Objective: To construct growth standards for Chinese children under 7 years of age. Methods: Cross-sectional study design based on national representative data on children's growth and development in 2015 was used. Stratified cluster sampling method was used. A total of 83 628 healthy children aged 0-<7 years from 9 cities, including Beijing, Harbin, Xi'an, Shanghai, Nanjing, Wuhan, Guangzhou, Fuzhou, and Kunming, were investigated from June to November 2015, excluding those with adverse conditions that may impact the establishment of the growth standards. Weight, length (height) and head circumference were measured using unified measurement tools and measurement methods. The Lambda-Mu-Sigma method was employed to establish percentile and standard deviation score reference values of weight-for-age, length (height)-for-age, head circumference-for-age, weight-for-length (height) and body mass index (BMI)-for-age of the study population. The standard deviation score curves of the new-established growth standards were compared with the 2009 reference standards. Results: Reference values of percentile (P₃, P₁₀, P₂₅, P₅₀, P₇₅, P₉₀, P₉₇) and standard deviation score (-3, -2, -1, 0,+1,+2,+3) of weight-for-age, length (height)-for-age, head circumference-for-age, weight-for-length (height) and BMI-for-age were obtained. Compared with the 2009 growth standards, the difference of weight at P₅₀ was -0.1-0.4 kg, the difference of length (height) at P₅₀ was 0.1-1.3 cm, the difference of head circumference at P₅₀ was -0.2-0.2 cm, the difference of weight for length (height) at P₅₀ was -0.2-0.5 kg, and the difference of BMI at P₅₀ was -0.2-0.2 kg/m². The main differences were as follows: weight for girls aged 5.0-<7.0 years was 0.4-0.6 kg higher at +2 s, height for boys and girls aged 2.0-<7.0 years was 0.4-1.4 cm higher at -2 s, and BMI for boys and girls aged 5.0-<7.0 years was 0.1-0.3 kg/m² higher at +2 s than the 2009 reference standards. Conclusion: The newly established growth standards for Chinese children under 7 years of age that have achieved a minor revision to the 2009 reference standards, are recommended for nationwide use in growth monitoring and nutritional assessment.
Male ; Female ; Child ; Humans ; Infant ; Child Development ; Body Weight ; Cross-Sectional Studies ; East Asian People ; Body Height ; China/epidemiology* ; Reference Standards ; Reference Values ; Body Mass Index

Objective: To establish the reference values and growth curves of length for weight and head circumference for weight among Chinese newborns in order to provide a reference for the assessment of body proportionality at birth. Methods: A cross-sectional design was applied. A total of 24 375 singleton live birth newborns with gestational ages at birth of 24⁺⁰ to 42⁺⁶ weeks were recruited from June 2015 to November 2018 from 13 cities including Beijing, Harbin, Xi'an, Shanghai, Nanjing, Wuhan, Guangzhou, Fuzhou, Kunming, Tianjin, Shenyang, Changsha, and Shenzhen, excluding those with maternal or newborn conditions that may impact the establishment of the reference values. The generalized additive model for location, scale, and shape was employed to establish reference values in terms of percentile and growth curves of length for weight and head circumference for weight for male and female newborns. The random forest machine learning method was employed to analyze the importance of variables between the established reference values in this study and the previous published weight/length, body mass index (BMI), ponderal index (PI), weight/head circumference, length/head circumference in the assessment of symmetrical and asymmetrical small for gestational age (SGA) newborns. Results: A total of 24 375 newborns with 13 197 male infants (preterm birth 7 042 infants and term birth 6 155 infants) and 11 178 female infants (preterm birth 5 222 infants and term birth 5 956 infants) were included in this study. The reference values in terms of percentile (P₃, P₁₀, P₂₅, P₅₀, P₇₅, P₉₀, P₉₇) and growth curves of length for weight and head circumference for weight were obtained for male and female newborns with gestational ages of 24⁺⁰ to 42⁺⁶ weeks. The median birth lengths corresponding to the birth weights of 1 500, 2 500, 3 000, and 4 000 g were 40.4, 47.0, 49.3 and 52.1 cm for males and 40.4, 47.0, 49.2, and 51.8 cm for females, respectively; the median birth head circumferences were 28.4, 32.0, 33.2 and 35.2 cm for males and 28.4, 32.0, 33.1, and 35.1 cm for females, respectively. The differences of length for weight between males and females were minimum, with the difference range of -0.3 to 0.3 cm at P₅₀; the differences of head circumference for weight between males and females were minimum, with the difference range of 0 to 0.2 cm at P₅₀. Based on the match between birth length and birth weight for classifying symmetrical and asymmetrical SGA, length for weight and PI contributed the most, accounting for 0.32 and 0.25, respectively; based on the match between birth head circumference and birth weight, head circumference for weight and weight/head circumference contributed the most, accounting for 0.55 and 0.12, respectively; based on the match between birth length or head circumference with birth weight, head circumference for weight and length for weight contributed the most, accounting for 0.26 and 0.21, respectively. Conclusion: The establishment of the new standardized growth reference values and growth curves of length for weight and head circumference for weight among Chinese newborns are useful for clinical practice and scientific research.
Female ; Humans ; Infant, Newborn ; Male ; Birth Weight ; Body Height ; China ; Cross-Sectional Studies ; East Asian People ; Fetal Growth Retardation ; Gestational Age ; Premature Birth ; Reference Values

