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Objective: To understand the current status of pubertal sexual characteristics development of girls aged 6-18 years in Tongzhou District of Beijing and to compare the differences in sexual characteristics development among girls characterized as thin, normal, overweight, and obese. Methods: A cross-sectional survey was conducted among 2 844 girls aged 6-18 years in Tongzhou District of Beijing from September 2022 to July 2023. The developmental stages of breast and pubic hair were assessed on site, and menarche status was inquired. Weight and height were measured. The girls were subsequently characterized into thin, normal, overweight and obese groups. Basic information (including family and personal history) was obtained through questionnaires. Probit probability unit regression was applied to calculate the age of each Tanner stage of sexual characteristics development and the age of menarche. The χ 2 test was applied to compare the counting data between two or multiple groups. Results: A total of 2 844 girls were surveyed and 2 704 girls met the inclusion criteria, resulting in a valid response rate of 95.1%. Among these girls, 1 105 (40.9%) were aged 6-9 years, 1 053 (38.9%) were aged 10-13 years, and 546 (20.2%) were aged 14-18 years. The of height-for-age Z-score (HAZ), weight-for-age Z-score (WAZ), and body mass index-for-age Z-score (BAZ) were 0.46(-0.23,1.16), 0.69(-0.16,1.67), and 0.67(-0.27,1.73) respectively. The prevalences of thin, overweight, and obesity were respectively 1.7% (45/2 704), 17.3% (467/2 704), and 19.9% (538/2 704), respectively. There were 45 girls in the thin group, 1 654 girls in the normal weight group, 1 005 girls in the overweight and obesity group. The age of Tanner stage breast 2 (B2), Tanner stage pubic hair 2 (P2), and menarche was 9.0 (95% CI 8.9-9.1), 10.5 (95% CI 10.4-10.6), and 11.4 (95% CI 11.3-1.5) years, respectively. The current status of breast and pubic hair maturity in girls with pubertal development shows that 64.6% (1 211/1 874) of these girls had breast development preceding pubic hair development, 32.4% (607/1 874) had concurrent breast and pubic hair development, and 3.0% (56/1 874) had pubic hairs development preceding breast development. The interval age between B2 and B5 was 4.7 (95% CI 4.6-4.8) years, between P2 and P5 was 4.5 (95% CI 4.4-4.6) years, and between B2 and menarche was 2.4 (95% CI 2.3-2.5) years. The ages of sexual characteristics development in overweight and obese groups were earlier than that in normal and thin groups. The ages of B2 in thin, normal, overweight, and obese groups were 10.0 (95% CI 9.5-10.6), 9.3 (95% CI 9.2-9.4), and 8.6 (95% CI 8.4-8.7) years, respectively. The age of menarche in thin, normal, overweight, and obese groups were 13.1 (95% CI 12.4-13.7), 11.6 (95% CI 11.4-11.7), and 11.1 (95% CI 11.0-11.2) years, respectively. The interval ages between B2 and B5 and between P2 and P5 was 4.5 and 4.1 years, respectively in the overweight and obese groups, and those in normal group and thin group was 4.7 and 4.5 years, 4.6 and 4.7 years, respectively. Conclusions: The ages of sexual characteristics development and menarche tend in Tongzhou District of Beijing to be earlier than that being reported of Beijing's survey 20 years ago. Girls characterized as overweight and obese not only start puberty at an earlier age than girls of normal weight, but also have a shorter developmental process.

The eruption of primary teeth is a basic event during physical development of children, which is affected by heredity and environment. This study aimed to analyze the changes in primary teeth eruption among Chinese children with social development. A total of 249,264 healthy children under 2 years were extracted from the 1995, 2005, and 2015 National Survey on the Physical Growth and Development of Children in Nine Cities of China. Their primary teeth were examined and percentiles of primary teeth eruption age were calculated by probit analysis. The median primary teeth eruption age were 6.8 months, 6.7 months, 6.6 months in 1995, 2005 and 2015. Primary teeth eruption age of boys was 0.2 months, 0.3 months, 0.3 months earlier than that of girls in 1995, 2005 and 2015. Primary teeth eruption age was the earliest in children from northern region and was the latest in children from southern region, and this regional difference did not change over time. These findings suggest that primary teeth eruption age slightly advanced with social development, and their gender difference and regional difference have always existed, which supplied some data for understanding the secular trend of primary teeth development in stomatology, pediatrics, anthropology, and other related fields., (© 2024. The Author(s).)

Background: A more comprehensive assessment of growth and nutrition in children is required in China due to rapid socioeconomic processes. We aimed to investigate height and body mass index (BMI) trajectories from 1975 to 2015 and the prevalence of stunting and obesity in 2016 among children in Chinese cities., Methods: A total of 904,263 children from birth to 6.9 years were collected from a series of nationally representative surveys in China. Height and BMI trajectories and prevalence of stunting, underweight, overweight and obesity were assessed., Results: The average height level of Chinese urban children under 7 years presented a positive secular trend from 1975 to 2015; however, a slowing tendency occurred in 2005‒2015. An apparent increase was observed at the 5th, 50th and 95th percentiles of BMI in urban children aged 3 years and older, with a more prominent increase at the 95th percentile. The total prevalence of stunting and underweight under 7 years was 1.4% and 2.0%, respectively. The total prevalence of overweight and obesity under 7 years was 12.6% and 4.3%, respectively, with 12.7% and 4.9% for boys, 12.6% and 3.6% for girls, 12.1% and 4.0% in urban areas and 13.1% and 4.5% in suburban rural areas., Conclusions: The average height level of Chinese urban children has reached World Health Organization child growth standards since 2005 and presented a slowing tendency in secular trend in 2005‒2015. More attention and efforts and public health interventions should be urgently made to combat overweight and obesity among preschool children. Video Abstract., (© 2023. The Author(s).)

Objective: This study aimed to analyze the growth patterns of height and foot length (FL) among Chinese children aged 3-18 and examine their associations with puberty development., Methods: A cross-sectional survey was conducted in September 2022 in Beijing. Data were collected through questionnaires and on-site physical examinations. The growth patterns and velocity of height and FL in different age groups were described, and their associations with puberty development were analyzed., Results: From an age perspective, the peak FL growth occurred between 9 and 11 years (boys were 11 years and girls were 9 years), while the peak height growth occurred at 11 ~ 13 years for boys and 9 ~ 11 years for girls. Additionally, boys and girls reached 99.0% of their final FL at the ages of 14 and 13, respectively, while they reached 99.0% of their final height at the ages of 16 and 15, respectively. From the perspective of Tanner stage, the age of peak FL growth in boys coincided with the age of the G 2 stage, while in girls it occurred slightly earlier than the mean age of the B 2 stage. The peak height growth for both boys and girls occurred between Tanner stages 2 and 3., Conclusion: Boys and girls reach their peak FL growth at 11 and 9 years old, respectively, which were both 2 years earlier than their peak height growth. The peak FL growth occurred around the onset of puberty, while the peak height growth occurred between Tanner stages 2 and 3., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Wu, Zhang, Yu, Yang, Tao, Shu, Li, Huang, Hou, Chen, Liu, Li and Zong.)

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 ( P 3 , P 10 , P 25 , P 50 , P 75 , P 90 , P 97 ) 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 P 50 was -0.1-0.4 kg, the difference of length (height) at P 50 was 0.1-1.3 cm, the difference of head circumference at P 50 was -0.2-0.2 cm, the difference of weight for length (height) at P 50 was -0.2-0.5 kg, and the difference of BMI at P 50 was -0.2-0.2 kg/m 2 . 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/m 2 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.

Background: Farnesol is a Candida-secreted quorum-sensing molecule of great interest as a potential antifungal agent for serious and hardly curable infections-candidiasis, especially vulvovaginal candidiasis (VVC)., Methods: The effect of farnesol on cellular morphology and viability and evaluated the production of Th1 (IL-2), Th2 (IL-4), proinflammatory (IL-6), chemotactic (IL-8), and Th17 (IL-17) cytokines in the culture supernatants of vaginal epithelial cell line (VK2) were evaluated. Moreover, we tested the inhibitory effect of farnesol on C. albicans adhesion. Scanning electron microscopy was conducted to observe any VK2 cell ultrastructural changes., Results: Only low concentrations (≤ 50 µmol/L) of farnesol did not affect the morphology and viability of the VK2 cells (P > 0.05). Farnesol reduced the adhesion of C. albicans to the VK2 cells. When treated with farnesol, statistical elevated levels of both IL-4 and IL-17 secreted by the infected VK2 cells were present in the culture supernatants (P < 0.05)., Conclusions: Farnesol acts as a stimulator to up-regulate the Th17-type innate immune response, as well as Th2-type humoral immunity following C. albicans infection. Further research is required to select the optimal therapeutic dose to develop efficacious and safe mucosal immune adjuvant for treating VVCs., (© 2023. BioMed Central Ltd., part of Springer Nature.)

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 ( P 3 , P 10 , P 25 , P 50 , P 75 , P 90 , P 97 ) 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 P 50 ; the differences of head circumference for weight between males and females were minimum, with the difference range of 0 to 0.2 cm at P 50 . 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.

