[Current status of pubertal sexual characteristics development of 2 704 girls aged 6-18 years in Tongzhou District of Beijing].

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 χ2 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.

[Association between hyperuricemia and incidence risk for cardiometabolic abnormity in children].

Objective: To investigate the relationships between hyperuricemia and the incidence risk for cardiometabolic abnormity in children. Methods: Data were obtained from School-based Cardiovascular and Bone Health Promotion Program. In 2017, a total of 15 391 children aged 6-16 years in Beijing were selected through stratified cluster sampling at baseline survey. Follow-up investigation was conducted in 2019. Logistic regression model was used to analyze the relationships of uric acid quartiles and change in uric acid levels with incidence risks for cardiometabolic abnormity (hypertension, hyperglycemia and dyslipidemia). Results: A total of 8 807 children (4 376 boys, 4 431 girls) were included in the analysis, the average age of the children was (11.1±3.3) years at baseline survey. The adjusted odds ratios (ORs) and 95% confidence intervals (CIs) of incidence risk for hypertension in the third and fourth quartiles of the UA were 1.39 (1.11-1.75) and 1.56 (1.19-1.81), respectively. The ORs and 95% CIs of risk for high LDL-C in the second, third and fourth quartiles were 1.88 (1.16-3.05),1.98 (1.23-3.17) and 2.25 (1.42-3.57). The uric acid level increased by one standard deviation, the risk increased by 17% for hypertension and 27% for high LDL-C. The uric acid level increased by 10 µmol/L, the risk increased by 2.1% for hypertension and 2.9% for high LDL-C. The gender-stratified analysis showed that the similar results. The ORs and 95% CIs were 1.32 (1.09-1.60) and 1.50 (1.05-2.16) for hypertension, 1.90 (1.38-2.60) and 2.96 (1.58-5.52) for high TC, 1.78 (1.26-2.51) and 2.84 (1.60-5.03) for high LDL-C in the groups of newly diagnosed hyperuricemia and persistent hyperuricemia. Conclusions: Higher uric acid level was associated with increased incidence risks for hypertension, abnormal TC and LDL-C. Maintaining optimal uric acid level by children might contribute to the early prevention of cardiovascular diseases.

[Change in obesity status and development of cardiometabolic disorders in school-age children].

Objective: To analyze the influence of obesity status on the development of cardiometabolic disorders in school-age children. Methods: Information about children's body weight, body height and cardiovascular risk factors were collected in baseline survey in 2017 and follow-up survey in 2019. The school-age children were divided into four groups based on their baseline and follow-up obesity status, i.e. sustained non-obesity group, restored obesity group, newly classified obesity group, and persistent obesity group. Analysis of covariance was used to compare the difference of change in levels of cardiometabolic factors among the four groups. The multivariate logistic regression model was used to analyze the relationship between obesity status and the incidence risk of cardiometabolic disorders. Results: The present study included 11 379 school-age children (boys accounting for 49.6%). During the 2 years, the incidence of obesity was 3.2% (95%CI: 2.9%-3.5%) with the restoration ratio of obesity of 4.4% (95%CI: 4.0%-4.8%). Compared with the sustained non-obesity group, increases in SBP, DBP, TG, LDL-C and non-HDL-C were much higher in newly classified obesity group and persistent obesity group, but lower in restored obesity groups except for DBP (all P<0.05). In addition, the incidence risk of hypertension, high glucose, dyslipidemia and cardiometabolic disorders (≥2 risks) were much higher in newly classified and persistent obese children than in sustained non-obese children. No difference was found in incidence risks of most cardiovascular disorders between restored obese children and sustained non-obese children, except for hypertension and cardiometabolic risks. Conclusion: Both newly classified obesity and persistent obesity increased the incidence risks for multi cardiovascular disorders, while these risks could be reduced when non-obese status restore.

[Incidence and risk factors of pediatric fractures in school-age children and adolescents in Beijing].