Objective: This study was to investigate the main characteristics and related factors of wideband absorbance (WBA) in children with normal hearing and to obtain age-specific reference range of WBA. Methods: 384 children between 0-12 years old (615 ears) who visited the Beijing Children's Hospital, Capital Medical University from October 2019 to February 2021 were enrolled, including 230 males (376 ears) and 154 females (239 ears), with totally 306 left ears and 309 right ears. Wideband tympanometry (WBT) was performed and normative WBA data were analyzed by SPSS 24.0 statistical software. Repeated measures and multivariate analysis of variance were applied to the data from 16 points at 1/3-octave frequencies (226, 324, 408, 500, 667, 841, 1 000, 1 297, 1 682, 2 000, 2 670, 3 364, 4 000, 5 339, 6 727 and 8 000 Hz) to evaluate the effects of frequency, age, external auditory canal pressures, gender and ear on WBA. Results: According to the WBT frequency-absorbance curve, the subjects were divided into seven groups: 1-month old group, 2-month old group, 3-month old group, 4-5 month old group, 6-24 month old group,>2-6 year old group and>6-12 year old group. The WBA of normal-hearing children underwent a series of developmental changes with age at both ambient pressure and tympanometric peak pressures. WBA results for 1-month group and 2-month old group exhibited a multipeaked pattern, with the peaks occurring around 2 000 and 4 897 Hz, and a notch around 3 886 Hz. WBA results for 3-month group and 4-5 month old group exhibited a single broad-peaked pattern, with the peak occurring between 2 000-4 757 Hz. The WBA of 1-month old group to 4-5 month old group decreased gradually at low frequency (226-408 Hz) and 6 727 Hz, and increased at middle to high frequency (2 670-4 000 Hz). The WBA of 6-24 month old group were significantly lower than that of 2-month old group to 4-5 month old group at all frequencies except 3 364 and 4 000 Hz. WBA results for 6-24 month old group,>2-6 year old group and>6-12 year old group exhibited a single-peaked pattern, and the peak frequency of WBA moved to the lower frequency successively. From 6-24 month old group to>6-12 year old group, the WBA gradually increased at low to middle frequencies (667-2 670 Hz) and 8 000 Hz, and decreased at middle to high frequencies (3 364-5 339 Hz). Among the 16 frequencies of all age groups, the difference between WBA under ambient pressure and tympanometric peak pressure were -0.09-0.06, and 43.75%-81.25% frequency points had statistically significant difference, which was mainly manifested in that WBA under ambient pressure were lower than that under tympanometric peak pressure at 226-1 682 Hz. There was no significant ear effect on all of the age groups. Similarly, there was no significant gender effect except for 3-month old group and 4-5 month old group. Conclusions: The WBA of normal-hearing children measured at ambient pressure and tympanometric peak pressure varied across the frequencies with age from 1 month to 12 years old, and different frequencies followed different change patterns (increase vs. decrease) in WBA. There was also significant external auditory canal pressures effect on all of the age groups. The establishment of age-specific reference range of WBA for 0-12 years old normal-hearing children in this study would be useful for clinical practice of determining normative data regarding WBT.
Male ; Female ; Humans ; Child ; Infant, Newborn ; Infant ; Child, Preschool ; Cross-Sectional Studies ; Acoustic Impedance Tests/methods* ; Ear ; Reference Values ; Ear Canal