Objective: To analyze the vaginal microecological status of vaginitis population and non-vaginitis population of gynecological female outpatients. Methods: A total of 30 265 women who visited the gynecological outpatient clinic of Beijing Obstetrics and Gynecology Hospital from December 2018 to December 2020 completed vaginal microecological examination. After removing the follow-up patients, 23 181 women were divided into group with symptoms and signs of vaginitis (6 697 cases) and group without symptoms and signs of vaginitis (16 484 cases), according to whether the women with symptoms and signs of vaginitis or not. And the vaginal microecological status of the two groups was compared and analyzed. Results: (1) The total detection rate of vaginitis in the initial women was 34.87% (8 083/23 181), of which 46.10% (3 087/6 697) in group with symptoms and signs of vaginitis and 30.31% (4 996/16 484) in group without symptoms and signs of vaginitis, nearly 1/3 of the gynecological outpatients without signs and symptoms of vaginitis had vaginitis. (2) Among the types of simple vaginitis, vulvovaginal candidiasis (VVC) was the most frequent in group with symptoms and signs of vaginitis (16.01%, 1 072/6 697), followed by aerobic vaginitis (AV; 12.83%, 859/6 697), with significant differences compared with group without symptoms and signs of vaginitis (all P <0.001). There were no statistical differences between the two groups of bacterial vaginosis (BV) and trichomonal vaginitis (TV), indicating that BV and TV were more likely to be neglected (all P >0.05). (3) The proportion of various combinations of vaginitis among 2 632 cases of mixed vaginitis were, in descending order: BV+AV, VVC+AV, BV+AV+VVC, AV+TV, AV+TV+BV, BV+VVC. (4) Microecological analysis of 15 098 cases diagnosed with non-vaginitis had normal flora (including those with normal flora and those with normal flora but decreased function) in 14 013 cases (92.81%, 14 013/15 098), abnormal flora in 429 cases (2.84%, 429/15 098) and the BV intermediate in 656 cases (4.34%, 656/15 098); this indicated that the vast majority of the microecological tests were normal in the vaginal microbiota of those without vaginitis. Conclusions: Microecological examination could diagnose multiple pathogenic infections at once, and is especially important as a guide for the definitive diagnosis of mixed vaginitis and vaginitis with atypical clinical symptoms. Vaginal infections such as BV and TV that are easily overlooked should be concerned.

Background: INTERGROWTH-21st Newborn Cross-Sectional Study (NCSS) charts were established and recommended for global application. However, whether one international reference is appropriate for all populations is still unclear. We aim to compare the updated Chinese birth size charts by gestational age with INTERGROWTH-21st NCSS charts., Methods: A cross-sectional survey was carried out, and the birth weight, length and head circumference of 24,375 infants born after uncomplicated pregnancies at gestational age ranging from 24 +0 to 42 +6 weeks were measured in 13 cities in China from 2015 to 2018. Growth charts were constructed. The measurements of all these infants were evaluated by the methods of calculating their Z scores using the INTERGROWTH-21st standards. The prevalence of small for gestational age (SGA) and large for gestational age (LGA) based on birth weight was analyzed using Chinese charts and INTERGROWTH-21st charts., Results: The mean Z scores were 0.10 for birth weight, 0.35 for length and - 0.02 for head circumference. Compared to the INTERGROWTH-21st charts, the Chinese birth weight percentile curves were higher except for the 90th percentile at 29-37 weeks gestational age, and the length percentile curves were higher after 33 weeks gestational age, while the 10th percentile of the head circumference was lower and the other percentiles were similar. The prevalence of SGA was 10.1% [95% confidence interval (CI) = 9.7%-10.5%] using the Chinese birth weight chart and 6.5% (95% CI = 6.2%-6.8%) using the INTERGROWTH-21st birth weight chart. The prevalence of LGA was 9.9% (95% CI = 9.5%-10.2%) and 8.2% (95% CI = 7.9%-8.6%) using the Chinese and INTERGROWTH-21st birth weight charts, respectively., Conclusions: Chinese birth size charts based on infants born after uncomplicated pregnancies were different from the INTERGROWTH-21st charts. Differences in the classification of newborns by the two charts should receive attention, and whether the application of INTERGROWTH-21st in Chinese newborns will lead to misclassification needs to be validated in future clinical practice., (© 2022. The Author(s).)

Objective: To investigate the dynamic changes of vaginal microbiota in different phases of menstrual cycle in healthy Chinese women of childbearing age. Methods: A total of 11 healthy women of childbearing age with regular menstruation, who had physical examination in the Gynecology Clinic of Beijing Obstetrics and Gynecology Hospital from September to December 2020 were randomly selected as research subjects. Vaginal secretions were collected during menstrual phase (2nd-3rd day), mid-follicular phase (7th-8th day), and mid-luteal phase (21st-22nd day) for microbiota analysis through metagenomic sequencing. Results: (1) Vaginal microbiota species were the most diverse in menstrual phase and the least in follicular phase, observing dominant vaginal bacteria gradually changing to Lactobacillus from menstrual phase to follicular phase and then to luteal phase. (2) The dynamic evolution of vaginal microbiota from menstrual phase to follicular phase and then to luteal phase was divided into: no change in dominant bacteria, replacement of dominant bacteria, changes in the proportion of dominant bacteria, and recurrence of dominant bacteria (non-Lactobacillus-dominance appeared again in luteal phase after returning to normal Lactobacillus-dominance in follicular phase). (3) Prevotella, especially Prevotella&#95;bivia, was significantly higher during menstrual phase. Conclusions: Healthy vaginal microbiota should be relatively stable, but also have the ability of dynamic change and self-recovery. Prevotella plays a central role among opportunistic pathogens in the vagina, whose function remains to be investigated.

Objective: To examine risk factors of simple obesity and their interaction in preschool children in China. Methods: A total of 63 292 preschool children aged 3-7 years selected by cluster random sampling in 9 cities of China, including Beijing, Harbin, Xi'an, Shanghai, Nanjing, Wuhan, Guangzhou, Fuzhou and Kunming, were investigated from June to November in 2016. Based on the BMI-for-age cut off points of overweight and obesity for Chinese children aged 2-18 years, a total of 1 522 obese children (1 006 boys and 516 girls) were screened. By population-based matched case-control design, a normal weight child was randomly selected to match with an obese child by sex, age (difference ≤6 months) and body height (difference ≤5 cm) from the survey area. Conditional logistic regression model was used to analyze association of risk factors with obesity and the interaction of risk factors. Results: ① Univariate conditional logistic regression model showed that 17 risk factors of simple obesity had statistical significance ( P <0.001), including high birth weight, cesarean section, gestational diabetes, gestational hypertension, formula feeding in the first 6 months after birth, strong appetite, fast or slow eating speed, low intensity of outdoor activities, daily outdoor activity time <1 hour, daily screen viewing time < 1 hour or ≥2 hours, daily night sleep time <9 hours, mother overweight, father overweight, mother's low educational level, father's low educational level, non-nuclear family structure, and parents not being the primary caregivers of children. ②Multivariate conditional logistic regression model showed that 12 risk factors had statistical significance, including high birth weight ( OR =1.83, 95% CI :1.29-2.61, P <0.001), cesarean section ( OR =1.22, 95% CI :1.07-1.39, P =0.003), gestational diabetes ( OR =4.57, 95% CI :2.13-9.79, P <0.001), mother's low educational level ( OR =1.52, 95% CI :1.11-2.07, P =0.008), single parent family ( OR =4.79, 95% CI :1.44-15.88, P =0.010), mother overweight ( OR =2.58, 95% CI :1.93-3.46, P <0.001), father overweight ( OR =2.40, 95% CI :1.86-3.10, P <0.001), strong appetite ( OR =7.78, 95% CI :5.38-11.27, P <0.001), fast eating speed ( OR =6.59, 95% CI :4.86-8.94, P <0.001), daily outdoor activity time <1 hour ( OR =1.42, 95% CI : 1.09-1.85, P =0.009), daily night sleep time <9 hours ( OR =1.59, 95% CI : 1.13-2.23, P =0.007), daily screen viewing time ≥2 hours ( OR =1.69, 95% CI :1.27-2.24, P <0.001). ③ Interaction of the four groups of risk factors had statistical significance, including interaction between mother overweight and father overweight ( OR =5.53, 95% CI : 3.76-8.13, P <0.001), interaction between strong appetite and fast eating speed ( OR =54.48, 95% CI : 32.95-90.06, P <0.001), interaction between low intensity of outdoor activity and daily outdoor activity time <1 hour ( OR =2.12, 95% CI : 1.29-3.48, P =0.002), interaction between daily night sleep time <9 hours and daily screen viewing time ≥2 hours ( OR =2.83, 95% CI : 1.71-4.68, P <0.001). Conclusions: This study identified 12 risk factors of childhood obesity, including high birth weight, cesarean section, gestational diabetes, mother's low educational level, single parent family, mother overweight, father overweight, strong appetite, fast eating speed, daily short outdoor activity time, daily short night sleep time, daily long screen viewing time, and interaction of the four groups of risk factors had statistical significance, including strong interaction between mother overweight and father overweight, interaction between strong appetite and fast eating speed, interaction between low intensity of outdoor activity and daily short outdoor activity time, interaction between daily short night sleep time and daily long screen viewing time.