Objective: To investigate the incidence and risk factors of pediatric fracture in school-age children and adolescents in Beijing. Methods: A total of 12 056 students with complete fracture data of 2017 baseline survey and 2019 follow-up survey of School-based Cardiovascular and Bone Health (SCVBH) Promotion Program in Beijing were selected as study subjects. Logistic regression model was used to analyze associations of fracture incidence with age, BMI, fracture history and lifestyle. Results: The 2-year accumulative incidence rate of pediatric fracture was 3.1% (95%CI: 2.8%-3.4%) in school-age children and adolescents in Beijing, which was much higher in boys (4.1%) than in girls (2.1%) and increased with age in boys but decreased with age in girls. Fractures mainly occurred at upper-limb (69.0%), no gender and age specific significant in fracture sites were observed. Fracture history was the risk factor for fracture incidence in both boys and girls (boys: RR=1.81, 95%CI: 1.18-2.64; girls: RR=3.11, 95%CI: 1.74-5.13). In addition, higher duration and frequency of moderate to vigorous physical activities (≥120 min/day) and frequent consumption of sugar sweetened beverage (≥1 time/week) were also found to increase fracture risk in boys. Conclusion: The incidence of pediatric fracture was associated with gender, age, fracture history and lifestyle habits in school-age children and adolescents in Beijing. Targeted strategies are needed to prevent childhood fracture.

[Association of vitamin D nutritional status with calcaneal bone mineral density in school-age children: a prospective cohort study].

Objective: To investigate the relationships between vitamin D nutritional status and the calcaneal bone mineral density (BMD) in children. Methods: Data were obtained from School-based Cardiovascular and Bone Health Promotion Program. In 2017, a total of 15 391 children aged 6-16 years in Beijing selected through stratified cluster sampling were included in the baseline survey. A follow-up investigation was conducted in 2019. The questionnaire survey, detection of serum 25-hydroxyvitamin D [25(OH)D] level and ultrasound measurement of calcaneal BMD were conducted. Multivariable linear and logistic regression models were used to analyze the relationships between baseline vitamin D nutritional status and the follow-up calcaneal BMD. Results: A total of 10 914 children aged (11.5±3.3) years (boys accounting for 49.6%) were included in the analysis. The average 25(OH)D level was (35.4±12.0) nmol/L, and the deficiency rate was 36.1%. After the adjustment for age, gender, body mass index, smoking status, alcohol use status, dairy products intake, vitamin D supplement, calcium supplement, physical activity, pubertal development, and baseline calcaneal BMD Z-score, for per 10 nmol/L increase in 25(OH)D, the follow-up calcaneal BMD Z-score increased by 0.01(P=0.041), and the OR(95%CI) of decreased calcaneal BMD Z-score after 2 years was 0.96 (0.93-1.00)(P=0.030). Compared with vitamin D adequacy, the follow-up calcaneal BMD Z-score of children with vitamin D insufficiency and deficiency decreased by 0.03(P=0.307) and 0.06 (P=0.046), and the risk of decreased calcaneal BMD Z-score after 2 years increased by 15%(P=0.037) and 21%(P=0.006), respectively (P for trend<0.05). Conclusions: Vitamin D nutritional status was closely related to calcaneal BMD, and children with adequate vitamin D nutritional status tended to obtain higher BMD. Children and adolescents are encouraged to maintain sufficient vitamin D levels, strengthen nutrition and exercise to promote bone health.

[Association of vitamin D nutritional status with body muscle mass in school-age children adolescents].

Objective: To investigate the association between vitamin D nutritional status and the body muscle mass in children. Methods: Data were obtained from School-based Cardiovascular and Bone Health Promotion Program. In 2017, a total of 15 391 children aged 6-16 years in Beijing were selected through stratified cluster sampling in baseline survey. A follow-up investigation was conducted in 2019. The questionnaire survey and the detection of serum 25-hydroxyvitamin D [25(OH)D] level were conducted. The bioelectrical impedance analysis (BIA) apparatus was used to measure body muscle mass, and muscle mass index (MMI) was calculated. Multivariable linear models were used to analyze the association of vitamin D nutritional status with the baseline and follow-up MMI measures. Results: A total of 10 890 children aged (11.5±3.3) years(boys accounting for 49.6%) were included in the analysis. The average 25(OH)D level was (35.4±12.0) nmol/L, with an adequacy ratio of 11.1%. After multivariate linear regression adjustment for age, sex, body fat mass, smoking status, alcohol use status, dairy supplement, calcium supplement, physical activity, and pubertal development, no statistically significant association between vitamin D nutritional status and baseline MMI level was observed (P>0.05). For the follow-up MMI, the Z-score increased by 0.008 (P=0.058) for per 10 nmol/L increase in 25(OH)D, which were 0.002 (P=0.815) and 0.037 (P=0.031) higher in children with insufficient and adequate vitamin D than those with vitamin D deficiency, respectively (P for trend =0.089). Subgroup analysis showed that in the normal BMI group, for per 10 nmol/L increase in 25 (OH) D, the MMI at baseline survey and MMI Z-score at follow-up of children with adequate vitamin D and increased by 0.019 and 0.014, respectively (both P<0.05). Conclusions: Vitamin D nutritional status was related to muscle mass in children, and children with adequate vitamin D tended to obtain higher MMI. Children and adolescents are encouraged to maintain sufficient vitamin D levels, strengthen nutrition and exercise to promote body health.

