodevelopmental deficits. Thus, if the reference value remains at a high level, a large percent of children with exposure levels that are high but lower than the current reference value will be diagnosed as 'safe' and be ignored. Thus, we appeal that the reference value should be lowered according to local actual exposure level. A more stringent reference value would give care givers, doctors, communities, and officials more opportunities to take action earlier. [ABSTRACT FROM AUTHOR]

The human biological monitoring of metals (metalloids) is of importance, which concentrations could indicate a wide range of health related information. Reference values (RVs) of metals (metalloids) in specific matix of populations are critically required when performing a statistical evaluation accurately. Recent studies show that RVs of metals (metalloids) are influenced by many multiple factors, including lifestyle, diet, dissimilar environment, location, as well as race. However, it is virtually absent across many nations/regions, especially multi-race coexistence regions. The aim of the work was to establish RVs of metals (metalloids) in urine of adult in Xinjiang, China. Totally 178 urine samples from healthy volunteers were collected and analyzed by inductively coupled plasma mass spectrometer or optical emission spectrometer (ICP-MS/OES). RVs of 26 metals (metalloids) in urine for adult of Xinjiang, China were then established. Effects of race, gender and age on RVs were investigated using partial least squares discriminant analysis and student T-test. The result demonstrated that above factors showed mild influence for the establishment of RVs. The RVs derived from total 178 urine adult samples (Han and Uygur half of each) can be applied for different race, gender and age periods. Moreover, it was observed that three metals (metalloids), As, Sc and Ba significantly varied between some subgroups. The established RVs will be valuable for future health or environmental evaluation, and can serve as a theoretical reference for RVs establishment in multi-race coexistence region., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Objective: To establish normal reference values of total and segmental body fat distribution of children aged 6-9 years old in Guangzhou, which can be used for abnormal fat accumulation surveillance., Methods: A total of 456 children aged 6-9 years old were enrolled between December, 2015 to March, 2017 in Guangzhou, China. Body composition was measured by dual-energy X-ray absorptiometry( DXA). The LMS regression method was used to construct age-and gender-specific smooth percentile curves of total body fat mass( TBFM), percentage of total body fat( % TBF), android fat mass, gynoid fat mass, appendicular fat mass( AFM), percentage android fat, percentage gynoid fat, percentage appendicular fat mass( % AFM) and android/gynoid ratio. The 5th to 85th, 85th and 95th centiles of body fat indexes were applied to define "normal", "overfat", and "obese"status., Results: Linear trend test showed that except for total body fat percentage( % TBF) in girls, total body fat mass( TBFM), segmental body fat mass and % TBF increased significantly with age in both genders. The reference values of TBFM for boys in each age group were 3. 87-6. 04, 3. 72-7. 74, 3. 82-9. 85, 4. 30-13. 35 kg, respectively, and for girls were 3. 86-7. 76, 3. 97-8. 50, 4. 23-9. 46, 4. 78-10. 74 kg, respectively. The corresponding values for the % TBF were 20. 07%-28. 84%, 18. 50%-30. 32%, 17. 93%-31. 97%, 18. 10%-34. 81% in boys, and20. 91%-34. 14%, 20. 64%-34. 60%, 20. 18%-33. 99%, 20. 28%-34. 40% in girls, respectively. In terms of android/gynoid ratio, the values were 0. 62-0. 78, 0. 58-0. 83, 0. 58-0. 88, 0. 57-0. 93 for boys, and 0. 50-0. 76, 0. 54-0. 81, 0. 57-0. 85, 0. 50-0. 82 for girls, respectively., Conclusion: The data provided normal reference range for assessing body fat distribution in children aged 6-9 years in Guangzhou, China.

Objective: The aim of this study was to explore the possible influences of age and gender on urinary Alpha 1-Microglobulin (α1-MG) concentrations and establish specific reference values of urinary α1-MG in a group of healthy adults., Methods: Two hundred and ninety-nine adults (141 males and 158 females) aged 20-60 were selected and grouped by gender and age. Urinary levels of α1-MG were detected in morning spot-urine samples, and statistical analysis was performed to explore the association between urinary α1-MG and clinical parameters, and the differences between groups were compared. The 95th percentile of distribution was used as the normal upper limit., Results: The value of urinary α1-MG was sex-dependent (P<0.001), the 95th percentile of urinary α1-MG of males was 26.4 mg/L, whereas females was 8.6 mg/L. Whereas urinary α1-microglobulin-to-creatinine ratio (α1-MG/Cr) was both gender-and age-dependent (both P<0.001), and age 30 may be the cut-off point in this study. The 95th percentile of males and females aged 20-30 was 16.9 mg/g, of males aged 31-60 was 19.8 mg/g, of females aged 31-60 was 28.5 mg/g., Discussions: The relationship between urinary α1-MG concentrations and gender, age is different from previous studies. It is recommended that hospitals and laboratories should develop their own α1-MG reference intervals based on their experimental conditions., (© 2017 Wiley Periodicals, Inc.)

Objectives: To establish reference values for left ventricular (LV) myocardial strains in a cohort of healthy Chinese volunteers with feature tracking cardiac magnetic resonance imaging., Methods: A total of 60 healthy volunteers were recruited, receiving a cardiac magnetic resonance imaging (CMR) examination at 3.0T scanner (Tim Trio, Magnetum, Siemens, Germany). A new feature tracking CMR software (Trufisp-strain, Siemens) was used to analyze left ventricular myocardial strain parameters, including radial, circumferential, longitudinal strain, systolic strain rate, and early diastolic strain rate., Results: The image quality was sufficient to perform strain analysis.The reference values of global strain, global strain rate and segmental strains were obtained. A good inter- and intra-observer agreement was achieved in global strain analysis (except circumferential straininter-observer in apical level), with (37.7±9.6)% for LV global mean radial strain, (-18.4±3.3)% for circumferential strain and (-15.2±2.3%) for longitudinal strain, respectively.Age was positively correlated with global mean radial strain ( r =0.416, P <0.001) and negatively correlated with early diastolic strain rate (circumferential or longitudinal) and circumferential strain( r =-0.436, P <0.001; r =-0.326, P =0.011; r =-0.273, P =0.035, respectively). Women showed higher circumferential and longituinal strain values and lower systolic circumferential strain rate than men. The strain parameters were correlated with left ventricular ejection fraction (LVEF) ( P <0.05)., Conclusions: FT-CMR (Trufisp-strain software) is a fast, convenient and highly reproducible method for analyzing left ventricular myocardial strains, which can sensitively detect gender and age differences. The reference values of LV myocardial strains can support further studies in the future.

Background: The reference value for the urine albumin/creatinine ratio (ACR) varies between races and has not been previously validated in children. We assessed the ACR reference values and the factors that affect them in a population of healthy Chinese children., Methods: A total of 1986 healthy children (1078 males, 908 females) aged 6-19 y were enrolled. The 95th percentile of ACR was used as the normal upper limit. The associations between ACR and gender, age, body mass index (BMI), systolic blood pressure (SBP), preterm birth, intake of fruits, smoking, and geographical area were examined., Results: The normal upper limit of ACR was 14.7 mg/g for male children and 19.8 mg/g for female children. The ACR value for girls was significantly higher than that for boys (P<0.001). ACR was inversely correlated with age (P<0.001) and positively correlated with BMI, SBP, and smoking (all P<0.01)., Conclusions: The ACR reference value for healthy children in southwest China is approximately the same as the value for adults, but lower than that for the Western population. Age, SBP, BMI, and smoking in children influence ACR., (Copyright © 2014 Elsevier B.V. All rights reserved.)