Objective: To analyze the influential factors of stunting among children under 7 years of age in nine cities of China in order to provide empirical data for early prevention and intervention for stunting. Methods: The survey was carried out with 1∶1 case-control study design in the communities and kindergartens of nine cities (Beijing, Harbin, Xi'an, Shanghai, Nanjing, Wuhan, Guangzhou, Fuzhou, and Kunming) from June to November in 2016. Children of heights lower than the 3 rd percentile according to the 2009 children's height standard in China were included as the stunting case group ( n =1 281), and those with normal height matched for geolocation, gender, and age were recruited as the control group ( n =1 281). The height and weight were measured on site, and the information related to family, perinatal status, diet and feeding, lifestyle, and medical history was collected by questionnaire. Continuous variables were compared by paired samples t test and Wilcoxon matched-pair signed ranks test, and proportions were compared by paired Chi square test. Multivariate analysis were carried out using conditional Logistic regression model. Results: Among 1 281 pairs of stunting and control group, there were 677 pairs of boys and 604 pairs of girls, with 238 pairs of children under age 3 years and 1 043 pairs of children aged 3 to 7 years. The Z scores for height and weight of stunting group were lower than that of control group (-2.27 (-2.54, -2.08) vs. -0.59 (-1.04, -0.10), -1.85 (-2.35, -1.38) vs. -0.69 (-1.20, -0.21), Z =30.982, 25.580, both P <0.01). Among family related factors, parental education level, height, weight, and height of grandparents in stunting children were all lower than those in control group (all P <0.05). Among individual related factors, proportion of preterm birth, low birth weight, shorter birth length, mother's pregnancy complications, difficulties adding milk or complementary feeding, poor appetite, slow eating, picky and partial eating, passive eating, more snack intake, shorter sleep duration, difficulty falling asleep, disturbed sleep, and recurrent infectious diseases in infant in stunting children were all higher than those in control group (all P <0.05). Multivariate Logistic regression analysis results illustrate that the lower the parental education level and the parental height, the higher the risk of stunting. For example, the risk of stunting in children whose fathers had short stature was 6.46 times (95% CI : 2.73-15.30) of those children whose fathers' height were medium and the risk of stunting in children whose mothers were short stature was 10.56 times (95% CI : 4.92-22.69) of those children whose mothers' height were medium. The risks of stunting increase significantly among preterm children or those with low birth weight ( OR =2.27, 95% CI : 1.33-3.88), birth length<45 cm ( OR =3.56, 95% CI : 1.41-8.98), difficulties adding milk or complementary feeding ( OR =2.04, 95% CI : 1.32-3.15), poor appetite ( OR =3.20, 95% CI : 1.74-5.89), slow eating ( OR =1.85, 95% CI : 1.31-2.63), and food allergy ( OR =1.80, 95% CI : 1.02-3.16). Conclusion: Parental short stature, preterm birth or low birth weight, shorter birth length, feeding difficulty in infant, poor appetite, slow eating, and food allergy are the main risk factors for stunting in infants and children.

Most published newborn growth references are based on conventional monitoring data that usually included both low- and high-risk pregnancies. We sought to develop a set of neonatal growth standards constructed from only a large sample of low-risk pregnancies. A total of 24,375 naturally conceived singleton live births with gestational ages of 24-42 weeks were collected in 69 hospitals in thirteen Chinese cities between 2015 and 2018. Unhealthy infants or those with high-risk mother were excluded. Smoothed percentile curves of six anthropometric indicators were established using the Generalized Additive Model for Location, Scale and Shape. The 3rd, 10th, 25th, 50th, 75th, 90th, and 97th percentile references for birth weight, length, head circumference, weight/length, body mass index, and ponderal index were calculated for neonates with gestational ages of 24-42 weeks. This set of neonatal growth standards with six anthropometric indicators can provide more tools for growth and nutrition assessment and body proportionality in neonatal clinical practice. These standards might also help to show the differences between growth curves based on low-risk and mixed low- and high-risk pregnancies., (© 2021. The Author(s).)

Objective: To establish the reference values and growth curves of weight/length, body mass index, and ponderal index for Chinese newborns with gestational ages of 24 to 42 weeks, in order to provide a reference for the assessment of body proportionality and nutritional status at birth. Methods: Cross-sectional study design was applied. From June 2015 to November 2018, a total of 24 375 singleton live birth newborns with gestational ages of 24 to 42 weeks from 13 cities including Beijing, Harbin, Xi'an, Shanghai, Nanjing, Wuhan, Guangzhou, Fuzhou, Kunming, Tianjin, Shenyang, Changsha, and Shenzhen were selected, excluding those impacting the establishment of the reference values. The generalized additive model for location, scale, and shape (GAMLSS) was employed to establish percentile (P 3 , P 10 , P 25 , P 50 , P 75 , P 90 , P 97 ) reference values and growth curves of weight/length, body mass index, and ponderal index for male and female newborns with gestational ages of 24 to 42 weeks. The established growth standards in this study were compared with the standards from the 1988 Chinese data, the INTERGROWTH project, and the USA reference values. Results: A total of 24 375 newborns with 12 264 preterm newborns (7 042 males and 5 222 females) and 12 111 full-term newborns (6 155 males and 5 956 females) were included in this study. The percentile reference values and growth curves of weight/length, body mass index, and ponderal index were obtained for male and female newborns with gestational ages of 24 to 42 weeks. Weight/length of males in all gestational ages at P 10 , P 50 and P 90 was 0 to 0.2 kg/m higher than that of females, and body mass index of males in all gestational ages at the P 10 , P 50 and P 90 was 0.1 to 0.3 kg/m 2 higher than that of females. The established growth curves of weight/length and body mass index at the upper percentile and ponderal index at both upper and lower percentiles were greatly different from those of the 1988 Chinese data, which, for example, reported the difference ranges at P 90 as -1.09 to 0.40 kg/m for weight/length, -1.19 to 0.92 kg/m 2 for body mass index, and -0.64 to 0.81 kg/m 3 for ponderal index. The established weight/length curves were generally consistent with the reference values from the INTERGROWTH project with a difference of -0.17 to 0.20 kg/m at P 50 , while being 0.02 to 0.40 kg/m lower at P 90 and 0.13 to 0.41 kg/m higher at P 10 than that of the INTERGROWTH reference values at gestational ages of ≤32 weeks. The established body mass index curves differed from that of the USA reference values with a difference of -0.47 to 0.17 kg/m 2 at P 50 , while being 0.53 to 1.10 kg/m 2 lower at gestational ages of ≥37 weeks but 0.17 to 0.45 kg/m 2 higher at gestational ages of ≤28 weeks than that of the USA reference values at P 90 . Conclusion: The establishment of the new standardized growth reference values of weight/length, body mass index, and ponderal index for Chinese newborns by different gestational ages are useful for clinical practice and scientific research.

The prevalence of stunting, wasting, overweight and their coexistence are various in different populations and they also have changed with social developing and environmental improving. In this paper, we aimed to analyze the prevalence of stunting, wasting, overweight and their coexistence in some developed regions of China. Data were collected in a population-based cross-sectional survey by a multi-stage cluster sampling method in nine cities located in the northern, central, and southern region of China in 2016. Children under seven years (n = 110,491) were measured. WHO growth standards were used to assess the growth status. Stunting, underweight, wasting, overweight and obesity were considered as the primary forms of malnutrition (includes undernutrition and overnutrition) for infant or young children at population-levels. The prevalence of stunting, underweight, wasting, and overweight or obesity were respectively 0.7%, 0.6%, 1.2%, and 7.6%. Most of these children (95.4%) suffered from one form of malnutrition, and only 0.2% of them concurrently stunted and wasted, 0.4% concurrently stunted and overweight, 1.7% concurrently stunted and underweight, 2.3% concurrently underweight and wasted. Among stunted children, 91.2% were appropriate body proportion, and only 2.3% were wasted, 6.5% were overweight or obesity. Among overweight or obese children, only 0.6% were stunted, whereas, 15.8% were high stature and 83.6% were the appropriate ranges of stature. Sex, age, urban/suburban, and region were associated with these primary forms of malnutrition in the multivariate logistic analysis. In conclusion, we found that the coexistence of stunting and overweight was not common at both population-level and individual-level. The situation for undernutrition had significantly improved, and overweight may be the leading public health issue for children under seven years in the nine cities of China., Competing Interests: The authors have declared that no competing interests exist.

Background: Little consensus exists for growth performance of different feeding patterns in infancy. The objective of this study is to assess the growth performance of exclusively breastfed, partially breastfed and formula fed infants in China., Methods: Data from a total of 109,052 infants aged 1-<12 months were collected from the 4th and 5th China National Surveys in 2005 and 2015. Feeding patterns were classified into three types for infants under 6 months of age: exclusive breastfeeding, partial breastfeeding and formula feeding. Exclusive breastfeeding refers to feeding exclusively from the mother's own milk (bottle-feeding included)., Results: 34.0% and 43.9% of infants were exclusively breastfed and 41.5% and 36.3% were partially breastfed at 4-<6 months in 2005 and 2015 respectively. Exclusively breastfed infants were generally a little heavier than partially breastfed and formula fed infants aged 1-<6 months; however, there was not a significant statistical difference between continued breastfeeding and formula feeding infants aged 6-<12 months. No significant statistical difference for length was observed among the three groups for ages 1-<6 months; however, infants who were continued to be breastfed were a little shorter compared to those who were formula fed (ages 6-<12 months). For infants aged 1-<2 months there was not a substantial difference from the 2006 WHO growth standards; however, for infants aged 2-<12 months the average weight and length of different feeding infants in China were a little heavier and longer than the 2006 WHO growth standards., Conclusions: Partial breastfed and formula fed infants were a little lighter than exclusively breastfed infants in the first half of the first year. Formula fed infants were a little longer than continued breastfed infants in the second half., Competing Interests: NO authors have competing interests.