Objective: To establish reference values for carotid intima-media thickness (CIMT) of adult dwellers in Shenzhen City. Methods: The study was conducted based on the Shenzhen heart failure epidemiological survey from 2021 to 2022. In this survey, residents aged 18 years and above in Shenzhen were selected by using a multi-stage stratified random sampling method. General information, cardiovascular disease (CVD) related behavior and carotid ultrasound examination and etc. were collected from the participants. People with CVD factors, a history of atherosclerotic cardiovascular disease, carotid plaque or having no carotid ultrasound examination results were excluded. The parameter regression model based on fractional polynomial was used to establish the reference values of CIMT by age and sex. Results: A total of 2 163 healthy individuals were enrolled in the final analysis, including 576 males (26.6%) and 1 587 females (73.4%). The fractional polynomial regression of the CIMT mean and standard deviation was obtained. For men, the regression was mean_CIMT=0.324 7+0.006 9×age and SD_CIMT=0.076 9+0.001 2×age. For women, the regression was mean_CIMT=0.354 9+0.005 4×age and SD_CIMT=0.041 6+0.002 0×age. Conclusion: The age and sex reference values for CIMT of adult people in Shenzhen established in this study could provide the latest reference standards for early screening of subclinical CVD.
Male ; Humans ; Adult ; Female ; Carotid Intima-Media Thickness ; Cardiovascular Diseases ; Reference Values ; Carotid Arteries/diagnostic imaging* ; Ultrasonography, Carotid Arteries ; Risk Factors ; Carotid Artery Diseases

Body mass index (BMI) is widely recognized as an important indicator of physical health. However, the current BMI standard and guidelines primarily focus on children and general adults, neglecting the specific needs of the oldest old aged 80 years or older. To address this gap, this guideline aims to provide recommendations on the appropriate range of BMI and weight management for the oldest old in China, including age calculation, defining the appropriate BMI range, BMI measurement indicators, and weight management strategies. It is intended to be utilized by medical and health organizations at all levels, as well as medical and nursing service institutions, to evaluate the BMI and manage the weight of the oldest old population.
Aged, 80 and over ; Humans ; Asian People ; Body Mass Index ; Body Weight ; China ; East Asian People ; Reference Values ; Health Promotion/standards*

Introduction: There is no global reference value for the 6-minute walking distance (6MWD) in paediatric populations, as it can vary greatly depending on local characteristics and anthropometric measures. This study aimed to identify a 6MWD reference value that could be applied in both local and regional settings. Methods: This cross-sectional multicentre study investigated a healthy paediatric population aged 4–18 years in Indonesia. The 6-minute walk test (6MWT) was conducted in accordance with the American Thoracic Society guidelines. Data were presented as the 6MWD according to age and sex per year. Univariate and multivariate analyses were conducted on the basis of the 6MWDpred Rizky formula. Results: A total of 634 participants were included in this study. Age, sex, weight, leg length and height affected the 6MWD (P<0.001). In the regression model, sex and height were the predictors of 6MWD, with height as the best single predictor. Conclusion The reference charts and 6MWDpred Rizky formula are applicable in multi-ethnic paediatric Indonesian populations but in limited settings.
Pediatrics ; Walk Test ; Reference Values