[Study on the association between vitamin D and body fat distribution in children and adolescents].

Objective: To investigate the association of vitamin D with distribution of body fat in children and adolescents. Methods: Data were obtained from the baseline survey of School-based Cardiovascular and Bone Health Promotion Program in 2017. Multiple linear regression and multinomial logistic regression models were applied to analyze the relationships of body mass index (BMI), fat mass index (FMI), trunk fat mass index (TFMI), appendicular fat mass index (AFMI), and visceral fat area(VFA) with vitamin D level and status in children and adolescents. Results: A total of 11 960 children and adolescents were included in the analysis (boys accounting for 49.7%). The average age and serum vitamin D level of study population were (11.0±3.3) years and (35.0±11.9) nmol/L, respectively. The deficiency rate of vitamin D was 37.2%. Gender-specific associations of BMI, FMI, TFMI, and AFMI with vitamin D level were found (P for interaction <0.05): they were inversely associated with vitamin D level in boys (BMI: ß=-0.56; FMI: ß =-0.59; TFMI: ß=-0.60; AFMI: ß=-0.59; all P<0.05), but not in girls (P>0.05). VFA was positively associated with vitamin D deficiency and insufficiency in both boys and girls, and the risks of vitamin D deficiency and insufficiency all increased by 17%(95%CI: 9%-25%) for per increment of standard deviation in VFA. Conclusions: The higher level of visceral fat was associated with the lower vitamin D levels in children. Abdominal obese children and boys with excessive body fat are the key population in the prevention and control of vitamin D deficiency.

[A prospective cohort study on the associations between vitamin D nutritional status and cardiometabolic abnormities in children].

Objective: To investigate the relationships between vitamin D nutritional status and the risks of cardiometabolic abnormities in children. Methods: Data were obtained from the School-based Cardiovascular and Bone Health Promotion Program. In 2017, a total of 15 391 children aged 6-16 years in Beijing were selected by using a stratified cluster sampling method in the baseline survey. A Follow-up investigation was conducted in 2019. Log-binomial regression was used to analyze the relationships between baseline vitamin D nutritional status and the risks of cardiometabolic abnormities (obesity, hypertension, hyperglycemia, and dyslipidemia). Results: A total of 10 482 participants were involved in the study. The average vitamin D level was (35.6 ± 12.0) nmol/L, and the deficiency rate was 35.1%. The 2-year cumulative incidence rates of obesity, hypertension, hyperglycemia, high TC, high LDL-C, low HDL-C, high TG, and high non-HDL-C were 4.3%, 10.8%, 8.5%, 3.1%, 2.5%, 3.4%, 2.5%, and 3.9% respectively. After the adjustment of potential confounding factors, children with vitamin D inadequacy or deficiency had higher risks of high TC [RR (95%CI): inadequacy, 2.06 (1.19-3.58); deficiency, 2.80 (1.61-4.89)], high LDL-C [RR (95%CI): inadequacy, 1.67 (1.02-2.73); deficiency, 1.99 (1.19-3.33)], and high non-HDL-C [RR (95%CI): inadequacy, 2.00 (1.26-3.17); deficiency, 2.45 (1.53-3.92)] compared with children with adequate vitamin D, and the risks of them increased with the decrease of vitamin D level (trend P<0.05). The gender-stratified analysis showed that vitamin D deficiency was remained associated with high TC [RR (95%CI): boy, 2.64 (1.19-5.87); girl, 3.13 (1.43-6.83)] and high non-HDL-C [RR (95%CI): boy, 2.58(1.40-4.77); girl, 2.31 (1.10-4.84)]. Conclusions: The risks of abnormal TC, LDL-C, and non-HDL-C were inversely associated with vitamin D level. Maintenance of adequate vitamin D status in children may contribute to the early prevention of cardiovascular diseases.

[Application of obesity indicators based on body fat in the screening of persistent dyslipidemia among school-aged children].