Objective: To study and establish the percentile reference values of waist circumference (WC) for Chinese children aged 3-7 years. Methods: A total of 26 480 children aged 3-7 years were collected as part of the National Survey on Physical Growth and Development of Children in nine cities (Beijing, Harbin, Xi'an, Shanghai, Nanjing, Wuhan, Guangzhou, Fuzhou and Kunming) in China from June to November 2015. Sex- and age-specific smoothed percentile reference values of WC were established using the Lambda Mu Sigma method. The P(75) and P(90) curves of WC for children aged 3-7 years in this study were linked with the published P(75) and P(90) cut-off points for Chinese children and adolescents aged 7-18 years. The P(50) percentile of WC in this study was compared with the corresponding percentiles of several foreign studies. Results: The P(5) , P(10) , P(15) , P(20) , P(25) , P(50) , P(75) , P(80) , P(85) , P(90) and P(95) reference values of WC were obtained for boys and girls aged 3-7 years biannually, at the interval of every six months. Results showed that WC at the P(50) had significantly increased from 47.5 cm at the age of 3 to 54.2 cm at the age of 7 for boys and from 47.0 cm at the age of 3 to 52.2 cm for girls at the age of 7. The corresponding WC percentile values appeared a bit higher in boys than those in girls at the same age, with the differences from 0.4 to 3.6 cm. The differences between measured and fitted WC at each empirical percentile ranged from -0.3 to 0.5 cm for both boys and girls aged 3-7 years. The P(75) and P(90) values of WC for boys and girls aged 3-7 years in this study presented a consistent, continuous tendency on age with the published WC cut-off points ( P(75) and P(90) ) for Chinese children and adolescent aged 7-18. The increasing trend of WC by age in Chinese children aged 3-7 years was consistent with those of foreign studies, at the middle level for boys and lower middle level for girls. Conclusions: Through this study, we established the WC percentile values for Chinese children aged 3-7 years and achieved the continuity in age with the published WC cut-off points for Chinese children and adolescents aged 7-18. These established WC percentile values can be used as reference for clinical practice, health care and scientific research.

Objective: To detect karyotype homology of vaginal isolates from patients with recurrent vulvovaginal candidiasis (RVVC) in recurrent episodes, and to discuss changes of susceptibility of Candida strains to antifungal drugs with clinical progress. Method: s Ten patients were recruited from Beijing Obstetrics and Gynecology Hospital, Capital Medical University from September 2018 to June 2019, who were firstly diagnosed with RVVC. Vaginal discharges were collected before first treatment and after first relapse. Vaginal strains were isolated, purificated and identificated. Then karyotype of 20 strains isolated from 10 patients were detected by restriction endonuclease analysis of genomic DNA (REAG) using enzyme BssH Ⅱand pulsed field gel electrophoresis (PFGE) methods, and sensitivity of clinical isolates to 5 antifungal drugs (clostridium, fluconazole, miconazole, itraconazole and nystatin) was also detected using disk diffusion method. Result: s (1) All 20 strains of 10 patients with RVVC were Candida albicans, and their chromosomes were extremely similar after BssH Ⅱ enzyme digestion. The gene bands of isolated strains from the same patient were completely identical. (2) After clinical medication, the sensitivity of vaginal isolates to azoles was generally decreased, but remained highly sensitive to nystatin, nystatin (first and second clinical isolates: 100% sensitivity and 100% sensitivity)>clotrimazole (100% sensitivity and 90% sensitivity)>fluconazole (80% sensitivity and 70% sensitivity)>itraconazole (60% sensitivity and 50% sensitivity)>miconazole (30% sensitivity and 20% sensitivity). Conclusions: (1) The latency of the same colonized strain in the vagina may be the cause of repeated RVVC episodes. (2) Antifungal agents could selectively induce drug resistance to Candidas, and Candidas show cross-resistance to antifungal agents. Repeated fungal culture and drug sensitivity test in patients with RVVC are very necessary for correct selection of antifungals.

Objective: To survey the children under 7 years of age in nine cities of China for a better understanding of the current situation of childhood stunting. Methods: According to a stratified cluster sampling design, a cross-sectional survey on children under 7 years of age was carried out in 9 cities (Beijing, Harbin and Xi'an in northern China; Shanghai, Nanjing and Wuhan in central China; and Guangzhou, Fuzhou and Kunming in southern China) from June to November in 2016. A total of 110 499 children were recruited. Height of children was evaluated using the growth standards for Chinese children (2009 edition) .Children with height less than the 3rd percentile of the growth standards were considered as stunting, and children with height between the 3rd and 10th percentiles of the growth standards were considered as relatively short stature. Chi-square test was used for comparison between data of boys and girls, urban and suburban, as well as among different ages and regions. Results: Totally 113 084 children under 7 years of age should be investigated and actually 110 499 children were investigated, with a rate of 97.7%. The prevalence of stunting was 1.9% (2 141/110 499) among all the children. The prevalence of stunting in urban children (1.6%, 904/55 524) was lower than that in suburban children (2.3%, 1 237/54 975, χ(2)=56.246, P< 0.01). The gender difference in stunting prevalence was not statistically significant (1.9% (1 121/57 921) in boys and 1.9% (1 020/52 578) in girls, χ(2)=0.003, P= 0.965). The prevalence of stunting decreased with age for children younger than 3 years, from 1.8% (312/17 080) in 0-<1 year of age group to 1.2% (168/13 740) in 2-<3 years of age group, but increased to 2.2% (240/11 073) at 6-<7 years group. Comparison among different regions showed that the stunting prevalence in southern region was higher than those in the central and northern regions (0.9% (193/20 374) in northern urban, 0.8% (154/18 486) in central urban, and 3.3% (557/16 664) in southern urban children), showing a statistical significance (χ(2)=437.736, P< 0.01); 1.1% (241/21 924) in northern suburban, 1.4% (227/16 775) in central suburban and 4.7% (769/16 276) in southern suburban children, showing a statistical significance (χ(2)=646.533, P< 0.01). In urban areas, the difference between the central and northern regions showed no statistical significance (χ(2)=1.429, P= 0.232) and the stunting prevalence of central Chinese children was slightly higher than that of northern Chinese children in suburban areas (χ(2)=5.130, P= 0.024). Among the nine cities, the stunting prevalence of Guangzhou (6.1%, 613/10 019) was higher than those of other cities (χ(2)=1 559.64, P< 0.01). Among the stunting children, 78.4% (1 679/2 141) were classified as borderline or mild and only 7.2% (154/2 141) were classified as severe. The prevalence of relatively short stature was 5.2% (5 721/110 499). Conclusions: The prevalence of stunting among children under 7 years of age in nine cities of China is low and most of the stunting children were classified as mild; the prevalence of stunting in suburban children is higher than that in urban children; the gender difference show no statistical significance; and the prevalence of stunting in southern Chinese children is higher than those in central and northern Chinese children.