OBJECTIVES: To develop the birth weight curve of singleton neonates with a gestational age of 24-42 weeks, and to investigate the regional differences of the birth weight curve. METHODS: A total of 11 maternal and child health hospitals with more than 7 000 neonates delivered annually were selected in 11 cities of China (Haikou, Guangzhou, Shenzhen, Liuzhou, Guilin, Quanzhou, Chongqing, Chengdu, Changsha, Ningbo, and Lianyungang), and all live singleton neonates delivered in the 11 hospitals from January 1, 2017 to December 31, 2020 were enrolled for the development of birth weight curves. RESULTS: A total of 93 720 singleton neonates with a gestational age of 24-42 weeks from the 11 cities were included in the study. The reference values of the 3rd-97th percentiles of birth weight of singleton neonates for the total of the 11 cities and for each of the 11 cities were established, and the birth weight percentile curves were drawn. The birth weight curve level of singleton neonates in Shenzhen and Quanzhou was almost the same as the average level of the 11 cities; the birth weight curve level of singleton neonates in Haikou, Guangzhou, Guilin, and Liuzhou was slightly lower than the average level of the 11 cities; the birth weight curve level of singleton neonates in Chongqing, Chengdu, and Changsha was slightly higher than the average level of the 11 cities; the birth weight curve level of singleton neonates in Ningbo and Lianyungang was higher than the average level of the 11 cities. The average birth weight curve level of singleton neonates in the 11 cities were very close to that of China Neonatal Cooperation Network in 2011-2014. CONCLUSIONS The reference values of the 3rd-97th percentiles of birth weight of singleton neonates for the total of the 11 cities and for each of the 11 cities are developed, which can be used as a reference for evaluating the intrauterine growth of singleton neonates in the region. The level of intrauterine growth of neonates in some cities is different from the national level.
Birth Weight ; Child ; China ; Cities ; Gestational Age ; Humans ; Infant ; Infant, Newborn ; Reference Values

OBJECTIVES: There is a high coagulation state in pregnant women, which is prone to coagulation and fibrinolysis system dysfunction. This study aims to explore the latest coagulation markers-thrombomodulin (TM), thrombin-antithrombin complex (TAT), plasmin-α2 plasmin inhibitor complex (PIC), and tissue plasminogen activator/plasminogen activator inhibitor compound (tPAI-C) in different stages of pregnancy, establish reference intervals (RIs) for healthy pregnant women of Chinese population, and to provide an effective and reliable reference for clinicians. METHODS: A total of 492 healthy pregnant women, who underwent pregnancy examination and delivery in the Department of Obstetrics, Second Xiangya Hospital of Central South University from October 2019 to October 2020, were enrolled for this study. They were assigned into the first trimester group, the second trimester group, the third trimester group, and the puerperium group according to the pregnancy period, and 123 healthy non-pregnant women were selected as the controls. Plasma levels of TM, TAT, PIC and tPAI-C were analyzed by automatic chemiluminescence immunoassay analyzer. The RIs for TM, TAT, PIC, and tPAI-C were defined using non-parametric 95% intervals, determined following Clinical and Laboratory Standards Institute Document C28-A3c (CLSI C28-A3c), and Formulation of Reference Intervals for the Clinical Laboratory Test Items (WS/T402-2012). RESULTS: TM and TAT levels increased gradually in the first, second, and third trimester women and decreased in the puerperium women (P<0.05 or P<0.01). PIC level of healthy non-pregnant women was lower than that of pregnant women (P<0.05 or P<0.01), but PIC level of pregnant and puerperium women did not differ significantly (P>0.05). tPAI-C level in healthy non-pregnant women was lower than that of pregnant women (P<0.05 or P<0.01), and tPAI-C level was significantly decreases in the puerperium women (P<0.01). The RIs for TM were as follows: Healthy non-pregnant women at 3.20-4.60 TU/mL, the first and second trimester at 3.12-7.90 TU/mL, the third trimester at 3.42-8.29 TU/mL, puerperium at 2.70-6.40 TU/mL. The RIs for TAT were as follows: Healthy non-pregnant women at 0.50-1.64 ng/mL, the first and second trimester at 0.52-6.91 ng/mL, the third trimester at 0.96-12.92 ng/mL, puerperium at 0.82-3.75 ng/mL. The RIs for PIC were as follows: Healthy non-pregnant women at 0.160-0.519 ng/mL, pregnant women at 0.162-0.770 μg/mL. The RIs for tPAI-C were as follows: Healthy non-pregnant women at 1.90-4.80 ng/mL, the first and second trimester at 2.03-9.33 ng/mL, the third trimester at 2.80-14.20 ng/mL, puerperium at 1.10-8.40 ng/mL. CONCLUSIONS The levels of 4 new coagulation markers TM, TAT, PIC, and tPAI-C in pregnant women are increased significantly during pregnancy and gradually return to normal after delivery. The RIs for TM, TAT, PIC, and tPAI-C in pregnant women by trimester are established according to CLSI C28-A3c, thus providing a clinical reference for clinician in judgement of thrombotic risk.
Biomarkers/blood* ; Blood Coagulation ; Female ; Humans ; Postpartum Period ; Pregnancy ; Reference Values