Objective: To explore the screening effect of obesity assessed by body fat indicators on persistent dyslipidemia among children. Methods: Data were obtained from the baseline and follow-up survey of 'School-based Cardiovascular and Bone Health Promotion Program.' BMI, fat mass index (FMI), and fat mass percentage (FMP) were used to define obesity. Dyslipidemia, diagnosed both in the baseline and a follow-up survey, was defined as persistent dyslipidemia. The area under the receiver operating characteristic curve (AUC) was used to compare the predictive capabilities of obesity defined by different indicators on persistent dyslipidemia. Results: A total of 10 783 children (boys accounted for 49.6%) were included in the analysis, with the average age as (10.9±3.3) years old. The detection rates of persistent high TC, high LDL-C, low HDL-C, high TG, and high non-HDL-C were 1.3%, 1.2%, 4.3%, 1.3%, and 0.8%, respectively. In boys, the capabilities of FMI- and FMP-defined obesity in the prediction of persistent high LDL-C [FMI: AUC=0.626 (95%CI: 0.558-0.694), P=0.024; FMP: AUC=0.642 (95%CI: 0.574-0.710), P=0.004] and high non-HDL-C [FMI: AUC=0.637 (95%CI: 0.584-0.689), P=0.017; FMP: AUC=0.641 (95%CI: 0.588- 0.693), P=0.018] were significantly higher than BMI-defined obesity. Besides, obese boys defined by FMI had the stronger capability in predicting persistent low HDL-C than that defined by BMI [AUC=0.784 (95%CI: 0.742-0.826) vs. 0.750 (95%CI: 0.726-0.773), P=0.047]. In girls, the capabilities of FMI- and FMP-defined obesity in the prediction of persistent dyslipidemia were not statistically different from BMI. Conclusions: The obesity assessed by body fat performed better in predicting persistent high LDL-C, low HDL-C, and high non-HDL-C than that assessed by BMI among boys, which can be further applied to cardiovascular disease prevention.

[A comparative study on diagnostic cut points of dyslipidemia in children and adolescents in China].

Objective: To compare the power of dyslipidemia diagnosis by different sets of cut points in the prediction of cardiovascular metabolic risk factors and identify the appropriate cut points for the diagnosis of dyslipidemia in children and adolescents in China. Methods: Data were obtained from the baseline survey of 'School-based Cardiovascular and Bone Health Promotion Program' in Beijing in 2017. Dyslipidemia was diagnosed by using two set of cut points. Receiver operating characteristic curve analysis was conducted to assess the power of dyslipidemia diagnosis by the two set of cut points to predict the prevalence of hypertension, obesity, high fat mass percentage and impaired fasting glucose. Results: A total of 14 390 children and adolescents were in included in the study. The prevalence rates of high TC, high LDL-C, low HDL-C, and high TG in the participants were 2.7%, 2.7%, 14.4%, and 3.7% according to 'Chinese Reference Standard', and 5.0%, 3.7%, 13.3%, and 3.5% according to 'China Expert Consensus'. Low HDL-C and high TG defined by the 'Chinese Reference Standard' had better performance for the prediction of high fat mass percentage and obesity in boys, but worse performance in girls (P<0.001). Conclusions: Using 'China Reference Standard' can increase the true positive rate in the prediction of obesity or high fat mass percentage in boys, and reduce the false positive rate in girls. The cut points for the diagnosis of dyslipidemia in Chinese children and adolescents need to be further validated by using national representative sample and in longitudinal study.

[Relationship between plasma fibroblast growth factor-23 and subclinical cardiovascular damages in children with primary hypertension].

Objective: To examine the plasma fibroblast growth factor-23 (FGF-23) concentration in children with primary hypertension and to investigate the association between plasma FGF-23 and subclinical cardiovascular damages,and to identify its predictive value for diagnosis. Methods: With prospective study,77 patients (61 males and 16 females) who were diagnosed as primary hypertension with the average age of (11.8±2.2) years were enrolled with informed consent in Children's Hospital,Capital Institute of Pediatrics from October 2016 to December 2017. Carotid wall intima-media thickness (cIMT) measured by Doppler ultrasound and left ventricular hypertrophy (LVH) identified by echocardiography were assessed as parameters of subclinical cardiovascular damages. Patients were divided into increased cIMT group (n=18) and normal cIMT group (n=46) (64 patients with complete data of cIMT). According to left ventricular geometry,patients were divided into LVH group (n=27) and normal geometry group (n=50). Concentration of plasma FGF-23 was detected in all children by enzyme linked immunosorbent assay test. Mann-Whitney U test was used to compare plasma levels of FGF-23 between groups. Kendall's tau-b correlation coefficient was used to analyze the correlation between plasma FGF-23 and cIMT/LVH. Receiver operating characteristic (ROC) curve was used to analyze the value of plasma FGF-23 in the prediction of subclinical cardiovascular damage. Results: The concentration of plasma FGF-23 in the increased cIMT group was higher than that in the normal cIMT group (55.6 (46.2,63.5) vs. 48.6 (39.4, 57.3) ×10(3) RU/L, Z=-2.143, P=0.032) . Also, plasma FGF-23 showed positive correlation with cIMT(r=0.222, P=0.032). According to ROC curve analysis,the cutoff value of plasma FGF-23 for prediction of increased cIMT was 53.9×10(3) RU/L (55.6% sensitivity and 71.7% specificity). The concentration of plasma FGF-23 in the LVH group was significantly higher than that in normal geometry group (55.0 (46.8, 65.7) vs. 48.2 (39.5, 56.0)×10(3) RU/L, Z=-2.375, P=0.018). And,plasma FGF-23 was correlated positively with LVH (r=0.224, P=0.018). The concentration of plasma FGF-23 in patients with concentric remodeling (n=10) was significantly higher than that of the normal geometry group (56.9 (49.6, 66.3) vs. 48.2 (39.5,56.0) ×10(3) RU/L, Z=-2.093, P=0.036). According to ROC curve analysis,the cutoff value of plasma FGF-23 for prediction of LVH was 49.1×10(3) RU/L (70.4% sensitivity and 60.0% specificity). Conclusion: The concentration of plasma FGF-23 in children with primary hypertension was correlated positively with LVH and cIMT and had certain predictive value of diagnosis for subclinical cardiovascular damages.