Objective: To investigate the timing of permanent tooth emergence and its association with physical growth among children aged 4-7 years in 9 cities of China, and to analyze the trend of permanent teeth development. Methods: According to a stratified cluster sampling design, a cross-sectional survey on the timing of permanent tooth emergence children aged 4-7 years was carried out in 9 cities (Beijing, Harbin and Xi'an in northern China; Shanghai, Nanjing and Wuhan in central China; Guangzhou, Fuzhou and Kunming in southern China) from June to October in 2015. A total of 37 973 children (19 035 boys and 18 938 girls) were recruited and were divided into different age groups (4.0-<4.5, 4.5-5.0, 5.0-5.5 and 6.0-<7.0 years of age). The situation of the exfoliation of primary teeth and the eruption of permanent teeth were investigated. Height and weight were measured using the standardized methods. Z-scores of physical growth indicators were calculated using the growth standards for Chinese children in 2009. Probit regression analysis was used to determine the median and percentile age of transition from deciduous to permanent teeth. Chi-square test was used for comparison of categorical data and t test was used for comparison of measurement data between boys and girls, urban and suburban as well as among different ages and regions. Meanwhile, the data from the national survey on physical growth and development of children under 7 years of age in 9 cities of China in 1995 were used to analyze the trends of the permanent teeth development. Results: The rate of transition from deciduous to permanent teeth in 37 973 children aged 4-7 years was higher with age, which was 0.6% (42/7 568) in 4.0-<4.5 years of age group, 30.3% (2 295/7 583) in 5.5-<6.0 years of age group, and 74.5% (5 680/7 627) in 6.0-<7.0 years of age group. The rates of transition from deciduous to permanent teeth in boys were all lower than those of girls except for children aged 4.0-<4.5 years (all P< 0.01). The rate of transition from deciduous to permanent teeth in urban children was higher than that in suburban children for older than 5.5-6.0 years of age group in boys and older than 4.5-5.0 years of age group in girls, which was 74.2% (1 427/1 924) in urban boys aged 6.0-<7.0 years and 69.2% (1 305/1 885) in suburban boys aged 6.0-<7.0 years (χ(2)=11.446, P< 0.01). The age of transition from deciduous to permanent teeth was 6.00 (95 %CI : 5.98-6.01) years and the range of the 3-97 percentile was 4.88-7.11 years of age. The median permanent tooth emergence age of girls was lower than that of boys (5.94 vs. 6.06 years) and the median age of urban children was lower than that of suburban children (5.94 vs. 6.05 years). The median permanent tooth emergence age of southern Chinese children (6.05 years) was higher than that of northern (5.97 years) and central Chinese children (5.97 years). The weight for age Z-scores (WAZ), height for age Z-scores (HAZ) and body mass index for age Z-scores (BMIZ) of children with transition from deciduous to permanent teeth (0.35±1.17, 0.32±1.00, 0.23±1.16) were significantly higher than those of children without transition from deciduous to permanent teeth (0.03±1.13, 0.03±1.02, 0.04±1.13, t= 20.81,21.67,12.09, all P< 0.05). In comparison with the data in 1995, data in 2015 showed that the rate of transition from deciduous to permanent teeth was higher, for example, the rate of urban boys aged 6.0-<7.0 years group was 63.8% (1 146/1 796) in 1995, and increased to 74.2% (1 427/1 924) in 2015 (χ(2)=46.748, P< 0.01). The median permanent tooth emergence age decreased by 0.24 years in 2015 as compared with that in 1995. Conclusions: The development of permanent teeth is earlier in girls than in boys, earlier in urban children than in suburban children and slightly delay in southern children than in central and northern Chinese children. In addition, the development of permanent teeth, which is related to the physical growth, slightly accelerate in China during the past 20 years.

Objective: To analyse the secular trends in mean value and distribution of weight, height and weight for height in children under 7 years in developed regions in China., Design: Five repeated cross-sectional surveys were conducted using the same methods at the same sites during 1975-2015., Setting: Nine cities in northern, central and southern regions of China., Population: Healthy children under 7 years; the sample sizes were 94 496 in 1975, 79 177 in 1985, 79 152 in 1995, 69 760 in 2005 and 83 583 in 2015., Main Outcome Measures: Weight and height were measured by the same methods in the five surveys., Results: The increasing trends in the mean value of weight, height and weight for height were observed and their distribution was found to have shifted upwards. There were unbalanced increments in various centiles and the relative increments in the 3rd centile of height for children under 7 years were larger than those in the 50th and 97th centiles. Although the relative increments in the 3rd centile of weight for children under 2 years were larger than those in the 50th and 97th centiles, the increments in the 97th centile for children older than 2 years became the largest compared with other centiles. The changes in each centile of weight for height were similar with those of weight. The annual increments of height and weight increased over time and were more significant between birth and 2 years of age for height and between ages 4 years and 6 years for weight. The per-decade increments in 1975-1985, 1985-1995 and 1995-2005 became larger, while those in 2005-2015 slowed down., Conclusions: The rapid increasing trends of weight, height and weight for height had slowed down since 2005 in developed regions of China. The relative increments in the low centile of height were more significant, while the high centile of weight and weight for height increased more significantly in older children., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2019. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Objective: To investigate the status of the development of primary teeth and to identify the development patterns among infants and toddlers in nine cities of China in 2015. Methods: Healthy children aged 1-<36 months were investigated by across-sectional survey and retrospective studies, which was carried out in 9 cities (Beijing, Harbin and Xi'an in northern China; Shanghai, Nanjing and Wuhan in central China; and Guangzhou, Fuzhou and Kunming in southern China) from June to October in 2015. Subjects ( n =103 995) were divided into 14 age groups (1-<2, 2-<3, 3-<4, 4-<5, 5-<6, 6-<8, 8-<10, 10-<12, 12-<15, 15-<18, 18-<21, 21-<24, 24-<30, 30-<36 months). There were 150-200 boys and girls respectively in each group of urban and suburb areas in each city. The eruption status and the number of primary teeth were examined by the trained child health care physician or pediatrician on the spot. The timing of primary teeth eruption of children was retrospectively surveyed using a questionnaire. The prevalence of primary teeth was calculated and χ(2) test was used for comparison of categorical data. Probit regression analysis was used to determine the median and percentile age of eruption of primary teeth. Results: Totally 103 995 children aged 1-<36 months were investigated. There were 52 346 children in urban areas (boys 26 228, girls 26 118) and 51 649 children in suburb areas (boys 25 912, girls 25 737). The eruption rate of primary teeth in children under 2 years became higher with age and the difference among each age group was statistically significant (χ(2)=85 913.868, P< 0.01), which was 0.3% (22/7 450) in 3-<4 months group, 43.0% (3 227/7 503) in 6-<8 months group and 99.9% (7 441/7 446) in 15-<18 months group. The eruption age of primary teeth was 6.6 months (95 %CI : 6.5-6.7 months), and the range of the 3rd to 97th percentile was 4.1-10.6 months. The eruption ages of primary teeth in urban and suburb areas children were 6.6 months (95 %CI : 6.5-6.7 months) and 6.6 months (95 %CI : 6.5-6.7 months) respectively. The eruption age of primary teeth was earlier in boys (6.4 months, 95 %CI : 6.3-6.5 months) than that in girls (6.7 months, 95 %CI : 6.6-6.8 months). The median eruption age of primary teeth was earlier in northern China (6.2 months) than that in central (6.7 months) and southern China (6.9 months). The eruption rate of primary teeth became higher with age, showing that the median number of primary teeth was 2 in 8-<10 months group, 8 in 12-<15 months group and 20 in 30-<36 months group. Conclusions: The timing of eruption of primary teeth was similar between urban and suburb areas children and that of the boys was slightly earlier than that of the girls. There were slight differences among different regions in the eruption timing of primary teeth. The range of the 3rd to 97th percentile in the eruption age of primary teeth was 4.1-10.6 months and the number of primary teeth followed the regular development pattern with age.

Objective: To develop the reference values of carotid intima-media thickness (cIMT) in Chinese children aged 6-11 years. Methods: A convenient cluster sampling method was used to conduct a cross-sectional survey from November 2017 to January 2018 in a primary school in Huantai County, Zibo City, Shandong Province. A total of 1 033 children aged 6-11 years (excluding children with obesity or hypertension) were included. Percentile curves for cIMT were drawn using the lambda, mu and sigma (LMS) method. Results: This study developed the cIMT reference values ( P (90) and P (95)) for sex and age aged 6-11 years, including P (90) and P (95) reference values of mean cIMT, left cIMT and right cIMT, respectively. With the increase of age, the cIMT percentile values also increased. For the same age and the same percentile, the cIMT values of boys were higher than those of girls. Conclusion: This study developed sex-specific and age-specific cIMT percentile reference values in children aged 6-11 years.

Objective: To develop and validate a simplified height-specific blood pressure cutoffs table for screening hypertension in Chinese children and adolescents. Methods: We developed a simplified height-specific blood pressure cut offs table according to Chinese Blood Pressure Reference for Children and Adolescents aged 7-18 years (WS/T 610-2018) (hereafter referred to as "complex definition"). Populations from Early Warning, Diagnosis and Treatment of Children Cardiovascular Disease Project ("Ji'nan sample") and Shandong Children Cardiovascular Cohort Study Project ("Zibo sample") were used as validation populations for evaluating the screening effect of the simplified table for elevated blood pressure and hypertension in children and adolescents. Results: We developed simplified height-specific blood pressure cutoffs table including 7 height groups and 28 cutoffs. Both Ji'nan and Zibo samples were selected by convenient sampling method, and the former included 7 233 participants aged 7 to 17 years, among whom 3 790 (52.4%) were boys. Latter population included 1 277 participants aged 7 to 11 years, among whom 681 (53.3%) were boys. The simplified table performed well for identifying elevated blood pressure in Ji'nan sample, with values of area under the receiver operating curve (AUC) (95 %CI ), sensitivity, specificity, and Kappa statistic as 0.96 (0.95-0.97), 93.0%, 98.5% and 0.91, respectively, which were similar with results in Zibo sample [the values were 0.92 (0.90-0.95), 87.0%, 98.0% and 0.85, respectively]. The simplified table also performed well for identifying hypertension in Ji'nan sample with values of AUC (95 %CI ), sensitivity, specificity, and Kappa statistic as 0.92 (0.91-0.94), 86.9%, 98.1% and 0.85, respectively, which were similar with results in Zibo sample [the values were 0.94 (0.91-0.96), 88.2%, 98.9% and 0.88, respectively]. Conclusion: Screening for elevated and high blood pressure based on simplified height-specific blood pressure cutoffs table is easy to use and it shows satisfying effect.