INTRODUCTION: ADAMTS13 (a disintegrin-like and metalloproteinase with a thrombospondin Type 1 motif, member 13) plays a fundamental role in the regulation of haemostasis and thrombosis. Its deficiency leads to an accumulation of ultra-large von Willebrand multimers, inducing spontaneous platelet aggregation, thrombosis in the microvasculature, and thrombotic thrombocytopenic purpura (TTP), a condition with 90% mortality when left untreated. Prompt quantification of ADAMTS13 antigen, activity and autoantibody plays a crucial role in the diagnosis and management of TTP and can help differentiate it from other thrombotic microangiopathies (TMAs). Reference ranges for ADAMTS13 are generally derived from Caucasian patients. Given that polymorphism in the ADAMTS13 gene can be associated with variable ADAMTS13 levels, we aimed to establish the first reference range in Singapore and provide a crucial laboratory test for institutions here and elsewhere. METHODS: 150 healthy voluntary donors (75 men, 75 women) aged 21-60 years, with an ethnic mix mirroring Singapore's population profile, were recruited. ADAMTS13 antigen, activity and autoantibody levels were measured using the fluorescence resonance energy transfer-vWF73 and enzyme-linked immunosorbent assay methodologies. RESULTS: Levels (activity 0.65-1.79 IU/mL, antigen 0.36-1.17 IU/mL, autoantibody 1.4-12.5 U/mL) were not statistically different between the genders and various age groups. CONCLUSION TTP and TMAs are encountered in a wide range of specialties. The availability of new assays in Singapore will aid clinicians in the timely management of these conditions. Standardising reference ranges established for Singapore against World Health Organization standards allows harmonisation of measurements between laboratories and for future research collaborations.
ADAMTS13 Protein/analysis* ; Adult ; Enzyme-Linked Immunosorbent Assay ; Female ; Humans ; Male ; Purpura, Thrombotic Thrombocytopenic/diagnosis* ; Reference Values ; Singapore

Virility and sexual pleasure have long been associated with penile size and this, in turn, has typically been linked to some anthropometric measurements, such as foot size or height, leading to various misconceptions from both men and women. Our intention is to estimate penile size parameters in Argentina and evaluate the correlation between penile size and certain anthropometric measurements. This is a cross-sectional, descriptive, multicenter, and observational study. Male patients who underwent a urological procedure were included in four hospitals located in different regions of the country. Different anthropometric measurements were obtained: height, weight, penile circumference, flaccid and stretched length, and foot length. A total of 800 patients were evaluated. Mean left foot was 26.4 cm. Mean flaccid penile length was 11.4 (95% confidence interval [CI]: 8-14) cm, and mean penile circumference was 10.1 (95% CI: 8-12) cm. Finally, mean stretched penis was 15.2 (95% CI: 11-18.5) cm. We can confirm that estimates of the average penile measurements in Argentina are flaccid penis length of 11.4 cm, penile circumference of 10.1 cm, and stretching the penis to the maximum in flaccidity of 15.2 cm. Correlations between flaccid penis length, stretched out, penile circumference, height, weight, and length of the left foot were evaluated, finding low or no correlation between those mentioned, except for flaccid and stretched length.
Humans ; Male ; Female ; Prospective Studies ; Cross-Sectional Studies ; Anthropometry ; Penis ; Body Height ; Reference Values