[The association between body fat distribution and calcaneal bone mineral density in children and adolescents aged 6-16 years in Beijing].

Objective: To understand the association between body fat distribution and calcaneal bone mineral density (BMD) in children and adolescents aged 6-16 years in Beijing. Methods: Children and adolescents were selected in 30 schools (8 primary schools, 21 middle schools and one 12-year education school) from Dongcheng, Tongzhou, Fangshan and Miyun districts of Beijing by using a stratified cluster sampling method from November 2017 to January 2018. A total of 15 030 students in grade 1 to 4 of primary school, grade 1 of junior and senior middle school were enrolled after excluding subjects who were not able to participate into this study due to trauma or other uncomfortable physical conditions or with missing key values or with diabetes and kidney diseases. Questionnaire survey, body composition and calcaneus bone mineral density were conducted. The relation of fat mass percentage (FMP), trunk to total fat ratio (TrTFR), trunk to limb fat ratio (TrLFR), limb to total fat ratio (LTFR) and viscera to total fat ratio (VTFR) with calcaneus BMD were assessed using the multivariate linear regression models after adjusting for possible confounding effects. The central fat distribution types were divided into 4 groups including type 1: both trunk fat and visceral fat greater than the sex-and age-specific internal P(75); type 2: barely trunk fat greater than P(75); type 3: barely visceral fat greater than P(75); type 4: both trunk fat and visceral fat greater than P(75). The central fat distribution types were included into the model in the form of dummy variables to analyze its relationship with calcaneal BMD. The sex-and age-specific z-scores of fat distribution indicators and BMD were calculated. Results: A total of 15 030 participants aged (11.4±3.3) years (50.2% boys) were involved in the analysis. In both genders, after adjusting for age, height, lean mass index, smoking, drinking, physical activity, milk intake, vitamin D and calcium supplementation, FMP, TrTFR, TrLFR and VTFR were negatively correlated with calcaneal BMD (all P value<0.05), while LTFR was positively associated with calcaneal BMD (all P values<0.05). Compared to the central fat distribution type 1, the regression coefficients (95% CI) of type 2, 3 and 4 were -0.253 (-0.418, -0.087), -0.385 (-0.567, -0.204) and -0.428 (-0.487, -0.369) in boys, respectively; the regression coefficients (95% CI) of type 3 and 4 were -0.158 (-0.301, -0.015) and -0.226 (-0.290, -0.163), respectively. Conclusion: Body fat distribution and central fat distribution in children and adolescents were correlated with calcaneus bone mineral density.

[The association between blood lipids and calcaneus bone mineral density in children and adolescents aged 6-16 years in Beijing].