Background: Both child under- and over-nutrition are major global public health challenges. We aimed to examine thirty-year trends in physical growth, under- and over-nutrition in Chinese urban and suburban children between 1985 and 2015, and discuss implications for child health programmes., Methods: A total of 610,785 urban and suburban children from birth to 7 years of age were collected from a series of large-scale national surveys in China. Height, weight and body mass index (BMI) Z-scores and prevalence of stunting, underweight, wasted and possible risk of overweight, overweight and obesity were calculated according to the World Health Organization (WHO) 2006 growth standards. The trends in the prevalence were tested across different survey years by Cochran-Armitage trend test., Results: Rapid secular growth trend was observed in China over the past 30 years, but the trend showed a slowing sign in urban children in recent 10 years. The growth level of Chinese urban and suburban children surpassed the WHO 2006 growth standards in 2015. Between 1985 and 2015 the stunting, underweight and wasted prevalence decreased from 12.21, 4.44, 1.68 to 0.97%, 0.59, 0.87% for children under 5 years and from 12.69, 10.02, 3.41 to 0.42%, 0.67, 2.17% for children aged 5- < 7 respectively; the possible risk of overweight prevalence increased from 6.51 to 12.57%, overweight from 0.70 to 3.48% and obesity from 0.17 to 0.86% for children aged 2- < 7 and the increasing rates of overweight and obesity prevalence in suburban children first outnumbered urban children in recent 10 years. The overweight prevalence overtook the wasted or underweight in children aged 2- < 7 in 2005 and onward., Conclusion: Slowing secular height trend and overweight prevalence overtaking the wasted or underweight suggested child nutrition and health strategies should adjust swiftly and deliberately from primarily reducing under-nutrition prevalence to controlling rapid weight gain and promoting integrated early development.

Background: In China, as the social transformation and economic development from 1985 to 2015, children's feeding pattern has undergone some changes. So we aimed to analyze the secular trend on feeding patterns of city children in China., Methods: All data were from a series of national survey which implemented once every 10 years in China from 1985 to 2015. We use same indexes to evaluate the feeding pattern of children in these four surveys., Results: From 1985 to 2005, the exclusive breastfeeding rates in infants under 6 months of age decreased, especially in suburban areas decreased by 17.7%; the continuous breastfeeding rate of 1-year-old children in suburban area decreased from 60.1 to 27.6%. However, from 2005 to 2015, the exclusive breastfeeding rates under 6 months of age increased by 16.0% in urban areas and 5.9% in suburban areas; the continuous breastfeeding rate of 1-year-old children in urban increased from 17.0 to 36.0%. The overall feeding rate of complementary food in infants under 6 months of age declined from 1985 to 2015; the average age at introduction of all complementary foods was around 6 months of age in 2015., Conclusions: There is an obvious trend on feeding pattern of Chinese children. From 1985 to 2005, the breastfeeding rate decreased, the duration time of breastfeeding was shortened and the age at introduction of complementary food was advanced. From 2005 to 2015, the breastfeeding rate increased, the duration time of breastfeeding was prolonged, and the age at introduction of complementary food was postponed.

Objective: To analyze the current situation of gross motor development of infants in nine cities of China and their relationship with physical growth. Methods: Healthy full-term infants aged 1-24 months were investigated by cross-sectional survey, which was carried out in nine cities (Beijing, Harbin, Xi'an in northern, Shanghai, Nanjing, Wuhan in central, and Guangzhou, Fuzhou, Kunming in southern regions of China) from June to October in 2015. Subjects were grouped into 12 age groups (1 - <2, 2 - <3, 3 - <4, 4 - <5, 5 - <6, 6 - <8, 8 - <10, 10 - <12, 12 - <15, 15 - <18, 18 - <21, 21 - <24 months). Gross motor development of infants was examined by fieldworkers and the information on parental education, family income and birth status were obtained by questionnaire. Weight, length and head circumference was measured by fieldworkers according to standard methods in the fields and their Z scores were calculated by using WHO growth standard. Z scores of weight (WZ), length (LZ) and head circumference (HCZ) <-2 s was considered as lower group, -2 s- <-1 s as medium-lower group, -1 s- 1 s as medium group, 1 s- <2 s as medium-higher group and ≥2 s as higher group. The age of gross motor development was calculated by Probit regression analysis and χ(2) test was used for comparison of categorical data. Results: (1) The number of infants whose gross motor development was examined were 88 968 in the nine cities. The proportion of achievement of motor development became larger with the chronological age, i.e. it was 11.1% (800/7 236) at 5-<6 months, 65.2% (4 921/7 545) at 6-<8 months and 98.5% (7 417/7 531) at 8-<10 months for sitting alone without support. There was no gender difference in the proportion of achievement of sitting alone without support, hand-knee crawl, stand alone and walk alone (χ(2)=2.873, 0.275, 0.250, 0.576, all P> 0.05). (2) The median age of achievement of sitting alone without support, hand-knee crawl, stand alone, walk alone was respectively 5.9, 7.8, 10.8, 13.0 months, and their ranges from 1(st) to 99(th) percentile were respectively 4.2 - 8.3 months, 4.9 - 12.6 months, 7.6 - 15.4 months, 9.8 - 17.4 months. The gender difference of median age of gross motor development was 0.0-0.1 months and their regional difference was 0.0 - 0.7 months. (3) In the lower weight group, their median age of sitting alone without support and walk alone were 0.2 - 0.6 months later than the medium weight group, while their median age of hand-knee crawl and stand alone were similar to those of the medium weight group. In higher weight group, the median age of sitting alone without support and stand alone were similar to that of the medium weight group, while their median age of hand-knee crawl was 0.3 later months and their median age of walk alone was 0.3 months earlier than that of the medium weight group. There was no significant relationship between length and the age of sitting alone or standing alone (the difference was 0.0 - 0.2 months in each group). The median age of hand-knee crawl and walk alone was 0.4 - 0.7 months later in lower length group than in other length groups. The median age of gross motor development was similar among different head circumference groups (0.0 - 0.2 months). The relationship between weight/length and motor development was similar to that between weight and motor development. Conclusions: There were no gender difference and slightly regional difference in the age of achievement of gross motor skills. The percentile age of gross motor skills helps to understand the population variation in healthy infants. The gross motor development is related with weight, length and body proportion.

Aim: This 2015 study was a part of the National Growth Survey of Children under seven years of age, which has been carried out in nine Chinese cities every 10 years since 1975. Our aim was to assess children's feeding practices and nutritional supplements., Methods: This was a cross-sectional survey of 89 006 healthy children aged one to 24 months. All data were collected by face-to-face interviews during child health visits, using a questionnaire., Results: The exclusive breastfeeding rate was 53% in infants under six months of age, and the continued breastfeeding rate was 51% among infants who were 10-12 months and 5% when they were 21-24 months. Infants were weaned at a mean of 9.3 months in urban areas and 9.4 months in suburban areas. Cereals were provided as complementary food at a mean age of five months, eggs at six months, meat at eight and a half months and bean products at over 12 months. The most common nutritional supplements given to the children were vitamins A and D and calcium., Conclusion: The feeding practices of Chinese city children were similar to those in developed countries, but strategies are needed to promote more rational consumption of nutritional supplements., (©2018 Foundation Acta Pædiatrica. Published by John Wiley & Sons Ltd.)

Objective: To observe the development of the anterior fontanel (AF) in healthy Chinese children from 1 to 36 months, and to assess the relationship between the closure of the AF and physical development in Chinese children. Method: This was a cross-sectional evaluation of the AF in a series of 104 147 healthy children between June 2015 and October 2015 from nine cities in China. The size and closure of AF of the children were measured and recorded, and the age for the closure of AF was calculated using probit analysis. The data in 2015 were compared with the data from the same surveys in 1985, 1995 and 2005 respectively. Result: (1) Totally, 104 147 healthy children (52 216 boys and 51 931 girls; range 1 month to 36 months) from nine cities enrolled in this cross-sectional study. (2)The size of AF gradually decreased with age, and the mean size of AF was 2.0(95% confidence interval ( CI )2.0-2.1) cm at the age of 1 month, 0.6(95% CI 0.5-0.6) cm at the ages of 12-14 months, and 0.0(95% CI 0.0-0.0) cm at the ages of 21-23 months, respectively. (3) The percentage for the closure of AF was 0.1% at the age of 3 months, 67.5% at the ages of 15-17 months. The oldestt age for closure was 35 months. The mean age for the closure of AF was 14.5 months (95% CI 14.4-14.6), and the 3rd and 97th centiles of the age for the closure of AF were 6.6 and 22.4 months. (4) Over the past 30 years from 1985 to 2015, no significant change was found regarding the mean age for the closure of AF in children from urban area, contrarily, the mean age was 1.1 months earlier in suburban area. (5) The height and weight of children in the closed AF group were significantly higher than those of children in unclosed AF group(all P <0.01), but no significant difference was found regarding the head circumference between the two groups. Conclusion: The size of AF at 1 month was maximum, then decreases gradually with age, and the mean age for the closure of AF was 14.5 (95% CI 14.4-14.6) months. No significant correlation was found between the development of AF and the head circumference, but there was a positive correlation between the development of AF and the height and weight. There was no significant change regarding the secular trend of the age for the closure of AF.

Objectives: To describe the physical growth of healthy children under 7 years in China based on the latest national survey and provide more data for revising growth reference and monitoring the impact of social development on children's health and growth., Methods: In the cross-sectional survey, 161,774 healthy children under 7 years were selected by multistage stratified cluster sampling method in nine cities of China. According to the geographical location, the nine cities were divided into northern, central and southern regions, and each city included urban and suburban areas. Anthropometric measurements were obtained on the spots and other related information was collected with questionnaires., Results: There were slight urban-suburban difference and obvious regional difference in anthropometric measurements in China. Comparison with the 4th NSPGDC in 2005, measurements increased 0.1-1.1 kg in weight, 0.5-1.8 cm in height in urban areas (except children under 3 years) and 0.1-2.5 kg in weight, 0.2-3.8 cm in height in suburban areas. The urban-suburban difference of those measurements became smaller than 10 years ago, but their regional difference persistently exist. Chinese children were 0.36 SD in weight, 0.43 SD in height in urban areas and 0.30 SD in weight, 0.30 SD in height in suburban areas higher than WHO standards., Conclusions: Physical growth of children under 7 years old was undergoing a slowly positive secular trend during the latest decade in more economically developed regions of China. Urban-suburban difference of those measurements became smaller, while their regional difference persistently exist. Chinese healthy children under 7 years in nine cities was taller and heavier than WHO standards., (© 2017 Wiley Periodicals, Inc.)

The objective of this study was to examine the effect of socioeconomic development on secular trend in height among children and adolescents in China. Body height and spermarcheal/menarcheal ages were obtained from two periodic large-scale national representative surveys in China between 1975 and 2010. Chinese socioeconomic development indicators were obtained from the United Nations world population prospects. The effects of plausible determinants were assessed by partial least-squares regression. The average height of children and adolescents improved in tandem with socioeconomic development, without any tendency to plateau. The increment of height trend presented larger around puberty than earlier or later ages. The partial least-squares regressions with gross national income, life expectancy and spermarcheal/menarcheal age accounted for increment of height trend from 88.3% to 98.3% for males and from 82.9% to 97.3% for females in adolescence. Further, through the analysis of the variable importance for projection, the contributions of gross national income and life expectancy on height increment were confirmed to be significant in childhood and adolescence, and the contribution of spermarcheal/menarcheal age was superior to both of them in adolescence. We concluded that positive secular trend in height in China was significantly associated with socioeconomic status (GNI as indicator) and medical and health conditions (life expectancy as indicator). Earlier onset of spermarche and menarche proved to be an important role in larger increment of the trend over time of height at puberty for a population., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Background: Family-based child obesity prevention and control strategy has not yet established in many countries or regions, including China, thus what it needs to do now is to continuously develop and improve the strategies. The purpose of this study were to describe a wider spectrum of risk factors of obesity among preschool children and add to the mounting evidence for further improving suggested intervention measures in future family-based programs., Methods: Data was collected as part of a series of national epidemiological surveys in childhood conducted in 9 Chinese cities. A population-based, 1:1 matched case-control design was employed to examine risk factors of obesity by means of conditional logistic regression. Obesity was defined as the International Obesity Task Force (IOTF) BMI-for-age cut offs. Eligible subjects were 1234 boys and 610 girls aged 3-7 years in 1996 and 2290 boys and 1008 girls in 2006, including obese and non-obese., Results: High birth weight, gestational hypertension and parents' BMI were closely associated with childhood obesity. Breast feeding in the first 4 months was a protective factor in univariate model in 2006 (OR = 0.834, P = 0.0234), but the association was not seen in multivariate. Appetite, eating speed, daily time and intensity for outdoor activities, night sleep time, and time for TV viewing were identified statistically by multivariate model. Those children brought up in extended family or mainly raised by their grandparents or lived in high income or low education families might have an increased risk of becoming obese. Parents' attitudes on weight control of their children significantly differed between obese and non-obese groups., Discussion: A wider spectrum of risk factors and an empirical aggregation of family-related risk factors are discussed to further improve future family-based child obesity prevention and control strategies. Most of the risk factors identified by this study presented ranked or quantitative characteristics which might be transformed from unhealthy threshold to healthy range by behavior modification. Some variables are likely to interact each other, such as appetite and eating speed, or outdoor activity and TV viewing, or BMI and income, but which needs to be further explored in future surveys., Conclusions: The family-related risk factors were summarized from our identified risk factors of obesity among preschool children which strongly supported the further development of family-based programs in preschool period.

Objective: To examine if economic development in China correlates with physical growth among Chinese children and adolescents., Methods: The height, body weight and physical activity level of children and adolescents aged 18 years and under, as well as dietary data, were obtained from seven large surveys conducted in China between 1975 and 2010. Chinese economic development indicators were obtained from the World Bank. Trends in body weight, height, economic data and diet were examined. Tests were conducted to check for correlations between height at 17 years of age and three indicators of economic development: gross domestic product, urbanization and infant mortality rate. Regional differences in physical growth were assessed., Findings: Between 1975 and 2010, the growth of children and adolescents improved in tandem with economic development. The largest increment in height was observed during the period of puberty. Regional inequalities in nutritional status were correlated with disparities in economic development among regions. Over the past two decades, undernutrition declined among children less than 5 years of age, but in 2010 underweight and stunting were still common in poor rural areas. A large increase in obesity was observed in both urban and rural areas, but especially in large cities and, more recently, in small and medium-sized cities and affluent rural areas., Conclusion: The average weight of children and adolescents has been increasing progressively since the 1970s. Current strategies to combat both child undernutrition and obesity need to be improved, especially in poor rural areas.

Introduction: Growth references for Chinese children should be updated due to the positive secular growth trends and the progress of the smoothing techniques. Human growth differs among the various ethnic groups, so comparison of the China references with the WHO standards helps to understand such differences., Methods: The China references, including weight, length/height, head circumference, weight-for-length/height and body mass index (BMI) aged 0-18 years, were constructed based on 69,760 urban infants and preschool children under 7 years and 24,542 urban school children aged 6-20 years derived from two cross-sectional national surveys. The Cole's LMS method is employed for smoothing the growth curves., Results: The merged data sets resulted in a smooth transition at age 6-7 years and continuity of curves from 0 to 18 years. Varying differences were found on the empirical standard deviation (SD) curves in each indicator at nearly all ages between China and WHO. The most noticeable differences occurred in genders, final height and boundary centiles curves. Chinese boys' weight is strikingly heavier than that of the WHO at age 6-10 years. The height is taller than that of the WHO for boys below 15 years and for girls below 13, but is significantly lower when boys over 15 years and girls over 13. BMI is generally higher than that of the WHO for boys at age 6-16 years but appreciably lower for girls at 3-18 years., Conclusions: The differences between China and WHO are mainly caused by the reference populations of different ethnic backgrounds. For practitioners, the choices of the standards/references depend on the population to be assessed and the purpose of the study. The new China references could be applied to facilitate the standardization assessment of growth and nutrition for Chinese children and adolescents in clinical pediatric and public health.

Introduction: No prevalence/trends were reported in Chinese infants and preschool children at the national level in this historical period of 1980s-2000s. The objectives of this paper were to present the 20-year trends in prevalence and risk factors of obesity in children below 7 years., Methods: Data obtained from a series of three sequential national surveys performed using the same design in the same 9 cities in 1986, 1996 and 2006. Weight and height (length <3 years) were measured using unified procedures at each period. Obesity was defined as a weight-for-height ≥120% of median of the NCHS/WHO international reference. A population-based paired matching case-control study was employed for screening risk factors., Results: In 1986, there was no substantial obesity epidemic, but the overall obesity prevalence reached 3.4% (boys 4.1% and girls 2.7%) in 2006, rising by 2.8 times between 1986 and 2006. Reversed gender difference, relatively higher prevalence in preschool age and more rapid increase in the second 10-year were three very obvious characteristics in China, e.g. prevalence of boys 9.9% and girls 4.9% in 2006 and increasing rate of boys 0.45 percentage points per year (pp/y) and girls 0.21 pp/y at 6-7 years groups, 0.17 pp/y of the second 10-year higher 1-fold than previous., Conclusions: China has been moving into the alarming epidemic of childhood obesity. Effort should be immediately made to prevent further deterioration. High birth weight, high parental BMI and several behavioral and family-related factors were identified and had important practical value for obesity intervention.

Objectives: To report the secular growth changes of Chinese children aged 0-7 years between 1975 and 2005., Methods: Height and weight measurements obtained from four consecutive national surveys were used to analyze the secular trends. Urban-rural difference and regional difference in growth were compared, respectively., Results: A rapid positive secular trend was observed in China over the last three decades, increased by 5.3 and 5.0 cm in height for urban boys and girls at age 6-7 years, respectively. Urban-rural height difference has continuously reduced, but weight difference has gradually widened after 3-years old which results from the excessive weight increase of urban children, 2.68 kg for rural boys aged 6-7 years but 3.26 kg for urban during the 30 years. Clear regional differences in growth are not narrowing over time. Generally, the growth level in eastern China is higher than central-western, successively higher than southern., Conclusions: The rapid positive secular trends will still continue with the rapid socio-economic development in China. Urban-rural height difference will further narrow. Currently no sufficient evidence indicates that growth difference in inter-city has reduced. Weight increases rapidly for urban children, which does not match with height., (Copyright © 2010 Wiley-Liss, Inc.)