Objective: To investigate the association between blood lipid and calcaneus bone mineral density (BMD) in children and adolescents aged 6-16 years in Beijing. Methods: Children and adolescents were selected in 30 schools (8 primary schools, 21 middle schools and one 12-year education school) from Dongcheng, Tongzhou, Fangshan and Miyun districts of Beijing by using a stratified cluster sampling method from November 2017 to January 2018. A total of 14 303 students in grade 1 to 4 of primary school, grade 1 of junior and senior middle school were enrolled after excluding subjects who were not able to participate into this study due to trauma or other uncomfortable physical conditions or with missing key values or with diabetes and kidney diseases. Questionnaire survey, blood lipid and calcaneus BMD were conducted. Multivariate linear regression was applied to quantify the association between calcaneal BMD as a dependent variable and blood lipid level as an independent variable after adjusting for the potential confounding factors. Furthermore, quantile regression was used to analyze the association between blood lipid level and different percentiles (P(25), P(50) and P(75)) of ultrasonic velocity values of bone mineral density, and parallel test was conducted for regression coefficients of different percentiles. Results: A total of 14 303 participants aged (11.4±3.3) years (49.9% boys) were involved in the analysis. The mean age of 14 303 participants was (11.0±3.3) years. 7 142 boys accounted for 49.9%. The mean±SD of calcaneal BMD, total cholesterol (TC), low density lipoprotein-cholesterol (LDL-C), and high density lipoprotein-cholesterol (HDL-C) were (1 540.9±33.8) m/s, (3.90±0.76), (2.18±0.62), and (1.40±0.32) mmol/L, respectively. The P(5)0 (P(25), P(75)) of triglyceride (TG) was 0.69 (0.49-0.94) mmol/L. After the adjustment of age, height, smoking, drinking, vitamin D and calcium supplementation, dairy intake, physical activity, FMI, and MMI, a significantly inverse association (P<0.05) between TG level and calcaneus BMD was observed in both genders, which the regression coefficients (95%CI) in boys and girls were -0.064 (-0.085, -0.044) and -0.073 (-0.094, -0.053), respectively. Conclusion: The level of BMD was associated with TG in boys and girls. Therefore, it is important to prevent children from hypertriglyceridemia for the bone health promotion.

[The baseline characteristics of School-based Cardiovascular and Bone Health Promotion Program in Beijing].

Objective: To describe the baseline characteristics of School-based Cardiovascular and Bone Health Promotion Program(SCVBH) in Beijing. Methods: Children and adolescents were selected in 30 schools (8 primary schools, 21 middle schools and one 12-year education school) from Dongcheng, Tongzhou, Fangshan and Miyun districts of Beijing by using a stratified cluster sampling method. 15 391 students in grade 1 to 4 from primary schools, grade 1 from junior and senior high schools were enrolled in the investigation with an exclusion of students who were not able to participate due to trauma or other uncomfortable physical conditions. The baseline survey including a questionnaire survey, physical examination and blood biochemical test was conducted from September 2017 to January 2018. Obesity, blood pressure, fasting blood glucose, lipid, bone density and grip were evaluated. Results: The prevalence of obesity, hypertension, hyperglycemia (impaired fasting glucose and diabetes), dyslipidemia, lower bone density were 22.3%(3 394), 14.8%(2 248), 10.4%(1 490), 20.3%(2 919) and 2.1%(316) in total respectively, and 27.2%(2 081), 16.3%(1 244), 12.8%(922), 22.2%(1 595) and 1.2%(94) for boys, 17.3%(1 313), 13.3% (1 004), 7.9%(568), 18.4%(1 324) and 2.9%(229) for girls. Boys had higher prevalence of obesity, hypertension, hyperglycemia, and dyslipidemia and lower prevalence of low bone density than girls (all P values <0.05) The mean of body mass index, systolic blood pressure, fasting plasma glucose and grip of boys were significantly higher than that of girls (all P values <0.05).The mean of body mass index, systolic blood pressure, fasting plasma glucose and grip of boys were significantly higher than that of girls (all P values <0.05), the mean of fat mass percentage, total cholesterol, triglyceride, high density lipoprotein-cholesterol and low density lipoprotein-cholesterol of boys were significantly lower than those of girls (all P values <0.05). Conclusion: The prevalence of risk factors of chronic cardiovascular disease was high and the low bone density was appearing in children and adolescents in this study. The promotion of cardiovascular and bone health should be implemented in children and adolescents.

[Characteristics of cardiovascular health of children and adolescents aged 6-16 years in Beijing during 2017-2018].