Objective: To study the body cut-offs of mass index (BMI) for the purpose of screening overweight and obesity for Chinese children and adolescents aged 2 - 18 years., Methods: Based on the BMI growth reference values for Chinese children aged 0 - 18, using the common methods to establish the BMI cut-offs for screening overweight and obesity. These methods were having the same empirical percentile or Z scores and the BMI value at 18 years consistent with adults. Three sets of BMI cut-offs, including (BMI₂₄, BMI₂₈), (P₈₅, P₉₅) and (Z₁, Z₂), were initially identified. Differences were compared on different cut-off points and prevalence rates of overweight and obesity with different BMI reference, different values and "prevalence" of overweight and obesity based on "2004 Beijing Child and Adolescent Metabolic Syndrome Study". Cut-offs standards which recommended by the Chinese Working Group on Obesity for Children (WGOC) and by the International Obesity Task Force (IOTF) were also used. Finally the appropriate cut-offs were defined., Results: Three sets of BMI cut-offs for screening overweight and obesity for Chinese children and adolescents aged 2 - 18 years were obtained according to the above mentioned methods for selection. The prevalence rates of overweight and obesity defined by those cut-offs appeared not to be significantly different. Compared with the WGOC, the BMI cut-off points for screening overweight and obesity for both boys and girls from our study were very close to the WGOC', but cut-off points for screening overweight for girls aged 8.5 - 15.5 y was 0.3 - 1.0 kg/m² lower than the WGOC'. Going through the database on screening of "2004 Beijing Children's Metabolic Syndrome Survey", the prevalence of overweight for girls was about 3.4% higher than using the cut-offs of WGOC., Conclusion: Results from this study suggested that the BMI cut-offs passed through the cut-off point of BMI₂₄ and BMI₂₈ at 18 years was appropriate for screening overweight and obesity in Chinese children from 2 to 18 years, and achieved the continuity in age and consistency in screening standard when using the BMI indicator in children and adolescents.

Objective: To construct the body mass index (BMI) reference data and curves for Chinese children and adolescents from birth to 18 years of age., Methods: Data from two national representative cross-sectional surveys which were The National Growth Survey of Children under 7 years in the Nine Cities of China in 2005 and The Physical Fitness and Health Surveillance of Chinese School Students in 2005. Height (length was measured for children under 3 years) and weight data of 93,702 urban healthy children from nine cities/provinces used to calculate the BMI. The LMS method was used to smooth the BMI, with estimates of L, M, and S parameters, values of percentile and Z-score curves which were required were calculated, and then standardized growth charts were generated. Adult cut-offs for overweight and obesity at 18 years was used to study the cut-offs for children 2 to 18 years of age., Results: The smoothed percentiles and Z-scores reference data and curves of BMI-for-age for boys and girls aged 0-18 years were made out respectively. BMI cut-off values for overweight and obesity for children from 2 to 18 years of age were also defined. At 18 years, the BMI values are equivalent to the overweight cut-off (> or =24 kg/m2) and obesity cut-off (> or =28 kg/m2) for Chinese adults. Comparison with the reference of the WHO and 2000 CDC for the United States, there were some difference among them, at the 97th percentile curve there was a big difference between Chinese and U. S. adolescents. On the whole, the China BMI curve for boys was higher than the new WHO curve and lower than 2000 CDC at 97 percentile curve, but the China BMI curve for girls was lowest among the three curves. There was also significant difference between China and Japan BMI values at 97 percentile curve., Conclusion: BMI growth curves are very useful in child growth monitoring and nutritional surveillance, discovering overweight and obesity. The BMI growth charts are recommended for use in pediatric clinic and public health service.

Objective: To construct the height and weight growth charts for Chinese children and adolescents from birth to 18 years for both clinical and preventive health care uses., Methods: Data from two national representative cross-sectional surveys which were The National Growth Survey of Children under 7 years in the Nine Cities of China in 2005 and The Physical Fitness and Health Surveillance of Chinese School Students in 2005. The data from 94,302 urban healthy children were used to set up the database of length/height (length was measured for children under 3 years) and weight. The LMS method was used to smooth the growth curves, with estimates of L, M, and S parameters, values of percentile and Z-score curves which were required were calculated, and then generated standardized growth charts., Results: The 3rd, 10th, 25th, 50th, 75th, 90th, 97th smoothed percentiles curves and -3, -2, -1, 0, +1, +2, +3 Z-scores curves of weight-for-age, length/height-for-age for boys and girls aged 0-18 years were made out respectively. Comparison with the new WHO growth charts and 2000 CDC growth charts for the United States, the results showed that there was some big difference in weight and height among the three growth charts. For boys under 15 years of age and girls under 13 years of age, the China curves are slightly higher than WHO and CDC curves, but after those ages, the China curves fall behind and the difference became larger as age progresses. At the age of 18 years, the Chinese children are 3.5 cm shorter in boys and 2.5 cm shorter in girls as compared with the U. S. children. The difference in weights are very large for the school children, especially in girls. The weight of Chinese boys was 5.9 kg less than that of the U. S. boys at 18 years, and the difference was much bigger in girls, the weight of U.S. girls between 8 to 18 years was 4.1-20.5 kg more than that of Chinese girls at the same age range., Conclusion: The new growth charts of height and weight were based on national survey data and therefore are recommended as the China national growth standards for use in pediatric clinics and public health service. Application of the charts will promote child growth monitoring, discovering early growth disorder, and will be useful to diagnosis of diseases and assessment of therapeutic effects.

Objective: To explore the growth patterns and simple mathematic models of height and weight of Chinese children., Methods: The original data had been obtained from two national representative cross-sectional surveys which were 2005 National Survey of Physical Development of Children (under 7 years of age) and 2005 Chinese National Survey on Students Constitution and Health (6 - 18 years). Reference curves of height and weight of children under 7 years of age was constructed by LMS method, and data of children from 6 to 18 years of age were smoothed by cubic spline function and transformed by modified LMS procedure. Growth velocity was calculated by smoothed values of height and weight. Simple linear model was fitted for children 1 to 10 years of age, for which smoothed height and weight values were used., Results: (1) Birth length of Chinese children was about 50 cm, average length 61 cm, 67 cm, 76 cm and 88 cm at the 3rd, 6th, 12th and 24th month. Height gain was stable from 2 to 10 years of age, average 6 - 7 cm each year. Birth length doubles by 3.5 years, and triples by 12 years. The formula estimating average height of normal children aged 2 - 10 years was, height (cm) = age (yr) x 6.5 + 76 (cm). (2) Birth weight was about 3.3 kg. Growth velocity was at peak about 1.0 - 1.1 kg/mon in the first 3 months, decreased by half and was about 0.5 - 0.6 kg/mon in the second 3 months, and was reduced by a quarter, which was about 0.25 - 0.30 kg/mon, in the last 6 months of the first year. Body mass was up to doubles, triples and quadruple of birth weight at about the 3rd, 12th and 24th month. Average annual gain was about 2 kg and 3 kg from 1 - 6 years and 7 - 10 years, respectively. The estimated formula for children 1 to 6 years of age was weight (kg) = age (yr) x 2 + 8 (kg), but for those 7 - 10 years old, weight (kg) = age (yr) x 3 + 2 (kg)., Conclusions: Growth patterns of height and weight at the different age stages were summarized for Chinese children, and simple reference data of height and weight velocity from 0 to 18 years and approximate estimation formula from 1 - 10 years was presented for clinical practice.

Aim: Obesity has been proved as one of the main risk factors for gastric cardia adenocarcinoma (GCA) in the West. The objective of our research was to evaluate the relationship between obesity and the risk of GCA in people from North China., Methods: A total of 300 patients who had been diagnosed as GCA and had accepted surgical operation at Beijing Cancer Hospital from 1995 to 2002 were enrolled. Data were collected from pathology materials and hospital records. Two hundred and fifty-eight healthy people who had accepted health examination at the same hospital during the same period were enrolled as controls. Height, weight and gender of them at the time of examination were also collected. Obesity was estimated by body mass index (BMI), computed as weight in kilograms per square surface area (Kg/m2). The degree of obesity was determined by using BMI< or =18.5, 24-27.9 and > or =28 (Kg/m2) as the cut-off points for underweight/normal, overweight and obesity, respectively. Associations with obesity were estimated by odds ratios (ORs) and 95 % confidence intervals (CIs). All ORs were adjusted for age and sex., Results: The mean level of BMI was significantly lower in the patient group than that in the control group. The ORs for obesity in age groups 30-59 and 60-79 were 1.15 (95% CI=0.37-3.65) and 0.16 (95% CI=0.05-0.44) for males and 0.78 (95% CI=0.26-2.36) and 0.28 (95% CI=0.04-2.05) for females, respectively. The ORs for underweight were 2.42 (95% CI=0.56-10.53) and 4.68 (95% CI=1.13-19.40) for males in age subgroups 30-59 and 60-79 and 40.7 (95% CI=9.32-177.92) for females older than 60 yrs. BMI was significantly associated with GCA (P<0.01). Underweight people were at high risk for GCA., Conclusion: BMI is an independent risk factor for GCA. Underweight is positively associated with GCA.