Objective: To describe the status of cardiovascular health (CVH) of children and adolescents aged 6-16 years in Beijing during 2017-2018. Methods: The school-based Cardiovascular and Bone Health Promotion Program(SCVBH) was conducted from November 2017 to January 2018. 15 391 children and adolescents aged 6-16 years were selected from grade 1 to 4 in 8 primary schools, grade 1 in 21 middle schools and senior grade 1 in one twelve-year education school in Dongcheng, Fangshan, Miyun and Haidian Districts of Beijing by using a cluster sampling method. Seven cardiovascular health indicators, including smoking, body mass index, dietary intake, physical activity, blood pressure, blood glucose, and total cholesterol, were categorized as poor, intermediate, and ideal according to American Heart Association (AHA) criteria. The status of CVH was evaluated according to the criteria of the ideal CVH related behaviors and factors defined by AHA. Results: The proportion of children and adolescents with an ideal smoking, dietary intake and physical activity indicators reached 99.2%(4 982/15 108), 19.7%(2 921/14 805), 17.8% (2 499/14 056), respectively. The proportion of children and adolescents with 7 and 4-5 ideal cardiovascular health indicators was 1.7%(209/12 560) and 65.1%(8 176/12 560). The proportion of children and adolescents with 4-7 ideal cardiovascular health indicators, 2-4 ideal health behavior indicators and 2-3 ideal health factors was significantly higher in urban than that in rural all P values<0.001. The proportion of females with 4-7 ideal cardiovascular health indicators, 2-4 ideal health behavior indicators and 2-3 ideal health factors was significantly higher than that in males (all P values<0.001). Conclusion: The prevalence of ideal cardiovascular health of children and adolescents aged 6-16 years in Beijing during 2017-2018 was very low, particularly for healthy dietary intake and physical activity. Effective public health interventions should be implemented to improve the status of cardiovascular health of them.

[The analysis of the association of sleep with high blood pressure among children and adolescents aged 6-16 years in Beijing].

Objective: To investigate the sleep status in children and adolescents and explore the relationship between the sleep and high blood pressure in them. Methods: Data was from the Schoolbased Cardiovascular and Bone Health Promotiow Program (SCVBH) in Beijing. And 13 471 children and adolescents aged 6-16 years were selected from grades 1 to 4 in 8 primary schools, grade 1 in 21 middle schools and senior grade 1 in one twelve-year education school in Dongcheng, Fangshan, Miyun and Tongzhou Districts of Beijing during 2017-2018 by using a cluster sampling method. Self-reported questionnaires were used to collect the demographic characteristics, lifestyle habits of children and adolescents. The blood pressure was measured by electronic sphygmomanometer. Multiple logistic regression model was used to analyze the association between sleep and hypertension risk. Results: The sleep duration was (8.4±1.1) hours. The prevalence of high blood pressure was 15.0%(2 021/13 471). The incidence of mouth breathing, slobber, snoring, and suffocate was 28.4%(3 823/13 471), 23.6%(3 184/13 471) and 18.7%(2 513/13 471), 2.8%(378/13 471) respectively. After adjusting for age, gender, snoring, mouth breaking, slobber, suffocate, the time for bed and sleep duration, we found that snoring and sleep duration (5.0-6.9 h) were both associated with high blood pressure (OR=1.49, 95%CI:1.32-1.69; OR=1.53, 95%CI: 1.28-1.81). Conclusion: Snoring and sleep duration were positively associated with high blood pressure in this study. Interventions focusing on sleep status should be developed to reduce the incidence of high blood pressure in children and adolescents.

[Influence of change in blood pressure status from childhood to adulthood on renal dysfunction: a cohort study].

Objective: To investigate the influence of change in blood pressure status from childhood to adulthood on renal damage. Methods: Data were obtained from Beijing Blood Pressure Cohort initiated from 1987. 3 198 children and adolescents aged 6-18 years from 6 primary and 6 middle schools in Chaoyang, Xicheng and Haidian Districts of Beijing were enrolled at baseline by using a cluster random sampling method, and 1 222 participants were followed up during 2010-2012. The measurements included weight, height, and blood pressure at baseline and microalbumin, serum creatinine, cystatin C and blood pressure at follow-up. Based on blood pressure status in childhood and adulthood, the participants were divided into four groups: participants with normal blood pressure in both childhood and adulthood, participants with elevated blood pressure in childhood but normal blood pressure in adulthood, participants with normal blood pressure in childhood but elevated blood pressure in adulthood, and participants with elevated blood pressure in both childhood and adulthood. Multivariate linear regression model was used to investigate the association of change in blood pressure from childhood to adulthood on renal dysfunction. Results: The prevalence of elevated blood pressure in childhood and adulthood was 17.9% and 39.9%, respectively. The P(50) (P(25)-P(75)) of microalbumin was 5.7(3.0-12.0) mg/L, and the concentration of eGFR and cystatin C were (118.0±19.8)% and (0.734±0.184)mg/L, respectively. With adjustment for sex, baseline age and follow-up years, compared with participants with persistently normal blood pressure from childhood to adulthood, participants with normal blood pressure in childhood but elevated blood pressure in adulthood had significantly higher levels of microalbumin (ß=0.502, 95%CI: 0.320-0.684) and cystatin C (ß=0.049, 95%CI: 0.025-0.073). After adjustment for sex, baseline age, follow-up duration, and adult BMI, smoking and drinking, participants with normal blood pressure in childhood and elevated blood pressure in adulthood had higher levels of adult urine microalbumin (ß=0.322, 95%CI: 0.128-0.516) and cystatin C (ß=0.032, 95%CI:0.007-0.057). Conclusion: An increase in blood pressure during childhood and adulthood has an adverse impact on renal functional damage in adulthood. These findings underscore the importance of maintaining normal blood pressure during life course to prevent the development of chronic kidney disease.

Hypertension outcomes in metabolically unhealthy normal-weight and metabolically healthy obese children and adolescents.

Metabolically healthy obesity (MHO) begins in childhood and continues into adulthood. However, the association between MHO and the risk of developing hypertension remains controversial. A prospective cohort study was conducted to investigate the risk of hypertension in MHO and metabolically unhealthy normal-weight (MUNW) Chinese children and adolescents. A total of 1183 participants, 6-18 years old at baseline with normal blood pressure values, were studied using follow-up data from the cohort of the Beijing Child and Adolescent Metabolic Syndrome (BCAMS) study. The participants were classified according to the body mass index and the presence/absence of metabolic abnormality, which was defined by metabolic syndrome (MetS) or insulin resistance (IR). During the 6-year follow-up period, 239 (20.2%) participants developed incident hypertension. After adjusting for age, sex, physical activity, pubertal stage, dietary habits and family history of hypertension, an increased risk for hypertension was observed in the MHO individuals (risk ratio, RRMetS 5.42; 95% confidence interval (CI) 3.19-9.22 and RRIR 7.59; 95% CI 1.64-35.20) compared with their metabolically healthy normal-weight counterparts. Independent of the definition of metabolic abnormality, the MUNW subjects did not have an elevated incidence of hypertension. These results suggest that the risk of developing hypertension is increased in the MHO but not in the MUNW individuals.

Developmental origin of metabolic syndrome: interaction of thinness at birth and overweight during adult life in Chinese population.

In the present study we explore the association between the ponderal index (PI) at birth and the metabolic syndrome (MetS) in middle-aged population in China. A total of 975 men and women aged 41-52 years with detailed birth records were followed up and recruited for clinic examinations, involving anthropometry and measurements of blood pressure, fasting plasma glucose, serum lipid profile. The MetS was diagnosed according to the National Cholesterol Education Program (Adult Treatment Panel III) definition. Multivariate logistic regression analysis estimated the effect of PI on MetS and the interaction between PI at birth and adult body mass index (BMI). The average prevalence of MetS was 19.3%, with rates of 23.7%, 22.9%, 16.9% and 16.5% in those who at birth were <25th percentile, the 25th-50th percentile, the 50th-75th percentile and >75th percentile PI respectively, with a significant decreasing trend (x(2) (for trend) = 5.661, P = 0.017). Logistic regression analysis showed that 25.7% of the occurrence of MetS was attributable to PI at birth and adult BMI both acting independently and synergistically. In summary thinness at birth predicts the later occurrence of MetS, as well as modifying the association between later BMI and MetS. Overweight later in life was most deleterious for those with growth retardation at birth.

Reversal of the gastric effects of nicotine by nitric oxide donor treatment.

Nicotine intensifies experimental gastric ulceration by reducing gastric mucosal blood flow (GMBF) and mucus. As both these parameters can be improved by nitric oxide (NO), we evaluated the impact of a NO donor in ethanol-induced gastric mucosal injury in rats administered nicotine. A nicotine solution or water was administered for 20 days to Sprague-Dawley rats. NO donor (isosorbide dinitrate) was given 60 and 10 min before preparation of ex vivo gastric chambers and exposure to ethanol. Chronic nicotine intake significantly reduced GMBF and gastric mucus content. Nicotine intensifies ethanol-induced gastric injury and short-term administration of NO donor failed to antagonize the ulcerogenic action from either nicotine or alcohol. In another study, rats drank nicotine solution for 20 days, after which the nicotine was withdrawn and replaced by water for 10 additional days. NO donor was provided during these last 10 days. The gastric effects of nicotine persisted for at least 10 days after nicotine was withdrawn but then these effects could be abolished by prolonged NO treatment. Nicotine reduces plasma nitrite level, but gastric mucosal MPO activity remained unchanged. Our data suggest that nicotine cessation plus a longer period of NO donor administration can completely abolish the gastric effects of nicotine.